WO2024173352A2

WO2024173352A2 - Methods of treating cancer with a sirp1a-based chimeric protein

Info

Publication number: WO2024173352A2
Application number: PCT/US2024/015542
Authority: WO
Inventors: Arundathy PANDITE; Fatima RANGWALA; Thomas LAMPKIN; Taylor Schreiber; George FROMM; Suresh DE SILVA
Original assignee: Shattuck Labs, Inc.
Priority date: 2023-02-13
Filing date: 2024-02-13
Publication date: 2024-08-22
Also published as: WO2024173352A3

Abstract

The present disclosure relates, in part, to compositions and methods, including chimeric proteins, which find use in the treatment of disease, such as immunotherapies for cancer.

Description

METHODS OF TREATING CANCER WITH A SIRP1 A-BASED CHIMERIC PROTEIN

TECHNICAL FIELD

The present technology relates to, inter alia, compositions and methods, including chimeric proteins that find use in the treatment of disease, such as immunotherapies for cancer comprising doses, dosing regimens that including biphasic dosing or dosing regimens comprising three cycles.

PRIORITY

This application claims the benefit of, and priority to, U.S. Provisional Application No. 63/484,727, filed February 13, 2023, and U.S. Provisional Application No. 63/502,039, filed May 12, 2023, the contents of each of which are hereby incorporated by reference in their entirety.

SEQUENCE LISTING

The instant application contains a sequence listing, which has been submitted in XML format via EFS-Web. The contents of the XML copy named “SHK-080PC_116981-5080_Sequence_Listing,” which was created on February 12, 2024, and is 82,568 bytes in size, and the contents of which are incorporated herein by reference in their entirety.

BACKGROUND

The field of cancer immunotherapy has grown tremendously over the past several years. This has been largely driven by the clinical efficacy of antibodies targeting the family of checkpoint molecules (e.g., CTLA- 4 and PD-1/L1) in many tumor types. However, despite this success, clinical response to these agents as monotherapy occurs in a minority of patients (10-45% in various solid tumors), and these therapies are hindered by side effects.

Rational dose selection and optimization of dosing regimens are of clinical importance and are prerequisites for enhancing patients’ medication compliance and obtaining maximum clinical benefits. Developing dosing regimen typically relies on pharmacokinetic/pharmacodynamic studies performed in animal models. However, since immunotherapy does not exert direct anti-proliferative activity on cancer cells, but are instead expected to harness tumor immunity, typically murine surrogates are used for some animal studies, making the pharmacokinetic/pharmacodynamic studies not available. In addition, physicians may vary the dosing regimen of immunotherapy based on the immunogenicity of a tumor, disease stage, and physical status of patients. Therefore, novel strategies to develop dosing and regimens are required. SUMMARY

The present disclosure is based, in part, on the discoveries of near maximal target engagement, margination certain immune cells from peripheral blood; and cytokine induction at a dosage of > 3 mg/kg of the SIRPo- Fc-CD40L chimeric protein. In various aspects, the present disclosure provides compositions and methods that provide strategies for developing doses and dosing regimen of cancer immunotherapy.

Accordingly, in some aspects, the present disclosure relates to a method for treating a cancer in a human subject, the method comprising: (i) administering to the human subject a first dose of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPo)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein the dose of the chimeric protein is administered at a dosage of at least about 0.3 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 1 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 3 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 10 mg/kg.

In some aspects, the present disclosure relates to a method for treating a cancer in a human subject, the method comprising: (i) administering to the human subject a first dose at a dosage of at least about 0.3 mg/kg of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPo)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a background level and/or activity of CD40+ B cells has been measured in a pre-dose blood sample obtained from the subject before the administration of the first dose, wherein a post-dosing level and/or activity of CD40+ B cells has been measured after at least 15 minutes after administering the first dose; and (ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if the post-dosing level and/or activity of CD40+ B cells is at least about 60% lower compared to the background level and/or activity, or administering to the human subject a second dose of the chimeric protein at a higher dosage than the dosage of the first dose if the post-dosing level and/or activity of CD40+ B cells is less than about 80% lower compared to the background level and/or activity, wherein the second dose is administered at least about 48 hours after the administration of the first dose. In embodiments, the post-dosing level and/or activity is measured less than 12, or less than 8, or less than 6, or less than 4, or less than 3, or less than 2, or less than 1 hours post dosing. In embodiments, the second dose comprises substantially the same dosage as the first dose if the post-dosing level and/or activity of CD40+ B cells is lower compared to the background level and/or activity by at least about 60%, or at least about 65%, or at least about 70%, or at least about 75%, or at least about 80%, or at least about 85%, or at least about 90%, or at least about 95% or more. In embodiments, the second dose comprises an increased dosage compared to the first dose if the post-dosing level and/or activity of CD40+ B cells is the chimeric protein lower compared to the background level and/or activity by less than about 70%, or less than about 60%, or less than about 50%, or less than about 40%.

In embodiments, the level and/or activity of CD40+ B cells is measured by contacting the sample with an agent that specifically binds to CD40 protein, a fragment and/or an epitope thereof and/or a B-cell marker, a fragment and/or an epitope thereof. In embodiments, the B-cell marker is selected from CD19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD. In embodiments, the agent that specifically binds to the CD40 protein, the fragment and/or the epitope thereof, and/or the B-cell marker, the fragment and/or the epitope thereof is an antibody or fragment thereof. In embodiments, the antibody is a recombinant antibody, a monoclonal antibody, a polyclonal antibody, or fragment thereof. In embodiments, the level and/or activity of CD40+ B cells is measured by immunohistochemical staining, western blotting, in cell western, immunofluorescent staining, ELISA, and fluorescent activating cell sorting (FACS) or a combination thereof. In embodiments, the level and/or activity of CD40+ B cells is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding a CD40 and/or a B-cell marker. In embodiments, the B-cell marker is selected from CD 19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD.

In embodiments, the agent that specifically binds to one or more of the nucleic acids is a nucleic acid primer or probe. In embodiments, the level and/or activity of CD40+ B cells is measured by polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR), quantitative PCR (qPCR), multiplex polymerase chain reaction, nested polymerase chain reaction, hot start polymerase chain reaction, long-range PCR, assembly polymerase chain reaction, asymmetric polymerase chain reaction, digital droplet PCR, a recombinase polymerase amplification (RPA), a loop-mediated amplification (LAMP), a helicasedependent amplification (HDA), RNA or DNA gel electrophoresis or Southern or Northern blotting, a microarray-based assay, a hybridization technique, optionally selected from solution hybridization, capillary hybridization, hybridization to nucleic acid arrays, optionally macroarrays, microarrays or high-density oligonucleotide arrays (Gene Chips). In embodiments, the chimeric protein is administered at the dosage of about 1 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 3 mg/kg.

In some aspects, the present disclosure relates to a method for treating a cancer in a human subject, the method comprising: (i) administering to the human subject a first dose at a dosage of at least about 0.3 mg/kg of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a post-dosing level and/or activity of one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 have been measured after at least 15 minutes after administering the first dose; and (ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if: the post-dosing level and/or activity of IL-12 is at least about 3-fold greater than a predose amount or post-first dose amount (e.g. at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, at least about 8-fold greater, at least about 9-fold greater, at least about 10-fold greater, at least about 11 -fold greater, or at least about 12- fold greater), the post-dosing level and/or activity of CXCL-8 is at least about 3-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, at least about 8-fold greater, at least about 9-fold greater, at least about 10-fold greater, at least about 11 -fold greater, at least about 12- fold greater, at least about 13-fold greater, at least about 14-fold greater, or at least about 15-fold greater), the post-dosing level and/or activity of CXCL-10 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 2-fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, or at least about 6-fold greater), the post-dosing level and/or activity of IL-10 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 2- fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 10-fold greater, or at least about 20-fold greater), the post-dosing level and/or activity of CCL2 is at least at least about 4-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 4- fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, or at least about 8-fold greater), the post-dosing level and/or activity of CCL20 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 2-fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 10-fold greater, or at least about 20- fold greater), and/or the post-dosing level and/or activity of CCL22 is at least about 2-fold greater than a predose amount or post-first dose amount (e.g. at least about 2-fold greater, at least about 3-fold greater, or at least about 4-fold greater); or administering to the human subject a second dose of the chimeric protein at a higher dosage than the dosage of the first dose if the post-dosing level and/or activity of IL-12 is equal or less than about 2-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CXCL-8 is equal or less than about 2-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CXCL-10 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of IL-10 is equal or less than about 1- fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CCL2 is equal or less than about 3-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CCL20 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, and/or the post-dosing level and/or activity of CCL22 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount; wherein the second dose is administered at least about 48 hours after the administration of the first dose. In embodiments, the post-dosing level and/or activity is measured less than 12, or less than 8, or less than 6, or less than 4, or less than 3, or less than 2, or less than 1 hours post dosing.

In embodiments, the second dose comprises substantially the same dosage as the first dose if: the postdosing level and/or activity of IL-12 is at least about 3-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, at least about 8-fold greater, at least about 9-fold greater, at least about 10-fold greater, at least about 11 -fold greater, or at least about 12-fold greater), the post-dosing level and/or activity of CXCL-8 is at least about 3-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, at least about 8-fold greater, at least about 9-fold greater, at least about 10-fold greater, at least about 11 -fold greater, at least about 12-fold greater, at least about 13- fold greater, at least about 14-fold greater, or at least about 15-fold greater), the post-dosing level and/or activity of CXCL-10 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 2-fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, or at least about 6-fold greater), the post-dosing level and/or activity of IL-10 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 2-fold greater, at least about 3- fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 10-fold greater, or at least about 20-fold greater), the post-dosing level and/or activity of CCL2 is at least at least about 4-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 4-fold greater, at least about 5- fold greater, at least about 6-fold greater, at least about 7-fold greater, or at least about 8-fold greater), the post-dosing level and/or activity of CCL20 is at least about 2-fold greater than a pre-dose amount or post- first dose amount (e.g. at least about 2-fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 10-fold greater, or at least about 20-fold greater), and/or the postdosing level and/or activity of CCL22 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 2-fold greater, at least about 3-fold greater, or at least about 4-fold greater).

In embodiments, the second dose comprises an increased dosage compared to the first dose if the postdosing level and/or activity of IL-12 is equal or less than about 2-fold greater than a pre-dose amount or post- first dose amount, the post-dosing level and/or activity of CXCL-8 is equal or less than about 2-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CXCL-10 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of IL-10 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CCL2 is equal or less than about 3-fold greater than a predose amount or post-first dose amount, the post-dosing level and/or activity of CCL20 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, and/or the post-dosing level and/or activity of CCL22 is equal or less than about 1 -fold greater than a pre-dose amount or post-first dose amount.

In embodiments, the level and/or activity of one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 is measured by contacting the sample with an agent that specifically binds to one or more of IL- 12 protein, CXCL-8 protein, CXCL-10 protein, IL-10 protein, CCL2 protein, CCL20 protein, and CCL22 protein, a fragment and/or an epitope thereof. In embodiments, the agent that specifically binds to the IL-12 protein, CXCL-8 protein, CXCL-10 protein, IL-10 protein, CCL2 protein, CCL20 protein, and CCL22 protein, the fragment and/or the epitope thereof is an antibody or fragment thereof. In embodiments, the antibody is a recombinant antibody, a monoclonal antibody, a polyclonal antibody, or fragment thereof. In embodiments, the level and/or activity of one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 is measured by immunohistochemical staining, western blotting, in cell western, immunofluorescent staining, ELISA, and fluorescent activating cell sorting (FACS) or a combination thereof.

In embodiments, the level and/or activity of one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 and/or a nucleic acid complementary thereto. In embodiments, the agent that specifically binds to one or more of the nucleic acids is a nucleic acid primer or probe. In embodiments, the level and/or activity of one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 is measured by polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR), quantitative PCR (qPCR), multiplex polymerase chain reaction, nested polymerase chain reaction, hot start polymerase chain reaction, long-range PCR, assembly polymerase chain reaction, asymmetric polymerase chain reaction, digital droplet PCR, a recombinase polymerase amplification (RPA), a loop-mediated amplification (LAMP), a helicase-dependent amplification (HDA), RNA or DNA gel electrophoresis or Southern or Northern blotting, a microarray-based assay, a hybridization technique, optionally selected from solution hybridization, capillary hybridization, hybridization to nucleic acid arrays, optionally macroarrays, microarrays or high-density oligonucleotide arrays (Gene Chips).

In some aspects, the present disclosure relates to a method for treating a cancer in a human subject, the method comprising: (i) administering to the human subject a first dose at a dosage of at least about 0.3 mg/kg of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a post-dosing level of CD47 receptor occupancy of CD4 T cells and/or CD40 receptor occupancy of B cells in a post-dose blood sample obtained from the subject have been measured after at least 15 minutes after administering the first dose; and (ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if (ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is at least about 60%, or administering to the human subject a second dose of the chimeric protein at a higher dosage than the dosage of the first dose if the post-dosing level and/or activity of CD40+ B cells is less than about 80% lower compared to the background level and/or activity, wherein the second dose is administered at least about 48 hours after the administration of the first dose. In embodiments, the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is measured less than 12, or less than 8, or less than 6, or less than 4, or less than 3, or less than 2, or less than 1 hours post dosing. In embodiments, the second dose comprises substantially the same dosage as the first dose if the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is at least about 65%, or at least about 70%, or at least about 75%, or at least about 80%, or at least about 85%, or at least about 90%, or at least about 95% or more. In embodiments, the second dose comprises an increased dosage compared to the first dose if the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is less than about 70%, or less than about 60%, or less than about 50%, or less than about 40%.

In embodiments, the post-dosing level of CD40 occupancy of B cells is measured using the following formula:

%CRI @postdose

Receptor engagement =

%CR @ Predose wherein %CR @ predose is the percentage of target receptor-expressing lymphocytes in a pre-dose blood sample obtained from the subject; %CR @ postdose is the percentage of target receptor-expressing lymphocytes in the post-dose blood sample; and %CRI @ postdose is the percentage of the chimeric proteinbound CD40⁺ B cells in the post-dose blood sample, wherein: the presence, absence, or level of CD40⁺ B cells has been determined in the pre-dose blood sample, the presence, absence, or level of CD40⁺ B cells has been determined in the post-dose blood sample, and the presence, absence, or level of the chimeric protein-bound CD40⁺ B cells has been determined in the post-dose blood sample.

In embodiments, the post-dosing level of CD47 occupancy of CD4 T cells is measured using the following formula:

Receptor occupancy = [%ARC(subj) — %ARC(iso)]/[%ARC(spike) — %ARC(ISO)] wherein %ARC(subj) is the percentage of chimeric protein-bound target receptor-expressing CD4+ T lymphocytes blood sample obtained from the subject; %ARC(iso) is the percentage of chimeric protein-bound target receptor-expressing CD4+ T lymphocytes blood sample obtained from the subject, stained with only drug detecting antibody; and %ARC(spike) is the percentage of chimeric protein-bound target receptorexpressing CD4+T lymphocytes blood sample obtained from the subject with a saturating amount of chimeric protein added at processing wherein: the presence, absence, or level of CD40⁺ B cells has been determined in the pre-dose blood sample, the presence, absence, or level of CD40⁺ B cells has been determined in the post-dose blood sample, and the presence, absence, or level of the chimeric protein-bound CD40⁺ B cells has been determined in the post-dose blood sample.

In embodiments, the presence, absence, or level of CD47⁺ CD4⁺ T cells is measured by contacting the sample with an agent that specifically binds to one or more of CD47 protein, CD4 protein, and a T cell marker, or a fragment or an epitope thereof. In embodiments, the T-cell marker is selected from CD3, CD4, CD8, CCR7, CD62L, CD45RA, CXCR3, CCR4, CCR5, FOXP3 and IL2RA (CD25). In embodiments, the presence, absence, or level of CD40+ B cells is measured by contacting the sample with an agent that specifically binds to CD40 protein and/or a B cell marker, or a fragment or an epitope thereof. In embodiments, the B-cell marker is selected from CD19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD. In embodiments, the agent is an antibody or fragment thereof. In embodiments, the antibody is a recombinant antibody, a monoclonal antibody, a polyclonal antibody, or fragment thereof. In embodiments, the level and/or activity of CD40+ B cells is measured by immunohistochemical staining, western blotting, in cell western, immunofluorescent staining, ELISA, and fluorescent activating cell sorting (FACS) or a combination thereof.

In embodiments, the presence, absence, or level of CD47⁺ CD4⁺ T cells is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding CD47, CD4 and/or a T cell marker. In embodiments, the T-cell marker is selected from CD3, CD4, CD8, CCR7, CD62L, CD45RA, CXCR3, CCR4, CCR5, FOXP3 and IL2RA (CD25). In embodiments, the presence, absence, or level of CD40+ B cells is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding CD40 and/or a B cell marker. In embodiments, the B-cell marker is selected from CD19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD. In embodiments, the agent that specifically binds to one or more of the nucleic acids is a nucleic acid primer or probe. In embodiments, the presence, absence, or level of CD47⁺ CD4⁺ T cells and/or presence, absence, or level of CD40+ B cells is measured by polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR), quantitative PCR (qPCR), multiplex polymerase chain reaction, nested polymerase chain reaction, hot start polymerase chain reaction, long-range PCR, assembly polymerase chain reaction, asymmetric polymerase chain reaction, digital droplet PCR, a recombinase polymerase amplification (RPA), a loop-mediated amplification (LAMP), a helicase-dependent amplification (HDA), RNA or DNA gel electrophoresis or Southern or Northern blotting, a microarray-based assay, a hybridization technique, optionally selected from solution hybridization, capillary hybridization, hybridization to nucleic acid arrays, optionally macroarrays, microarrays or high-density oligonucleotide arrays (Gene Chips). In embodiments, the chimeric protein is administered at the dosage of about 1 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 3 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 1 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 3 mg/kg. In embodiments, the first dose of the chimeric protein is in the range of from about 0.3 mg/kg to 10 mg/kg. In embodiments, the first dose is about 0.3 mg/kg, or about 1 mg/kg, or about 2 mg/kg, or about 3 mg/kg, or about 4 mg/kg, or about 6 mg/kg, or about 8 mg/kg, or about 10 mg/kg. In embodiments, the first dose is in the range of about 0.3 mg/kg to about 2 mg/kg, or about 1 mg/kg to about 3 mg/kg, or about 2 mg/kg to about 4 mg/kg, or about 3 mg/kg to about 6 mg/kg, or about 5 mg/kg to about 10 mg/kg.

In some aspects, the present disclosure relates to a method for treating a cancer in a human subject, the method comprising: (i) administering to the human subject a first dose at a dosage of at least about 0.3 mg/kg of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a background level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells has been measured in a pre-dose blood sample obtained from the subject before the administration of the first dose, wherein a post-dosing level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells has been measured in a blood sample obtained from the subject after at least about 12 hours after administering the first dose; and (ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if the post-dosing level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is at least about 60% lower compared to the background level and/or activity, or administering to the human subject a second dose of the chimeric protein at a higher dosage than the dosage of the first dose if the post-dosing level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is at least about 60% lower compared to the background level and/or activity, wherein the second dose is administered at least about 48 hours after the administration of the first dose.

In embodiments, the post-dosing level and/or activity is measured more than about 12, or more than about 16, or more than about 18, or more than about 24, or more than about 28, or more than about 32, or more than about 40, or more than about 48 hours post dosing. In embodiments, the second dose comprises substantially the same dosage as the first dose if the post-dosing level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is lower compared to the background level and/or activity by at least about 65%, or at least about 70%, or at least about 75%, or at least about 80%, or at least about 85%, or at least about 90%, or at least about 95% or more. In embodiments, the second dose comprises an increased dosage compared to the first dose if the post-dosing level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is the chimeric protein not lower compared to the background level and/or activity by less than about 55%, or less than about 50%, or less than about 40%, or less than about 30%, or less than about 20%.

In embodiments, the level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is measured by contacting the sample with an agent that specifically binds to CD47, CD40, CD4, a CD40+ B cell marker, a marker specific to CD40 expressing monocytes and/or a CD4 T cell marker. In embodiments, the B-cell marker is selected from CD 19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD, the marker specific to CD40 expressing monocytes is selected from CD163, CD192, CD14, CD11 b, CCR2, CD16, CD141 , CD11c, HLA-DR, and CCR7, and the CD4 T cell marker is selected from CD4, CD25, CD127, FoxP3, CCR4, Cith2, CCR6, CXCR5, CD39, CD45RA, CTLA-4, CD127, IL-2R, IL-4R, IL-9R, IL-15R, IL-21 R, and CD25. In embodiments, the agent that specifically binds to CD47, CD40, CD4, a CD40+ B cell marker, a marker specific to CD40 expressing monocytes and/or a CD4 T cell marker is an antibody or fragment thereof. In embodiments, the antibody is a recombinant antibody, a monoclonal antibody, a polyclonal antibody, or fragment thereof. In embodiments, the level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is measured by immunohistochemical staining, western blotting, in cell western, immunofluorescent staining, ELISA, and fluorescent activating cell sorting (FACS) or a combination thereof.

In embodiments, the level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding CD47, CD40, CD4, a CD40+ B cell marker, a marker specific to CD40 expressing monocytes and/or a CD4 T cell marker. In embodiments, the B-cell marker is selected from CD19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD, the marker specific to CD40 expressing monocytes is selected from CD163, CD192, CD14, CD11 b, CCR2, CD16, CD141, CD11c, HLA-DR, and CCR7, and the CD4 T cell marker is selected from CD4, CD25, CD127, FoxP3, CCR4, Cith2, CCR6, CXCR5, CD39, CD45RA, CTLA- 4, CD127, IL-2R, IL-4R, IL-9R, IL-15R, IL-21 R, and CD25. In embodiments, the agent that specifically binds to one or more of the nucleic acids is a nucleic acid primer.

In embodiments, the agent that specifically binds to one or more of the nucleic acids is a nucleic acid probe In embodiments, the level and/or activity of CD40+ B cells is measured by polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR), quantitative PCR (qPCR), multiplex polymerase chain reaction, nested polymerase chain reaction, hot start polymerase chain reaction, long-range PCR, assembly polymerase chain reaction, asymmetric polymerase chain reaction, digital droplet PCR, a recombinase polymerase amplification (RPA), a loop-mediated amplification (LAMP), a helicase-dependent amplification (HDA), RNA or DNA gel electrophoresis or Southern or Northern blotting, a microarray-based assay, a hybridization technique, optionally selected from solution hybridization, capillary hybridization, hybridization to nucleic acid arrays, optionally macroarrays, microarrays or high-density oligonucleotide arrays (Gene Chips).

In embodiments, the chimeric protein is administered at the dosage of about 1 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 3 mg/kg.

In some aspects, the present disclosure relates to a method for treating a cancer in a human subject, the method comprising: (i) administering to the human subject a first dose of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPo)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a background amount and/or activity of M1 macrophages, M2 macrophages and/or granzyme B producing-T cells has been measured in a pre-dose biological sample obtained from the subject before the administration of the first dose, and wherein a postdose amount and/or activity of M1 macrophages, M2 macrophages and/or granzyme B producing-T cells has been measured in a pre-dose biological sample obtained from the subject before the administration of the first dose; (ii) administering to the human subject a second dose of the chimeric protein if a post-dosing ratio of amount and/or activity of the M1 macrophages to M2 macrophages is greater than a pre-dose ratio of amount and/or activity of the M1 macrophages to M2 macrophages, and/or post-dosing amount and/or activity of the granzyme B producing-T cells is greater than the background amount and/or activity of the granzyme B producing-T cells, wherein the second dose is administered at least about 48 hours after the administration of the first dose. In embodiments, the post-dosing level and/or activity is measured more than about 12, or more than about 16, or more than about 18, or more than about 24, or more than about 28, or more than about 32, or more than about 40, or more than about 48 hours, or more post dosing.

In embodiments, the second dose comprises substantially the same dosage as the first dose if the post dosing amount and/or activity of the granzyme B producing-T cells is greater than the background amount and/or activity of the granzyme B producing-T cells by at least about 1 .25*, or at least about 1 .5*, or at least about 2x, or at least about 5*, or at least about 10x, or more. In embodiments, the second dose comprises substantially the same dosage as the first dose if the post-dosing ratio of amount and/or activity of the M1 macrophages to M2 macrophages is greater than the pre-dose ratio of amount and/or activity of the M1 macrophages to M2 macrophages by at least about 1 .25*, or at least about 1.5*, or at least about 2x, or at least about 5x, or at least about 10x, or more.

In embodiments, the second dose comprises an increased dosage compared to the first dose if the post dosing amount and/or activity of the granzyme B producing-T cells is not greater than the background amount and/or activity of the granzyme B producing-T cells by at least about 1.2x, or at least about 1 x. In embodiments, the second dose comprises an increased dosage compared to the first dose if the post-dosing ratio of amount and/or activity of the M1 macrophages to M2 macrophages is not greater than the pre-dose ratio of amount and/or activity of the M1 macrophages to M2 macrophages by at least about 1 .2x, or at least about 1 x.

In embodiments, the biological sample is selected from blood, plasma, serum, blood cells, lacrimal fluid, tears, bone marrow, ascites, tissue or fine needle biopsy sample, cell-containing body fluid, free floating nucleic acids, sputum, saliva, urine, cerebrospinal fluid, peritoneal fluid, pleural fluid, feces, lymph, gynecological fluid, skin swab, vaginal swab, oral swab, nasal swab, washing or lavage, aspirate, scraping, bone marrow specimen, a biopsy specimen and a surgical specimen. In embodiments, the biological sample is a biopsy sample or a surgical specimen, optionally wherein the biological sample is a tumor biopsy sample or a tumor surgical specimen. In embodiments, the tumor biopsy sample or the tumor surgical specimen derived from a tumor selected ovarian cancer, fallopian tube cancer, peritoneal cancer, cutaneous squamous cell carcinoma (CSCC), and squamous cell carcinoma of the head and neck (SCCHN).

In embodiments, the level of the cell is measured by RNA sequencing, immunohistochemical staining, western blotting, in cell western, immunofluorescent staining, ELISA, and fluorescent activating cell sorting (FACS) or a combination thereof. In embodiments, the level of the cell is measured by contacting the sample with an agent that specifically binds to a marker specific to M1 macrophages, M2 macrophages and/or granzyme B producing-T cells. In embodiments, the marker specific to M1 macrophages is selected from CD80, CD86, CD64, CD16, CD32, and nitric oxide synthase (iNOS), the marker specific to M2 macrophages is selected from CD163, CD206, CD68, arginase 1 (Arg1) and DECTIN-1. In embodiments, the marker specific to granzyme B producing-T cells is selected from granzyme B (GrzB), CD69 and integrin aE (CD103).

In embodiments, the agent that specifically binds to the a marker specific to M1 macrophages, M2 macrophages and/or granzyme B producing-T cells is an antibody or fragment thereof In embodiments, the antibody is a recombinant antibody, a monoclonal antibody, a polyclonal antibody, or fragment thereof. In embodiments, the level of the cell is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding a marker specific to M1 macrophages, M2 macrophages and/or granzyme B producing-T cells. In embodiments, the marker specific to M1 macrophages is selected from CD80, CD86, CD64, CD16, CD32, and nitric oxide synthase (iNOS), the marker specific to M2 macrophages is selected from CD163, CD206, CD68, arginase 1 (Arg1) and DECTIN-1. In embodiments, the marker specific to granzyme B producing-T cells is selected from granzyme B (GrzB), CD69 and integrin aE (CD103). In embodiments, the agent that specifically binds to one or more of the nucleic acids is a nucleic acid primer or probe.

In embodiments, the level and/or activity of CD40+ B cells is measured by polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR), quantitative PCR (qPCR), multiplex polymerase chain reaction, nested polymerase chain reaction, hot start polymerase chain reaction, long-range PCR, assembly polymerase chain reaction, asymmetric polymerase chain reaction, digital droplet PCR, a recombinase polymerase amplification (RPA), a loop-mediated amplification (LAMP), a helicase-dependent amplification (HDA), RNA or DNA gel electrophoresis or Southern or Northern blotting, a microarray-based assay, a hybridization technique, optionally selected from solution hybridization, capillary hybridization, hybridization to nucleic acid arrays, optionally macroarrays, microarrays or high-density oligonucleotide arrays (Gene Chips).

In embodiments, the chimeric protein is administered at the dosage of about 1 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 3 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 6 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 10 mg/kg.

In embodiments, the first domain is capable of binding a CD172a (SIRPa) ligand. In embodiments, the first domain comprises substantially all of the extracellular domain of CD172a (SIRPa). In embodiments, the first domain comprises an amino acid sequence that is at least about 90%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% identical to the amino acid sequence of SEQ ID NO: 57.

In embodiments, the second domain is capable of binding a CD40 receptor. In embodiments, the second domain comprises substantially all of the extracellular domain of CD40L. In embodiments, the second domain comprises an amino acid sequence that is at least about 90%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% identical to the amino acid sequence of SEQ ID NO: 58.

In embodiments, the linker comprises a hinge-CH2-CH3 Fc domain derived from lgG4. In embodiments, the linker comprises a hinge-CH2-CH3 Fc domain derived from human lgG4. In embodiments, the linker comprises an amino acid sequence that is at least about 90%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3.

