Exosomes are cell-derived nanovesicles involved in regulating intercellular communications. In contrast to conventional nanomedicines, exosomes are characterized by unique advantages for therapeutic development. Despite their major successes in drug delivery, the full potential of exosomes for immunotherapy remains untapped. Herein we designed genetically engineered exosomes featured with surfaced-displayed antibody targeting groups and immunomodulatory proteins. Through genetic fusions with exosomal membrane proteins, Expi293F cell-derived exosomes were armed with monoclonal antibodies specific for human T-cell CD3 and epidermal growth factor receptor (EGFR) as well as immune checkpoint modulators, programmed death 1 (PD-1) and OX40 ligand (OX40L). The resulting genetically engineered multifunctional immune-modulating exosomes (GEMINI-Exos) can not only redirect and activate T cells toward killing EGFR-positive triple negative breast cancer (TNBC) cells but also elicit robust anti-cancer immunity, giving rise to highly potent inhibition against established TNBC tumors in mice. GEMINI-Exos represent candidate agents for immunotherapy and may offer a general strategy for generating exosome-based immunotherapeutics with desired functions and properties.

Introduction: Survivors of colorectal cancer (CRC) are at risk for late effects of therapy and recurrence of cancer. With recurrence rates ranging between 30−40%, follow-up care is needed for both early detection and management of late effects. Cancer care delivery for CRC patients was significantly disrupted by the SARS-CoV-2 pandemic, with decreases of 40% in such services in the United States between April 2020 and 2019. Survivors were left with fewer options for care, potentially causing increases in emergency room (ER) utilization. Methods: This cross-sectional study examined the patterns of ER utilization during the SARS-CoV-2 pandemic among young adult CRC survivors and assessed the relationship between self-reported care satisfaction and ER use. Eligible participants were colon or rectal cancer survivors diagnosed between 18−39 years of age, 6−36 months from diagnosis/relapse, English speaking and residing in the United States. Multivariable logistic regression assessed the association between patient care satisfaction and ER utilization, adjusting for pandemic factors. Covariates were chosen by significance of p < 0.1 at the univariate level and perceived clinical significance. Results: The overall sample (N = 196) had mean age (SD) 32.1 (4.5); 59% were male. Tumor location was colon or rectal in 42% and 57%, respectively, and the majority (56%) were diagnosed with stage 2 disease; 42.6% reported relapsed disease, and 20% had an ostomy. Most survivors (72.5%) had between 1−4 visits to an ER in the last 12 months and were categorized as normal utilizers. Approximately 24.7% of the sample had greater than 4 visits to the ER in the last 12 months and were categorized as super-utilizers. CRC survivors that reported a delay in their follow-up care as a result of the pandemic were two times (OR: 2.05, 95% CI 0.99, 4.24) more likely to be super-utilizers of the ER. Higher self-reported satisfaction with care was associated with a 13.7% lower likelihood of being a super-utilizer (OR: 0.86, 95%CI: −0.68, 1.09). Conclusions: This study found strong associations between delays in care, self-reported care satisfaction, and being a super-utilizer of the ER during the pandemic among young adult CRC survivors off treatment. Increasing patient satisfaction and minimizing care interruptions amongst this vulnerable population may aid in mitigating over-utilization in the ER during an ongoing pandemic.

Purpose

MAVERICC compared the efficacy and safety of modified leucovorin/5-fluorouracil/oxaliplatin plus bevacizumab (mFOLFOX6-BV) with leucovorin/5-fluorouracil/irinotecan plus bevacizumab (FOLFIRI-BV) in patients with previously untreated metastatic colorectal cancer (mCRC).Patients and Methods: MAVERICC was a global, randomized, open-label, phase II study. Primary objectives were to assess associations between (i) excision repair cross-complementing 1 (ERCC1) expression with progression-free survival (PFS), and (ii) plasma VEGF A (VEGF-A) with PFS in patients with previously untreated mCRC receiving mFOLFOX6-BV or FOLFIRI-BV. Before randomization, patients were stratified by tumoral ERCC1/β-actin mRNA expression level and region.

Results

Of 376 enrolled patients, 188 each received mFOLFOX6-BV and FOLFIRI-BV. PFS and overall survival (OS) were comparable between FOLFIRI-BV and mFOLFOX6-BV, with numerically higher PFS [HR = 0.79; 95% CI (confidence interval): 0.61-1.01; P = 0.06] and OS (HR = 0.76; 95% CI: 0.56-1.04; P = 0.09) observed for FOLFIRI-BV. In the high ERCC1 subgroup, PFS and OS were comparable between treatment groups (PFS, HR = 0.84; 95% CI: 0.56-1.26; P = 0.40; OS, HR = 0.80; 95% CI: 0.51-1.26; P = 0.33). Across treatment groups, high plasma VEGF-A levels (>5.1 pg/mL) were observed with shorter PFS (HR = 1.19; 95% CI: 0.93-1.53; P = 0.17) and significantly shorter OS (HR = 1.64; 95% CI: 1.20-2.24; P < 0.01) versus low levels (≤5.1 pg/mL). Safety findings for FOLFIRI-BV or mFOLFOX6-BV were comparable with those reported previously.

