Proof of principle study of sequential combination atezolizumab and Vigil in relapsed ovarian cancer.

Vigil® is a personalized vaccine that enhances tumor neoantigen expression. We investigated for the first time safety and efficacy of Vigil in combination with atezolizumab in relapsed ovarian cancer (OC) patients. This is a randomized, Phase 1 study of Vigil, an autologous tumor tissue transfected vaccine encoding for GMCSF and bi-shRNA-furin thereby creating enhanced immune activation and TGFß expression control. Part 1 is a safety assessment of Vigil (1 × 10e7 cells/mL/21 days) plus atezolizumab (1200 mg/21 days). Part 2 is a randomized study of Vigil first (Vigil-1st) or atezolizumab first (Atezo-1st) for two cycles followed by the combination of both agents. The primary endpoint of the study was the determination of safety. Twenty-four patients were enrolled in the study; three patients to Part 1 and 21 to Part 2. Patients in Part 1 completed combination therapy without dose-limiting toxicity justifying expansion to Part 2. Twenty-one patients were randomized (1:1) to Part 2 to Vigil-1st (n = 11) or Atezo-1st (n = 10). Grade 3/4 treatment-related adverse events of Atezo-1st vs. Vigil-1st were 17.2% vs. 5.1%. Median overall survival (OS) was not reached (NR) (Vigil-1st) vs. 10.8 months (Atezo-1st) (hazard ratio [HR] 0.33). The exploratory subset analysis of BRCAwt suggested improved OS benefit [NR in Vigil-1st vs. 5.2 months in Atezo-1st, HR 0.16, p 0.027]. The Vigil-1st combination therapy with atezolizumab was safe and results in support continued investigation in BRCAwt patients.

Gemogenovatucel-T (Vigil) immunotherapy as maintenance in frontline stage III/IV ovarian cancer (VITAL): a randomised, double-blind, placebo-controlled, phase 2b trial.

BACKGROUND: Gemogenovatucel-T is an autologous tumour cell vaccine manufactured from harvested tumour tissue, which specifically reduces expression of furin and downstream TGF-ß1 and TGF-ß2. The aim of this study was to determine the safety and efficacy of gemogenovatucel-T in front-line ovarian cancer maintenance. METHODS: This randomised, double-blind, placebo-controlled, phase 2b trial involved 25 hospitals in the USA. Women aged 18 years and older with stage III/IV high-grade serous, endometrioid, or clear cell ovarian cancer in clinical complete response after a combination of surgery and five to eight cycles of chemotherapy involving carboplatin and paclitaxel, and an Eastern Cooperative Oncology Group status of 0 or 1 were eligible for inclusion in the study. Patients were randomly assigned (1:1) to gemogenovatucel-T or placebo by an independent third party interactive response system after successful screening using randomly permuted block sizes of two and four and stratified by extent of surgical cytoreduction and neoadjuvant versus adjuvant chemotherapy. Gemogenovatucel-T (1 × 107 cells per injection) or placebo was administered intradermally (one per month) for a minimum of four and up to 12 doses. Patients, investigators, and clinical staff were masked to patient allocation until after statistical analysis. The primary endpoint was recurrence-free survival, analysed in the per-protocol population. All patients who received at least one dose of gemogenovatucel-T were included in the safety analysis. The study is registered with ClinicalTrials.gov, NCT02346747. FINDINGS: Between Feb 11, 2015, and March 2, 2017, 310 patients consented to the study at 22 sites. 217 were excluded. 91 patients received gemogenovatucel-T (n=47) or placebo (n=44) and were analysed for safety and efficacy. The median follow-up from first dose of gemogenovatucel-T was 40·0 months (IQR 35·0-44·8) and from first dose of placebo was 39·8 months (35·5-44·6). Recurrence-free survival was 11·5 months (95% CI 7·5-not reached) for patients assigned to gemogenovatucel-T versus 8·4 months (7·9-15·5) for patients assigned to placebo (HR 0·69, 90% CI 0·44-1·07; one-sided p=0·078). Gemogenovatucel-T resulted in no grade 3 or 4 toxic effects. Two patients in the placebo group had five grade 3 toxic events, including arthralgia, bone pain, generalised muscle weakness, syncope, and dyspnea. Seven patients (four in the placebo group and three in the gemogenovatucel-T group) had 11 serious adverse events. No treatment-related deaths were reported in either of the groups. INTERPRETATION: Front-line use of gemogenovatucel-T immunotherapy as maintenance was well tolerated but the primary endpoint was not met. Further investigation of gemogenovatucel-T in patients stratified by BRCA mutation status is warranted. FUNDING: Gradalis.

Antitumor and Antiangiogenic Effects of Aspirin-PC in Ovarian Cancer.