In embodiments, (a) the first domain comprises the amino acid sequence of SEQ ID NO: 57, (b) the second domain comprises the amino acid sequence of SEQ ID NO: 58, and (c) the linker comprises an amino acid sequence that is at least about 90%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the chimeric protein further comprises the amino acid sequence of SEQ ID NO: 5 or SEQ ID NO: 7. In embodiments, the chimeric protein further comprises the amino acid sequence of SEQ ID NO: 5 and SEQ ID NO: 7.

In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 90%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61.

In embodiments, the method of any of the aspects disclosed herein further comprises administration of a second dose of the chimeric protein. In embodiments, the second dose is administered at least about 3 days, or at least about 4 days, or at least about 5 days, or at least about 6 days, or at least about 7 days, or at least about 8 days, or at least about 9 days, or at least about 10 days, or at least about 14 days, or at least about 21 days, or at least about 28 days after the administration of the first dose. In embodiments, the second dose of the chimeric protein is in the range of from about 0.3 mg/kg to 10 mg/kg. In embodiments, the second dose is about 0.3 mg/kg, or about 1 mg/kg, or about 2 mg/kg, or about 3 mg/kg, or about 4 mg/kg, or about 6 mg/kg, or about 8 mg/kg, or about 10 mg/kg. In embodiments, the second dose is in the range of about 0.3 mg/kg to about 2 mg/kg, or about 1 mg/kg to about 3 mg/kg, or about 2 mg/kg to about 4 mg/kg, or about 3 mg/kg to about 6 mg/kg, or about 5 mg/kg to about 10 mg/kg.

In embodiments, the human subject suffers from or is suspected to suffer from an advanced solid tumor or a lymphoma. In embodiments, the human subject suffers from or is suspected to suffer from a cancer is selected from ovarian cancer, fallopian tube cancer, peritoneal cancer, cutaneous squamous cell carcinoma (CSCC), and squamous cell carcinoma of the head and neck (SCCHN). In embodiments, the human subject has failed one or more platinum-based therapies. In embodiments, the human subject is ineligible for a platinum therapy. In embodiments, the human subject is not receiving a concurrent chemotherapy, immunotherapy, biologic or hormonal therapy, and/or wherein the human subject has received, been tolerant to, or is ineligible for standard therapy and/or the cancer has no approved therapy considered to be standard of care. In embodiments, the human subject has failed one or more platinum-based therapies. In embodiments, the human subject is ineligible for a further platinum therapy. In embodiments, the human subject is ineligible for a platinum therapy. In embodiments, the human subject is not receiving a concurrent chemotherapy, immunotherapy, biologic or hormonal therapy, and/or wherein the human subject has received, been tolerant to, or is ineligible for standard therapy and/or the cancer has no approved therapy considered to be standard of care.

Any aspect or embodiment disclosed herein can be combined with any other aspect or embodiment as disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A to FIG. 1 F summarize the study design of phase 1 clinical trial of the SIRPa-Fc-CD40L chimeric protein (SL-172154), study subject and tumor characteristics, and adverse events (AEs). FIG. 1A shows a diagrammatic representation of the SIRPa-Fc-CD40L chimeric protein (SL-172154). SL-172154 (SIRPa-Fc- CD40L) is a hexameric, bi-functional fusion protein consisting of SIRPa (binding affinity to CD47 is 0.628 nM) linked to CD40L (binding affinity to CD40 is 4.74 nM) through an Fc linker protein. FIG. 1 B shows a diagrammatic representation of the phase 1 dose escalation study. FIG. 1C shows the details of the study population. FIG. 1D shows the details of the tumor characteristics. FIG. 1 E tabulates all causality AEs observed in >3 subjects. FIG. 1F shows the drug-related AEs (any grade) observed in >10% subjects.

FIG. 2A to FIG. 2E summarize the pharmacokinetics of the SIRPa-Fc-CD40L chimeric protein (SL-172154). FIG. 2A shows a Cycle 1 Day 1 concentration profile. FIG. 2B shows Cmax and AUC at Cycle 1 Day 1. SL- 172154 Cmax and AUC increased with dose with greater than proportional exposure noted at 3 and 10 mg/kg. FIG. 2C shows dose-normalized PK parameters at Cycle 1 Day 1 (C1 D1) (left panels), Cycle 1 Day 15 (C1 D1) (middle panels), and Cycle 2 Day 1 (C1 D1) (right panels). Cmax/D (top panels) and AUCiast/D (bottom panels) are shown. FIG. 2D shows dose-normalized Cmax, which is the maximum observed concentration. FIG. 2E shows dose-normalized AUCiast, which is the area under the curve, time 0 to last concentration. FIG. 3A and FIG. 3B demonstrate that SL-172154 binds to B cells and stimulates B cell margination. FIG. 3A shows CD40 engagement of CD40+ B cells across doses of SL-127154. FIG. 3B shows dose-dependent egress of CD40+ B cells with maximal egress noted at 1 mg/kg and 3 mg/kg.

FIG. 4A and FIG. 4B demonstrate the binding of SL-172154 to CD47⁺ cells. FIG. 4A shows percentage receptor occupancy of CD47 on CD4 T cell with maximal occupancy noted between 1 mg/Kg and 3 mg/Kg. Without wishing to be bound by theory, the reduction of receptor occupancy seen at 10 mg/Kg may be due to CD4 T cell egress. FIG. 4B shows the CD47 receptor saturation on CD4 T cells.

FIG. 5 shows dose-dependent egress of CD4 T cells. Without wishing to be bound by theory, the reduction of receptor occupancy seen at 10 mg/Kg may be due to CD4 T cell egress.

FIG. 6A to FIG. 6K show dose-dependent & persistent cytokine responses: IL-12, CXCL-10, CCL-22, CXCL- 8 and IL-10. FIG. 6A shows a dose-dependent induction of IL-12. FIG. 6B shows the induction of IL-12 and return to normal levels before the next dose. FIG. 6C and FIG. 6D show a dose-dependent induction of CXCL-8. FIG. 6E and FIG. 6F show a dose-dependent induction of CXCL-10. FIG. 6G and FIG. 6H shows a dose-dependent induction of IL-10. FIG. 61 shows a dose-dependent induction of CCL2. FIG. 6J shows a dose-dependent induction of n CCL20. FIG. 6K shows a dose-dependent induction of CCL22.

FIG. 7A to FIG. 7C show that SL-172154 Stimulates dose-dependent margination of B cells (FIG. 7A), CD40 monocytes (FIG. 7B) and CD4 T cells (FIG. 7C).

FIG. 8A and FIG. 8B show the PK/PD model simulation in B cell margination (FIG. 8A) and IL-12 stimulation (FIG. 8B) demonstrating the pharmacodynamic activity at 3 mg/kg.

FIG. 9A to FIG. 9C show the changes in tumor nest induced by SL-172154. FIG. 9A shows immunofluorescence images demonstrating the induction of CD68, CD206, MHC II, CD3, CD8 and granzyme B-expressing cells after dosing with SL-172154. FIG. 9B and FIG. 9C show the induction of polarization of M1 macrophages (FIG. 9B) and infiltration of cytotoxic T cells (FIG. 9C) in the tumor nest

DETAILED DESCRIPTION

The present disclosure is based, in part, on the discoveries that (1) the target engagement of CD47 on CD4 T cells and CD40 on B cells approaches 100% by the 3 mg/kg dose level of the SIRPa-Fc-CD40L chimeric protein; (2) the margination CD40+ B cells from peripheral blood following the administration of the SIRPa- Fc-CD40L chimeric protein reaches maximum at the dosages > 3 mg/kg, and (3) the induction of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 following the administration of the SIRPa-Fc-CD40L chimeric protein approached a plateau at the dosages >3 mg/kg. The present disclosure is based, in part, on the discoveries that infusion related reaction (IRR), if any, may be mitigated by slowing the rate of infusion. These discoveries help determine doses and dosing regimens.

In some aspects, the present disclosure relates to a method for treating a cancer in a human subject, the method comprising: (i) administering to the human subject a first dose at a dosage of at least about 0.3 mg/kg of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPo)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a post-dosing level and/or activity of one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 have been measured after at least 15 minutes after administering the first dose; and (ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if: the post-dosing level and/or activity of IL-12 is at least about 3-fold greater than a predose amount or post-first dose amount (e.g. at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, at least about 8-fold greater, at least about 9-fold greater, at least about 10-fold greater, at least about 11 -fold greater, or at least about 12- fold greater), the post-dosing level and/or activity of CXCL-8 is at least about 3-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, at least about 8-fold greater, at least about 9-fold greater, at least about 10-fold greater, at least about 11 -fold greater, at least about 12- fold greater, at least about 13-fold greater, at least about 14-fold greater, or at least about 15-fold greater), the post-dosing level and/or activity of CXCL-10 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 2-fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, or at least about 6-fold greater), the post-dosing level and/or activity of IL-10 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 2- fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 10-fold greater, or at least about 20-fold greater), the post-dosing level and/or activity of CCL2 is at least at least about 4-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 4- fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, or at least about 8-fold greater), the post-dosing level and/or activity of CCL20 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 2-fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 10-fold greater, or at least about 20- fold greater), and/or the post-dosing level and/or activity of CCL22 is at least about 2-fold greater than a predose amount or post-first dose amount (e.g. at least about 2-fold greater, at least about 3-fold greater, or at least about 4-fold greater); or administering to the human subject a second dose of the chimeric protein at a higher dosage than the dosage of the first dose if the post-dosing level and/or activity of IL-12 is equal or less than about 2-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CXCL-8 is equal or less than about 2-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CXCL-10 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of IL-10 is equal or less than about 1- fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CCL2 is equal or less than about 3-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CCL20 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, and/or the post-dosing level and/or activity of CCL22 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount; wherein the second dose is administered at least about 48 hours after the administration of the first dose. In embodiments, the post-dosing level and/or activity is measured less than 12, or less than 8, or less than 6, or less than 4, or less than 3, or less than 2, or less than 1 hours post dosing.

In embodiments, the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is measured using the following formula:

%CRI @postdose

Receptor engagement =

%CR @ Predose wherein %CR @ predose is the percentage of target receptor-expressing lymphocytes in a pre-dose blood sample obtained from the subject; %CR @ postdose is the percentage of target receptor-expressing lymphocytes in the post-dose blood sample; and %CRI @ postdose is the percentage of the chimeric proteinbound CD47⁺ CD4⁺ T cells and/or the chimeric protein-bound CD40⁺ B cells in the post-dose blood sample, wherein: the presence, absence, or level of CD47⁺ CD4⁺ T cells and/or CD40⁺ B cells has been determined in the pre-dose blood sample, the presence, absence, or level of CD47⁺ CD4⁺ T cells and/or CD40⁺ B cells has been determined in the post-dose blood sample, and the presence, absence, or level of the chimeric protein-bound CD47⁺ CD4⁺ T cells and/or the chimeric protein-bound CD40⁺ B cells has been determined in the post-dose blood sample.

In some aspects, the present disclosure relates to a method for treating a cancer in a human subject, the method comprising: (i) administering to the human subject a dose at a dosage of at least about 0.3 mg/kg of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein the chimeric protein is administered by infusion wherein a post-dosing infusion related reaction (IRR) monitored during and immediately after the administration a dose; and (ii) slowing the rate of infusion if an IRR is observed during the dose and/or during the subsequent infusion. In embodiments, the rate of infusion is decreased to about 90%, or about 80%, or about 75%, or about 70%, or about 60%, or about 50%, or about 40%, or about 33%, or about 30%, or about 25%, or about 20%, or less of the starting infusion rate. In embodiments, the IRR is selected from headache, nausea, chills, pruritus, urticaria, fever, rigors, diaphoresis, dizziness, flush, bronchospasms, chest, and back pain.

Importantly, since a chimeric protein of the present disclosure via binding of the extracellular domain of CD172a (SIRPa) to its receptor/ligand on a cancer cell) disrupts, blocks, reduces, inhibits, and/or sequesters the transmission of immune inhibitory signals, e.g., originating from a cancer cell that is attempting to avoid its phagocytosis and/or destruction, and via binding of CD40L to its receptor) enhances, increases, and/or stimulates the transmission of an immune stimulatory signal to an anti-cancer immune cell, it can provide an anti-tumor effect by two distinct pathways; this dual-action is more likely to provide any anti-tumor effect in a patient and/or to provide an enhanced anti-tumor effect in a patient. Furthermore, since such chimeric proteins can act via two distinct pathways, they can be efficacious, at least, in patients who respond poorly to treatments that target one of the two pathways. Thus, a patient who is a poor responder to treatments acting via one of the two pathways, can receive a therapeutic benefit by targeting the other pathway. Chimeric Proteins

The chimeric proteins of the present disclosure comprise an extracellular domain of CD172a (SIRPa) and an extracellular domain of CD40L which together can simultaneously block immune inhibitory signals and stimulate immune activating signals.

Aspects of the present disclosure provide a chimeric protein comprising a general structure of: N terminus -

(a) - (b) - (c) - C terminus, where (a) is a first domain comprising an extracellular domain of CD 172a (SIRPa),

(b) is a linker adjoining the first domain and the second domain, e.g., the linker comprising at least one cysteine residue capable of forming a disulfide bond and/or comprising a hinge-CH2-CH3 Fc domain, and

(c) is a second domain comprising an extracellular domain of CD40L; wherein the linker connects the first domain and the second domain.

In embodiments, the first domain comprises substantially all of the extracellular domain of CD172a (SIRPa). In embodiments, the first domain is capable of binding a CD172a (SIRPa) ligand. In embodiments, the first domain is capable of binding a CD172a (SIRPa) ligand (e.g., CD47) expressed on cancer cell surface. In embodiments, the first domain is capable of inhibiting the binding of a CD172a (SIRPa) ligand e.g., CD47) to the CD172a (SIRPa) protein located on myeloid and hematopoietic stem cells and neurons. In embodiments, the first domain is capable of inhibiting an immunosuppressive signal. In embodiments, the first domain is capable of inhibiting an immunosuppressive signal. In embodiments, the first domain is capable of inhibiting a macrophage checkpoint or “do not eat me” signal. In embodiments the therapy with the SIRPa- Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEQ ID NO: 61) stimulates macrophages to phagocytize tumor cells and effectively present the tumor antigens of phagocytized tumor cells to T cells.

In embodiments, the second domain is capable of binding a CD40 receptor. In embodiments, the second domain comprises substantially all of the extracellular domain of CD40L. In embodiments, the second domain is capable of activating an immune stimulatory signal.

In embodiments, the chimeric protein is a recombinant fusion protein, e.g., a single polypeptide having the extracellular domains disclosed herein. For example, in embodiments, the chimeric protein is translated as a single unit in a prokaryotic cell, a eukaryotic cell, or a cell-free expression system.

In embodiments, the presentchimeric protein is producible in a mammalian host cell as a secretable and fully functional single polypeptide chain. In embodiments, chimeric protein refers to a recombinant protein of multiple polypeptides, e.g., multiple extracellular domains disclosed herein, that are combined {via covalent or non-covalent bonding) to yield a single unit, e.g., in vitro {e.g., with one or more synthetic linkers disclosed herein).

In embodiments, the chimeric protein is chemically synthesized as one polypeptide, or each domain is chemically synthesized separately and then combined. In embodiments, a portion of the chimeric protein is translated, and a portion is chemically synthesized.

In embodiments, an extracellular domain refers to a portion of a transmembrane protein which is capable of interacting with the extracellular environment. In embodiments, an extracellular domain refers to a portion of a transmembrane protein which is sufficient for binding to a ligand or receptor and is effective in transmitting a signal to a cell. In embodiments, an extracellular domain is the entire amino acid sequence of a transmembrane protein which is normally present at the exterior of a cell or of the cell membrane. In embodiments, an extracellular domain is that portion of an amino acid sequence of a transmembrane protein which is external of a cell or of the cell membrane and is needed for signal transduction and/or ligand binding as may be assayed using methods know in the art {e.g., in vitro ligand binding and/or cellular activation assays).

Transmembrane proteins typically consist of an extracellular domain, one or a series of transmembrane domains, and an intracellular domain. Without wishing to be bound by theory, the extracellular domain of a transmembrane protein is responsible for interacting with a soluble receptor or ligand or membrane-bound receptor or ligand {i.e., a membrane of an adjacent cell). Without wishing to be bound by theory, the transmembrane domain(s) is responsible for localizing the transmembrane protein to the plasma membrane. Without wishing to be bound by theory, the intracellular domain of a transmembrane protein is responsible for coordinating interactions with cellular signaling molecules to coordinate intracellular responses with the extracellular environment (or visa-versa).

There are generally two types of single-pass transmembrane proteins: Type I transmembrane proteins which have an extracellular amino terminus and an intracellular carboxy terminus and Type II transmembrane proteins which have an extracellular carboxy terminus and an intracellular amino terminus. Type I and Type II transmembrane proteins can be either receptors or ligands. For Type I transmembrane proteins {e.g., CD172a (SIRPo)), the amino terminus of the protein faces outside the cell, and therefore contains the functional domains that are responsible for interacting with other binding partners (either ligands or receptors) in the extracellular environment. For Type II transmembrane proteins {e.g., CD40L), the carboxy terminus of the protein faces outside the cell, and therefore contains the functional domains that are responsible for interacting with other binding partners (either ligands or receptors) in the extracellular environment. Thus, these two types of transmembrane proteins have opposite orientations to each other relative to the cell membrane.

The description of CD47 as a “do not eat me” signal in a broad range of cancers stimulated exploration of what combinations of “eat me” signals may enhance antitumor immunity in the setting of CD47 blockade. Willingham et al., The CD47-signal regulatory protein alpha (SIRPa) interaction is a therapeutic target for human solid tumors. Proc Natl Acad Sci U S A 109: 6662-6667 (2012); Jaiswal et al., CD47 is upregulated on circulating hematopoietic stem cells and leukemia cells to avoid phagocytosis. Cell 138:271-285 (2009); Weiskopf et al., Engineered SI Palpha variants as immunotherapeutic adjuvants to anticancer antibodies. Science 341:88-91 (2013). Preclinical combinations of CD47 blockade and ADCP-competent antibodies, including rituximab and trastuzumab, enhance tumor phagocytosis. Kauder et al., ALX148 blocks CD47 and enhances innate and adaptive antitumor immunity with a favorable safety profile. PLoS One 13: e0201832 (2018); Chao et al., Anti- CD47 antibody synergizes with rituximab to promote phagocytosis and eradicate non-Hodgkin lymphoma. Cell 142:699-713 (2010); Chao et al., Calreticulin is the dominant pro-phagocytic signal on multiple human cancers and is counterbalanced by CD47. Sci Transl Med 2: 63ra94 (2010); Advani et al., CD47 Blockade by Hu5F9-G4 and rituximab in non-Hodgkin's lymphoma. N Engl J Med 379:1711- 1721 (2018); Zhao et al., CD47-signal regulatory protein-alpha (SIRPalpha) interactions form a barrier for antibody-mediated tumor cell destruction. Proc Natl Acad Sci U S A 108:18342-18347 (2011). At least 50% of patients with relapsed or refractory diffuse large B-cell lymphoma or follicular lymphoma treated with Hu5F9-G4, a humanized, lgG4 isotype, CD47-blocking mAb, in combination with rituximab demonstrate objective responses. Advani et al., CD47 Blockade by Hu5F9-G4 and rituximab in non-Hodgkin's lymphoma. N Engl J Med 379:1711-1721 (2018). CD47 blockade enhances antigen presentation in immune-neglected tumors (Tseng et al., Anti-CD47 antibody-mediated phagocytosis of cancer by macrophages primes an effective antitumor T-cell response. Proc Natl Acad Sci U S A 110:11103-11108 (2013)), yet only sporadic clinical responses have been observed using CD47/SIRPO blocking therapeutics as monotherapy or in combination with PD-1/L1 -blocking antibodies.

Disrupting the binding of CD47 to SIRPa has emerged as a promising immunotherapeutic strategy for advanced cancers by potentiating antibody-dependent cellular phagocytosis (ADCP) of targeted antibodies. Preclinically, CD47/SIRPa blockade induces antitumor activity by increasing the phagocytosis of tumor cells by macrophages and enhancing the cross-presentation of tumor antigens to CD8+T cells by dendritic cells; both of these processes are potentiated by CD40 signaling. Here a novel, two-sided fusion protein incorporating the extracellular domains of SIRPo and CD40L, adjoined by a central Fc domain, termed SIRPa-Fc-CD40L was generated. As shown herein, the SIRPa-Fc-CD40L chimeric protein bound CD47 and CD40 with high affinity and activated CD40 signaling in the absence of Fc receptor cross-linking. No evidence of hemolysis, hemagglutination, or thrombocytopenia was observed in vitro or in cynomolgus macaques. Further, as shown herein, the SIRPa- Fc-CD40L chimeric protein outperformed CD47 blocking and CD40 agonist antibodies in murine CT26 tumor models and synergized with immune checkpoint blockade of PD-1 and CTLA4. SIRPa-Fc-CD40L activated a type I interferon response in macrophages and potentiated the activity of ADCP-competent targeted antibodies both in vitro and in vivo. These data illustrated that whereas CD47/SIRPo inhibition could potentiate tumor cell phagocytosis, CD40-mediated activation of a type I interferon response provided a bridge between macrophage- and T-cell-mediated immunity that significantly enhanced durable tumor control and rejection.

Chimeric proteins of the present disclosure comprise an extracellular domain of CD172a (SIRPo) and an extracellular domain of CD40L. Thus, a chimeric protein of the present disclosure comprises, at least, a first domain comprising the extracellular domain of CD172a (SIRPo), which is connected - directly or via a linker - to a second domain comprising the extracellular domain of CD40L. When the domains are linked in an amino-terminal to carboxy-terminal orientation, the first domain is located on the “left”’ side of the chimeric protein and is “outward facing” and the second domain is located on “right” side of the chimeric protein and is “outward facing.”

Other configurations of first and second domains are envisioned, e.g., the first domain is outward facing and the second domain is inward facing, the first domain is inward facing and the second domain is outward facing, and the first and second domains are both inward facing. When both domains are “inward facing,” the chimeric protein would have an amino-terminal to carboxy-terminal configuration comprising an extracellular domain of CD40L, a linker, and an extracellular domain of CD172a (SIRPo). In such configurations, it may be necessary for the chimeric protein to include extra “slack,” as described elsewhere herein, to permit binding domains of the chimeric protein to one or both of its receptors/ligands.

Constructs could be produced by cloning of the nucleic acids encoding the three fragments (the extracellular domain of CD172a (SIRPo), followed by a linker sequence, followed by the extracellular domain of CD40L) into a vector (plasmid, viral or other) wherein the amino terminus of the complete sequence corresponded to the ‘left’ side of the molecule containing the extracellular domain of CD172a (SIRPo) and the carboxy terminus of the complete sequence corresponded to the ‘right’ side of the molecule containing the extracellular domain of CD40L. In some embodiments of chimeric proteins having one of the other configurations, as described above, a construct would comprise three nucleic acids such that the translated chimeric protein produced would have the desired configuration, e.g., a dual inward-facing chimeric protein. Accordingly, in embodiments, the present chimeric proteins are engineered as such.

In embodiments, the chimeric protein is capable of contemporaneously binding the human CD172a (SIRPa) ligand and the human CD40 receptor, wherein the CD172a (SIRPa) ligand is CD47 and the CD40L receptor is CD40.

The chimeric protein has a general structure of: N terminus - (a) - (b) - (c) - C terminus, in which (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L). In embodiments, the linker comprises at least one cysteine residue capable of forming a disulfide bond.

Chimeric proteins of the present disclosure have a first domain which is sterically capable of binding its ligand/receptor and/or a second domain which is sterically capable of binding its ligand/receptor. This means that there is sufficient overall flexibility in the chimeric protein and/or physical distance between an extracellular domain (or portion thereof) and the rest of the chimeric protein such that the ligand/receptor binding domain of the extracellular domain is not sterically hindered from binding its ligand/receptor. This flexibility and/or physical distance (which is herein referred to as “slack”) may be normally present in the extracellular domain(s), normally present in the linker, and/or normally present in the chimeric protein (as a whole). Alternately, or additionally, the chimeric protein may be modified by including one or more additional amino acid sequences (e.g., the joining linkers described below) or synthetic linkers (e.g., a polyethylene glycol (PEG) linker) which provide additional slack needed to avoid steric hindrance.

In embodiments, the chimeric proteins of the present disclosure comprise variants of the extracellular domain of CD172a (SIRPa). As examples, the variant may have at least about 60%, or at least about 61%, or at least about 62%, or at least about 63%, or at least about 64%, or at least about 65%, or at least about 66%, or at least about 67%, or at least about 68%, or at least about 69%, or at least about 70%, or at least about 71 %, or at least about 72%, or at least about 73%, or at least about 74%, or at least about 75%, or at least about 76%, or at least about 77%, or at least about 78%, or at least about 79%, or at least about 80%, or at least about 81%, or at least about 82%, or at least about 83%, or at least about 84%, or at least about 85%, or at least about 86%, or at least about 87%, or at least about 88%, or at least about 89%, or at least about 90%, or at least about 91%, or at least about 92%, or at least about 93%, or at least about 94%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% sequence identity with the known amino acid sequence of CD172a (SIRPa), e.g., human CD172a (SIRPa).

In embodiments, the extracellular domain of CD172a (SIRPa) has the following amino acid sequence:

EEELQVIQPDKSVLVAAGETATLRCTATSLIPVGPIQWFRGAGPGRELIYNQKEGHFPRVTTVSDLT KRNNMDFSIRIGNITPADAGTYYCVKFRKGSPDDVEFKSGAGTELSVRAKPSAPWSGPAARATPQ HTVSFTCESHGFSPRDITLKWFKNGNELSDFQTNVDPVGESVSYSIHSTAKWLTREDVHSQVICEV AHVTLQGDPLRGTANLSETIRVPPTLEVTQQPVRAENQVNVTCQVRKFYPQRLQLTWLENGNVSR TETASTVTENKDGTYNWMSWLLVNVSAHRDDVKLTCQVEHDGQPAVSKSHDLKVSAHPKEQGSN TAAENTGSNERNIY (SEQ ID NO: 57).

In embodiments, a chimeric protein comprises a variant of the extracellular domain of CD172a (SIRPa). As examples, the variant may have at least about 60%, or at least about 61 %, or at least about 62%, or at least about 63%, or at least about 64%, or at least about 65%, or at least about 66%, or at least about 67%, or at least about 68%, or at least about 69%, or at least about 70%, or at least about 71 %, or at least about 72%, or at least about 73%, or at least about 74%, or at least about 75%, or at least about 76%, or at least about 77%, or at least about 78%, or at least about 79%, or at least about 80%, or at least about 81 %, or at least about 82%, or at least about 83%, or at least about 84%, or at least about 85%, or at least about 86%, or at least about 87%, or at least about 88%, or at least about 89%, or at least about 90%, or at least about 91 %, or at least about 92%, or at least about 93%, or at least about 94%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% sequence identity with SEQ ID NO: 57.

In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 57.

One of ordinary skill may select variants of the known amino acid sequence of CD172a (SI RPa) by consulting the literature, e.g., Hatherley et al., “Paired receptor specificity explained by structures of signal regulatory proteins alone and complexed with CD47.” Mol Cell 31 : 266-277 (2008); Hatherley et al., ‘The Structure of the Macrophage Signal Regulatory Protein Alpha (Sirpalpha) Inhibitory Receptor Reveals a Binding Face Reminiscent of that Used by T Cell Receptors.” J Biol Chem 282: 14567 (2007); Hatherley et al., “Structure of Signal-Regulatory Protein Alpha: A Link to Antigen Receptor Evolution.” J Biol Chem 284: 26613 (2009); Hatherley et al., “Polymorphisms in the Human Inhibitory Signal-Regulatory Protein Alpha Do not Affect Binding to its Ligand Cd47.” J Biol Chem 289: 10024 (2014); Ring et al., “Anti-SIRP alpha antibody immunotherapy enhances neutrophil and macrophage antitumor activity.” Proc Natl Acad Sci U S A 114: E10578-E10585 (2017), each of which is incorporated by reference in its entirety.

In embodiments, the chimeric proteins of the present disclosure comprise variants of the extracellular domain of CD40L. As examples, the variant may have at least about 60%, or at least about 61%, or at least about 62%, or at least about 63%, or at least about 64%, or at least about 65%, or at least about 66%, or at least about 67%, or at least about 68%, or at least about 69%, or at least about 70%, or at least about 71 %, or at least about 72%, or at least about 73%, or at least about 74%, or at least about 75%, or at least about 76%, or at least about 77%, or at least about 78%, or at least about 79%, or at least about 80%, or at least about 81%, or at least about 82%, or at least about 83%, or at least about 84%, or at least about 85%, or at least about 86%, or at least about 87%, or at least about 88%, or at least about 89%, or at least about 90%, or at least about 91 %, or at least about 92%, or at least about 93%, or at least about 94%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% sequence identity with the known amino acid sequence of CD40L, e.g., human CD40L.

In embodiments, the extracellular domain of CD40L has the following amino acid sequence:

HRRLDKIEDERNLHEDFVFMKTIQRCNTGERSLSLLNCEEIKSQFEGFVKDIMLNKEETKKENSFEM QKGDQNPQIAAHVISEASSKTTSVLQWAEKGYYTMSNNLVTLENGKQLTVKRQGLYYIYAQVTFCS NREASSQAPFIASLCLKSPGRFERILLRAANTHSSAKPCGQQSIHLGGVFELQPGASVFVNVTDPSQ VSHGTGFTSFGLLKL (SEQ ID NO: 58).