Conclusions

First-line FOLFIRI-BV and mFOLFOX6-BV had comparable PFS and OS, similar to results in patients with high baseline tumor ERCC1 levels. There were no new safety signals with these bevacizumab-containing regimens.

Patients with cancer demonstrate particularly poor outcomes from COVID-19. To provide information essential for understanding the biologic underpinnings of this association, we analyzed whole-transcriptome RNA expression data obtained from a large cohort of cancer patients to characterize expression of ACE2, TMPRSS2, and other proteases that are involved in viral attachment to and entry into target cells. We find substantial variability of expression of these factors across tumor types and identify subpopulations expressing ACE2 at very high levels. In some tumor types, especially in gastrointestinal cancers, expression of ACE2 and TMPRSS2 is highly correlated. Furthermore, we found infiltration with T-cell and natural killer (NK) cell infiltration to be particularly pronounced in ACE2-high tumors. These findings suggest that subsets of cancer patients exist with gene expression profiles that may be associated with heightened susceptibility to SARS-CoV-2 infection, in whom malignant tumors function as viral reservoir and possibly promote the frequently detrimental hyper-immune response in patients infected with this virus.

Purpose

Tumor levels of thymidylate synthase (TS), a target of 5-fluorouracil (5-FU)-based chemotherapy for colorectal cancer, have been studied as a predictive or prognostic biomarker with mixed results.

Patients and methods

Tumor TS levels were prospectively evaluated in two adjuvant therapy trials for patients with resected stage II or III colon cancer. TS expression was determined by standard immunohistochemistry and by automated quantitative analysis. Tumor mismatch repair deficiency (MMR-D) and BRAF c.1799T > A (p.V600E) mutation status were also examined. Relationships between tumor TS, MMR-D, and BRAF mutation status, overall survival (OS), and disease-free survival (DFS) were investigated in the subset of stage III patients.

Results

Patients whose tumors demonstrated high TS expression experienced better treatment outcomes, with DFS hazard ratio (HR) = 0.67, 95% confidence interval (CI) = 0.53, 0.84; and OS HR = 0.68, 95% CI = 0.53, 0.88, for high versus low TS expression, respectively. No significant interaction between TS expression and stage was observed (DFS: interaction HR = 0.94; OS: interaction HR = 0.94). Tumors with high TS expression were more likely to demonstrate MMR-D (22.2% vs. 12.8%; p =  .0003). Patients whose tumors demonstrated both high TS and MMR-D had a 7-year DFS of 77%, compared with 58% for those whose tumors had low TS and were non-MMR-D (log-rank p =  .0006). Tumor TS expression did not predict benefit of a particular therapeutic regimen.

Conclusion

This large prospective analysis showed that high tumor TS levels were associated with improved DFS and OS following adjuvant therapy for colon cancer, although tumor TS expression did not predict benefit of 5-FU-based chemotherapy. The Oncologist 2017;22:107-114Implications for Practice: This study finds that measurement of tumor levels of thymidylate synthase is not helpful in assigning specific adjuvant treatment for colorectal cancer. It also highlights the importance of using prospective analyses within treatment clinical trials as the optimal method of determining biomarker utility.

Random conjugations of chemotherapeutics to monoclonal antibodies result in heterogeneous antibody-drug conjugates (ADCs) with suboptimal pharmacological properties. We recently developed a new technology for facile generation of homogeneous ADCs by harnessing human CD38 catalytic domain and its dinucleotide-derived covalent inhibitor, termed ADP-ribosyl cyclase-enabled ADCs (ARC-ADCs). Herein we advance this technology by designing and synthesizing ARC-ADCs with customizable drug-to-antibody ratios (DARs). Through varying numbers and locations of CD38 fused to an antibody targeting human C-type lectin-like molecule-1 (hCLL-1), ARC-ADCs featuring DARs of 2 and 4 were rapidly generated via a single step with cytotoxic monomethyl auristatin F (MMAF) as payloads. In contrast to anti-hCLL-1 ARC-ADC carrying 2 drug molecules, anti-hCLL-1 ARC-ADC with a DAR of 4 shows highly potent activity in killing hCLL-1-positive acute myeloid leukemia (AML) cells both in vitro and in vivo. This work provides novel ADC candidates for combating AML and supports ARC-ADC as a general and versatile approach for producing site-specific ADCs with defined DARs.