To determine the efficacy of a novel and safer (for gastrointestinal tract) aspirin (aspirin-PC) in preclinical models of ovarian cancer, in vitro dose-response studies were performed to compare the growth-inhibitory effect of aspirin-PC versus aspirin on three human (A2780, SKOV3ip1, and HeyA8) and a mouse (ID8) ovarian cancer cell line over an 8-day culture period. In the in vivo studies, the aspirin test drugs were studied alone and in the presence of a VEGF-A inhibitor (bevacizumab or B20), due to an emerging role for platelets in tumor growth following antiangiogenic therapy, and we examined their underlying mechanisms. Aspirin-PC was more potent (vs. aspirin) in blocking the growth of both human and mouse ovarian cancer cells in monolayer culture. Using in vivo model systems of ovarian cancer, we found that aspirin-PC significantly reduced ovarian cancer growth by 50% to 90% (depending on the ovarian cell line). The efficacy was further enhanced in combination with Bevacizumab or B20. The growth-inhibitory effect on ovarian tumor mass and number of tumor nodules was evident, but less pronounced for aspirin and the VEGF inhibitors alone. There was no detectable gastrointestinal toxicity. Both aspirin and aspirin-PC also inhibited cell proliferation, angiogenesis, and increased apoptosis of ovarian cancer cells. In conclusion, PC-associated aspirin markedly inhibits the growth of ovarian cancer cells, which exceeds that of the parent drug, in both cell culture and in mouse model systems. We also found that both aspirin-PC and aspirin have robust antineoplastic action in the presence of VEGF-blocking drugs. Mol Cancer Ther; 15(12); 2894-904. ©2016 AACR.

Resistance and escape from antiangiogenesis therapy: clinical implications and future strategies.

Angiogenesis has long been considered an important target for cancer therapy. Initial efforts have primarily focused on targeting of endothelial and tumor-derived vascular endothelial growth factor signaling. As evidence emerges that angiogenesis has significant mechanistic complexity, therapeutic resistance and escape have become practical limitations to drug development. Here, we review the mechanisms by which dynamic changes occur in the tumor microenvironment in response to antiangiogenic therapy, leading to drug resistance. These mechanisms include direct selection of clonal cell populations with the capacity to rapidly upregulate alternative proangiogenic pathways, increased invasive capacity, and intrinsic resistance to hypoxia. The implications of normalization of vasculature with subsequently improved vascular function as a result of antiangiogenic therapy are explored, as are the implications of the ability to incorporate and co-opt otherwise normal vasculature. Finally, we consider the extent to which a better understanding of the biology of hypoxia and reoxygenation, as well as the depth and breadth of systems invested in angiogenesis, may offer putative biomarkers and novel therapeutic targets. Insights gained through this work may offer solutions for personalizing antiangiogenesis approaches and improving the outcome of patients with cancer.

Targeting SRC in mucinous ovarian carcinoma.

PURPOSE: Mucinous ovarian carcinomas have a distinct clinical pattern compared with other subtypes of ovarian carcinoma. Here, we evaluated (i) stage-specific clinical significance of mucinous ovarian carcinomas in a large cohort and (ii) the functional role of Src kinase in preclinical models of mucinous ovarian carcinoma. EXPERIMENTAL DESIGN: A total of 1,302 ovarian cancer patients including 122 (9.4%) cases of mucinous carcinoma were evaluated for survival analyses. Biological effects of Src kinase inhibition were tested using dasatinib-based therapy in a novel orthotopic mucinous ovarian cancer model (RMUG-S-ip2). RESULTS: Patients with advanced-stage mucinous ovarian cancer had significantly worse survival than those with serous histology: median overall survival, 1.67 versus 3.41 years, P = 0.002; median survival time after recurrence of 0.53 versus 1.66 years, P < 0.0001. Among multiple ovarian cancer cell lines, RMUG-S-ip2 mucinous ovarian cancer cells showed the highest Src kinase activity. Moreover, oxaliplatin treatment induced phosphorylation of Src kinase. This induced activity by oxaliplatin therapy was inhibited by concurrent administration of dasatinib. Targeting Src with dasatinib in vivo showed significant antitumor effects in the RMUG-S-ip2 model but not in the serous ovarian carcinoma (SKOV3-TR) model. Combination therapy of oxaliplatin with dasatinib further showed significant effects on reducing cell viability, increasing apoptosis, and in vivo antitumor effects in the RMUG-S-ip2 model. CONCLUSIONS: Our results suggest that poor survival of women with mucinous ovarian carcinoma is associated with resistance to cytotoxic therapy. Targeting Src kinase with a combination of dasatinib and oxaliplatin may be an attractive approach for this disease.