In embodiments, a chimeric protein comprises a variant of the extracellular domain of CD40L. As examples, the variant may have at least about 60%, or at least about 61 %, or at least about 62%, or at least about 63%, or at least about 64%, or at least about 65%, or at least about 66%, or at least about 67%, or at least about 68%, or at least about 69%, or at least about 70%, or at least about 71%, or at least about 72%, or at least about 73%, or at least about 74%, or at least about 75%, or at least about 76%, or at least about 77%, or at least about 78%, or at least about 79%, or at least about 80%, or at least about 81 %, or at least about 82%, or at least about 83%, or at least about 84%, or at least about 85%, or at least about 86%, or at least about 87%, or at least about 88%, or at least about 89%, or at least about 90%, or at least about 91 %, or at least about 92%, or at least about 93%, or at least about 94%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% sequence identity with SEQ ID NO: 58.

In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 58.

One of ordinary skill may select variants of the known amino acid sequence of CD40L by consulting the literature, e.g., Karpusas et al., “2 A crystal structure of an extracellular fragment of human CD40 ligand.” Structure 3: 1031-1039 (1995); Karpusas et al., “Structure of CD40 ligand in complex with the Fab fragment of a neutralizing humanized antibody.” Structure 9: 321-329 (2001); Silvian et al., “Small Molecule Inhibition of the TNF Family Cytokine CD40 Ligand through a Subunit Fracture Mechanism.” ACS Chem Biol 6: 636- 647 (2011); An et al., “Crystallographic and mutational analysis of the CD40-CD154 complex and its implications for receptor activation.” J Biol Chem 286: 11226-11235 (2011 ); Karnell et al., “A CD40 L-targeting protein reduces autoantibodies and improves disease activity in patients with autoimmunity.” Sci Transl Med 11 (2019), each of which is incorporated by reference in its entirety.

In embodiments, the linker of a chimeric protein comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker of a chimeric protein comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 1 , SEO ID NO: 2, or SEO ID NO: 3. In embodiments, the linker of a chimeric protein comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker of a chimeric protein comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker of a chimeric protein comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO:

1 , SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker of a chimeric protein comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3.

In embodiments, a chimeric protein of the present disclosure comprises: (1) a first domain comprising the amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to SEQ ID NO: 57, (b) a second domain comprises the amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to SEQ ID NO: 58, and (c) a linker comprises an amino acid sequence that is that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3.

In embodiments, a chimeric protein of the present disclosure comprises: (1) a first domain comprising the amino acid sequence that is at least 95% identical to SEQ ID NO: 57, (b) a second domain comprises the amino acid sequence that is at least 95% identical to SEQ ID NO: 58, and (c) a linker comprises an amino acid sequence that is that is at least 95% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO:

2, or SEQ ID NO: 3. In embodiments, a chimeric protein of the present disclosure comprises: (1) a first domain comprising the amino acid sequence that is at least 97% identical to SEQ ID NO: 57, (b) a second domain comprises the amino acid sequence that is at least 97% identical to SEQ ID NO: 58, and (c) a linker comprises an amino acid sequence that is that is at least 97% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, a chimeric protein of the present disclosure comprises: (1) a first domain comprising the amino acid sequence that is at least 98% identical to SEQ ID NO: 57, (b) a second domain comprises the amino acid sequence that is at least 98% identical to SEQ ID NO: 58, and (c) a linker comprises an amino acid sequence that is that is at least 98% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, a chimeric protein of the present disclosure comprises: (1) a first domain comprising the amino acid sequence that is at least 99% identical to SEQ ID NO: 57, (b) a second domain comprises the amino acid sequence that is at least 99% identical to SEQ ID NO: 58, and (c) a linker comprises an amino acid sequence that is that is at least 99% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEO ID NO: 3. In embodiments, a chimeric protein of the present disclosure comprises: (1) a first domain comprising the amino acid sequence of SEQ ID NO: 57, (b) a second domain comprises the amino acid sequence of SEQ ID NO: 58, and (c) a linker comprises an amino acid sequence that is at least 95% identical to SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, a chimeric protein of the present disclosure comprises: (1) a first domain comprising the amino acid sequence identical to SEQ ID NO: 57, (b) a second domain comprises the amino acid sequence that is to SEQ ID NO: 58, and (c) a linker comprises an amino acid sequence that is that is identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3.

In embodiments, a CD172a (SIRPa)-Fc-CD40L chimeric protein of the present disclosure has the following amino acid sequence (the extracellular domain of CD172a (SIRPa) is shown in a boldface font, the extracellular domain of CD40L is indicated by underline, Fc domain is shown in italic:

EEELQVIQPDKSVLVAAGETATLRCTATSLIPVGPIQWFRGAGPGRELIYNQKEGHFPRVTTVSD LTKRNNMDFSIRIGNITPADAGTYYCVKFRKGSPDDVEFKSGAGTELSVRAKPSAPWSGPAAR ATPQHTVSFTCESHGFSPRDITLKWFKNGNELSDFQTNVDPVGESVSYSIHSTAKWLTREDVHS QVICEVAHVTLQGDPLRGTANLSETIRVPPTLEVTQQPVRAENQVNVTCQVRKFYPQRLQLTWL ENGNVSRTETASTVTENKDGTYNWMSWLLVNVSAHRDDVKLTCQVEHDGQPAVSKSHDLKVS AHPKEQGSNTAAENTGSNERNIYSKYGPPCPPCPAPEFLGGPSVF/.FPP P/<DQ/.M/SRTPEV7C VVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLSGKEYKCKVS SKGLPSSIEKTISNATGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPEN NYKTTPPVLDSDGSFFL YSRL TVDKSRWQEGNVFSCSVLHEALHNHYTQKSLSLSLGKI EGRMDH RRLDKIEDERNLHEDFVFMKTIQRCNTGERSLSLLNCEEIKSQFEGFVKDIMLNKEETKKENSFEM QKGDQNPQIAAHVISEASSKTTSVLQWAEKGYYTMSNNLVTLENGKQLTVKRQGLYYIYAQVTFC SNREASSQAPFIASLCLKSPGRFERILLRAANTHSSAKPCGQQSIHLGGVFELQPGASVFVNVTDP SQVSHGTGFTSFGLLKL (SEQ ID NO: 59).

The 792 amino acid sequence of the CD172a (SIRPa)-Fc-CD40L chimeric protein (SL-172154) (not including the leader sequence) is shown above. The CD172a (SIRPo)-Fc-CD40L chimeric protein exists as a profile of oligomeric forms. There are 17 cysteines in the amino acid sequence with 8 likely disulfide pairs. Both N and O-linked glycosylation have been identified.

In embodiments, the chimeric protein of the present disclosure comprises at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 potential N glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least two potential N glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least four potential N glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least six potential N glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least eight potential N glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least ten potential N glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least 1 , 2, 3, 4, 5, 6, 7, or 8 potential 0 glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least two potential 0 glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least four potential 0 glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least six potential 0 glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least eight potential 0 glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least two potential N glycosylation sites, and at least two potential 0 glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least four potential N glycosylation sites, and at least four potential 0 glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least six potential N glycosylation sites, and at least six potential 0 glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least eight potential N glycosylation sites, and at least eight potential 0 glycosylation sites. In embodiments, the chimeric protein of the present disclosure comprises at least ten potential N glycosylation sites, and at least eight potential 0 glycosylation sites. In embodiments, the chimeric protein expressed in Chinese Hamster Ovary (CHO) cells is glycosylated.

There are 17 cysteines present in the SL-172154 chimeric protein. In some embodiments, the SL-172154 chimeric protein has no disulfide bonds. In some embodiments, the SL-172154 chimeric protein has at least one, or at least two, or at least 3, or at least 4, or at least 5, or at least 6, or at least 7, or at least 8, or at least 9, or at least 10 disulfide bonds. In some embodiments, the SL-172154 chimeric protein has at least one, or at least two interchain disulfide bonds. In some embodiments, the SL-172154 chimeric protein has at least one, or at least two, or at least 3, or at least 4, or at least 5, or at least 6, or at least 7, or 8 intrachain disulfide bonds. In some embodiments, the SL-172154 chimeric protein has a C350=C350 interchain disulfide bond. In some embodiments, the SL-172154 chimeric protein has a C353=C353 interchain disulfide bond. In some embodiments, the SL-172154 chimeric protein has a C153=C153 interchain disulfide bond. In some embodiments, the SL-172154 chimeric protein has a C25 = C91 disulfide bond. In some embodiments, the SL-172154 chimeric protein has a C140 - C198 disulfide bond. In some embodiments, the SL-172154 chimeric protein has a C243 = C301 disulfide bond. In some embodiments, the SL-172154 chimeric protein has a C385 = C445 disulfide bond. In some embodiments, the SL-172154 chimeric protein has a C491 = C549 disulfide bond. In some embodiments, the SL-172154 chimeric protein has a C603 = C615 disulfide bond. In some embodiments, the SL-172154 chimeric protein has a C709 = C725 disulfide bond. In some embodiments, the SL-172154 chimeric protein has a C140 = C243 = C709/C725 scrambled disulfide bond. In some embodiments, the SL-172154 chimeric protein has a C615 (chain 1) = C615 (chain 2) scrambled disulfide bond.

In some embodiments, the CD172a (SIRPo)-Fc-CD40L chimeric protein of the present disclosure is encoded by the following nucleotide sequence (leader sequence is shown by a bold-underlined font):

ATGGAATGGAGCTGGGTGTTCTTGTTCTTCCTGTCCGTGACCACCGGCGTGCACTCGGAGGAGGAG CTCCAGGTCATCCAGCCGGACAAGTCGGTGCTCGTGGCCGCCGGAGAAACTGCCACCCTGAGGTGC ACCGCGACCTCGCTGATTCCCGTGGGCCCGATTCAGTGGTTCCGGGGGGCCGGGCCTGGCAGAGAA CTGATCTACAACCAGAAGGAAGGCCATTTCCCTCGCGTGACTACTGTGTCCGATCTTACTAAGCGGAA CAACATGGACTTCAGCATTAGGATCGGCAACATCACCCCTGCTGACGCGGGAACCTACTACTGCGTCA AGTTCAGGAAAGGAAGCCCGGACGACGTGGAGTTCAAGAGCGGGGCGGGCACCGAACTGTCCGTGC GCGCCAAGCCATCCGCGCCCGTGGTGTCCGGACCCGCAGCCAGAGCAACTCCGCAGCACACCGTGT CGTTCACTTGCGAATCACACGGATTCTCCCCGCGCGATATCACGCTTAAGTGGTTCAAGAACGGGAAC GAACTGAGCGACTTCCAGACCAACGTGGACCCCGTCGGAGAAAGCGTCAGCTACTCCATTCACTCGA CCGCCAAAGTGGTGCTGACCAGGGAGGACGTGCATAGCCAAGTGATCTGCGAGGTCGCCCACGTCA CTCTGCAAGGAGATCCGCTGCGGGGAACAGCCAACCTGTCCGAAACTATCCGCGTGCCTCCCACCCT GGAAGTGACCCAGCAGCCCGTCCGAGCGGAGAATCAAGTCAATGTGACCTGTCAAGTCCGGAAATTC TACCCTCAACGGCTCCAGCTGACCTGGCTGGAAAACGGAAACGTGTCCCGCACGGAAACCGCCTCGA CCGTGACCGAGAACAAGGACGGCACCTACAACTGGATGTCCTGGCTCTTGGTGAACGTGTCAGCCCA CCGGGACGATGTCAAGCTGACTTGCCAAGTGGAACATGATGGGCAGCCAGCTGTCAGCAAGAGCCAC GACCTGAAGGTGTCCGCGCACCCGAAGGAACAGGGTTCGAATACTGCCGCCGAAAACACTGGTAGCA ACGAACGGAACATCTACTCTAAGTACGGCCCACCTTGCCCTCCCTGCCCGGCACCTGAATTTCTGGGT GGACCCTCCGTGTTTCTTTTCCCGCCCAAGCCAAAGGACCAGTTGATGATCTCCCGCACTCCGGAAGT GACATGCGTGGTGGTGGACGTGTCCCAGGAAGATCCGGAAGTGCAGTTCAATTGGTACGTGGATGGC GTGGAGGTCCATAACGCCAAGACTAAGCCGCGCGAGGAACAGTTCAATTCCACCTACCGGGTGGTGT CCGTGCTGACCGTGCTGCATCAGGACTGGCTCTCCGGCAAAGAGTACAAGTGCAAGGTGTCATCCAA GGGTCTGCCGTCGTCAATCGAAAAGACCATTTCCAATGCCACTGGGCAGCCCAGAGAACCTCAAGTCT ACACCCTCCCACCGTCCCAAGAGGAAATGACCAAGAACCAAGTCTCGCTGACGTGTCTCGTGAAGGG ATTCTACCCATCCGACATTGCTGTGGAATGGGAGTCCAACGGCCAGCCCGAGAACAACTACAAGACTA CCCCTCCCGTCCTGGACTCCGACGGTTCCTTCTTCCTTTACTCTCGCCTCACCGTGGATAAGTCGCGG

TGGCAGGAGGGGAACGTGTTCTCCTGCTCCGTCCTGCACGAAGCATTGCACAACCACTACACCCAGA AGTCCCTGTCACTGTCCCTGGGAAAGATTGAGGGTCGGATGGATCATCGGCGCCTGGACAAGATCGA GGACGAGCGGAACCTCCACGAGGATTTCGTGTTCATGAAAACCATCCAGAGATGCAACACCGGAGAG AGAAGCCTGTCCCTGCTCAACTGCGAGGAAATCAAGTCCCAGTTTGAAGGATTTGTGAAGGACATTAT GCTGAACAAGGAAGAGACTAAGAAGGAAAACTCCTTCGAGATGCAGAAGGGCGATCAGAACCCACAG ATCGCGGCCCACGTGATCTCCGAGGCCTCGTCAAAGACCACTTCAGTGCTCCAATGGGCCGAGAAGG GTTACTATACCATGAGCAACAACCTTGTGACCCTGGAGAACGGAAAGCAGCTCACCGTGAAAAGACAG GGACTGTACTATATCTATGCCCAAGTCACCTTCTGTTCGAACCGCGAGGCTAGCAGCCAGGCCCCGTT CATCGCCTCCCTCTGTTTGAAGTCGCCGGGGCGGTTTGAAAGGATTCTGCTGAGAGCTGCGAATACC CATTCGTCCGCCAAGCCTTGCGGACAGCAGTCAATCCACCTGGGGGGAGTGTTCGAGCTGCAGCCTG GCGCGAGCGTGTTCGTCAACGTGACCGACCCCTCCCAAGTGTCTCACGGCACCGGATTCACTTCGTT

TGGCCTGCTGAAGCTGTAA (SEQ ID NO: 60)

In some embodiments, the SEQ ID NO: 60 encodes for a precursor of the CD172a (SIRPa)-Fc-CD40L chimeric protein of the present disclosure having the following amino acid sequence (leader sequence is shown by an italic font):

MEWSWVFLFFLSVTTGVHSEEELQVIQPDKSVLVAAGETATLRCTATSLIPVGPIQWFRGAGPGRELIYNQK

EGHFPRVTTVSDLTKRNNMDFSIRIGNITPADAGTYYCVKFRKGSPDDVEFKSGAGTELSVRAKPSAPWS

GPAARATPQHTVSFTCESHGFSPRDITLKWFKNGNELSDFQTNVDPVGESVSYSIHSTAKWLTREDVHSQ VICEVAHVTLQGDPLRGTANLSETIRVPPTLEVTQQPVRAENQVNVTCQVRKFYPQRLQLTWLENGNVSRT ETASTVTENKDGTYNWMSWLLVNVSAHRDDVKLTCQVEHDGQPAVSKSHDLKVSAHPKEQGSNTAAENT GSNERNIYSKYGPPCPPCPAPEFLGGPSVFLFPPKPKDQLMISRTPEVTCVWDVSQEDPEVQFNWYVDG VEVHNAKTKPREEQFNSTYRWSVLTVLHQDWLSGKEYKCKVSSKGLPSSIEKTISNATGQPREPQVYTLP PSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNV FSCSVLHEALHNHYTQKSLSLSLGKIEGRMDHRRLDKIEDERNLHEDFVFMKTIQRCNTGERSLSLLNCEEI KSQFEGFVKDIMLNKEETKKENSFEMQKGDQNPQIAAHVISEASSKTTSVLQWAEKGYYTMSNNLVTLENG KQLTVKRQGLYYIYAQVTFCSNREASSQAPFIASLCLKSPGRFERILLRAANTHSSAKPCGQQSIHLGGVFEL

QPGASVFVNVTDPSQVSHGTGFTSFGLLKL (SEQ ID NO: 61) The chimeric protein of SEQ ID NO: 59 (also referred to herein as SL-172154) is a recombinant fusion glycoprotein comprising the extracellular domain of human CD172a (SIRPa) (PDCD1 , CD272a), a central domain including the hinge-CH2-CH3 region from human immunoglobulin constant gamma 4 (Inhibitory receptor SHPS-1 , 1 gG4), and the extracellular domain of human CD40L (TNFSF5, TRAP, CD154). The linear configuration of SL-172154 is CD172a (SIRPa)-Fc-CD40L.

The predicted molecular weight for the monomeric chimeric protein of SEQ ID NO: 59 is 88.1 kDa. The predicted molecular weight for the glycosylated monomeric chimeric protein of SEQ ID NO: 59 is about 115 kDa.

The dual-sided nature of the chimeric proteins disclosed herein, such as the CD172a (SIRPa)-Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEQ ID NO: 61), is designed to intercept one of the key immunosuppressive pathways within the tumor microenvironment (TME): the CD172a (SIRPa) - CD47 macrophage checkpoint.

Tumor cells may express CD47 on their cell surface, which can bind to CD172a (SIRPa) expressed by a macrophage to suppress phagocytosis of the tumor cells. Thus, the CD172a (SIRPa)-Fc-CD40L chimeric protein (e.g. SEQ ID NO: 59 or SEQ ID NO: 61) can bind to CD47 expressed on the surface of tumor, with the CD172a (SIRPa) domain of the CD172a (SIRPa)-Fc-CD40L chimeric proteins disclosed herein intended to provide competitive inhibition of CD47, and to replace the CD47 inhibitory signal with functionally trimerized/hexamerized CD40L, resulting in an incoming T cell experiencing co-stimulation via engagement through its CD40 receptor instead of suppression through CD172a (SIRPa) interactions. In other words, because the extracellular domains (ECDs) of CD172a (SIRPa) and CD40L are physically linked to one another and localized to the TME, tumor infiltrating T cells will receive co-stimulation at the same time they recognize a tumor antigen via its T cell receptor (TCR). Importantly, because the ECDs of CD172a (SIRPa) and CD40L are physically linked to one another, and localized to the TME, tumor infiltrating T cells will receive costimulation at the same time they recognize a tumor antigen via the T cell receptor. Together, these would result in replacement of an inhibitory CD47 signal with a co-stimulatory CD40L signal to enhance the antitumor activity of T cells.

The three constituent components of the chimeric proteins disclosed herein, including the CD172a (SIRPa)- Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEQ ID NO: 61), have unique attributes that facilitate dimerization or oligomerization. The extracellular domain of CD172a (SIRPa) normally exists as a monomer and is not known to form higher order homomeric complexes. The central Fc domain contains cysteine residues that are capable of disulfide bonding to form a dimeric structure. In embodiments, the chimeric proteins disclosed herein, including the CD172a (SIRPo)-Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEQ ID NO: 61), contains an S228P mutation in the hinge region of the Fc domain to prevent Fab arm exchange. The CD40L domain is known to form homotrimeric complexes, which are stabilized through noncovalent, electrostatic interactions. Although the chimeric proteins disclosed herein, including the CD172a (SIRPa)-Fc-CD40L chimeric protein (e.g. SEQ ID NO: 59 or SEQ ID NO: 61), are expressed as a continuous monomeric protein by production cell lines, the resulting monomeric proteins self-assemble into higher-order species based on these disulfide and charge-based interactions of CD40L (creating a trimer) and the combined influence of these attractive forces, resulting in a hexamer (dimer of trimers). The majority (>80%) of the CD172a (SIRPo)-Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEQ ID NO: 61) comprises the hexamer and trimer forms, which have similar activity. Importantly, because the CD172a (SIRPa)-Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEQ ID NO: 61), are comprised of hexamers and trimers, they stimulate CD40 signaling in the absence of cross-linking by Fc receptors or any other cross-linking agent. The predicted tertiary structures of the CD172a (SIRPa)-Fc-CD40L chimeric protein (e.g. SEQ ID NO: 59 or SEQ ID NO: 61) as a monomer and in various oligomeric states, based on disulfide (Fc) and charge-based (CD40L) interactions shows visualization by electron microscopy of the CD172a (SIRPo)-Fc-CD40L chimeric protein (e.g. SEQ ID NO: 59 or SEQ ID NO: 61) hexamers (top two images) and the CD172a (SIRPa)-Fc- CD40L chimeric protein (e.g. SEQ ID NO: 59 or SEQ ID NO: 61) trimers (bottom two images). Accordingly, the CD172a (SIRPa)-Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEQ ID NO: 61) forms trimers/hexamers and activates CD40 without the need for cross-linking. It is noteworthy that, unlike monoclonal antibodies, Fc receptor cross-linking is not required for functional activity of the CD172a (SIRPa)- Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEQ ID NO: 61).

In embodiments, a chimeric protein comprises a variant of the CD172a (SIRPa)-Fc-CD40L chimeric protein (e.g, SEQ ID NO: 59 or SEQ ID NO: 61). As examples, the variant may have at least about 60%, or at least about 61%, or at least about 62%, or at least about 63%, or at least about 64%, or at least about 65%, or at least about 66%, or at least about 67%, or at least about 68%, or at least about 69%, or at least about 70%, or at least about 71%, or at least about 72%, or at least about 73%, or at least about 74%, or at least about 75%, or at least about 76%, or at least about 77%, or at least about 78%, or at least about 79%, or at least about 80%, or at least about 81 %, or at least about 82%, or at least about 83%, or at least about 84%, or at least about 85%, or at least about 86%, or at least about 87%, or at least about 88%, or at least about 89%, or at least about 90%, or at least about 91 %, or at least about 92%, or at least about 93%, or at least about 94%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99%, or at least about 99.2%, or at least about 99.4%, or at least about 99.6%, or at least about 99.8% sequence identity with SEQ ID NO: 59 or SEQ ID NO: 61.

In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61 . In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61.

In embodiments, the first domain is capable of binding a CD172a (SIRPa) ligand.

In embodiments, the first domain comprises substantially all of the extracellular domain of CD172a (SIRPa).

In embodiments, the second domain is capable of binding a CD40 receptor.

In embodiments, the second domain comprises substantially all of the extracellular domain of CD40L.

In embodiments, the linker comprises a hinge-CH2-CH3 Fc domain derived from lgG4, e.g., human lgG4.

In embodiments, the linker comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3.

In embodiments, the first domain comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain of a chimeric protein comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 57.

In embodiments, the second domain comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the second domain of a chimeric protein comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 58.

In embodiments, the (a) the first domain comprises the amino acid sequence of SEQ ID NO: 57, (b) the second domain comprises the amino acid sequence of SEQ ID NO: 58, and (c) the linker comprises an amino acid sequence that is at least 95% identical to SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3.

In embodiments, the chimeric protein further comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 5 and/or SEQ ID NO: 7. In embodiments, the chimeric protein further comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 5 and/or SEQ ID NO: 7. In embodiments, the chimeric protein further comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 5 and/or SEQ ID NO: 7. In embodiments, the chimeric protein further comprises the amino acid sequence of SEQ ID NO: 5 and/or SEQ ID NO: 7.

In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 95% identical to SEQ ID NO: 59 or SEQ ID NO: 61 , e.g., at least about 98% identical to SEQ ID NO: 59 or SEQ ID NO: 61 , at least about 99% identical to SEQ ID NO: 59 or SEQ ID NO: 61, at least about 99.2% identical to SEQ ID NO: 59 or SEQ ID NO: 61, at least about 99.4% identical to SEQ ID NO: 59 or SEQ ID NO: 61 , at least about 99.6% identical to SEQ ID NO: 59 or SEQ ID NO: 61 , or at least about 99.8% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61.

In any herein-disclosed aspect and embodiment, the chimeric protein may comprise an amino acid sequence having one or more amino acid mutations relative to any of the protein sequences disclosed herein. In embodiments, the one or more amino acid mutations may be independently selected from substitutions, insertions, deletions, and truncations.

In embodiments, the amino acid mutations are amino acid substitutions, and may include conservative and/or non-conservative substitutions. “Conservative substitutions” may be made, for instance, on the basis of similarity in polarity, charge, size, solubility, hydrophobicity, hydrophilicity, and/or the amphipathic nature of the amino acid residues involved. The 20 naturally occurring amino acids can be grouped into the following six standard amino acid groups: (1) hydrophobic: Met, Ala, Vai, Leu, lie; (2) neutral hydrophilic: Cys, Ser, Thr; Asn, Gin; (3) acidic: Asp, Glu; (4) basic: His, Lys, Arg; (5) residues that influence chain orientation: Gly, Pro; and (6) aromatic: Trp, Tyr, Phe. As used herein, “conservative substitutions” are defined as exchanges of an amino acid by another amino acid listed within the same group of the six standard amino acid groups shown above. For example, the exchange of Asp by Glu retains one negative charge in the so modified polypeptide. In addition, glycine and proline may be substituted for one another based on their ability to disrupt a-helices. As used herein, “non-conservative substitutions” are defined as exchanges of an amino acid by another amino acid listed in a different group of the six standard amino acid groups (1) to (6) shown above. In embodiments, the substitutions may also include non-classical amino acids (e.g., selenocysteine, pyrrolysine, M-formylmethionine p-alanine, GABA and 5-Aminolevulinic acid, 4-aminobenzoic acid (PABA), D-isomers of the common amino acids, 2,4-diaminobutyric acid, a-amino isobutyric acid, 4-aminobutyric acid, Abu, 2-amino butyric acid, y-Abu, s-Ahx, 6-amino hexanoic acid, Aib, 2-amino isobutyric acid, 3-amino propionic acid, ornithine, norleucine, norvaline, hydroxyproline, sarcosme, citrulline, homocitrulline, cysteic acid, t-butylglycine, t-butylalanine, phenylglycine, cyclohexylalanine, p-alanine, fluoro-amino acids, designer amino acids such as methyl amino acids, C a-methyl amino acids, N a-methyl amino acids, and amino acid analogs in general).

Mutations may also be made to the nucleotide sequences of the chimeric proteins by reference to the genetic code, including taking into account codon degeneracy.

In embodiments, a chimeric protein is capable of binding human ligand(s)/receptor(s).

In embodiments, each extracellular domain (or variant thereof) of the chimeric protein binds to its cognate receptor or ligand with a KD of about 1 nM to about 5 nM, for example, about 1 nM, about 1.5 nM, about 2 nM, about 2.5 nM, about 3 nM, about 3.5 nM, about 4 nM, about 4.5 nM, or about 5 nM. In embodiments, the chimeric protein binds to a cognate receptor or ligand with a KD of about 5 nM to about 15 nM, for example, about 5 nM, about 5.5 nM, about 6 nM, about 6.5 nM, about 7 nM, about 7.5 nM, about 8 nM, about 8.5 nM, about 9 nM, about 9.5 nM, about 10 nM, about 10.5 nM, about 11 nM, about 11.5 nM, about 12 nM, about

12.5 nM, about 13 nM, about 13.5 nM, about 14 nM, about 14.5 nM, or about 15 nM.

In embodiments, each extracellular domain (or variant thereof) of the chimeric protein binds to its cognate receptor or ligand with a KD of less than about 1 pM, about 900 nM, about 800 nM, about 700 nM, about 600 nM, about 500 nM, about 400 nM, about 300 nM, about 200 nM, about 150 nM, about 130 nM, about 100 nM, about 90 nM, about 80 nM, about 70 nM, about 60 nM, about 55 nM, about 50 nM, about 45 nM, about 40 nM, about 35 nM, about 30 nM, about 25 nM, about 20 nM, about 15 nM, about 10 nM, or about 5 nM, or about 1 nM (as measured, for example, by surface plasmon resonance or biolayer interferometry).

In embodiments, the chimeric protein binds to human CD47 with a KD of about 1 nM to about 5 nM, for example, about 1 nM, about 1 .5 nM, about 2 nM, about 2.5 nM, about 3 nM, about 3.5 nM, about 4 nM, about

4.5 nM, or about 5 nM. In embodiments, the chimeric protein binds to human CD47 with a KD of less than about 3 nM, about 2 nM, about 1 nM, about 900 pM, about 800 pM, about 700 pM, about 600 pM, about 500 pM, about 400 pM, about 300 pM, about 200 pM, about 100 pM, about 90 pM, about 80 pM, about 70 pM, about 60 pM about 55 pM about 50 pM about 45 pM, about 40 pM, about 35 pM, about 30 pM, about 25 pM, about 20 pM, about 15 pM, or about 10 pM, or about 1 pM (as measured, for example, by surface plasmon resonance or biolayer interferometry).

In embodiments, the chimeric protein binds to human CD40 with a KD of less than about 1 nM, about 900 pM, about 800 pM, about 700 pM, about 600 pM, about 500 pM, about 400 pM, about 300 pM, about 200 pM, about 100 pM, about 90 pM, about 80 pM, about 70 pM, about 60 pM about 55 pM about 50 pM about 45 pM, about 40 pM, about 35 pM, about 30 pM, about 25 pM, about 20 pM, about 15 pM, or about 10 pM, or about 1 pM (as measured, for example, by surface plasmon resonance or biolayer interferometry).