Purpose: Matrix metalloproteinase-9 (MMP9) is implicated in protumorigenic processes. Andecaliximab (GS-5745, a monoclonal antibody targeting MMP9) was evaluated as monotherapy and in combination with mFOLFOX6.Patients and Methods: Three dosages of andecaliximab monotherapy [200, 600, and 1800 mg i.v. every 2 weeks (q2w)] were investigated in patients with advanced solid tumors (n = 13 in a 3+3 design). After determining a recommended dose, patients with advanced HER2-negative gastric/gastroesophageal junction (GEJ) adenocarcinoma (n = 40) received 800 mg andecaliximab + mFOLFOX6 q2w. Pharmacokinetics, pharmacodynamics, safety, and efficacy were assessed.Results: Andecaliximab monotherapy demonstrated no dose-limiting toxicity (DLT) in any cohort, displaying target-mediated drug disposition at the lowest dose (200 mg) and linear pharmacokinetics at higher doses. Based on target engagement, recommended doses for further study are 800 mg q2w or 1,200 mg q3w. Maximal andecaliximab target binding, defined as undetectable andecaliximab-free MMP9 in plasma, was observed in the gastric/GEJ adenocarcinoma cohort. We observed no unusual toxicity, although there were four deaths on study not attributed to andecaliximab treatment. In first-line patients (n = 36), median progression-free survival (PFS) was 9.9 months [95% confidence interval (CI), 5-13.9 months], and the overall response rate (ORR) was 50%. Among all patients (n = 40), median PFS was 7.8 (90% CI, 5.5-13.9) months, and ORR was 48%, with a median duration of response of 8.4 months.Conclusions: Andecaliximab monotherapy achieved target engagement without DLT. Andecaliximab + mFOLFOX6 showed encouraging clinical activity without additional toxicity in patients with HER2-negative gastric/GEJ adenocarcinoma. A phase III study evaluating mFOLFOX6 ± andecaliximab in this setting is ongoing. Clin Cancer Res; 24(16); 3829-37. ©2018 AACR.

Colorectal cancer (CRC) is a heterogeneous and complex disease with limited treatment options. Targeting transforming growth factor β (TGF-β) and programmed death ligand 1 pathways may enhance antitumor efficacy. Bintrafusp alfa is a first-in-class bifunctional fusion protein composed of the extracellular domain of TGF-β receptor II (a TGF-β "trap") fused to a human IgG1 monoclonal antibody blocking programmed cell death ligand 1. We report results from an expansion cohort of a phase I study (NCT02517398) in patients with heavily pretreated advanced CRC treated with bintrafusp alfa. As of May 15, 2020, 32 patients with advanced CRC had received bintrafusp alfa for a median duration of 7.1 weeks. The objective response rate was 3.1% and the disease control rate was 6.3% (1 partial response, 1 stable disease); 2 patients were not evaluable. The safety profile was consistent with previously reported data.

Introduction

Prognosis after resection of hepatocellular carcinoma (HCC) is highly variable. Compared to clinicopathologic factors, the use of molecular markers to predict outcome has not been well studied. We investigated the prognostic importance of thymidylate synthase (TS) gene expression and polymorphisms in patients after resection of HCC.

Methods

Patients who underwent complete resection of HCC for whom tissue was available were identified. TS gene expression level and polymorphisms were determined in HCC specimens. Prognostic factors were evaluated using Kaplan-Meier curves and Cox proportional hazard models.

Results

The study included 67 patients. In univariate analysis, variables that negatively influenced survival included TNM stage, microvascular invasion, and high TS expression. For the high TS expression group, median survival was 54 months and 5-year actuarial survival was 47%. For the low TS expression group, median survival was not reached and the 5-year actuarial survival was 91%. In multivariate analysis, only high TS expression remained an independent predictor of poor survival (HR = 10.77, 95% CI 1.36-84.91; P = 0.02). TS gene polymorphisms were not associated with TS expression or overall survival.

Conclusions

High TS expression predicts poor outcome after resection of HCC. Molecular markers might be robust predictors of patient outcome after resection of HCC.

Background

Although canonical Wnt signaling is known to promote tumorigenesis in pancreatic ductal adenocarcinoma (PDAC), a cancer driven principally by mutant K-Ras, the detailed molecular mechanisms by which the Wnt effector β-catenin regulates such tumorigenesis are largely unknown. We have previously demonstrated that β-catenin's differential usage of the Kat3 transcriptional coactivator cyclic AMP-response element binding protein-binding protein (CBP) over its highly homologous coactivator p300 increases self-renewal and suppresses differentiation in other types of cancer.

Aim/methods

To investigate Wnt-mediated carcinogenesis in PDAC, we have used the specific small molecule CBP/β-catenin antagonist, ICG-001, which our lab identified and has extensively characterized, to examine its effects in human pancreatic cancer cells and in both an orthotopic mouse model and a human patient-derived xenograft (PDX) model of PDAC.

Results/conclusion

We report for the first time that K-Ras activation increases the CBP/β-catenin interaction in pancreatic cancer; and that ICG-001 specific antagonism of the CBP/β-catenin interaction sensitizes pancreatic cancer cells and tumors to gemcitabine treatment. These effects were associated with increases in the expression of let-7a microRNA; suppression of K-Ras and survivin; and the elimination of drug-resistant cancer stem/tumor-initiating cells.