As used herein, a variant of an extracellular domain is capable of binding the receptor/ligand of a native extracellular domain. For example, a variant may include one or more mutations in an extracellular domain which do not affect its binding affinity to its receptor/ligand; alternately, the one or more mutations in an extracellular domain may improve binding affinity for the receptor/ligand; or the one or more mutations in an extracellular domain may reduce binding affinity for the receptor/ligand, yet not eliminate binding altogether. In embodiments, the one or more mutations are located outside the binding pocket where the extracellular domain interacts with its receptor/ligand. In embodiments, the one or more mutations are located inside the binding pocket where the extracellular domain interacts with its receptor/ligand, as long as the mutations do not eliminate binding altogether. Based on the skilled artisan’s knowledge and the knowledge in the art regarding receptor-ligand binding, s/he would know which mutations would permit binding and which would eliminate binding.

In embodiments, the chimeric protein exhibits enhanced stability and protein half-life.

A chimeric protein of the present disclosure may comprise more than two extracellular domains. For example, the chimeric protein may comprise three, four, five, six, seven, eight, nine, ten, or more extracellular domains. A second extracellular domain may be separated from a third extracellular domain via a linker, as disclosed herein. Alternately, a second extracellular domain may be directly linked (e.g., via a peptide bond) to a third extracellular domain. In embodiments, a chimeric protein includes extracellular domains that are directly linked and extracellular domains that are indirectly linked via a linker, as disclosed herein.

Linkers

In embodiments, the chimeric protein comprises a linker.

In embodiments, the linker comprising at least one cysteine residue capable of forming a disulfide bond. The at least one cysteine residue is capable of forming a disulfide bond between a pair (or more) of chimeric proteins. Without wishing to be bound by theory, such disulfide bond forming is responsible for maintaining a useful multimeric state of chimeric proteins. This allows for efficient production of the chimeric proteins; it allows for desired activity in vitro and in vivo.

In a chimeric protein of the present disclosure, the linker is a polypeptide selected from a flexible amino acid sequence, an IgG hinge region, or an antibody sequence.

In embodiments, the linker is derived from naturally-occurring multi-domain proteins or is an empirical linker as described, for example, in Chichili et al., Protein Sci. 22(2):153-167 (2013); Chen et al., Adv Drug Deliv Rev. 65(10): 1357-1369 (2013), the entire contents of which are hereby incorporated by reference. In embodiments, the linker may be designed using linker designing databases and computer programs such as those described in Chen et al., Adv Drug DelivRev. 65(10): 1357-1369 (2013); and Crasto et al., Protein Eng. 13(5):309-312 (2000), the entire contents of which are hereby incorporated by reference.

In embodiments, the linker comprises a polypeptide. In embodiments, the polypeptide is less than about 500 amino acids long, about 450 amino acids long, about 400 amino acids long, about 350 amino acids long, about 300 amino acids long, about 250 amino acids long, about 200 amino acids long, about 150 amino acids long, or about 100 amino acids long. For example, the linker may be less than about 100, about 95, about 90, about 85, about 80, about 75, about 70, about 65, about 60, about 55, about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 19, about 18, about 17, about 16, about 15, about 14, about 13, about 12, about 11, about 10, about 9, about 8, about 7, about 6, about 5, about 4, about 3, or about 2 amino acids long.

In embodiments, the linker is flexible.

In embodiments, the linker is rigid.

In embodiments, the linker is substantially comprised of glycine and serine residues (e.g., about 30%, or about 40%, or about 50%, or about 60%, or about 70%, or about 80%, or about 90%, or about 95%, or about 97%, or about 98%, or about 99%, or about 100% glycines and serines).

In embodiments, the linker comprises a hinge region of an antibody (e.g., of IgG, IgA, IgD, and I g E, inclusive of subclasses (e.g., lgG1 , lgG2, lgG3, and lgG4, and lgA1 , and lgA2)). The hinge region, found in IgG, IgA, IgD, and IgE class antibodies, acts as a flexible spacer, allowing the Fab portion to move freely in space. In contrast to the constant regions, the hinge domains are structurally diverse, varying in both sequence and length among immunoglobulin classes and subclasses. For example, the length and flexibility of the hinge region varies among the IgG subclasses. The hinge region of lgG1 encompasses amino acids 216-231 and, because it is freely flexible, the Fab fragments can rotate about their axes of symmetry and move within a sphere centered at the first of two inter-heavy chain disulfide bridges. lgG2 has a shorter hinge than lgG1 , with 12 amino acid residues and four disulfide bridges. The hinge region of lgG2 lacks a glycine residue, is relatively short, and contains a rigid poly-proline double helix, stabilized by extra inter-heavy chain disulfide bridges. These properties restrict the flexibility of the lgG2 molecule. I gG3 differs from the other subclasses by its unique extended hinge region (about four times as long as the I gG 1 hinge), containing 62 amino acids (including 21 prolines and 11 cysteines), forming an inflexible poly-proline double helix. In lgG3, the Fab fragments are relatively far away from the Fc fragment, giving the molecule a greater flexibility. The elongated hinge in lgG3 is also responsible for its higher molecular weight compared to the other subclasses. The hinge region of I gG4 is shorter than that of lgG1 and its flexibility is intermediate between that of lgG1 and lgG2. The flexibility of the hinge regions reportedly decreases in the order I gG3> I gG 1 > I gG4>l gG2. In embodiments, the linker may be derived from human lgG4 and contain one or more mutations to enhance dimerization (including S228P) or FcRn binding.

According to crystallographic studies, the immunoglobulin hinge region can be further subdivided functionally into three regions: the upper hinge region, the core region, and the lower hinge region. See Shin et al., Immunological Reviews 130:87 (1992). The upper hinge region includes amino acids from the carboxyl end of CHI to the first residue in the hinge that restricts motion, generally the first cysteine residue that forms an interchain disulfide bond between the two heavy chains. The length of the upper hinge region correlates with the segmental flexibility of the antibody. The core hinge region contains the inter-heavy chain disulfide bridges, and the lower hinge region joins the amino terminal end of the CH2 domain and includes residues in CH2. Id. The core hinge region of wild-type human lgG1 contains the sequence CPPC (SEQ ID NO: 24) which, when dimerized by disulfide bond formation, results in a cyclic octapeptide believed to act as a pivot, thus conferring flexibility. In embodiments, the present linker comprises, one, or two, or three of the upper hinge region, the core region, and the lower hinge region of any antibody e.g., of IgG, IgA, IgD, and IgE, inclusive of subclasses (e.g., lgG1 , lgG2, lgG3, and lgG4, and lgA1 and lgA2)). The hinge region may also contain one or more glycosylation sites, which include a number of structurally distinct types of sites for carbohydrate attachment. For example, lgA1 contains five glycosylation sites within a 17-amino-acid segment of the hinge region, conferring resistance of the hinge region polypeptide to intestinal proteases, considered an advantageous property for a secretory immunoglobulin. In embodiments, the linker of the present disclosure comprises one or more glycosylation sites. In embodiments, the linker comprises an Fc domain of an antibody (e.g., of IgG, IgA, IgD, and IgE, inclusive of subclasses (e.g., lgG1, lgG2, lgG3, and lgG4, and lgA1 and lgA2)).

In a chimeric protein of the present disclosure, the linker comprises a hinge-CH2-CH3 Fc domain derived from lgG4. In embodiments, the linker comprises a hinge-CH2-CH3 Fc domain derived from a human I gG4. In embodiments, the linker comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of any one of SEQ ID NO: 1 to SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of any one of SEQ ID NO: 1 to SEQ ID NO: 3 (e.g., at least 95% identical to the amino acid sequence of SEQ ID NO: 2.). In embodiments, the linker comprises one or more joining linkers, such joining linkers independently selected from SEQ ID NOs: 4-50 (or a variant thereof). In embodiments, the linker comprises two or more joining linkers each joining linker independently selected from SEQ ID NOs: 4-50 (or a variant thereof); wherein one joining linker is N terminal to the hinge-CH2-CH3 Fc domain and another joining linker is C terminal to the hinge-CH2-CH3 Fc domain.

In embodiments, the linker comprises a hinge-CH2-CH3 Fc domain derived from a human lgG1 antibody. In embodiments, the Fc domain exhibits increased affinity for and enhanced binding to the neonatal Fc receptor (FcRn). In embodiments, the Fc domain includes one or more mutations that increases the affinity and enhances binding to FcRn. Without wishing to be bound by theory, it is believed that increased affinity and enhanced binding to FcRn increases the in vivo half-life of the present chimeric proteins.

In embodiments, the Fc domain in a linker contains one or more amino acid substitutions at amino acid residue 250, 252, 254, 256, 308, 309, 311 , 416, 428, 433, or 434 (in accordance with Kabat numbering, as in as in Kabat, etal., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, Md. (1991) expressly incorporated herein by reference), or equivalents thereof. In embodiments, the amino acid substitution at amino acid residue 250 is a substitution with glutamine. In embodiments, the amino acid substitution at amino acid residue 252 is a substitution with tyrosine, phenylalanine, tryptophan, or threonine. In embodiments, the amino acid substitution at amino acid residue 254 is a substitution with threonine. In embodiments, the amino acid substitution at amino acid residue 256 is a substitution with serine, arginine, glutamine, glutamic acid, aspartic acid, or threonine. In embodiments, the amino acid substitution at amino acid residue 308 is a substitution with threonine. In embodiments, the amino acid substitution at amino acid residue 309 is a substitution with proline. In embodiments, the amino acid substitution at amino acid residue 311 is a substitution with serine. In embodiments, the amino acid substitution at amino acid residue 385 is a substitution with arginine, aspartic acid, serine, threonine, histidine, lysine, alanine, or glycine. In embodiments, the amino acid substitution at amino acid residue 386 is a substitution with threonine, proline, aspartic acid, serine, lysine, arginine, isoleucine, or methionine. In embodiments, the amino acid substitution at amino acid residue 387 is a substitution with arginine, proline, histidine, serine, threonine, or alanine. In embodiments, the amino acid substitution at amino acid residue 389 is a substitution with proline, serine, or asparagine. In embodiments, the amino acid substitution at amino acid residue 416 is a substitution with serine. In embodiments, the amino acid substitution at amino acid residue 428 is a substitution with leucine. In embodiments, the amino acid substitution at amino acid residue 433 is a substitution with arginine, serine, isoleucine, proline, or glutamine. In embodiments, the amino acid substitution at amino acid residue 434 is a substitution with histidine, phenylalanine, or tyrosine.

In embodiments, the Fc domain linker (e.g., comprising an IgG constant region) comprises one or more mutations such as substitutions at amino acid residue 252, 254, 256, 433, 434, or 436 (in accordance with Kabat numbering, as in as in Kabat, et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, Md. (1991) expressly incorporated herein by reference). In embodiments, the IgG constant region includes a triple M252Y/S254T/T256E mutation or YTE mutation. In embodiments, the IgG constant region includes a triple H433K/N434F/Y436H mutation or KFH mutation. In embodiments, the IgG constant region includes an YTE and KFH mutation in combination.

In embodiments, the linker comprises an IgG constant region that contains one or more mutations at amino acid residues 250, 253, 307, 310, 380, 428, 433, 434, and 435 (in accordance with Kabat numbering, as in as in Kabat, et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, Md. (1991) expressly incorporated herein by reference). Illustrative mutations include T250Q, M428L, T307A, E380A, I253A, H310A, M428L, H433K, N434A, N434F, N434S, and H435A. In embodiments, the IgG constant region comprises a M428L/N434S mutation or LS mutation. In embodiments, the IgG constant region comprises a T250Q/M428L mutation or QL mutation. In embodiments, the IgG constant region comprises an N434A mutation. In embodiments, the IgG constant region comprises a T307A/E380A/N434A mutation or AAA mutation. In embodiments, the IgG constant region comprises an I253A/H310A/H435A mutation or IHH mutation. In embodiments, the IgG constant region comprises a H433K/N434F mutation. In embodiments, the IgG constant region comprises a M252Y/S254T/T256E and a H433K/N434F mutation in combination. Additional exemplary mutations in the IgG constant region are described, for example, in Robbie, et al., Antimicrobial Agents and Chemotherapy 57(12):6147-6153 (2013); Dall’Acqua ef al., Journal Biol Chem 281 (33):23514-24 (2006); Dall’Acqua et al., Journal of Immunology 169:5171-80 (2002); Ko et al. Nature 514:642-645 (2014); Grevys et al. Journal of Immunology 194(11):5497-508 (2015); and U.S. Patent No. 7,083,784, the entire contents of which are hereby incorporated by reference.

An illustrative Fc stabilizing mutant is S228P. Illustrative Fc half-life extending mutants are T250Q, M428L, V308T, L309P, and Q311 S and the present linkers may comprise 1 , or 2, or 3, or 4, or 5 of these mutants.

In embodiments, the chimeric protein binds to FcRn with high affinity. In embodiments, the chimeric protein may bind to FcRn with a KD of about 1 nM to about 80 nM. For example, the chimeric protein may bind to FcRn with a KD of about 1 nM, about 2 nM, about 3 nM, about 4 nM, about 5 nM, about 6 nM, about 7 nM, about 8 nM, about 9 nM, about 10 nM, about 15 nM, about 20 nM, about 25 nM, about 30 nM, about 35 nM, about 40 nM, about 45 nM, about 50 nM, about 55 nM, about 60 nM, about 65 nM, about 70 nM, about 71 nM, about 72 nM, about 73 nM, about 74 nM, about 75 nM, about 76 nM, about 77 nM, about 78 nM, about 79 nM, or about 80 nM. In embodiments, the chimeric protein may bind to FcRn with a KD of about 9 nM. In embodiments, the chimeric protein does not substantially bind to other Fc receptors (/.e., other than FcRn) with effector function.

In embodiments, the Fc domain in a linker has the amino acid sequence of SEQ ID NO: 1 (see Table 1, below), or at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identity thereto. In embodiments, mutations are made to SEQ ID NO: 1 to increase stability and/or half-life. For instance, in embodiments, the Fc domain in a linker comprises the amino acid sequence of SEQ ID NO: 2 (see Table 1, below), or at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identity thereto. For instance, in embodiments, the Fc domain in a linker comprises the amino acid sequence of SEQ ID NO: 3 (see Table 1, below), or at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identity thereto.

Further, one or more joining linkers may be employed to connect an Fc domain in a linker (e.g., one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3 or at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identity thereto) and the extracellular domains. For example, any one of SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, or variants thereof may connect an extracellular domain as disclosed herein and an Fc domain in a linker as disclosed herein. Optionally, any one of SEQ ID NOs: 4 to 50, 62 and 63, or variants thereof are located between an extracellular domain as disclosed herein and an Fc domain as disclosed herein. In embodiments, the presentchimeric proteins may comprise variants of the joining linkers disclosed in Table 1, below. For instance, a linker may have at least about 60%, or at least about 61 %, or at least about 62%, or at least about 63%, or at least about 64%, or at least about 65%, or at least about 66%, or at least about 67%, or at least about 68%, or at least about 69%, or at least about 70%, or at least about 71 %, or at least about 72%, or at least about 73%, or at least about 74%, or at least about 75%, or at least about 76%, or at least about 77%, or at least about 78%, or at least about 79%, or at least about 80%, or at least about 81 %, or at least about 82%, or at least about 83%, or at least about 84%, or at least about 85%, or at least about 86%, or at least about 87%, or at least about 88%, or at least about 89%, or at least about 90%, or at least about 91%, or at least about 92%, or at least about 93%, or at least about 94%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% sequence identity with the amino acid sequence of any one of SEQ ID NOs: 4 to 50, 62 and 63.

In embodiments, the first and second joining linkers may be different, or they may be the same.

Without wishing to be bound by theory, including a linker comprising at least a part of an Fc domain in a chimeric protein, helps avoid formation of insoluble and, likely, non-functional protein concatemers and/or aggregates. This is in part due to the presence of cysteines in the Fc domain which are capable of forming disulfide bonds between chimeric proteins.

In embodiments, a chimeric protein may comprise one or more joining linkers, as disclosed herein, and lack a Fc domain linker, as disclosed herein.

In embodiments, the first and/or second joining linkers are independently selected from the amino acid sequences of SEQ ID NOs: 4 to 50, 62 and 63 and are provided in Table 1 below:

Table 1 : Illustrative linkers (Fc domain linkers and joining linkers)

In embodiments, the joining linker substantially comprises glycine and serine residues (e.g., about 30%, or about 40%, or about 50%, or about 60%, or about 70%, or about 80%, or about 90%, or about 95%, or about 97%, or about 98%, or about 99%, or about 100% glycines and serines). For example, in embodiments, the joining linker is (Gly4Ser)_n, where n is from about 1 to about 8, e.g., 1 , 2, 3, 4, 5, 6, 7, or 8 (SEQ ID NO: 25 to SEQ ID NO: 9, respectively). In embodiments, the joining linker sequence is GGSGGSGGGGSGGGGS (SEQ ID NO: 33). Additional illustrative joining linkers include, but are not limited to, linkers having the sequence LE, (EAAAK)_n (n=1 -3) (SEQ ID NO: 36 to SEQ ID NO: 38), A(EAAAK)_nA (n = 2-5) (SEQ ID NO: 39 to SEQ ID NO: 42), A(EAAAK)₄ALEA(EAAAK)₄A (SEQ ID NO: 43), PAPAP (SEQ ID NO: 44), KESGSVSSEQLAQFRSLD (SEQ ID NO: 45), GSAGSAAGSGEF (SEQ ID NO: 46), and (XP)_n, with X designating any amino acid, e.g., Ala, Lys, or Glu. In embodiments, the joining linker is GGS. In embodiments, a joining linker has the sequence (Gly)n where n is any number from 1 to 100, for example: (Gly)s (SEQ ID NO: 34) and (Gly)₆ (SEQ ID NO: 35).

In embodiments, the joining linker is one or more of GGGSE (SEQ ID NO: 47), GSESG (SEQ ID NO: 48), GSEGS (SEQ ID NO: 49), GEGGSGEGSSGEGSSSEGGGSEGGGSEGGGSEGGS (SEQ ID NO: 50), and a joining linker of randomly placed G, S, and E every 4 amino acid intervals.

In embodiments, the chimeric protein comprises a joining linker comprising the amino acid sequence of SEQ ID NO: 5 and/or SEQ ID NO: 7.

In embodiments, where a chimeric protein comprises an extracellular domain (ECD) of CD172a (SIRPa), one joining linker preceding an Fc domain, a second joining linker following the Fc domain, and an ECD of CD40L, the chimeric protein may comprise the following structure:

ECD of human CD172a (SIRPa) - Joining Linker 1 - Fc Domain - Joining Linker 2 - ECD of human CD40L

The combination of a first joining linker, an Fc Domain linker, and a second joining linker is referend to herein are “modular linkers.” In embodiments, a chimeric protein comprises a modular linker as shown in Table 2:

TABLE 2: Illustrative modular linkers

In embodiments, the present chimeric proteins may comprise variants of the modular linkers disclosed in Table 2, above. For instance, a linker may have at least about 60%, or at least about 61 %, or at least about 62%, or at least about 63%, or at least about 64%, or at least about 65%, or at least about 66%, or at least about 67%, or at least about 68%, or at least about 69%, or at least about 70%, or at least about 71 %, or at least about 72%, or at least about 73%, or at least about 74%, or at least about 75%, or at least about 76%, or at least about 77%, or at least about 78%, or at least about 79%, or at least about 80%, or at least about 81%, or at least about 82%, or at least about 83%, or at least about 84%, or at least about 85%, or at least about 86%, or at least about 87%, or at least about 88%, or at least about 89%, or at least about 90%, or at least about 91 %, or at least about 92%, or at least about 93%, or at least about 94%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% sequence identity with the amino acid sequence of any one of SEQ ID NOs: 51 to 56.

In embodiments, the linker may be flexible, including without limitation highly flexible. In embodiments, the linker may be rigid, including without limitation a rigid alpha helix. Characteristics of illustrative joining linkers is shown below in Table 3:

TABLE 3: Characteristics of illustrative joining linkers

In embodiments, the linker may be functional. For example, without limitation, the linker may function to improve the folding and/or stability, improve the expression, improve the pharmacokinetics, and/or improve the bioactivity of the present chimeric protein. In another example, the linker may function to target the chimeric protein to a particular cell type or location.

In embodiments, a chimeric protein comprises only one joining linkers.

In embodiments, a chimeric protein lacks joining linkers.

In embodiments, the linker is a synthetic linker such as polyethylene glycol (PEG).

In embodiments, a chimeric protein has a first domain which is sterically capable of binding its ligand/receptor and/or the second domain which is sterically capable of binding its ligand/receptor. Thus, there is enough overall flexibility in the chimeric protein and/or physical distance between an extracellular domain (or portion thereof) and the rest of the chimeric protein such that the ligand/receptor binding domain of the extracellular domain is not sterically hindered from binding its ligand/receptor. This flexibility and/or physical distance (which is referred to as “slack”) may be normally present in the extracellular domain(s), normally present in the linker, and/or normally present in the chimeric protein (as a whole). Alternately, or additionally, an amino acid sequence (for example) may be added to one or more extracellular domains and/or to the linker to provide the slack needed to avoid steric hindrance. Any amino acid sequence that provides slack may be added. In embodiments, the added amino acid sequence comprises the sequence (Gly)n where n is any number from 1 to 100. Additional examples of addable amino acid sequence include the joining linkers described in Table 1 and Table 3. In embodiments, a polyethylene glycol (PEG) linker may be added between an extracellular domain and a linker to provide the slack needed to avoid steric hindrance. Such PEG linkers are well known in the art.

In embodiments, a chimeric protein of the present disclosure comprises the extracellular domain of human CD172a (SIRPo) (or a variant thereof), a linker, and the extracellular domain of human CD40L (or a variant thereof). In embodiments, the linker comprises a hinge-CH2-CH3 Fc domain, e.g., from an lgG1 or from lgG4, including human lgG1 or lgG4. Thus, in embodiments, a chimeric protein of the present disclosure comprises the extracellular domain of human CD172a (SIRPo) (or a variant thereof), linker comprising a hinge-CH2-CH3 Fc domain, and the extracellular domain of human CD40L (or a variant thereof). Such a chimeric protein may be referred to herein as “hCD172a (SIRPa)-Fc-CD40L” or “SL-172154”.

Diseases, Methods of Treatment, and Mechanisms of Action

In some aspects, the present disclosure relates to a method for treating a cancer in a human subject, the method comprising: (i) administering to the human subject a first dose of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein the dose of the chimeric protein is administered at a dosage of at least about 0.3 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 1 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 3 mg/kg. In embodiments, the chimeric protein is administered at the dosage of about 10 mg/kg.

The chimeric proteins disclosed herein, including the CD172a (SIRPa)-Fc-CD40L chimeric protein e.g., SEQ ID NO: 59 or SEQ ID NO: 61), finds use in methods for treating both advanced solid tumors and advanced lymphomas. These tumor types include melanoma, non-small cell lung cancer (squamous, adeno, adenosquamous), urothelial cancer, renal cell cancer, squamous cell cervical cancer, gastric or gastro-esophageal junction adenocarcinoma, squamous cell carcinoma of the anus, squamous cell carcinoma of the head and neck, squamous cell carcinoma of the skin, and microsatellite instability high or mismatch repair deficient solid tumors excluding central nervous system (CNS) tumors. Other tumors of interest include Hodgkin’s lymphoma (HL), diffuse large B cell lymphoma, acute myeloid leukemia (AML) and high-risk myelodysplastic syndromes (HR-MDS).

In embodiments, the cancer comprises an advanced solid tumor (local and/or metastatic). In embodiments, the human subject has a cancer, wherein the cancer being treated is characterized by having macrophages in the tumor microenvironment and/or having tumor cells that are CD47+ cells in the tumor. In embodiments, the administration of the SIRPa- Fc-CD40L chimeric protein blocks the “don’t eat me” signal of a tumor cell and /or stimulates an “eat me” signal. In embodiments the therapy with the SIRPa-Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEQ ID NO: 61) stimulates macrophages to phagocytize tumor cells and effectively present the tumor antigens of phagocytized tumor cells to T cells.

In embodiments, the cancer is a solid cancer. In embodiments, the cancer is a solid tumor. In embodiments, the cancer is a metastatic cancer. In embodiments, the cancer is a hematological cancer. In embodiments, the cancer expresses CD47.

In embodiments, the cancer comprises an advanced lymphoma. In embodiments, the cancer comprises acute myeloid leukemia (AML). In embodiments, the cancer comprises p53 mutant AML. In embodiments, the cancer comprises a high-risk myelodysplastic syndrome (HR-MDS).

Aspects of the present disclosure provide methods of treating cancer. The methods comprise a step of administering to a subject in need thereof an effective amount of a chimeric protein, e.g., in a pharmaceutical composition, as disclosed herein.

It is often desirable to enhance immune stimulatory signal transmission to boost an immune response, for instance to enhance a patient’s anti-tumor immune response.

In embodiments, the chimeric protein of the present disclosure comprises an extracellular domain of human CD172a (SIRPa), which disrupts, blocks, reduces, inhibits, and/or sequesters the transmission of immune inhibitory signals, e.g., originating from a cancer cell that is attempting to avoid its detection and/or destruction, and an extracellular domain of human CD40L, which enhances, increases, and/or stimulates the transmission of an immune stimulatory signal to an anti-cancer immune cell. Thus, the simultaneous binding of the extracellular domain of CD172a (SIRPa) to its ligand/receptor and the binding of the extracellular domain of CD40L with its receptor will prevent the transmission of an immunosuppressive signal from the cancer cell and will have stimulate immune activity in an immune system cell. In other words, chimeric proteins of the present disclosure are capable of treating cancer via two distinct mechanisms.

In embodiments, the present disclosure pertains to cancers and/or tumors; for example, the treatment or prevention of cancers and/or tumors. As disclosed elsewhere herein, the treatment of cancer involves, in embodiments, modulating the immune system with the present chimeric proteins to favor of increasing or activating immune stimulatory signals. In embodiments, the method reduces the amount and/or activity of regulatory T cells (Tregs) as compared to untreated subjects or subjects treated with antibodies directed to CD172a (SIRPo), CD40L, and/or their respective ligands or receptors. In embodiments, the method increases priming of effector T cells in draining lymph nodes of the subject as compared to untreated subjects or subjects treated with antibodies directed to CD172a (SIRPo), CD40L, and/or their respective ligands or receptors. In embodiments, the method causes an overall decrease in immunosuppressive cells and a shift toward a more inflammatory tumor environment as compared to untreated subjects or subjects treated with antibodies directed to the CD172a (SIRPo), CD40L, and/or their respective ligands or receptors.

In embodiments, the present chimeric proteins are capable of, or can be used in methods comprising, modulating the amplitude of an immune response, e.g., modulating the level of effector output. In embodiments, e.g., when used for the treatment of cancer, the present chimeric proteins alter the extent of immune stimulation as compared to immune inhibition to increase the amplitude of a T cell response, including, without limitation, stimulating increased levels of cytokine production, proliferation or target killing potential. In embodiments, the patient’s T cells are activated and/or stimulated by the chimeric protein, with the activated T cells being capable of dividing and/or secreting cytokines.

Cancers or tumors refer to an uncontrolled growth of cells and/or abnormal increased cell survival and/or inhibition of apoptosis which interferes with the normal functioning of the bodily organs and systems. Included are benign and malignant cancers, polyps, hyperplasia, as well as dormant tumors or micrometastases. Also, included are cells having abnormal proliferation that is not impeded by the immune system (e.g., virus infected cells). The cancer may be a primary cancer or a metastatic cancer. The primary cancer may be an area of cancer cells at an originating site that becomes clinically detectable and may be a primary tumor. In contrast, the metastatic cancer may be the spread of a disease from one organ or part to another non-adjacent organ or part. The metastatic cancer may be caused by a cancer cell that acquires the ability to penetrate and infiltrate surrounding normal tissues in a local area, forming a new tumor, which may be a local metastasis. The cancer may also be caused by a cancer cell that acquires the ability to penetrate the walls of lymphatic and/or blood vessels, after which the cancer cell is able to circulate through the bloodstream (thereby being a circulating tumor cell) to other sites and tissues in the body. The cancer may be due to a process such as lymphatic or hematogenous spread. The cancer may also be caused by a tumor cell that comes to rest at another site, re-penetrates through the vessel or walls, continues to multiply, and eventually forms another clinically detectable tumor. The cancer may be this new tumor, which may be a metastatic (or secondary) tumor.

The cancer may be caused by tumor cells that have metastasized, which may be a secondary or metastatic tumor. The cells of the tumor may be like those in the original tumor. As an example, if a breast cancer or colon cancer metastasizes to the liver, the secondary tumor, while present in the liver, is made up of abnormal breast or colon cells, not of abnormal liver cells. The tumor in the liver may thus be a metastatic breast cancer or a metastatic colon cancer, not liver cancer.

The cancer may have an origin from any tissue. The cancer may originate from melanoma, colon, breast, or prostate, and thus may be made up of cells that were originally skin, colon, breast, or prostate, respectively. The cancer may also be a hematological malignancy, which may be leukemia or lymphoma. The cancer may invade a tissue such as liver, lung, bladder, or intestinal.

In embodiments, the chimeric protein is used to treat a subject that has a treatment-refractory cancer. In embodiments, the chimeric protein is used to treat a subject that is refractory to one or more immune- modulating agents. For example, in embodiments, the chimeric protein is used to treat a subject that presents no response to treatment, or whose disease progresses, after 12 weeks or so of treatment. For instance, in embodiments, the subject is refractory to one or more CD172a (SIRPa) and/or CD47 agents, including, for example, Magrolimab (5F9), Hu5F9-G4, CC-90002, Ti-061, SRF231 , TTI-621 , TTI-622, or ALX148 refractory patients. For instance, in embodiments, the subject is refractory to an anti-CTLA-4 agent, e.g., ipilimumab (YERVOY)-refractory patients (e.g., melanoma patients). Accordingly, in embodiments the present disclosure provides methods of cancer treatment that rescue patients that are non-responsive to various therapies, including monotherapy of one or more immune-modulating agents.

In embodiments, the present disclosure provides chimeric proteins which target a cell or tissue within the tumor microenvironment. In embodiments, the cell or tissue within the tumor microenvironment expresses one or more targets or binding partners of the chimeric protein. The tumor microenvironment refers to the cellular milieu, including cells, secreted proteins, physiological small molecules, and blood vessels in which the tumor exists. In embodiments, the cells or tissue within the tumor microenvironment are one or more of: tumor vasculature; tumor-infiltrating lymphocytes; fibroblast reticular cells; endothelial progenitor cells (EPC); cancer-associated fibroblasts; pericytes; other stromal cells; components of the extracellular matrix (ECM); dendritic cells; antigen presenting cells; T-cells; regulatory T cells; macrophages; neutrophils; and other immune cells located proximal to a tumor. In embodiments, the present chimeric protein targets a cancer cell. In embodiments, the cancer cell expresses one or more of targets or binding partners of the chimeric protein.

The activation of regulatory T cells is critically influenced by costimulatory and co-inhibitory signals. Two major families of costimulatory molecules include the B7 and the tumor necrosis factor (TNF) families. These molecules bind to receptors on T cells belonging to the CD28 or TNF receptor families, respectively. Many well-defined co-inhibitors and their receptors belong to the B7 and CD28 families.

In embodiments, an immune stimulatory signal refers to a signal that enhances an immune response. For example, in the context of oncology, such signals may enhance antitumor immunity. For instance, without limitation, immune stimulatory signal may be identified by directly stimulating proliferation, cytokine production, killing activity, or phagocytic activity of leukocytes. For example, a chimeric protein may directly stimulate the proliferation and cytokine production of individual T cell subsets. Another example includes direct stimulation of an immune inhibitory cell with through a receptor that inhibits the activity of such an immune suppressor cell. This would include, for example, stimulation of CD4+FoxP3+ regulatory T cells, which would reduce the ability of those regulatory T cells to suppress the proliferation of conventional CD4+ or CD8+ T cells. In another example, this would include stimulation of CD40 on the surface of an antigen presenting cell, causing activation of antigen presenting cells including enhanced ability of those cells to present antigen in the context of appropriate native costimulatory molecules, including those in the B7 or TNF superfamily. In another example, the chimeric protein causes activation of the lymphoid cell and/or production of pro-inflammatory cytokines or chemokines to further stimulate an immune response, optionally within a tumor.

In embodiments, the present chimeric proteins are capable of, or find use in methods involving, enhancing, restoring, promoting and/or stimulating immune modulation. In embodiments, the present chimeric proteins described herein, restore, promote and/or stimulate the activity or activation of one or more immune cells against tumor cells including, but not limited to: T cells, cytotoxic T lymphocytes, T helper cells, natural killer (NK) cells, natural killer T (NKT) cells, anti-tumor macrophages (e.g., M1 macrophages), B cells, and dendritic cells. In embodiments, the present chimeric proteins enhance, restore, promote and/or stimulate the activity and/or activation of T cells, including, by way of a non-limiting example, activating and/or stimulating one or more T- cell intrinsic signals, including a pro-survival signal; an autocrine or paracrine growth signal; a p38 MAPK-, ERK-, STAT-, JAK-, AKT- or PI3K-mediated signal; an anti-apoptotic signal; and/or a signal promoting and/or necessary for one or more of: pro-inflammatory cytokine production or T cell migration or T cell tumor infiltration.

In embodiments, the present chimeric proteins are capable of, or find use in methods involving, causing an increase of one or more of T cells (including without limitation cytotoxic T lymphocytes, T helper cells, natural killer T (NKT) cells), B cells, natural killer (NK) cells, natural killer T (NKT) cells, dendritic cells, monocytes, and macrophages (e.g., one or more of M1 and M2) into a tumor or the tumor microenvironment. In embodiments, the chimeric protein enhances recognition of tumor antigens by CD8+ T cells, particularly those T cells that have infiltrated into the tumor microenvironment. In embodiments, the present chimeric protein induces CD19 expression and/or increases the number of CD19 positive cells (e.g., CD19 positive B cells). In embodiments, the present chimeric protein induces IL-15Roc expression and/or increases the number of I L-15Roc positive cells (e.g., I L-15Roc positive dendritic cells).

In embodiments, the present chimeric proteins are capable of, or find use in methods involving, inhibiting and/or causing a decrease in immunosuppressive cells (e.g., myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), tumor associated neutrophils (TANs), M2 macrophages, and tumor associated macrophages (TAMs)), and particularly within the tumor and/or tumor microenvironment (TME). In embodiments, the present therapies may alter the ratio of M1 versus M2 macrophages in the tumor site and/or TME to favor M1 macrophages. In embodiments, the SIRPa- Fc-CD40L chimeric protein suppresses/reduces/eliminates a “don’t eat me” signal via Sirpl a/CD47 from being transmitted on tumor cells. In embodiments, the SIRPa- Fc-CD40L chimeric protein makes a tumor more likely to be attacked by the immune system of the subject. In embodiments, the SIRPa- Fc-CD40L chimeric protein makes a tumor more likely to be attacked by the innate immune system of the subject. In embodiments, the SIRPa- Fc- CD40L chimeric protein makes a tumor more likely to be attacked by the adaptive immune system of the subject. S In embodiments, the SIRPa- Fc-CD40L chimeric protein can suppress/reduce/eliminate binding of tumor-overexpressed CD47 with phagocyte-expressed SIRPa to permit phagocytic removal of cancer cells and/or immunogenic processing of tumor antigens by macrophages and/or dendritic cells. In embodiments, the administration of the SIRPa- Fc-CD40L chimeric protein blocks the “don’t eat me” signal of a tumor cell and /or stimulates an “eat me” signal. In embodiments the therapy with the SIRPa-Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEO ID NO: 61) stimulates macrophages to phagocytize tumor cells and effectively present the tumor antigens of phagocytized tumor cells to T cells.

In embodiments, the present chimeric proteins are able to increase the serum levels of various cytokines including, but not limited to, one or more of IFNy, TNFa, IL-2, IL-4, IL-5, IL-9, IL-10, IL-13, IL-17A, IL-17F, and IL-22. In embodiments, the present chimeric proteins are capable of enhancing IL-2, IL-4, IL-5, IL-10, IL- 13, IL-17A, IL-22, or IFNy in the serum of a treated subject. In embodiments, the present chimeric proteins do not increase the serum levels of certain cytokines. In embodiments, the present chimeric proteins do not increase the serum levels of IL-6 and/ or TNFa. In embodiments, the present chimeric proteins do not increase the serum levels of IL-6 and/ or TNFa in the serum of a treated subject. In embodiments, the present chimeric proteins do not increase the serum levels of IL-6 and/ or TNFa in the serum of a treated subject, while increasing the levels of other cytokines, including but not limited to, CCL2, IL-8 and CXCL9 in serum of a treated subject. Detection of such a cytokine response may provide a method to determine the optimal dosing regimen for the indicated chimeric protein.

In a chimeric protein of the present disclosure, the chimeric protein is capable of increasing or preventing a decrease in a sub-population of CD4+ and/or CD8+T cells.

In a chimeric protein of the present disclosure, the chimeric protein is capable of enhancing tumor killing activity by T cells.

In embodiments, the chimeric protein activates the human subject’s T cells when bound by the CD40L domain of the chimeric protein and (a) one or more tumor cells are prevented from transmitting an immunosuppressive signal when bound by the first domain of the chimeric protein, (b) a quantifiable cytokine response in the peripheral blood of the subject is achieved, and/or (c) tumor growth is reduced in the subject in need thereof as compared to a subject treated with CD40 agonist antibodies and/or CD47 blocking antibodies.

In embodiments, the present chimeric proteins inhibit, block and/or reduce cell death of an anti-tumor CD8+ and/or CD4+ T cell; or stimulate, induce, and/or increase cell death of a pro-tumor T cell. T cell exhaustion is a state of T cell dysfunction characterized by progressive loss of proliferative and effector functions, culminating in clonal deletion. Accordingly, a pro-tumor T cell refers to a state of T cell dysfunction that arises during many chronic infections, inflammatory diseases, and cancer. This dysfunction is defined by poor proliferative and/or effector functions, sustained expression of inhibitory receptors and a transcriptional state distinct from that of functional effector or memory T cells. Exhaustion prevents optimal control of infection and tumors. Illustrative pro-tumor T cells include, but are not limited to, Tregs, CD4+ and/or CD8+ T cells expressing one or more checkpoint inhibitory receptors, Th2 cells and Th17 cells. Checkpoint inhibitory receptors refer to receptors expressed on immune cells that prevent or inhibit uncontrolled immune responses. In contrast, an anti-tumor CD8+ and/or CD4+ T cell refers to T cells that can mount an immune response to a tumor.

In embodiments, the present chimeric proteins are capable of, and can be used in methods comprising, increasing a ratio of effector T cells to regulatory T cells. Illustrative effector T cells include ICOS⁺ effector T cells; cytotoxic T cells e.g., ap TCR, CD3⁺, CD8⁺, CD45RO+); CD4⁺ effector T cells (e.g., a0 TCR, CD3⁺, CD4⁺, CCR7+, CD62Lhi, I L 7R/CD127 ); CD8⁺ effector T cells (e.g., ap TCR, CD3⁺, CD8⁺, CCR7+, CD62Lhi, IL7R/CD127+); effector memory T cells (e.g., CD62Llow, CD44⁺, TCR, CD3⁺, IL 7R/CD127*, IL-15R+, CCR7low); central memory T cells (e.g., CCR7⁺, CD62L⁺, CD27⁺; or CCR7hi, CD44⁺, CD62Lhi, TCR, CD3⁺, IL-7R/CD127*, IL-15R⁺); CD62L⁺ effector T cells; CD8⁺ effector memory T cells (TEM) including early effector memory T cells (CD27⁺ CD62L-) and late effector memory T cells (CD27~ CD62L-) (TemE and TemL, respectively); CD127(⁺)CD25(low/-) effectorT cells; CD127( )CD25( ) effectorT cells; CD8⁺ stem cell memory effector cells (TSCM) (e.g., CD44(low)CD62L(high)CD122(high)sca( )); TH1 effector T-cells (e.g., CXCR3⁺, CXCR6⁺ and CCR5⁺; or op TCR, CD3⁺, CD4⁺, IL-12R+, IFNyRt CXCR3⁺), TH2 effectorT cells (e.g., CCR3⁺, CCR4⁺ and CCR8⁺; or op TCR, CD3⁺, CD4⁺, I L-4R⁺, IL-33R⁺, CCR4⁺, I L-17RB⁺, CRTH2⁺); TH9 effector T cells (e.g., op TCR, CD3⁺, CD4⁺); TH17 effector T cells (e.g., op TCR, CD3⁺, CD4⁺, IL-23R⁺, CCR6⁺, IL-1 R*); CD4⁺CD45RO⁺CCR7⁺ effectorT cells, CD4⁺CD45RO⁺CCR7( ) effectorT cells; and effector T cells secreting IL-2, IL-4 and/or IFN-y. Illustrative regulatory T cells include ICOS⁺ regulatory T cells, CD4⁺CD25⁺FOXP3⁺ regulatory T cells, CD4⁺CD25⁺ regulatory T cells, CD4+CD25 regulatory T cells, CD4⁺CD25high regulatory T cells, TIM-3⁺CD172a (SI RPa)⁺ regulatory T cells, lymphocyte activation gene-3 (LAG-3)⁺ regulatory T cells, CTLA-4/CD152⁺ regulatory T cells, neuropilin-1 (Nrp-1)⁺ regulatory T cells, CCR4⁺CCR8⁺ regulatory T cells, CD62L (L-selectin)⁺ regulatory T cells, CD45RBIow regulatory T cells, CD127low regulatory T cells, LRRC32/GARP+ regulatory T cells, CD39⁺ regulatory T cells, GITR⁺ regulatory T cells, LAP⁺ regulatory T cells, 1 B11⁺ regulatory T cells, BTLA⁺ regulatory T cells, type 1 regulatory T cells (Tr1 cells), T helper type 3 (Th3) cells, regulatory cell of natural killer T cell phenotype (NKTregs), CD8⁺ regulatory T cells, CD8⁺CD28 regulatory T cells and/or regulatory T-cells secreting IL-10, IL-35, TGF-p, TNF-a, Galectin-1, IFN-y and/or MCP1.

In embodiments, the chimeric protein of the invention causes an increase in effectorT cells (e.g., CD4+CD25- T cells). In embodiments, the chimeric protein causes a decrease in regulatory T cells (e.g., CD4CD25+T cells).

In embodiments, the chimeric protein generates a memory response which may, e.g., be capable of preventing relapse or protecting the animal from a recurrence and/or preventing, or reducing the likelihood of, metastasis. Thus, an animal treated with the chimeric protein is later able to attack tumor cells and/or prevent development of tumors when rechallenged after an initial treatment with the chimeric protein. Accordingly, a chimeric protein of the present disclosure stimulates both active tumor destruction and also immune recognition of tumor antigens, which are essential in programming a memory response capable of preventing relapse.

In embodiments, the chimeric protein is capable of causing activation of antigen presenting cells. In embodiments, the chimeric protein is capable enhancing the ability of antigen presenting cells to present antigen.

In embodiments, the present chimeric proteins are capable of, and can be used in methods comprising, transiently stimulating effector T cells for longer than about 12 hours, about 24 hours, about 48 hours, about 72 hours or about 96 hours or about 1 week or about 2 weeks. In embodiments, the transient stimulation of effector T cells occurs substantially in a patient’s bloodstream or in a particular tissue/location including lymphoid tissues such as for example, the bone marrow, lymph-node, spleen, thymus, mucosa-associated lymphoid tissue (MALT), non-lymphoid tissues, or in the tumor microenvironment.

In a chimeric protein of the present disclosure, the present chimeric protein unexpectedly provides binding of the extracellular domain components to their respective binding partners with slow off rates (Kd or Kotf). In embodiments, this provides an unexpectedly long interaction of the receptor to ligand and vice versa. Such an effect allows for a longer positive signal effect, e.g., increase in or activation of immune stimulatory signals. For example, the present chimeric protein, e.g., via the long off rate binding allows sufficient signal transmission to provide immune cell proliferation, allow for anti-tumor attack, allows sufficient signal transmission to provide release of stimulatory signals, e.g., cytokines.

In a chimeric protein of the present disclosure, the chimeric protein is capable of forming a stable synapse between cells. The stable synapse of cells promoted by the chimeric proteins (e.g., between cells bearing negative signals) provides spatial orientation to favor tumor reduction - such as positioning the T cells to attack tumor cells and/or sterically preventing the tumor cell from delivering negative signals, including negative signals beyond those masked by the chimeric protein of the invention. In embodiments, this provides longer on-target e.g., intratumoral) half-life (ti/2) as compared to serum ti/2 of the chimeric proteins. Such properties could have the combined advantage of reducing off-target toxicities associated with systemic distribution of the chimeric proteins.

In embodiments, the chimeric protein is capable of providing a sustained immunomodulatory effect.

The present chimeric proteins provide synergistic therapeutic effects (e.g., anti-tumor effects) as it allows for improved site-specific interplay of two immunotherapy agents. In embodiments, the present chimeric proteins provide the potential for reducing off-site and/or systemic toxicity.

In embodiments, the presentchimeric protein exhibits enhanced safety profiles. In embodiments, the present chimeric protein exhibits reduced toxicity profiles. For example, administration of the present chimeric proteins may result in reduced side effects such as one or more of diarrhea, inflammation (e.g., of the gut), or weight loss, which occur following administration of antibodies directed to the ligand(s)/receptor(s) targeted by the extracellular domains of the present chimeric proteins. In embodiments, the present chimeric protein provides improved safety, as compared to antibodies directed to the ligand(s)/receptor(s) targeted by the extracellular domains of the present chimeric proteins, yet, without sacrificing efficacy.

In embodiments, the present chimeric proteins provide reduced side-effects, e.g., Gl complications, relative to current immunotherapies, e.g., antibodies directed to ligand(s)/receptor(s) targeted by the extracellular domains of the present chimeric proteins. Illustrative Gl complications include abdominal pain, appetite loss, autoimmune effects, constipation, cramping, dehydration, diarrhea, eating problems, fatigue, flatulence, fluid in the abdomen or ascites, gastrointestinal (Gl) dysbiosis, Gl mucositis, inflammatory bowel disease, irritable bowel syndrome (IBS-D and IBS-C), nausea, pain, stool or urine changes, ulcerative colitis, vomiting, weight gain from retaining fluid, and/or weakness.

Pharmaceutical composition

Aspects of the present disclosure include a pharmaceutical composition comprising a therapeutically effective amount of a chimeric protein as disclosed herein.

Any chimeric protein disclosed herein may be used in a pharmaceutical composition.

In embodiments, a chimeric protein disclosed herein is provided as a sterile frozen solution in a vial or as a sterile liquid solution in a vial. A drug product comprising a chimeric protein disclosed herein comprises a sterile-filtered, formulated chimeric protein disclosed herein solution filled into a 10 mL single-use glass vial stoppered with a Flurotec® rubber stopper and sealed with an aluminum flip off seal. In embodiments, a chimeric protein disclosed herein is formulated at between about 10 mg/mL to about 30 mg/mL, e.g., about 20 mg/mL in between about 30 mM to about 70 mM L-histidine, e.g., about 50 mM L-histidine and between about 125 mM and about 400 mM sucrose, e.g., about 250 mM sucrose in water for injection. In embodiments, each vial contains about 1 mL of drug product or about 20 mg of a chimeric protein disclosed herein.

The chimeric proteins disclosed herein, including the CD172a (SIRPo)-Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEQ ID NO: 61), can possess a sufficiently basic functional group, which can react with an inorganic or organic acid, or a carboxyl group, which can react with an inorganic or organic base, to form a pharmaceutically acceptable salt. A pharmaceutically-acceptable acid addition salt is formed from a pharmaceutically acceptable acid, as is well known in the art. Such salts include the pharmaceutically acceptable salts listed in, for example, Journal of Pharmaceutical Science, 66, 2-19 (1977) and The Handbook of Pharmaceutical Salts; Properties, Selection, and Use. P. H. Stahl and C. G. Wermuth (eds.), Verlag, Zurich (Switzerland) 2002, which are hereby incorporated by reference in their entirety.

In embodiments, the compositions disclosed herein are in the form of a pharmaceutically acceptable salt.

Further, any chimeric protein disclosed herein can be administered to a subject as a component of a composition, e.g., pharmaceutical composition, which comprises a pharmaceutically acceptable carrier or vehicle. Such pharmaceutical compositions can optionally comprise a suitable amount of a pharmaceutically acceptable excipient so as to provide the form for proper administration. Pharmaceutical excipients can be liquids, such as water and oils, including those of petroleum, animal, vegetable, or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. The pharmaceutical excipients can be, for example, saline, gum acacia, gelatin, starch paste, talc, keratin, colloidal silica, urea and the like. In addition, auxiliary, stabilizing, thickening, lubricating, and coloring agents can be used. In embodiments, the pharmaceutically acceptable excipients are sterile when administered to a subject. Water is a useful excipient when any agent disclosed herein is administered intravenously. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid excipients, specifically for injectable solutions. Suitable pharmaceutical excipients also include starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like. Any agent disclosed herein, if desired, can also comprise minor amounts of wetting or emulsifying agents, or pH buffering agents.

In embodiments, the compositions, e.g., pharmaceutical compositions, disclosed herein are resuspended in a saline buffer (including, without limitation TBS, PBS, and the like). In embodiments, the chimeric proteins may by conjugated and/or fused with another agent to extend half-life or otherwise improve pharmacodynamic and pharmacokinetic properties. In embodiments, the chimeric proteins may be fused or conjugated with one or more of PEG, XTEN (e.g., as rPEG), polysialic acid (POLYXEN), albumin (e.g., human serum albumin or HAS), elastin-like protein (ELP), PAS, HAP, GLK, CTP, transferrin, and the like. In embodiments, each of the individual chimeric proteins is fused to one or more of the agents described in Strohl, BioDrugs 29(4):215— 239 (2015), the entire contents of which are hereby incorporated by reference.

The present disclosure includes the disclosed chimeric protein in various formulations of pharmaceutical composition. Any chimeric protein disclosed herein can take the form of solutions, suspensions, emulsion, drops, tablets, pills, pellets, capsules, capsules containing liquids, powders, sustained-release formulations, suppositories, emulsions, aerosols, sprays, suspensions, or any other form suitable for use. DNA or RNA constructs encoding the protein sequences may also be used. In embodiments, the composition is in the form of a capsule (see, e.g, U.S. Patent No. 5,698,155). Other examples of suitable pharmaceutical excipients are described in Remington’s Pharmaceutical Sciences 1447-1676 (Alfonso R. Gennaro eds, 19th ed. 1995), incorporated herein by reference.

Where necessary, the pharmaceutical compositions comprising the chimeric protein (can also include a solubilizing agent. Also, the agents can be delivered with a suitable vehicle or delivery device as known in the art. Compositions for administration can optionally include a local anesthetic such as, for example, lignocaine to lessen pain at the site of the injection.

The pharmaceutical compositions comprising the chimeric protein of the present disclosure may conveniently be presented in unit dosage forms and may be prepared by any of the methods well known in the art of pharmacy. Such methods generally include the step of bringing therapeutic agents into association with a carrier, which constitutes one or more accessory ingredients. Typically, the pharmaceutical compositions are prepared by uniformly and intimately bringing therapeutic agent into association with a liquid carrier, a finely divided solid carrier, or both, and then, if necessary, shaping the product into dosage forms of the desired formulation (e.g, wet, or dry granulation, powder blends, etc, followed by tableting using conventional methods known in the art)

In embodiments, any chimeric protein disclosed herein is formulated in accordance with routine procedures as a pharmaceutical composition adapted for a mode of administration disclosed herein. Administration, Dosing, and Treatment Regimens

In embodiments, the second dose comprises an increased dosage compared to the first dose if the postdosing level and/or activity of IL-12 is equal or less than about 2-fold greater than a pre-dose amount or post- first dose amount, the post-dosing level and/or activity of CXCL-8 is equal or less than about 2-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CXCL-10 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of IL-10 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CCL2 is equal or less than about 3-fold greater than a predose amount or post-first dose amount, the post-dosing level and/or activity of CCL20 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, and/or the post-dosing level and/or activity of CCL22 is equal or less than about 1 -fold greater than a pre-dose amount or post-first dose amount. In some aspects, the present disclosure relates to a method for treating a cancer in a human subject, the method comprising: (i) administering to the human subject a first dose at a dosage of at least about 0.3 mg/kg of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a post-dosing level of CD47 receptor occupancy of CD4 T cells and/or CD40 receptor occupancy of B cells in a post-dose blood sample obtained from the subject have been measured after at least 15 minutes after administering the first dose; and (ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if (ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is at least about 60%, or administering to the human subject a second dose of the chimeric protein at a higher dosage than the dosage of the first dose if the post-dosing level and/or activity of CD40+ B cells is less than about 80% lower compared to the background level and/or activity, wherein the second dose is administered at least about 48 hours after the administration of the first dose. In embodiments, the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is measured less than 12, or less than 8, or less than 6, or less than 4, or less than 3, or less than 2, or less than 1 hours post dosing. In embodiments, the second dose comprises substantially the same dosage as the first dose if the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is at least about 65%, or at least about 70%, or at least about 75%, or at least about 80%, or at least about 85%, or at least about 90%, or at least about 95% or more. In embodiments, the second dose comprises an increased dosage compared to the first dose if the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is less than about 70%, or less than about 60%, or less than about 50%, or less than about 40%.

%CRI @postdose

Receptor engagement =

The present disclosure is based, in part, on the discoveries that (1) the target engagement of CD47 on CD4 T cells and CD40 on B cells approaches 100% by the 3 mg/kg dose level of the SIRPa-Fc-CD40L chimeric protein; (2) the margination CD40+ B cells from peripheral blood following the administration of the SIRPo- Fc-CD40L chimeric protein reaches maximum at the dosages > 3 mg/kg, and (3) the induction of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 following the administration of the SIRPa-Fc-CD40L chimeric protein approached a plateau at the dosages >3 mg/kg. The present disclosure is based, in part, on the discoveries that infusion related reaction (IRR), if any, may be mitigated by slowing the rate of infusion. These discoveries help determine doses and dosing regimens.

In some aspects, the present disclosure relates to a method for treating a cancer in a human subject, the method comprising: (i) administering to the human subject a first dose of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a background amount and/or activity of M1 macrophages, M2 macrophages and/or granzyme B producing-T cells has been measured in a pre-dose biological sample obtained from the subject before the administration of the first dose, and wherein a postdose amount and/or activity of M1 macrophages, M2 macrophages and/or granzyme B producing-T cells has been measured in a pre-dose biological sample obtained from the subject before the administration of the first dose; (ii) administering to the human subject a second dose of the chimeric protein if a post-dosing ratio of amount and/or activity of the M1 macrophages to M2 macrophages is greater than a pre-dose ratio of amount and/or activity of the M1 macrophages to M2 macrophages, and/or post-dosing amount and/or activity of the granzyme B producing-T cells is greater than the background amount and/or activity of the granzyme B producing-T cells, wherein the second dose is administered at least about 48 hours after the administration of the first dose. In embodiments, the post-dosing level and/or activity is measured more than about 12, or more than about 16, or more than about 18, or more than about 24, or more than about 28, or more than about 32, or more than about 40, or more than about 48 hours, or more post dosing.

In embodiments, the second dose comprises substantially the same dosage as the first dose if the post dosing amount and/or activity of the granzyme B producing-T cells is greater than the background amount and/or activity of the granzyme B producing-T cells by at least about 1 .25*, or at least about 1 .5x, or at least about 2x, or at least about 5x, or at least about 10x, or more. In embodiments, the second dose comprises substantially the same dosage as the first dose if the post-dosing ratio of amount and/or activity of the M1 macrophages to M2 macrophages is greater than the pre-dose ratio of amount and/or activity of the M1 macrophages to M2 macrophages by at least about 1 .25*, or at least about 1 .5x, or at least about 2x, or at least about 5x, or at least about 10x, or more.

In embodiments, the second dose comprises an increased dosage compared to the first dose if the post dosing amount and/or activity of the granzyme B producing-T cells is not greater than the background amount and/or activity of the granzyme B producing-T cells by at least about 1.2x, or at least about 1 x. In embodiments, the second dose comprises an increased dosage compared to the first dose if the post-dosing ratio of amount and/or activity of the M1 macrophages to M2 macrophages is not greater than the pre-dose ratio of amount and/or activity of the M1 macrophages to M2 macrophages by at least about 1 .2x, or at least about 1 x. In embodiments, the biological sample is selected from blood, plasma, serum, blood cells, lacrimal fluid, tears, bone marrow, ascites, tissue or fine needle biopsy sample, cell-containing body fluid, free floating nucleic acids, sputum, saliva, urine, cerebrospinal fluid, peritoneal fluid, pleural fluid, feces, lymph, gynecological fluid, skin swab, vaginal swab, oral swab, nasal swab, washing or lavage, aspirate, scraping, bone marrow specimen, a biopsy specimen and a surgical specimen. In embodiments, the biological sample is a biopsy sample or a surgical specimen, optionally wherein the biological sample is a tumor biopsy sample or a tumor surgical specimen. In embodiments, the tumor biopsy sample or the tumor surgical specimen derived from a tumor selected ovarian cancer, fallopian tube cancer, peritoneal cancer, cutaneous squamous cell carcinoma (CSCC), and squamous cell carcinoma of the head and neck (SCCHN).

In embodiments, the agent that specifically binds to the a marker specific to M1 macrophages, M2 macrophages and/or granzyme B producing-T cells is an antibody or fragment thereof. In embodiments, the antibody is a recombinant antibody, a monoclonal antibody, a polyclonal antibody, or fragment thereof.

In embodiments, the level of the cell is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding a marker specific to M1 macrophages, M2 macrophages and/or granzyme B producing-T cells. In embodiments, the marker specific to M1 macrophages is selected from CD80, CD86, CD64, CD16, CD32, and nitric oxide synthase (iNOS), the marker specific to M2 macrophages is selected from CD163, CD206, CD68, arginase 1 (Arg1) and DECTIN-1. In embodiments, the marker specific to granzyme B producing-T cells is selected from granzyme B (GrzB), CD69 and integrin oE (CD103).

In embodiments, the agent that specifically binds to one or more of the nucleic acids is a nucleic acid primer or probe.

In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 90%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 99% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 99.2% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 99.4% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 99.6% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 99.8% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61.

In embodiments, the human subject suffers from or is suspected to suffer from an advanced solid tumor or a lymphoma. In embodiments, the human subject suffers from or is suspected to suffer from a cancer is selected from ovarian cancer, fallopian tube cancer, peritoneal cancer, cutaneous squamous cell carcinoma (CSCC), and squamous cell carcinoma of the head and neck (SCCHN). In embodiments, the human subject has failed one or more platinum-based therapies. In embodiments, the human subject is ineligible for a platinum therapy. In embodiments, the human subject is not receiving a concurrent chemotherapy, immunotherapy, biologic or hormonal therapy, and/or wherein the human subject has received, been tolerant to, or is ineligible for standard therapy and/or the cancer has no approved therapy considered to be standard of care.

In embodiments, a chimeric protein disclosed herein is presented as a sterile frozen solution at a concentration of about 20 mg/mL and a total volume of about 1 mL, optionally in a 10 mL glass vial. In embodiments, a chimeric protein disclosed herein is administered by intravenous (IV) infusion following dilution with normal saline. Starting dose, dose escalation schema and dose schedules of certain embodiments are presented below. In embodiments, the dose of the chimeric protein administered is at least 0.0001 mg/kg, e.g., between about 0.0001 mg/kg and about 10 mg/kg. In embodiments, the dose of the chimeric protein administered is at least about 0.3 mg/kg, e.g., at least about 0.3 mg/kg, or about 1.0 mg/kg, or about 2 mg/kg, or about 3, about 4 mg/kg, or about 6 mg/kg, or about 8 mg/kg, or about 10 mg/kg. In embodiments, the dose of the chimeric protein administered is at least about 1 mg/kg, e.g., at least about 1.0 mg/kg, or about 2 mg/kg, or about 3, about 4 mg/kg, or about 6 mg/kg, or about 8 mg/kg, or about 10 mg/kg. In embodiments, the doses of the SIRPo-Fc-CD40L chimeric protein are not limited by anemia or another cytopenia effects and are therefore higher than doses are allowed compared to certain other therapeutics (e.g., anti-CD47 antibodies or SI RPalpha-Fc fusion protein). Further, in embodiments, a low dose priming is not needed.

In embodiments, the administration is intravenous. In embodiments, the administration is intratumoral. In embodiments, the administration is by injection. In embodiments, the administration is by infusion. In embodiments, the administration is performed by an intravenous infusion. In embodiments, the administration is performed by an intratumoral injection.

In embodiments, the human subject has failed one or more platinum-based therapies, and optionally is ineligible for a platinum therapy. In embodiments, the human subject is not receiving a concurrent chemotherapy, immunotherapy, biologic or hormonal therapy, and/or wherein the human subject has received, been tolerant to, or is ineligible for standard therapy and/or the cancer has no approved therapy considered to be standard of care.

In embodiments, the initial dose is less than the dose for at least one of the subsequent administrations., e.g., each of the subsequent administrations.

In embodiments, the initial dose is the same as the dose for at least one of the subsequent administrations, e.g., each of the subsequent administrations.

In embodiments, the chimeric protein is administered at least about one time a month.

In embodiments, the chimeric protein is administered at least about two times a month.

In embodiments, the chimeric protein is administered at least about three times a month.

In embodiments, the chimeric protein is first administered once a week for three weeks and the chimeric protein is then administered about once every three weeks or once every four weeks. In embodiments, the chimeric protein is first administered once a week for three weeks and the chimeric protein is then administered about two times per month. For example, the chimeric protein is first administered once a week for three weeks and the chimeric protein is then administered about once every two weeks.

In embodiments, the chimeric protein is administered at least about four times a month. For example, the chimeric protein is administered about once a week. In embodiments, the chimeric protein is administered once every week (once every seven days), in embodiments, the chimeric protein is administered once every two weeks.

In embodiments, the administration of the SIRPa-Fc-CD40L chimeric protein does not cause an anemia or another cytopenia in the patient. In embodiments, the administration of the does not cause lysis of RBCs. In embodiments, the administration of the SIRPa-Fc-CD40L chimeric protein is less likely to cause anemia or another cytopenia in than, e.g., an anti-CD47 Ab. In embodiments, the doses of the SIRPo-Fc-CD40L chimeric protein are not limited by anemia or another cytopenia effects and are therefore higher than doses are allowed compared to certain other therapeutics (e.g., anti-CD47 antibodies or SIRPalpha-Fc fusion protein). Further, in embodiments, a low dose priming is not needed.

Another advantage the SIRPo-Fc-CD40L chimeric protein (e.g., SEQ ID NO: 59 or SEQ ID NO: 61) offers is that despite targeting does not cause an anemia or another cytopenia in the patient. This is because although the CD47/SIRPO interaction plays a key role in the lysis of RBCs, as shown herein, the SIRPa-Fc-CD40L chimeric protein does not cause lysis of RBCs. Accordingly, the present methods are less likely to cause anemia or another cytopenia in than, e.g., an anti-CD47 Ab.

A chimeric protein may be administered intravenously by intravenous infusion or bolus injection into the bloodstream. A chimeric protein may be administered intravenously by intravenous infusion for patients suffering from advanced ovarian, fallopian tube and primary peritoneal cancers.

A chimeric protein may be administered an intratumoral injection. In embodiments, the therapeutic dose for intra-tumoral administration is equal or less than that of intravenous infusion. In embodiments, the therapeutic dose for intra-tumoral administration is equal to that of intravenous infusion. In embodiments, the therapeutic dose for intra-tumoral administration is less than that of intravenous infusion. In embodiments, the therapeutic dose for intra-tumoral administration for patients suffering from advanced or metastatic CSCC and HNSCC.

In embodiments, the present chimeric protein allows for a dual effect that provides less side effects than are seen in conventional immunotherapy (e.g., treatments with one or more of OPDIVO, KEYTRUDA, YERVOY, and TECENTRIQ). For example, the present chimeric proteins reduce or prevent commonly observed immune-related adverse events that affect various tissues and organs including the skin, the gastrointestinal tract, the kidneys, peripheral and central nervous system, liver, lymph nodes, eyes, pancreas, and the endocrine system, such as hypophysitis, colitis, hepatitis, pneumonitis, rash, and rheumatic disease.

Dosage forms suitable for intravenous administration include, for example, solutions, suspensions, dispersions, emulsions, and the like. They may also be manufactured in the form of sterile solid compositions (e.g., lyophilized composition), which can be dissolved or suspended in sterile injectable medium immediately before use. They may contain, for example, suspending or dispersing agents known in the art.

The dosage of any chimeric protein disclosed herein as well as the dosing schedule can depend on various parameters, including, but not limited to, the disease being treated, the subject’s general health, and the administering physician’s discretion.

In one aspect, the present disclosure relates to a method for treating a cancer in a human subject in need thereof, the method comprising a step of administering to the human subject an effective amount of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein the step of administering comprises biphasic dosing. In embodiments, the first phase, and the second phase each independently comprise a dosing frequency of from about twice a week to about once every two months. In embodiments, the linker comprises at least one cysteine residue capable of forming a disulfide bond. In embodiments, the chimeric protein exhibits a linear dose response in the dose range of e.g., about 0.3 mg/kg to about 3 mg/kg, or about 0.5 mg/kg to about 3 mg/kg, or about 0.7 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 3 mg/kg, or about 1 .5 mg/kg to about 3 mg/kg, or about 2 mg/kg to about 3 mg/kg, or about 2.5 mg/kg to about 3 mg/kg, or about 0.3 mg/kg to about 2.5 mg/kg, or about 0.3 mg/kg to about 2 mg/kg, or about 0.3 mg/kg to about 1 .5 mg/kg, or about 0.3 mg/kg to about 1 .0 mg/kg, or about 0.3 mg/kg to about 0.5 mg/kg. In embodiments, the chimeric protein does not exhibit a bell-shaped dose response.

In embodiments, the dosing frequency of the first phase, and the dosing frequency of the second phase are the same. In other embodiments, the dosing frequency of the first phase, and the dosing frequency of the second phase are different. In embodiments, the dosing frequency of the first phase is selected from about every three days, about twice a week, about every week, about every 10 days, about twice every 3 weeks, about every 2 weeks, about every 3 weeks, about every 4 weeks, about every month, about every 5 weeks, about every 6 weeks, about 7 seven weeks, about every 8 weeks and about every 2 months. In embodiments, the dosing frequency of the first phase is selected from about every 3 days to about every 10 days, about every week to about every 2 weeks, about every 10 days to about every 3 weeks, about every 2 weeks to about every 4 weeks, about every 3 weeks to about every 5 weeks, about every 4 weeks to about every 6 weeks, about every 5 weeks to about every 7 weeks, about every 6 weeks to about every 8 weeks, and , about every 6 weeks to about every 2 months.

In embodiments, the dosing frequency of the second phase is selected from about every three days, about twice a week, about every week, about every 10 days, about twice every 3 weeks, about every 2 weeks, about every 3 weeks, about every 4 weeks, about every month, about every 5 weeks, about every 6 weeks, about 7 seven weeks, about every 8 weeks and about every 2 months. In embodiments, the dosing frequency of the second phase is selected from about every 3 days to about every 10 days, about every week to about every 2 weeks, about every 10 days to about every 3 weeks, about every 2 weeks to about every 4 weeks, about every 3 weeks to about every 5 weeks, about every 4 weeks to about every 6 weeks, about every 5 weeks to about every 7 weeks, about every 6 weeks to about every 8 weeks, and , about every 6 weeks to about every 2 months.

In embodiments, the dosing frequency of the first phase is selected from about every 3 days to about every 10 days, about every week to about every 2 weeks, about every 10 days to about every 3 weeks; and the frequency of the second phase is selected from about every week to about every 2 weeks, about every 10 days to about every 3 weeks, about every 2 weeks to about every 4 weeks, about every 3 weeks to about every 5 weeks, about every 4 weeks to about every 6 weeks.

Additionally, or alternatively, in embodiments, the first phase, and the second phase each independently last from about two days to about 12 months. In embodiments, the first phase lasts from about two weeks to about 2 months; and the second phase lasts from about 2 weeks to about 12 months. In embodiments, the first phase lasts from about two weeks to about 1 month; and the second phase lasts from about 2 weeks to about 12 months. In embodiments, the first phase lasts from about two weeks to about 1 month; and the second phase lasts from about 4 weeks to about 12 months. Additionally, or alternatively, in embodiments, the effective amount for the first phase, the second phase and the third phase each independently comprise about 0.01 mg/kg to about 10 mg/ml. In embodiments, the effective amount for the first phase, the second phase and the third phase each independently selected from about 0.03 mg/kg, about 0.1 mg/kg, about 0.3 mg/kg, about 1 mg/kg, about 3 mg/kg, about 10 mg/kg, and any range including and/or in between any two of the preceding values. In embodiments, the effective amount for the first phase, the second phase and the third phase each independently selected from about 0.01 mg/kg to about O.1 mg/kg, about 0.03 mg/kg to about 0.3 mg/kg, about 0.1 mg/kg to about 1 mg/kg, about 0.3 mg/kg to about 3 mg/kg, and about 1 mg/kg to about 10 mg/kg. In embodiments, the effective amount for the first phase, the second phase and the third phase are same. In embodiments, the effective amount for the first phase, the second phase and the third phase are different. In embodiments, the effective amount for the first phase is greater than the effective amount for the second phase. In embodiments, the effective amount for the first phase is from about 0.03 mg/kg to about 0.3 mg/kg, about 0.1 mg/kg to about 1 mg/kg, about 0.3 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 10 mg/kg; and the effective amount for the second phase is from about 0.01 mg/kg to about 0.1 mg/kg, about 0.03 mg/kg to about 0.3 mg/kg, about 0.1 mg/kg to about 1 mg/kg, about 0.3 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 10 mg/kg.

In embodiments, the chimeric proteins disclosed herein is the human CD172a (SIRPa)-Fc-CD40L chimeric protein.

In one aspect, the present disclosure relates to a method for treating a cancer in a human subject in need thereof the method comprising a step of administering to the human subject an effective amount of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPo)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein the step of administration comprises a first cycle, a second cycle and a third cycle. In embodiments, the linker comprises at least one cysteine residue capable of forming a disulfide bond. In embodiments, the first cycle, the second cycle and the third cycle each independently comprise a dosing frequency of from about twice a week to about once every two months. In embodiments, the dosing frequency of the first cycle, the dosing frequency of the second cycle and the dosing frequency of the third cycle are the same. In embodiments, the dosing frequency of the first cycle, the dosing frequency of the second cycle and the dosing frequency of the third cycle are different. In embodiments, the dosing frequency of the first cycle is selected from about every three days, about twice a week, about every week, about every 10 days, about twice every 3 weeks, about every 2 weeks, about every 3 weeks, about every 4 weeks, about every month, about every 5 weeks, about every 6 weeks, about 7 seven weeks, about every 8 weeks and about every 2 months. In embodiments, the chimeric protein exhibits a linear dose response in the dose range of e.g., about 0.3 mg/kg to about 3 mg/kg, or about 0.5 mg/kg to about 3 mg/kg, or about 0.7 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 3 mg/kg, or about 1 .5 mg/kg to about 3 mg/kg, or about 2 mg/kg to about 3 mg/kg, or about 2.5 mg/kg to about

3 mg/kg, or about 0.3 mg/kg to about 2.5 mg/kg, or about 0.3 mg/kg to about 2 mg/kg, or about 0.3 mg/kg to about 1.5 mg/kg, or about 0.3 mg/kg to about 1.0 mg/kg, or about 0.3 mg/kg to about 0.5 mg/kg. In embodiments, the chimeric protein does not exhibit a bell-shaped dose response.

In embodiments, the dosing frequency of the first cycle is selected from about every 3 days to about every 10 days, about every week to about every 2 weeks, about every 10 days to about every 3 weeks, about every

2 weeks to about every 4 weeks, about every 3 weeks to about every 5 weeks, about every 4 weeks to about every 6 weeks, about every 5 weeks to about every 7 weeks, about every 6 weeks to about every 8 weeks, and , about every 6 weeks to about every 2 months. In embodiments, the dosing frequency of the second cycle is selected from about every three days, about twice a week, about every week, about every 10 days, about twice every 3 weeks, about every 2 weeks, about every 3 weeks, about every 4 weeks, about every month, about every 5 weeks, about every 6 weeks, about 7 seven weeks, about every 8 weeks and about every 2 months. In embodiments, the dosing frequency of the second cycle is selected from about every 3 days to about every 10 days, about every week to about every 2 weeks, about every 10 days to about every

3 weeks, about every 2 weeks to about every 4 weeks, about every 3 weeks to about every 5 weeks, about every 4 weeks to about every 6 weeks, about every 5 weeks to about every 7 weeks, about every 6 weeks to about every 8 weeks, and , about every 6 weeks to about every 2 months. In embodiments, the dosing frequency of the third cycle is selected from about every three days, about twice a week, about every week, about every 10 days, about twice every 3 weeks, about every 2 weeks, about every 3 weeks, about every 4 weeks, about every month, about every 5 weeks, about every 6 weeks, about 7 seven weeks, about every 8 weeks and about every 2 months. In embodiments, the dosing frequency of the third cycle is selected from about every 3 days to about every 10 days, about every week to about every 2 weeks, about every 10 days to about every 3 weeks, about every 2 weeks to about every 4 weeks, about every 3 weeks to about every 5 weeks, about every 4 weeks to about every 6 weeks, about every 5 weeks to about every 7 weeks, about every 6 weeks to about every 8 weeks, and , about every 6 weeks to about every 2 months. In embodiments, the dosing frequency of the first cycle is selected from about every 3 days to about every 10 days, about every week to about every 2 weeks, about every 10 days to about every 3 weeks; and the frequency of the second cycle is selected from about every week to about every 2 weeks, about every 10 days to about every 3 weeks, about every 2 weeks to about every 4 weeks, about every 3 weeks to about every 5 weeks, about every 4 weeks to about every 6 weeks.

Additionally, or alternatively, in embodiments, the first cycle, the second cycle and the third cycle each independently last from about two days to about 12 months. In embodiments, the first cycle lasts from about two weeks to about 2 months; and the second cycle lasts from about 2 weeks to about 12 months. In embodiments, the first cycle lasts from about two weeks to about 2 months; the second cycle lasts from about 2 weeks to about 12 months and the third cycle lasts from about 2 weeks to about 6 months.

Additionally, or alternatively, in embodiments, the effective amount for the first cycle, the second cycle and the third cycle each independently comprise about 0.01 mg/kg to about 10 mg/ml. In embodiments, the effective amount for the first cycle, the second cycle and the third cycle each independently selected from about 0.03 mg/kg, about 0.1 mg/kg, about 0.3 mg/kg, about 1 mg/kg, about 3 mg/kg, about 10 mg/kg, and any range including and/or in between any two of the preceding values. In embodiments, the effective amount for the first cycle, the second cycle and the third cycle each independently selected from about 0.01 mg/kg to about O.1 mg/kg, about 0.03 mg/kg to about 0.3 mg/kg, about 0.1 mg/kg to about 1 mg/kg, about 0.3 mg/kg to about 3 mg/kg, and about 1 mg/kg to about 10 mg/kg.

In embodiments, the effective amount for the first cycle, the second cycle and the third cycle are same. In other embodiments, the effective amount for the first cycle, the second cycle and the third cycle are different. In embodiments, the effective amount for the first cycle is greater than the effective amount for the second cycle. In other embodiments, the effective amount for the first cycle is lesser than the effective amount for the second cycle. In yet other embodiments, the effective amount for the first cycle and the effective amount for the second cycle are the same.

In embodiments, the effective amount for the first cycle is from about 0.03 mg/kg to about 0.3 mg/kg, about 0.1 mg/kg to about 1 mg/kg, about 0.3 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 10 mg/kg; and the effective amount for the second cycle is from about 0.01 mg/kg to about 0.1 mg/kg, about 0.03 mg/kg to about 0.3 mg/kg, about 0.1 mg/kg to about 1 mg/kg, about 0.3 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 10 mg/kg.

In embodiments, the chimeric proteins disclosed herein is the human CD172a (SIRPa)-Fc-CD40L chimeric protein. In one aspect, the present disclosure relates to a method for treating a cancer in a human subject in need thereof the method comprising a step of administering to the human subject an effective amount of an effective amount of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)J, (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L) with a dosing regimen, wherein the dosing regimen comprises dosing with a frequency in the range of about every three days to about every 2 months. In embodiments, the linker comprises at least one cysteine residue capable of forming a disulfide bond. In embodiments, the dosing regimen is selected from about every three days, about twice a week, about every week, about every 10 days, about twice every 3 weeks, about every 2 weeks, about every 3 weeks, about every 4 weeks, about every month, about every 5 weeks, about every 6 weeks, about 7 seven weeks, about every 8 weeks and about every 2 months. In embodiments, the dosing regimen is selected from about every week, about every 10 days, about every 2 weeks, about every 3 weeks, about every 4 weeks, about every month, about every 5 weeks, about every 6 weeks, about 7 seven weeks, about every 8 weeks and about every 2 months. In embodiments, the dosing regimen is about every 2 weeks, about every 3 weeks, or about every 4 weeks.

In one aspect, the present disclosure relates to a method for treating a cancer in a human subject in need thereof the method comprising a step of administering to the human subject an effective amount of an effective amount of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L) with a dosing regimen selected from about every 3 days to about every 10 days, about every week to about every 2 weeks, about every 10 days to about every 3 weeks, about every 2 weeks to about every 4 weeks, about every 3 weeks to about every 5 weeks, about every 4 weeks to about every 6 weeks, about every 5 weeks to about every 7 weeks, about every 6 weeks to about every 8 weeks, and , about every 6 weeks to about every 2 months. In embodiments, the linker comprises at least one cysteine residue capable of forming a disulfide bond. In embodiments, the dosing regimen is about every week to about every 2 weeks, about every 10 days to about every 3 weeks, or about every 2 weeks to about every 4 weeks. In embodiments, the chimeric protein exhibits a linear dose response in the dose range of e.g., about 0.3 mg/kg to about 3 mg/kg, or about 0.5 mg/kg to about 3 mg/kg, or about 0.7 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 3 mg/kg, or about 1 .5 mg/kg to about 3 mg/kg, or about 2 mg/kg to about 3 mg/kg, or about 2.5 mg/kg to about 3 mg/kg, or about 0.3 mg/kg to about 2.5 mg/kg, or about 0.3 mg/kg to about 2 mg/kg, or about 0.3 mg/kg to about 1 .5 mg/kg, or about 0.3 mg/kg to about 1 .0 mg/kg, or about 0.3 mg/kg to about 0.5 mg/kg. In embodiments, the chimeric protein does not exhibit a bell-shaped dose response.

In some embodiments of any of the aspects disclosed herein, the first domain is capable of binding a CD172a (SIRPa) ligand. In embodiments, the first domain comprises substantially all of the extracellular domain of CD172a (SIRPa). In embodiments, the second domain is capable of binding a CD40 receptor. In embodiments, the second domain comprises substantially all of the extracellular domain of CD40L. In embodiments, the linker comprises a hinge-CH2-CH3 Fc domain derived from lgG4, e.g., human I gG4. In embodiments, the linker comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the first domain comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO:

57. In embodiments, the first domain comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the first domain comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 57.

In some embodiments of any of the aspects disclosed herein, the second domain comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 58. In some embodiments of any of the aspects disclosed herein, the second domain comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:

58. In some embodiments of any of the aspects disclosed herein, the second domain comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 58. In some embodiments of any of the aspects disclosed herein, the second domain comprises an amino acid sequence that is at least 97% identical to the amino acid sequence of SEQ ID NO: 58. In some embodiments of any of the aspects disclosed herein, the second domain comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 58. 1 n some embodiments of any of the aspects disclosed herein, the second domain comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 58. In some embodiments of any of the aspects disclosed herein, the second domain comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, (a) the first domain comprises the amino acid sequence of SEQ ID NO: 57, (b) the second domain comprises the amino acid sequence of SEQ ID NO: 58, and (c) the linker comprises an amino acid sequence that is at least 95% identical to SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3.

In embodiments, the chimeric protein further comprises the amino acid sequence of SEQ ID NO: 5 or SEQ ID NO: 7. In embodiments, the chimeric protein further comprises the amino acid sequence of SEQ ID NO: 5 and SEQ ID NO: 7. In embodiments, the chimeric protein comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least 95% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least 96% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least 97% identical to SEQ ID NO: 59 or SEQ ID NO: 61 . In embodiments, the chimeric protein comprises an amino acid sequence that is at least 98% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least 99% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 98% identical to SEQ ID NO: 59 or SEQ ID NO: 61 . In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 99% identical to SEQ ID NO: 59 or SEQ ID NO: 61 .

Additionally or alternatively, in embodiments, the chimeric protein comprises an amino acid sequence that is at least about 99.2% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 99.4% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 99.6% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 99.8% identical to SEQ ID NO: 59 or SEQ ID NO: 61 . In embodiments, the chimeric protein comprises the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the human subject has received, been tolerant to, or is ineligible for standard therapy and/or the cancer has no approved therapy considered to be standard of care.

In one aspect, the present disclosure relates to a method for promoting the migration of lymphocytes from peripheral blood into secondary lymphoid organs e.g. the lymph nodes and spleen in a human subject in need thereof, the method comprising a step of administering to the human subject an effective amount of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L).

In some embodiments of any of the aspects disclosed herein, the human subject is not receiving a concurrent chemotherapy, immunotherapy, biologic or hormonal therapy.

In one aspect, the present disclosure relates to a chimeric protein for use in the method of any of the embodiments disclosed herein.

In one aspect, the present disclosure relates to a chimeric protein comprising an amino acid sequence that is at least about 98% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the chimeric protein comprises an amino acid sequence that is at least about 99% identical to SEQ ID NO: 59 or SEQ ID NO: 61 . In embodiments, the chimeric protein comprises an amino acid sequence that is identical to SEQ ID NO: 59 or SEQ ID NO: 61.

The dosing frequency of the first phase, and the dosing frequency of the second phase may be same or different. In embodiments, the dosing frequency of the first phase and the dosing frequency of the second phase are each independently selected from about every three days, about twice a week, about every week, about every 10 days, about twice every 3 weeks, about every 2 weeks, about every 3 weeks, about every 4 weeks, about every month, about every 5 weeks, about every 6 weeks, about 7 seven weeks, about every 8 weeks and about every 2 months. In embodiments, the dosing frequency of the first phase is selected from about every 3 days to about every 10 days, about every week to about every 2 weeks, about every 10 days to about every 3 weeks, about every 2 weeks to about every 4 weeks, about every 3 weeks to about every 5 weeks, about every 4 weeks to about every 6 weeks, about every 5 weeks to about every 7 weeks, about every 6 weeks to about every 8 weeks, and , about every 6 weeks to about every 2 months. In embodiments, the first phase, and the second phase each independently last from about two days to about 12 months. For example, in embodiments, the first phase lasts from about two weeks to about 2 months; and the second phase lasts from about 2 weeks to about 12 months. In embodiments, the first phase lasts from about two weeks to about 1 month; and the second phase lasts from about 2 weeks to about 12 months. In embodiments, the first phase lasts from about two weeks to about 1 month; and the second phase lasts from about 4 weeks to about 12 months.

The effective amount for the first phase, the second phase and the third phase may be same or different. In embodiments, the effective amount for the first phase, the second phase and the third phase each independently comprise about 0.01 mg/kg to about 10 mg/ml. In embodiments, the effective amount for the first phase is from about 0.03 mg/kg to about 0.3 mg/kg, about 0.1 mg/kg to about 1 mg/kg, about 0.3 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 10 mg/kg; and the effective amount for the second phase is from about 0.01 mg/kg to about 0.1 mg/kg, about 0.03 mg/kg to about 0.3 mg/kg, about 0.1 mg/kg to about 1 mg/kg, about 0.3 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 10 mg/kg. In embodiments, the chimeric proteins disclosed herein is the human CD172a (SIRPa)-Fc-CD40L chimeric protein.

In embodiments, the human CD172a (SIRPo)-Fc-CD40L chimeric protein is capable of providing a sustained immunomodulatory effect.

In embodiments, the linker comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments, the linker comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3.

In embodiments, the linker comprises hinge-CH2-CH3 Fc domain derived from IgG. In embodiments, the linker comprises hinge-CH2-CH3 Fc domain derived from an IgG selected from lgG1 and lgG4. In embodiments, the linker comprises hinge-CH2-CH3 Fc domain derived from human I gG1 or human I gG4. In embodiments, the linker comprises hinge-CH2-CH3 Fc domain derived from lgG4. In embodiments, the hinge-CH2-CH3 Fc domain is derived from human I gG4.

Additionally, or alternatively, in embodiments, the extracellular domain of human signal regulatory protein a (CD172a (SIRPa)) comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the extracellular domain of human signal regulatory protein a (CD172a (SIRPa)) comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the extracellular domain of human signal regulatory protein a (CD172a (SIRPa)) comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the extracellular domain of human signal regulatory protein a (CD172a (SIRPa)) comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the extracellular domain of human signal regulatory protein a (CD172a (SIRPa)) comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 57. In embodiments, the extracellular domain of human signal regulatory protein a (CD172a (SIRPa)) comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 57.

Additionally, or alternatively, in embodiments, the extracellular domain of human CD40 ligand (CD40L) comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the extracellular domain of human CD40 ligand (CD40L) comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the extracellular domain of human CD40 ligand (CD40L) comprises an amino acid sequence that is at least 96% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the extracellular domain of human CD40 ligand (CD40L) comprises an amino acid sequence that is at least 98% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the extracellular domain of human CD40 ligand (CD40L) comprises an amino acid sequence that is at least 99% identical to the amino acid sequence of SEQ ID NO: 58. In embodiments, the extracellular domain of human CD40 ligand (CD40L) comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO: 58.

Additionally, or alternatively, in embodiments, the human CD172a (SIRPa)-Fc-CD40L chimeric protein comprises an amino acid sequence that is at least 90%, or 93%, or 95%, or 97%, or 98%, or 99% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the human CD172a (SIRPa)-Fc-CD40L chimeric protein comprises an amino acid sequence that is at least 95% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the human CD172a (SIRPa)-Fc-CD40L chimeric protein comprises an amino acid sequence that is at least 96% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the human CD172a (SIRPa)-Fc-CD40L chimeric protein comprises an amino acid sequence that is at least 97% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the human CD172a (SIRPa)-Fc-CD40L chimeric protein comprises an amino acid sequence that is at least 98% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the human CD172a (SIRPa)-Fc-CD40L chimeric protein comprises an amino acid sequence that is at least 99% identical to SEQ ID NO: 59 or SEQ ID NO: 61. In embodiments, the human CD172a (SIRPa)-Fc-CD40L chimeric protein comprises an amino acid sequence that is identical to SEQ ID NO: 59 or SEQ ID NO: 61.

In one aspect, the present disclosure relates to a method for treating a cancer in a human subject comprising: (i) administering to the human subject a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises at least one cysteine residue capable of forming a disulfide bond and/or comprises a hinge- CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L); and (ii) administering a second therapeutic agent. In embodiments, the chimeric protein is administered at a dose between about 0.0001 mg/kg and about 10 mg/kg. In embodiments, the dose of the chimeric protein administered is at least about 0.3 mg/kg, e.g., at least about 0.3 mg/kg, or about 1 .0 mg/kg, or about 2 mg/kg, or about 3, about 4 mg/kg, or about 6 mg/kg, or about 8 mg/kg, or about 10 mg/kg. In embodiments, the dose of the chimeric protein administered is at least about 1 mg/kg, e.g., at least about 1.0 mg/kg, or about 2 mg/kg, or about 3, about 4 mg/kg, or about 6 mg/kg, or about 8 mg/kg, or about 10 mg/kg. In embodiments, the chimeric protein exhibits a linear dose response in the dose range of e.g., about 0.3 mg/kg to about 3 mg/kg, or about 0.5 mg/kg to about 3 mg/kg, or about 0.7 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 3 mg/kg, or about 1 .5 mg/kg to about 3 mg/kg, or about 2 mg/kg to about 3 mg/kg, or about 2.5 mg/kg to about 3 mg/kg, or about 0.3 mg/kg to about 2.5 mg/kg, or about 0.3 mg/kg to about 2 mg/kg, or about 0.3 mg/kg to about 1 .5 mg/kg, or about 0.3 mg/kg to about 1 .0 mg/kg, or about 0.3 mg/kg to about 0.5 mg/kg. In embodiments, the chimeric protein does not exhibit a bell-shaped dose response.

In embodiments, the administration of the chimeric protein causes a CD47 receptor occupancy (RO) on leukocytes that is at least about 30%, or at least about 40%, or at least about 50%, or at least about 60%, or at least about 65%, or at least about 70%, or at least about 75%, or at least about 80%, or at least about 85%, or at least about 90%, or at least about 95% compared to the RO prior to administration of the chimeric protein, a second subject that is not administered the chimeric protein and/or an external control. In embodiments, the administration of the chimeric protein causes a CD47 receptor occupancy (RO) on B cells that is at least about 30%, or at least about 40%, or at least about 50%, or at least about 60%, or at least about 65%, or at least about 70%, or at least about 75%, or at least about 80%, or at least about 85%, or at least about 90%, or at least about 95% compared to the RO prior to administration of the chimeric protein, a second subject that is not administered the chimeric protein and/or an external control. In embodiments, the administration of the chimeric protein causes an increase in the amount and/or activity of one or more of IL- 12, MCP-1, MIP-1 p, MIP-1a, and MDC % compared to the RO prior to administration of the chimeric protein, a second subject that is not administered the chimeric protein and/or an external control.

In one aspect, the present disclosure relates to a method for treating a cancer in a human subject comprising administering to a subject in need thereof: a chimeric protein of a general structure of N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises at least one cysteine residue capable of forming a disulfide bond and/or comprises a hinge- CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L); wherein: the subject is undergoing or has undergone treatment with a second therapeutic agent. In embodiments, the chimeric protein is administered at a dose between about 0.0001 mg/kg and about 10 mg/kg. In embodiments, the dose of the chimeric protein administered is at least about 0.3 mg/kg, e.g., at least about 0.3 mg/kg, or about 1 .0 mg/kg, or about 2 mg/kg, or about 3, about 4 mg/kg, or about 6 mg/kg, or about 8 mg/kg, or about 10 mg/kg. In embodiments, the dose of the chimeric protein administered is at least about 1 mg/kg, e.g., at least about 1 .0 mg/kg, or about 2 mg/kg, or about 3, about 4 mg/kg, or about 6 mg/kg, or about 8 mg/kg, or about 10 mg/kg. In embodiments, the chimeric protein exhibits a linear dose response in the dose range of e.g., about 0.3 mg/kg to about 3 mg/kg, or about 0.5 mg/kg to about 3 mg/kg, or about 0.7 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 3 mg/kg, or about 1.5 mg/kg to about 3 mg/kg, or about 2 mg/kg to about 3 mg/kg, or about 2.5 mg/kg to about 3 mg/kg, or about 0.3 mg/kg to about 2.5 mg/kg, or about 0.3 mg/kg to about 2 mg/kg, or about 0.3 mg/kg to about 1 .5 mg/kg, or about 0.3 mg/kg to about 1.0 mg/kg, or about 0.3 mg/kg to about 0.5 mg/kg. In embodiments, the chimeric protein does not exhibit a bellshaped dose response.

In one aspect, the present disclosure relates to a method for treating a cancer in a human subject comprising administering to a subject in need thereof a second anticancer therapeutic agent, wherein the subject is undergoing or has undergone treatment with a chimeric protein of a general structure of N terminus - (a) - (b) - (c) - C terminus, wherein: (a) is a first domain comprising an extracellular domain of human Signal regulatory protein a (CD172a (SIRPa)), (b) is a linker adjoining the first and second domains, wherein the linker comprises at least one cysteine residue capable of forming a disulfide bond and/or comprises a hinge- CH2-CH3 Fc domain, and (c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L). In embodiments, the chimeric protein is administered at a dose between about 0.0001 mg/kg and about 10 mg/kg. In embodiments, the chimeric protein exhibits a linear dose response in the dose range of e.g., about 0.3 mg/kg to about 3 mg/kg, or about 0.5 mg/kg to about 3 mg/kg, or about 0.7 mg/kg to about 3 mg/kg, or about 1 mg/kg to about 3 mg/kg, or about 1.5 mg/kg to about 3 mg/kg, or about 2 mg/kg to about 3 mg/kg, or about 2.5 mg/kg to about 3 mg/kg, or about 0.3 mg/kg to about 2.5 mg/kg, or about 0.3 mg/kg to about 2 mg/kg, or about 0.3 mg/kg to about 1 .5 mg/kg, or about 0.3 mg/kg to about 1 .0 mg/kg, or about 0.3 mg/kg to about 0.5 mg/kg. In embodiments, the chimeric protein does not exhibit a bell-shaped dose response.

In embodiments, the chimeric protein is administered before the second therapeutic agent. In embodiments, the second therapeutic agent is administered before the chimeric protein. In embodiments, the second therapeutic agent and the chimeric protein are administered substantially together.

In embodiments, the second therapeutic agent is selected from an antibody, and a chemotherapeutic agent. In embodiments, the antibody is capable of antibody-dependent cellular cytotoxicity (ADCC). In embodiments, the antibody is selected from cetuximab, rituximab, obinutuzumab, Hul4.18K322A, Hu3F8, dinituximab, and trastuzumab. In embodiments, the antibody is capable of antibody-dependent cellular phagocytosis (ADCP). In embodiments, the antibody is selected from cetuximab, daratumumab, rituximab, and trastuzumab. In embodiments, the antibody is capable of binding a molecule selected from carcinoembryonic antigen (CEA), EGFR, HER-2, epithelial cell adhesion molecule (EpCAM), and human epithelial mucin-1 , CD20, CD30, CD38, CD40, and CD52. In embodiments, the antibody is capable of binding EGFR. In embodiments, the antibody is selected from Mab A13, AMG595, cetuximab (Erbitux, C225), panitumumab (ABX-EGF, Vectibix), depatuxizumab (ABT 806), depatuxizumab, mafodotin, duligotuzumab (MEHD7945A, RG7597), Futuximab (Sym004), GC1118, imgatuzumab (GA201), matuzumab (EMD 72000), necitumumab (Portrazza), nimotuzumab (h-R3), anitumumab (Vectibix, ABX-EGF), zalutumumab, humMRI , and tomuzotuximab. In embodiments, the antibody is cetuximab. In embodiments, the chemotherapeutic agent is an anthracycline. In embodiments, the anthacycline is selected from doxorubicin, daunorubicin, epirubicin and idarubicin, and pharmaceutically acceptable salts, acids, or derivatives thereof. In embodiments, the chemotherapeutic agent is doxorubicin.

In embodiments, the cancer comprises an advanced solid tumor (local and/or metastatic) or a lymphoma. In embodiments, the cancer is selected from ovarian cancer, fallopian tube cancer, peritoneal cancer, cutaneous squamous cell carcinoma (CSCC), and squamous cell carcinoma of the head and neck (SCCHN). In embodiments, the cancer comprises an advanced solid tumor (local and/or metastatic) or advanced lymphoma.

EXAMPLES

The examples herein are provided to illustrate advantages and benefits of the present technology and to further assist a person of ordinary skill in the art with preparing or using the chimeric proteins of the present technology. The examples herein are also presented in order to more fully illustrate the preferred aspects of the present technology. The examples should in no way be construed as limiting the scope of the present technology, as defined by the appended claims. The examples can include or incorporate any of the variations, aspects or embodiments of the present technology described above. The variations, aspects or embodiments described above may also further each include or incorporate the variations of any or all other variations, aspects, or embodiments of the present technology.

Example 1: Design of Phase 1 Clinical T ai of the SIRPct-Fc-CD40L Chimeric Protein (SL-172154)

This first-in-human, phase 1 dose escalation study evaluated SL-172154 as monotherapy in patients (pts) with advanced platinum resistant ovarian, fallopian tube and primary peritoneal cancers (PROC). SL-172154 was administered intravenously across 5 dose levels (0.1, 0.3, 1.0, 3.0, 10 mg/kg). Dose escalation followed a modified toxicity probability interval 2 design. See FIG. 1 B. Objectives included evaluation of safety, doselimiting toxicity (DLT), recommended phase 2 dose, pharmacokinetic and pharmacodynamic (PD) parameters, and antitumor activity per RECIST 1.1.

27 pts (median age 66 years [range 33-85]; median of 4 prior systemic therapies [range 2-9]) with ovarian (70%), fallopian tube (15%) or primary peritoneal (15%) cancer were dosed with SL-172154.

FIG. 1C shows the details of the study population. FIG. 1D shows the details of the tumor characteristics.

Briefly, the eligibility criteria were as follows:

Illustrative Inclusion Criteria were: • Histologically confirmed unresectable, locally advanced or metastatic ovarian cancer, primary peritoneal cancer or fallopian tube cancer

• Refractory to existing therapy(ies) and ineligible for further platinum therapy

• Age 18 years or older

• ECOG performance status of 0 or 1

• Measurable disease per RECIST v1 .1

Illustrative Study Objectives were as follows:

• Evaluate the safety and tolerability of SL-172154

• Identify a recommended Phase 2 dose (RP2D) for SL-172154

• Characterize pharmacokinetics (PK), pharmacodynamics (PD) and immunogenicity of SL-172154

• Assess preliminary anti-tumor activity

Enrollment was carried out as follows:

• 27 subjects with platinum resistant ovarian cancers were treated with SL-172154, administered by IV infusion

• 9 subjects were treated on schedule 1

• 18 subjects were treated on schedule 2

Illustrative Exclusion Criteria were as follows:

• Primary platinum refractory as defined by progressing during or within 1 month of upfront platinum therapy

• Prior treatment with an anti-CD47 or anti -S I RPo targeting agent or a CD40 agonist

• Documented history of autoimmune disease or active pneumonitis

• Concurrent use of systemic corticosteroids or other immunosuppressive medication.

These results demonstrate, inter alia, that SL-172154 was overall well-tolerated in patients with heavily pretreated platinum resistant ovarian cancer. IRRs were the most common drug related AE and were readily manageable. A DLT of ALT increase was reported in one subject at 10.0 mg/kg dose.

Example 2: Observed Efficacy and Adverse Events in the Clinical Trial

The best response among 27 efficacy evaluable subjects with post-baseline scan was Stable Disease (SD) in 6 (22%) subjects. Median duration of SD was 138 days (range: 50 to 252 days). Adverse events (AEs) were documented. FIG. 1 E tabulates all causality AEs observed in >3 subjects. FIG. 1 F shows the drug-related AEs (any grade) observed in >10% subjects. The following was noted regarding the overall adverse event (AE) profile:

• A dose dependency in the overall AE profile was noted

• One DLT at 10.0 mg/kg of Grade (G) 3 ALT increase was observed

• G3/4 drug-related AEs (>1 subject): AST increased (G3) and lymphopenia (G4), all were fully resolved with no dose modifications. Treatment was delayed for one subject for G3 ALT increase. These events occurred at doses of 3.0 mg/kg or 10.0 mg/kg.

• No fatal AEs

• No AEs that led to drug discontinuation

• SAEs: 7 events reported in 6 (22%) subjects: embolism (2), sepsis (2), large intestine infection, lower Gl hemorrhage and small intestinal obstruction. None were considered related to SL-172154.

Infusion Related Reactions (IRR): 45 drug-related IRRs were reported from 18 subjects (67%).

• All drug-related IRRs were G1/2 events except one G3 IRR. Infusion was interrupted for G3 IRR and the subject was treated with steroids. The event resolved the same day.

• Severity and frequency of IRRs events were dose-dependent and correlated with rate of infusion

• At < 3.0 mg/kg, IRRs were typically limited to Cycle 1 Day 1 (C1 D1), C1 D8. At 10.0 mg/kg IRRs were recurrent, occurring beyond C1 D1, C1 D8

• All IRRs occurred either during the infusion or within 2 hrs after the end of infusion, except one event which occurred between 2 and 24 hrs after the end of infusion

• Most IRRs did not prevent completion of infusion, except 2 events

• Common symptoms of the IRR events variably included fever, chills, rigors, back pain, rash, hyper/ hypotension, tachycardia, nausea, and visual symptoms

• No IRRs led to discontinuation of SL-172154

• No evidence for cytokine release syndrome (no appreciable increases in IL-6 and TNFa)

Thus, treatment-emergent AEs (>15%) regardless of grade (G) included infusion related reaction (IRR) (67%), fatigue (44%), nausea (33%), back pain (26%), constipation, diarrhea (both 22%), decreased appetite and pruritus (both 19%). There was one DLT of G3 ALT increased at 10 mg/kg requiring dose interruption for resolution. A maximum tolerated dose was not reached. G3/4 treatment-related AEs (>1 patients) were AST increased (G3) and lymphopenia (G4), each in 2 pts (7%); all were fully resolved with no dose modifications. There were no fatal AEs, no AEs that led to drug discontinuation and no events of cytokine release syndrome. The frequency of IRR events increased with increasing dose, and slowing the rate of infusion was utilized for mitigation.

SL-172154 Cmax and AUC increased with dose with greater than proportional exposure noted at 3 and 10 mg/kg potentially due to target saturation. These findings were supported by dose-dependent target engagement of CD47 and CD40 on CD4 T cells and B cells respectively, approaching 100% by the 3 mg/kg dose level. Rapid dose-dependent egress of CD40+ B cells was maximal at >3 mg/kg. SL-172154 induced dose-dependent responses in IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22, which also approached a plateau at >3 mg/kg. Analysis of peripheral and tumor immunophenotypes and anti-drug antibodies in response to SL-172154 is ongoing. Best response per RECIST 1.1 was stable disease in 6/27 response evaluable (22%) pts.

These results suggest, inter alia, that SL-172154 is well tolerated in heavily pretreated PROC pts. IRRs were readily manageable. Maximal CD47 and CD40 target engagement and CD40-dependent PD effects were observed with >3 mg/kg SL-172154. 3 mg/kg is a safe, tolerable, and pharmacologically active dose for evaluation in combination studies in pts with PROC.

Low-titer anti-drug antibody (ADA) responses were detected in 8/25 evaluable subjects. No evidence of accelerated drug clearance, IRRs, or reductions in pharmacodynamic activity were detected in association with ADA.

Example 3: Pharmacokinetics of the SIRPa-Fc-CD40L Chimeric Protein (SL-172154)

Pharmacokinetic studies were performed by assaying quantifying the amount of SL-172154 at various times. The amounts of SL-172154 was plotted as a function of time. As shown in FIG. 2A, maximal concentrations were observed near the start of infusion, and the concentration gradually decreased. Cmax, which is the maximum observed concentration, was determined for each dose. Similarly, AUC, which is the area under the curve, time 0 to last time point where SL-172154 was above 10 mg/ml were calculated. SL-172154 Cmax and AUC increased with dose with greater than proportional exposure noted at 3 and 10 mg/kg (FIG. 2B). FIG. 2C shows dose-normalized PK parameters at Cycle 1 Day 1 (C1 D1) (left panels), Cycle 1 Day 15 (C1 D1) (middle panels), and Cycle 2 Day 1 (C1 D1) (right panels). Cmax/D (top panels) and AUCiast/D (bottom panels) are shown. FIG. 2D shows dose-normalized Cmax, which is the maximum observed concentration. FIG. 2E shows dose-normalized AUCiast, which is the area under the curve, time 0 to last concentration. SL-172154 exhibited greater than dose proportional pharmacokinetics at or above 3 mg/kg. Without wishing to be bound by theory, it is believed that the observed nonlinear increase in Cmax and AUC is largely due to target mediated drug disposition (binding to CD47 and CD40 receptors), and impacted by CD40 mediated pharmacodynamic effects such as rapid cell egress, receptor mediated endocytosis etc.

These results suggest, inter alia, that the PK parameters for SL-172154 suggest greater than dose proportional increase in exposure at > 3.0 mg/kg dose and target-mediated drug disposition via receptor binding.

Example 4: Engagement of CD40 and CD47 receptors by the SIRPo-Fc-CD40L Chimeric Protein (SL- 172154)

Pharmacodynamic studies were performed by assaying the effects of SL-172154 on CD40⁺ and CD47⁺ cells. The amounts of SL-172154 was plotted as a function of time. FIG. 3A and FIG. 3B demonstrate that SL- 172154 engages with the CD40 located on the B cells. B cells represent a large pool of circulating immune cells expressing elevated levels of CD40. Fluorescence activated cell sorting (FACS) panels were designed to interrogate CD40 receptor occupancy. On C1 D1 , nearly all (-80%) CD40+ B cells marginated, or exited the circulation, within one-hour post-infusion. Therefore, B cell engagement was studied using a formula shown in in FIG. 3A (bottom panel). Receptor engagement is -100% at all dose levels (FIG. 3A (top panel)). FIG. 3B shows dose-dependent egress of CD40+ B cells. These results demonstrate, inter alia, that SL- 172154 binds to B cell and stimulates B cell margination

FIG. 4A and FIG. 4B demonstrate the binding of SL-172154 to CD47⁺ cells. FIG. 4A shows percentage receptor occupancy of CD47 on CD4 T cell with maximal occupancy noted between 1 mg/Kg and 3 mg/Kg. Without wishing to be bound by theory, the reduction of receptor occupancy seen at 10 mg/Kg may be due to CD4 T cell egress. FIG. 4B shows the CD47 receptor saturation on CD4 T cells. These results indicate, inter alia, a dose dependent increase in CD47 receptor saturation on CD4 T cells, approaching 100% by > 3.0 mg/kg dose. Egress of CD4 T cells from the circulation was observed as a secondary pharmacodynamic effect of CD40 agonism. Without wishing to be bound by theory, the observed egress of CD4 T cells from the circulation may contribute to the observed variability in CD47 receptor saturation.

The numbers of CD4 T cells were also counted and compared pre- and post-dosing. As shown in FIG. 7A to FIG. 7C, a dose-dependent egress of CD4 T cells was observed. Without wishing to be bound by theory, the reduction of receptor occupancy seen at 10 mg/Kg may be due to CD4 T cell egress. Example 5: Cytokine Responses Induced by the SIRPa-Fc-CD40L Chimeric Protein (SL-172154)

Cytokine responses were measured as a function predose and at various time points pose dose. FIG. 6A shows that SL-172154 induced dose-dependent responses in IL-12 after the first infusion. Specifically, IL-12 change over C1 D1 predose showed a dose-dependent increase, approaching a plateau at >3 mg/kg. FIG. 6B shows that the mean IL-12 concentrations over time. Cyclical increases in IL-12, a mediator of TH1 proinflammatory responses is observed in study subjects. FIG. 6C shows that SL-172154 induced dosedependent responses in CXCL-8 which approached a plateau at >3 mg/kg. Specifically, CXCL-8 change over C1 D1 predose is shown. FIG. 6D shows that SL-172154 induced dose-dependent responses in CXCL- 8 after the first infusion. Specifically, CXCL-8 change over C1 D1 predose showed a dose-dependent increase, approaching a plateau at >3 mg/kg. FIG. 6E shows that SL-172154 induced dose-dependent responses in CXCL-10 which approached a plateau at ^3 mg/kg. Specifically, CXCL-10 change over C1 D1 predose is shown. FIG. 6F shows that SL-172154 induced dose-dependent responses in CXCL-8 after the first infusion. Specifically, CXCL-10 change over C1 D1 predose showed a dose-dependent increase, approaching a plateau at >3 mg/kg. FIG. 6G shows that SL-172154 induced dose-dependent responses in IL-10 which approached a plateau at >3 mg/kg. Specifically, IL-10 change over C1 D1 predose is shown. FIG. 6H shows that SL-172154 induced dose-dependent responses in IL-10 after the first infusion. Specifically, IL-10 change over C1 D1 predose showed a dose-dependent increase, approaching a plateau at >3 mg/kg. FIG. 6I shows that SL-172154 induced dose-dependent responses in CCL2 which approached a plateau at >3 mg/kg. Specifically, CCL2 change over C1 D1 predose is shown. FIG. 6J shows that SL-172154 induced dose-dependent responses in CCL20 which approached a plateau at >3 mg/kg. Specifically, CCL20 change over C1 D1 predose is shown. FIG. 6K shows that SL-172154 induced dose-dependent responses in CCL22 which approached a plateau at >3 mg/kg. Specifically, CCL22 change over C1 D1 predose is shown.

These results suggest, inter alia, cyclical increases in innate and adaptive serum cytokines consistent with CD40 receptor engagement and activation. There were no appreciable increases in IL-6 or TNFa, nor evidence of bell-shaped dose responses.

These results indicate, inter alia, dose-dependent increases of other on-target cytokines including CXCL-10, CCL-22, CXCL-8, and IL-10 are observed following SL-172154 administration. Similar to IL-12, these cytokine responses are persistent with each infusion. Example 6: Stimulation of Dose-Dependent Margination ofB cells, Monocytes and CD4 T cells by the SIRPa- Fc-CD40L Chimeric Protein (SL-172154)

The localization of lymphocytes following the treatment with SL-172154 was explored. Blood samples were obtained pre-dose, and 1 hour post-dose and 24 hour post-dose treated from patients with different doses and were subjected to lymphocyte counts. The changes in lymphocyte counts 1 hour post-dose, and 24 hour post-dose compared to the pre-dose sample was evaluated. As shown in FIG. 7A, the B cells rapidly marginated from the circulation post infusion in a dose-dependent manner. Maximal B cell margination was observed at 3 mg/kg and 10 mg/kg doses (FIG. 7A). Interestingly, unlike the lower doses, the patients treated with higher doses of SL-172154 showed reduced numbers of B cells returning to blood in the 24-hour blood samples (FIG. 7A). As shown in FIG. 7B, the CD40 expressing monocytes rapidly marginated from the circulation post infusion in a dose-dependent manner. Maximal margination of CD40 expressing monocytes was observed at 3 mg/kg and 10 mg/kg doses (FIG. 7B). Interestingly, unlike the lower doses, the patients treated with higher doses of SL-172154 showed reduced numbers of CD40 expressing monocytes returning to blood in the 24-hour blood samples (FIG. 7B). As shown in FIG. 7C, the CD4 T cells rapidly marginated from the circulation post infusion in a dose-dependent manner. Maximal margination of CD4 T cells was observed at 3 mg/kg and 10 mg/kg doses (FIG. 7C). Interestingly, unlike the lower doses, the patients treated with higher doses of SL-172154 showed reduced numbers of CD4 T cells returning to blood in the 24-hour blood samples (FIG. 70).

These results suggest, inter alia, that the high receptor occupancy was observed for SL-172154 on CD47+ CD4T cells. These results also suggest, inter alia, the binding of SL-172154 to CD40+B cells and monocytes led to rapid activation and margination post infusion.

Given than doses of >3 mg/kg were efficacious, these results demonstrate, inter alia, a correlation between efficacy and the prolonged margination (e.g., for >24 hr) of B cells, CD40 expressing monocytes, and CD4 T cells.

Example 7: Correlation of the Pharmacological Activity of the SIRPa-Fc-CD40L Chimeric Protein (SL- 172154) with the Simulation in B cell Margination and IL-12 Stimulation

The change in B cell margination was modeled in a PK/PD model. As shown in FIG. 8A, B cell margination showed a dose-dependent increase till about 3 mg/kg dose. Near maximal egress of B cells is reached at 3.0 mg/kg and did not change at 10.0 mg/kg (FIG. 8A), at the doses that show pharmacological activity. Given than doses of >3 mg/kg were efficacious, these results demonstrate, inter alia, a correlation between efficacy and the B cell margination.

The change in IL-12 levels was modeled in a PK/PD model. As shown in FIG. 8B, IL-12 induction showed a dose-dependent increase till about 3 mg/kg dose. IL-12 levels trended towards a plateau at >3.0 mg/kg (FIG. 8B). Given than doses of >3 mg/kg were efficacious, these results demonstrate, inter alia, a correlation between efficacy and the IL-12 induction.

Collectively, these results suggest, inter alia, that efficacy corelates with a combination of the B cell margination and IL-12 induction. These results suggest, inter alia, that the PK/PD modeling supports a 3.0 mg/kg as a dose for evaluation, including, e.g., in combination studies.

Example 8: Induction of Polarization to M1 Macrophages and Infiltration of Cytotoxic T cells in the Tumor Nest by the SIRPa-Fc-CD40L Chimeric Protein (SL-172154).

SL-172154 was administered to an ovarian cancer patient. A tumor biopsy sample was obtained from the patient prior to and after the administration of SL-172154. The biopsy samples were analyzed for CD68, CD206, MHC II, CD3, CD8 and granzyme B-expressing cells. Tumor samples SL-172154 at high dose levels (3.0 mg/kg [n=4 ] and 10.0 mg/kg [n=1]). As shown in FIG. 9A, CD68, CD206, MHC II, CD3, CD8 and granzyme B-expressing cells increased in tumor following the administration of SL-172154. M1 and M2 macrophages were analyzed in tumor stroma and tumor nest. As shown in FIG. 9B, the administration of SL- 172154 induced a shift in macrophages from an M2 to an M1 dominant phenotype both in the stroma and in the tumor nest. In contrast, at low dose levels (0.1 mg/kg [n=1], 0.3 and 1.0 mg/kg [n=3 each]) the M2 dominant phenotype persisted before and after treatment. Granzyme B producing-T cells were analyzed in tumor stroma and tumor nest. As shown in FIG. 9C, the frequencies of granzyme B producing-T cells increased in the tumor nest and tumor stroma in subjects in the high dose group compared to those in low dose group the administration of SL-172154.

These results suggest, inter alia, that polarization towards an M1 macrophage phenotype was observed in the tumor biopsies at the higher doses of 3.0 mg/kg and 10.0 mg/kg consistent with the mechanism of action, and was associated with an increase in cytotoxic T cells in tumor nest.

These results suggest, inter alia, that SL-172154 has been well-tolerated at doses which saturate both CD40 and CD47, with evidence of on-target PD activity which plateaus at dose of > 3.0 mg/kg. INCORPORATION BY REFERENCE

All patents and publications referenced herein are hereby incorporated by reference in their entireties.

The publications discussed herein are provided solely fortheir disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present disclosure is not entitled to antedate such publication by virtue of prior invention.

As used herein, all headings are simply for organization and are not intended to limit the disclosure in any manner. The content of any individual section may be equally applicable to all sections.

EQUIVALENTS

While the invention has been disclosed in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth and as follows in the scope of the appended claims. Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, numerous equivalents to the specific embodiments disclosed specifically herein. Such equivalents are intended to be encompassed in the scope of the following claims.

Claims

CLAIMS What is claimed is:

1 . A method for treating a cancer in a human subject, the method comprising:

(i) administering to the human subject a first dose of a chimeric protein having a general structure of: N terminus - (a) - (b) - (c) - C terminus, wherein:

(a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPa)),

(b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge- CH2-CH3 Fc domain, and

(c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein the dose of the chimeric protein is administered at a dosage of at least about 0.3 mg/kg.

2. The method of claim 1 , wherein the chimeric protein is administered at the dosage of about 1 mg/kg.

3. The method of claim 1 , wherein the chimeric protein is administered at the dosage of about 3 mg/kg.

4. The method of claim 1 , wherein the chimeric protein is administered at the dosage of about 10 mg/kg.

5. A method for treating a cancer in a human subject, the method comprising:

(i) administering to the human subject a first dose at a dosage of at least about 0.3 mg/kg of a chimeric protein having a general structure of:

N terminus - (a) - (b) - (c) - C terminus, wherein:

(c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a background level and/or activity of CD40+ B cells has been measured in a pre-dose blood sample obtained from the subject before the administration of the first dose, wherein a post-dosing level and/or activity of CD40+ B cells has been measured in a blood sample obtained from the subject after at least 15 minutes after administering the first dose; and

(ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if the post-dosing level and/or activity of CD40+ B cells is at least about 60% lower compared to the background level and/or activity, or administering to the human subject a second dose of the chimeric protein at a higher dosage than the dosage of the first dose if the post-dosing level and/or activity of CD40+ B cells is less than about 80% lower compared to the background level and/or activity, wherein the second dose is administered at least about 48 hours after the administration of the first dose.

6. The method of claim 5, wherein the post-dosing level and/or activity is measured less than about 12, or less than about 8, or less than about 6, or less than about 4, or less than about 3, or less than about 2, or less than about 1 hours post dosing.

7. The method of claim 5 or claim 6, wherein the second dose comprises substantially the same dosage as the first dose if the post-dosing level and/or activity of CD40+ B cells is lower compared to the background level and/or activity by at least about 60%, or at least about 65%, or at least about 70%, or at least about 75%, or at least about 80%, or at least about 85%, or at least about 90%, or at least about 95% or more.

8. The method of any one of claim 5 or claim 6, wherein the second dose comprises an increased dosage compared to the first dose if the post-dosing level and/or activity of CD40+ B cells is the chimeric protein lower compared to the background level and/or activity by less than about 70%, or less than about 60%, or less than about 50%, or less than about 40%.

9. The method of any one of claims 5 to 8, wherein the level and/or activity of CD40+ B cells is measured by contacting the sample with an agent that specifically binds to CD40 protein, a fragment and/or an epitope thereof and/or a B-cell marker, a fragment and/or an epitope thereof.

10. The method of claim 9, wherein the B-cell marker is selected from CD19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD.

11. The method of claim 9 or claim 10, wherein the agent that specifically binds to CD40 protein, the fragment and/or the epitope thereof, and/or the B-cell marker, the fragment and/or the epitope thereof is an antibody or fragment thereof.

12. The method of claim 11, wherein the antibody is a recombinant antibody, a monoclonal antibody, a polyclonal antibody, or fragment thereof.

13. The method of any one of claims 9 to 12, wherein the level and/or activity of CD40+ B cells is measured by immunohistochemical staining, western blotting, in cell western, immunofluorescent staining, ELISA, and fluorescent activating cell sorting (FACS) or a combination thereof.

14. The method of any one of claims 5 to 8, wherein the level and/or activity of CD40+ B cells is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding a CD40 and/or a B-cell marker.

15. The method of claim 14, wherein the B-cell marker is selected from CD19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD.

16. The method of claim 14 or claim 15, wherein the agent that specifically binds to one or more of the nucleic acids is a nucleic acid primer.

17. The method of claim 14 or claim 15, wherein the agent that specifically binds to one or more of the nucleic acids is a nucleic acid probe.

18. The method of claim 16 or 17, wherein the level and/or activity of CD40+ B cells is measured by polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR), quantitative PCR (qPCR), multiplex polymerase chain reaction, nested polymerase chain reaction, hot start polymerase chain reaction, long-range PCR, assembly polymerase chain reaction, asymmetric polymerase chain reaction, digital droplet PCR, a recombinase polymerase amplification (RPA), a loop-mediated amplification (LAMP), a helicase-dependent amplification (HDA), RNA or DNA gel electrophoresis or Southern or Northern blotting, a microarray-based assay, a hybridization technique, optionally selected from solution hybridization, capillary hybridization, hybridization to nucleic acid arrays, optionally macroarrays, microarrays or high- density oligonucleotide arrays (Gene Chips).

19. The method of any one of claims 5 to 18, wherein the chimeric protein is administered at the dosage of about 1 mg/kg.

20. The method of any one of claims 5 to 19, wherein the chimeric protein is administered at the dosage of about 3 mg/kg.

21 . A method for treating a cancer in a human subject, the method comprising:

N terminus - (a) - (b) - (c) - C terminus, wherein:

(b) is a linker adjoining the first and second domains, wherein the linker comprises a hinge-CH2-CH3 Fc domain, and

(c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a post-dosing level and/or activity of one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 have been measured a blood, serum or plasma sample obtained from the subject after at least 15 minutes after administering the first dose; and

(ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if: the post-dosing level and/or activity of IL-12 is at least about 3-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, at least about 8-fold greater, at least about 9-fold greater, at least about 10-fold greater, at least about 11 -fold greater, or at least about 12-fold greater), the post-dosing level and/or activity of CXCL-8 is at least about 3-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, at least about 8-fold greater, at least about 9-fold greater, at least about 10-fold greater, at least about 11 -fold greater, at least about 12-fold greater, at least about 13-fold greater, at least about 14-fold greater, or at least about 15-fold greater), the post-dosing level and/or activity of CXCL-10 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g., at least about 2-fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, or at least about 6-fold greater), the post-dosing level and/or activity of IL-10 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g., at least about 2-fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 10-fold greater, or at least about 20-fold greater), the post-dosing level and/or activity of CCL2 is at least at least about 4-fold greater than a pre-dose amount or post-first dose amount (e.g., at least about 4-fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7- fold greater, or at least about 8-fold greater), the post-dosing level and/or activity of CCL20 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g., at least about 2-fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 10-fold greater, or at least about 20-fold greater), and/or the post-dosing level and/or activity of CCL22 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g., at least about 2-fold greater, at least about 3-fold greater, or at least about 4-fold greater); or administering to the human subject a second dose of the chimeric protein at a higher dosage than the dosage of the first dose if the post-dosing level and/or activity of IL-12 is equal or less than about 2-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CXCL-8 is equal or less than about 2-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CXCL-10 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of IL-10 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CCL2 is equal or less than about 3-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CCL20 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, and/or the post-dosing level and/or activity of CCL22 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount; wherein the second dose is administered at least about 48 hours after the administration of the first dose.

22. The method of claim 21 , wherein the post-dosing level and/or activity is measured less than 12, or less than 8, or less than 6, or less than 4, or less than 3, or less than 2, or less than 1 hours post dosing.

23. The method of claim 21 or claim 22, wherein the second dose comprises substantially the same dosage as the first dose if: the post-dosing level and/or activity of IL-12 is at least about 3-fold greater than a pre-dose amount or post-first dose amount (e.g. at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, at least about 8-fold greater, at least about 9-fold greater, at least about 10-fold greater, at least about 11 -fold greater, or at least about 12-fold greater), the post-dosing level and/or activity of CXCL-8 is at least about 3-fold greater than a predose amount or post-first dose amount (e.g. at least about 3-fold greater, at least about 4- fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, at least about 8-fold greater, at least about 9-fold greater, at least about 10-fold greater, at least about 11 -fold greater, at least about 12-fold greater, at least about 13-fold greater, at least about 14-fold greater, or at least about 15-fold greater), the post-dosing level and/or activity of CXCL-10 is at least about 2-fold greater than a predose amount or post-first dose amount (e.g., at least about 2-fold greater, at least about 3- fold greater, at least about 4-fold greater, at least about 5-fold greater, or at least about 6- fold greater), the post-dosing level and/or activity of IL-10 is at least about 2-fold greater than a pre-dose amount or post-first dose amount (e.g., at least about 2-fold greater, at least about 3-fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 10-fold greater, or at least about 20-fold greater), the post-dosing level and/or activity of CCL2 is at least at least about 4-fold greater than a pre-dose amount or post-first dose amount (e.g., at least about 4-fold greater, at least about 5-fold greater, at least about 6-fold greater, at least about 7-fold greater, or at least about 8-fold greater), the post-dosing level and/or activity of CCL20 is at least about 2-fold greater than a predose amount or post-first dose amount (e.g., at least about 2-fold greater, at least about 3- fold greater, at least about 4-fold greater, at least about 5-fold greater, at least about 10- fold greater, or at least about 20-fold greater), and/or the post-dosing level and/or activity of CCL22 is at least about 2-fold greater than a predose amount or post-first dose amount (e.g., at least about 2-fold greater, at least about 3- fold greater, or at least about 4-fold greater).

24. The method of any one of claim 21 or claim 23, wherein the second dose comprises an increased dosage compared to the first dose if the post-dosing level and/or activity of IL-12 is equal or less than about 2-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CXCL-8 is equal or less than about 2-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CXCL-10 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of IL-10 is equal or less than about 1 -fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CCL2 is equal or less than about 3-fold greater than a pre-dose amount or post-first dose amount, the post-dosing level and/or activity of CCL20 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount, and/or the post-dosing level and/or activity of CCL22 is equal or less than about 1-fold greater than a pre-dose amount or post-first dose amount.

25. The method of any one of claims 21 to 24, wherein the level and/or activity of one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 is measured by contacting the sample with an agent that specifically binds to one or more of IL-12 protein, CXCL-8 protein, CXCL-10 protein, IL-10 protein, CCL2 protein, CCL20 protein, and CCL22 protein, a fragment and/or an epitope thereof.

26. The method of claim 25, wherein the agent that specifically binds to the one or more of IL-12 protein, CXCL-8 protein, CXCL-10 protein, IL-10 protein, CCL2 protein, CCL20 protein, and CCL22 protein, the fragment and/or the epitope thereof is an antibody or fragment thereof.

27. The method of 25 or claim 26, wherein the antibody is a recombinant antibody, a monoclonal antibody, a polyclonal antibody, or fragment thereof.

28. The method of any one of claims 25 to 27, wherein the level and/or activity of one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 is measured by immunohistochemical staining, western blotting, in cell western, immunofluorescent staining, ELISA, and fluorescent activating cell sorting (FACS) or a combination thereof.

29. The method of any one of claims 21 to 24, wherein the level and/or activity of one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding one or more of IL-12, CXCL-8, CXCL-10, IL-10, CCL2, CCL20, and CCL22 and/or one or more nucleic acids complementary thereto.

30. The method of claim 29, wherein the agent that specifically binds to one or more of the nucleic acids is a nucleic acid primer or probe.

31. The method of claim 30, wherein the level and/or activity of one or more of IL-12, CXCL-8, CXCL- 10, IL-10, CCL2, CCL20, and CCL22 is measured by polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR), quantitative PCR (qPCR), multiplex polymerase chain reaction, nested polymerase chain reaction, hot start polymerase chain reaction, long-range PCR, assembly polymerase chain reaction, asymmetric polymerase chain reaction, digital droplet PCR, a recombinase polymerase amplification (RPA), a loop-mediated amplification (LAMP), a helicase-dependent amplification (HDA), RNA or DNA gel electrophoresis or Southern or Northern blotting, a microarray-based assay, a hybridization technique, optionally selected from solution hybridization, capillary hybridization, hybridization to nucleic acid arrays, optionally macroarrays, microarrays or high-density oligonucleotide arrays (Gene Chips).

32. The method of any one of claims 21 to 31 , wherein the chimeric protein is administered at the dosage of about 1 mg/kg.

33. The method of any one of claims 21 to 32, wherein the chimeric protein is administered at the dosage of about 3 mg/kg.

34. The method of any one of claims 1 to 33, wherein the first domain is capable of binding a CD172a (SIRPa) ligand and/ or the first domain comprises substantially all of the extracellular domain of CD172a (SIRPa).

35. A method for treating a cancer in a human subject, the method comprising:

N terminus - (a) - (b) - (c) - C terminus, wherein:

(c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a post-dosing level of CD47 receptor occupancy of CD4 T cells and/or CD40 receptor occupancy of B cells in a post-dose blood sample obtained from the subject have been measured after at least 15 minutes after administering the first dose; and

(ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if

(ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is at least about 60%, or administering to the human subject a second dose of the chimeric protein at a higher dosage than the dosage of the first dose if the post-dosing level and/or activity of CD40+ B cells is less than about 80% lower compared to the background level and/or activity, wherein the second dose is administered at least about 48 hours after the administration of the first dose.

36. The method of claim 35, wherein the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is measured less than 12, or less than 8, or less than 6, or less than 4, or less than 3, or less than 2, or less than 1 hours post dosing.

37. The method of claim 35 or claim 36, wherein the second dose comprises substantially the same dosage as the first dose if the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is at least about 65%, or at least about 70%, or at least about 75%, or at least about 80%, or at least about 85%, or at least about 90%, or at least about 95% or more.

38. The method of any one of claim 35 or claim 36, wherein the second dose comprises an increased dosage compared to the first dose if the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is less than about 70%, or less than about 60%, or less than about 50%, or less than about 40%.

39. The method of any one of claims 35 to 38, wherein the post-dosing level of CD47 occupancy of CD4 T cells and/or CD40 occupancy of B cells is measured using the following formula: %CRI @postdose

Receptor engagement =

%CR @ Predose wherein

%CR @ predose is the percentage of target receptor-expressing lymphocytes in a pre-dose blood sample obtained from the subject;

%CR @ postdose is the percentage of target receptor-expressing lymphocytes in the postdose blood sample; and

%CRI @ postdose is the percentage of the chimeric protein-bound CD47⁺ CD4⁺ T cells and/or the chimeric protein-bound CD40⁺ B cells in the post-dose blood sample, wherein: the presence, absence, or level of CD47⁺ CD4⁺ T cells and/or CD40⁺ B cells has been determined in the pre-dose blood sample, the presence, absence, or level of CD47⁺ CD4⁺ T cells and/or CD40⁺ B cells has been determined in the post-dose blood sample, and the presence, absence, or level of the chimeric protein-bound CD47⁺ CD4⁺ T cells and/or the chimeric protein-bound CD40⁺ B cells has been determined in the post-dose blood sample.

40. The method of claim 39, wherein the presence, absence, or level of CD47⁺ CD4⁺ T cells is measured by contacting the sample with an agent that specifically binds to one or more of CD47 protein, CD4 protein, and a T cell marker, or a fragment or an epitope thereof.

41 . The method of claim 40, wherein the T-cell marker is selected from CD3, CD4, CD8, CCR7, CD62L, CD45RA, CXCR3, CCR4, CCR5, FOXP3 and IL2RA (CD25).

42. The method of claim 39, wherein the presence, absence, or level of CD40+ B cells is measured by contacting the sample with an agent that specifically binds to CD40 protein and/or a B cell marker, or a fragment or an epitope thereof.

43. The method of claim 42, wherein the B-cell marker is selected from CD19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD.

44. The method of any one of claims 40 to 43, wherein the agent is an antibody or fragment thereof.

45. The method of claim 44, wherein the antibody is a recombinant antibody, a monoclonal antibody, a polyclonal antibody, or fragment thereof.

46. The method of any one of claims 40 to 45, wherein the level and/or activity of CD40+ B cells is measured by immunohistochemical staining, western blotting, in cell western, immunofluorescent staining, ELISA, and fluorescent activating cell sorting (FACS) or a combination thereof.

47. The method of claim 39, wherein the presence, absence, or level of CD47⁺ CD4⁺ T cells is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding CD47, CD4 and/or a T cell marker.

48. The method of claim 47, wherein the T-cell marker is selected from CD3, CD4, CD8, CCR7, CD62L, CD45RA, CXCR3, CCR4, CCR5, FOXP3 and IL2RA (CD25).

49. The method of claim 39, wherein the presence, absence, or level of CD40+ B cells is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding CD40 and/or a B cell marker.

50. The method of claim 49, wherein the B-cell marker is selected from CD19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD.

51 . The method of any one of claims 47 to 50, wherein the agent that specifically binds to one or more of the nucleic acids is a nucleic acid primer or probe.

52. The method of any one of claims 47 to 51 , wherein the presence, absence, or level of CD47⁺ CD4⁺ T cells and/or presence, absence, or level of CD40+ B cells is measured by polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR), quantitative PCR (qPCR), multiplex polymerase chain reaction, nested polymerase chain reaction, hot start polymerase chain reaction, long-range PCR, assembly polymerase chain reaction, asymmetric polymerase chain reaction, digital droplet PCR, a recombinase polymerase amplification (RPA), a loop-mediated amplification (LAMP), a helicase-dependent amplification (HDA), RNA or DNA gel electrophoresis or Southern or Northern blotting, a microarray-based assay, a hybridization technique, optionally selected from solution hybridization, capillary hybridization, hybridization to nucleic acid arrays, optionally macroarrays, microarrays or high-density oligonucleotide arrays (Gene Chips).

53. A method for treating a cancer in a human subject, the method comprising:

N terminus - (a) - (b) - (c) - C terminus, wherein:

(c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a background level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells has been measured in a pre-dose blood sample obtained from the subject before the administration of the first dose, wherein a post-dosing level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells has been measured in a blood sample obtained from the subject after at least about 12 hours after administering the first dose; and

(ii) administering to the human subject a second dose of the chimeric protein at substantially the same dosage as the first dose if the post-dosing level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is at least about 60% lower compared to the background level and/or activity, or administering to the human subject a second dose of the chimeric protein at a higher dosage than the dosage of the first dose if the post-dosing level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is at least about 60% lower compared to the background level and/or activity, wherein the second dose is administered at least about 48 hours after the administration of the first dose.

54. The method of claim 53, wherein the post-dosing level and/or activity is measured more than about 12, or more than about 16, or more than about 18, or more than about 24, or more than about 28, or more than about 32, or more than about 40, or more than about 48 hours post dosing.

55. The method of claim 53 or claim 54, wherein the second dose comprises substantially the same dosage as the first dose if the post-dosing level and/or activity of CD40+B cells, CD40 expressing monocytes and/or CD4 T cells is lower compared to the background level and/or activity by at least about 65%, or at least about 70%, or at least about 75%, or at least about 80%, or at least about 85%, or at least about 90%, or at least about 95% or more.

56. The method of claim 53 or claim 54, wherein the second dose comprises an increased dosage compared to the first dose if the post-dosing level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is the chimeric protein not lower compared to the background level and/or activity by less than about 55%, or less than about 50%, or less than about 40%, or less than about 30%, or less than about 20%.

57. The method of any one of claims 53 to 56, wherein the level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is measured by contacting the sample with an agent that specifically binds to CD47, CD40, CD4, a CD40+ B cell marker, a marker specific to CD40 expressing monocytes and/or a CD4 T cell marker.

58. The method of claim 57, wherein: the B-cell marker is selected from CD19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD, the marker specific to CD40 expressing monocytes is selected from CD163, CD192, CD14, CD11 b, CCR2, CD16, CD141 , CD11c, HLA-DR, and CCR7, and the CD4 T cell marker is selected from CD4, CD25, CD127, FoxP3, CCR4, Cith2, CCR6, CXCR5, CD39, CD45RA, CTLA-4, CD127, IL-2R, IL-4R, IL-9R, IL-15R, IL-21 R, and CD25.

59. The method of claim 57 or claim 58, wherein the agent that specifically binds to CD47, CD40, CD4, a CD40+ B cell marker, a marker specific to CD40 expressing monocytes and/or a CD4 T cell marker is an antibody or fragment thereof.

60. The method of claim 59, wherein the antibody is a recombinant antibody, a monoclonal antibody, a polyclonal antibody, or fragment thereof.

61 . The method of any one of claims 57 to 60, wherein the level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is measured by immunohistochemical staining, western blotting, in cell western, immunofluorescent staining, ELISA, and fluorescent activating cell sorting (FACS) or a combination thereof.

62. The method of any one of claims 57 to 60, wherein the level and/or activity of CD40+ B cells, CD40 expressing monocytes and/or CD4 T cells is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding CD47, CD40, CD4, a CD40+ B cell marker, a marker specific to CD40 expressing monocytes and/or a CD4 T cell marker.

63. The method of claim 62, wherein: the B-cell marker is selected from CD19, CD20, CD24, CD27, CD34, CD38, CD45, CD86, CD95, IgM, and IgD, the marker specific to CD40 expressing monocytes is selected from CD163, CD192, CD14, CD11 b, CCR2, CD16, CD141 , CD11c, HLA-DR, and CCR7, and the CD4 T cell marker is selected from CD4, CD25, CD127, FoxP3, CCR4, Cith2, CCR6, CXCR5, CD39, CD45RA, CTLA-4, CD127, IL-2R, IL-4R, IL-9R, IL-15R, IL-21 R, and CD25.

64. The method of claim 62 or claim 63, wherein the agent that specifically binds to one or more of the nucleic acids is a nucleic acid primer.

65. The method of claim 63 or claim 64, wherein the agent that specifically binds to one or more of the nucleic acids is a nucleic acid probe.

66. The method of claim 63 or 64, wherein the level and/or activity of CD40+ B cells is measured by polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR), quantitative PCR (qPCR), multiplex polymerase chain reaction, nested polymerase chain reaction, hot start polymerase chain reaction, long-range PCR, assembly polymerase chain reaction, asymmetric polymerase chain reaction, digital droplet PCR, a recombinase polymerase amplification (RPA), a loop-mediated amplification (LAMP), a helicase-dependent amplification (HDA), RNA or DNA gel electrophoresis or Southern or Northern blotting, a microarray-based assay, a hybridization technique, optionally selected from solution hybridization, capillary hybridization, hybridization to nucleic acid arrays, optionally macroarrays, microarrays or high- density oligonucleotide arrays (Gene Chips).

67. The method of any one of claims 53 to 66, wherein the chimeric protein is administered at the dosage of about 1 mg/kg.

68. The method of any one of claims 53 to 67, wherein the chimeric protein is administered at the dosage of about 3 mg/kg.

69. A method for treating a cancer in a human subject, the method comprising:

(i) administering to the human subject a first dose of a chimeric protein having a general structure of:

N terminus - (a) - (b) - (c) - C terminus, wherein:

(a) is a first domain comprising an extracellular domain of human signal regulatory protein a (CD172a (SIRPo)),

(c) is a second domain comprising an extracellular domain of human CD40 ligand (CD40L), wherein a background amount and/or activity of M1 macrophages, M2 macrophages and/or granzyme B producing-T cells has been measured in a pre-dose biological sample obtained from the subject before the administration of the first dose, and wherein a post-dose amount and/or activity of M1 macrophages, M2 macrophages and/or granzyme B producing-T cells has been measured in a pre-dose biological sample obtained from the subject before the administration of the first dose;

(ii) administering to the human subject a second dose of the chimeric protein if: a post-dosing ratio of amount and/or activity of the M1 macrophages to M2 macrophages is greater than a pre-dose ratio of amount and/or activity of the M1 macrophages to M2 macrophages, and/or the post-dosing amount and/or activity of the granzyme B producing-T cells is greater than the background amount and/or activity of the granzyme B producing-T cells, wherein the second dose is administered at least about 48 hours after the administration of the first dose.

70. The method of claim 69, wherein the post-dosing level and/or activity is measured more than about 12, or more than about 16, or more than about 18, or more than about 24, or more than about 28, or more than about 32, or more than about 40, or more than about 48 hours, or more post dosing.

71. The method of claim 69 or claim 70, wherein the second dose comprises substantially the same dosage as the first dose if: the post-dosing amount and/or activity of the granzyme B producing-T cells is greater than the background amount and/or activity of the granzyme B producing-T cells by at least about 1 .25x, or at least about 1.5*, or at least about 2x, or at least about 5*, or at least about 10x, or more, and/or the post-dosing ratio of amount and/or activity of the M1 macrophages to M2 macrophages is greater than the pre-dose ratio of amount and/or activity of the M1 macrophages to M2 macrophages by at least about 1.25x, or at least about 1 .5x, or at least about 2x, or at least about 5x, or at least about 10x, or more; and wherein the second dose comprises an increased dosage compared to the first dose if: post-dosing amount and/or activity of the granzyme B producing-T cells is not greater than the background amount and/or activity of the granzyme B producing-T cells by at least about 1 .2x, or at least about 1 x, or less, and/or the post-dosing ratio of amount and/or activity of the M1 macrophages to M2 macrophages is not greater than the pre-dose ratio of amount and/or activity of the M1 macrophages to M2 macrophages by at least about 1 .2x, or at least about 1 x.

72. The method of any one of claims 69 to 71 , wherein the biological sample is selected from blood, plasma, serum, blood cells, lacrimal fluid, tears, bone marrow, ascites, tissue or fine needle biopsy sample, cell-containing body fluid, free floating nucleic acids, sputum, saliva, urine, cerebrospinal fluid, peritoneal fluid, pleural fluid, feces, lymph, gynecological fluid, skin swab, vaginal swab, oral swab, nasal swab, washing or lavage, aspirate, scraping, bone marrow specimen, a biopsy specimen and a surgical specimen.

73. The method of claim 72, wherein the biological sample is a biopsy sample or a surgical specimen, optionally wherein the biological sample is a tumor biopsy sample or a tumor surgical specimen.

74. The method of claim 73, wherein the tumor biopsy sample or the tumor surgical specimen derived from a tumor selected ovarian cancer, fallopian tube cancer, peritoneal cancer, cutaneous squamous cell carcinoma (CSCC), and squamous cell carcinoma of the head and neck (SCCHN).

75. The method of any one of claims 69 to 74, wherein the level of the cell is measured by RNA sequencing, immunohistochemical staining, western blotting, in cell western, immunofluorescent staining, ELISA, and fluorescent activating cell sorting (FACS) or a combination thereof.

76. The method of claim 75, wherein the level of the cell is measured by contacting the sample with an agent that specifically binds to a marker specific to M1 macrophages, M2 macrophages and/or granzyme B producing-T cells.

77. The method of claim 76, wherein: the marker specific to M1 macrophages is selected from CD80, CD86, CD64, CD16, CD32, and nitric oxide synthase (iNOS), the marker specific to M2 macrophages is selected from CD163, CD206, CD68, arginase 1 (Arg1) and DECTIN-1 , and/or the marker specific to granzyme B producing-T cells is selected from granzyme B (GrzB), CD69 and integrin aE (CD103).

78. The method of claim 74 or claim 75, wherein the agent that specifically binds to the a marker specific to M1 macrophages, M2 macrophages and/or granzyme B producing-T cells is an antibody or fragment thereof.

79. The method of claim 78, wherein the antibody is a recombinant antibody, a monoclonal antibody, a polyclonal antibody, or fragment thereof.

80. The method of any one of claims 69 to 79, wherein the level of the cell is measured by contacting the sample with an agent that specifically binds to one or more nucleic acids encoding a marker specific to M1 macrophages, M2 macrophages and/or granzyme B producing-T cells.

81 . The method of claim 80, wherein: the marker specific to M1 macrophages is selected from CD80, CD86, CD64, CD16, CD32, and nitric oxide synthase (iNOS), the marker specific to M2 macrophages is selected from CD163, CD206, CD68, arginase 1 (Arg1) and DECTIN-1 , and/or the marker specific to granzyme B producing-T cells is selected from granzyme B (GrzB), CD69 and integrin aE (CD103).

82. The method of claim 81 , wherein the agent that specifically binds to one or more of the nucleic acids is a nucleic acid primer or probe.

83. The method of claim 81 or 82, wherein the level and/or activity of CD40+ B cells is measured by polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR), quantitative PCR (qPCR), multiplex polymerase chain reaction, nested polymerase chain reaction, hot start polymerase chain reaction, long-range PCR, assembly polymerase chain reaction, asymmetric polymerase chain reaction, digital droplet PCR, a recombinase polymerase amplification (RPA), a loop-mediated amplification (LAMP), a helicase-dependent amplification (HDA), RNA or DNA gel electrophoresis or Southern or Northern blotting, a microarray-based assay, a hybridization technique, optionally selected from solution hybridization, capillary hybridization, hybridization to nucleic acid arrays, optionally macroarrays, microarrays or high- density oligonucleotide arrays (Gene Chips).

84. The method of any one of claims 69 to 83, wherein the chimeric protein is administered at the dosage of about 1 mg/kg.

85. The method of any one of claims 69 to 84, wherein the chimeric protein is administered at the dosage of about 3 mg/kg.

86. The method of any one of claims 1 to 85, wherein the chimeric protein is administered at the dosage of about 6 mg/kg or about 10 mg/kg.

87. The method of any one of claims 1 to 86, wherein the second domain is capable of binding a CD40 receptor.

88. The method of any one of claims 1 to 87, wherein the linker comprises a hinge-CH2-CH3 Fc domain derived from I gG4, optionally human lgG4.

89. The method of any one of claims 1 to 88, wherein the linker comprises an amino acid sequence that is at least about 90%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3.

90. The method of any one of claims 1 to 89, wherein the first domain comprises an amino acid sequence that is at least about 90%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% identical to the amino acid sequence of SEQ ID NO: 57.

91. The method of any one of claims 1 to 90, wherein the second domain comprises an amino acid sequence that is at least about 90%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% identical to the amino acid sequence of SEQ ID NO: 58.

92. The method of any one of claims 1 to 91 , wherein

(a) the first domain comprises the amino acid sequence of SEQ ID NO: 57,

(b) the second domain comprises the amino acid sequence of SEQ ID NO: 58, and

(c) the linker comprises an amino acid sequence that is at least about 90%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% identical to the amino acid sequence of SEQ ID NO: 1 , SEQ ID NO: 2, or SEQ ID NO: 3.

93. The method of any one of claims 1 to 92, wherein the chimeric protein further comprises the amino acid sequence of SEQ ID NO: 5 or SEQ ID NO: 7.

94. The method of any one of claims 1 to 93, wherein the chimeric protein further comprises the amino acid sequence of SEQ ID NO: 5 and SEQ ID NO: 7.

95. The method of any one of claims 1 to 94, wherein the chimeric protein comprises an amino acid sequence that is at least about 90%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% identical to the amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61.

96. The method of claim 95, wherein the chimeric protein comprises 1 , or 2, or 3, or 4, or 5, or 6, or 7, or 8 amino acid mutations with respect to an amino acid sequence of SEQ ID NO: 59 or SEQ ID NO: 61.

97. The method of any one of claims 1 to 96, wherein the human subject suffers from or is suspected to suffer from an advanced solid tumor or a lymphoma.

98. The method of any one of claims 1 to 97, wherein the human subject suffers from or is suspected to suffer from a cancer is selected from ovarian cancer, fallopian tube cancer, peritoneal cancer, cutaneous squamous cell carcinoma (CSCC), and squamous cell carcinoma of the head and neck (SCCHN).

99. The method of any one of claims 1 to 98, wherein the human subject has failed one or more platinumbased therapies.

100. The method of any one of claims 1 to 99, wherein the human subject is ineligible for a platinum therapy.

101 . The method of any one of claims 1 to 100, wherein the human subject is not receiving a concurrent chemotherapy, immunotherapy, biologic or hormonal therapy, and/or wherein the human subject has received, been tolerant to, or is ineligible for standard therapy and/or the cancer has no approved therapy considered to be standard of care.