BioVaxys Technology Corp. (CSE:BIOV) (USOTC:BVAXF) said it has reported positive early results from its Phase 1B/2 PESCO clinical study evaluating its cancer vaccine MVP-S in combination with pembrolizumab (Keytruda™) and low-dose cyclophosphamide in patients with recurrent epithelial ovarian cancer.
The open-label, investigator-initiated trial assessed safety, dosing and early signs of efficacy in patients with relapsed disease who had not previously received checkpoint inhibitors. A total of 47 patients were enrolled, including 16 in a Phase 1 dose-escalation stage and 31 in Phase 2.
According to the company, the combination therapy delivered an overall response rate (ORR) of 24% and a disease control rate (DCR) of 82% in high-grade disease, with responses lasting a median of 5.5 months. Outcomes were strongest in patients with platinum-sensitive cancer, where ORR reached 40% and DCR 90%. Even in platinum-resistant patients, results exceeded historical benchmarks, with an ORR of 16% and DCR of 54%, compared with typical response rates of around 12% for standard single-agent chemotherapy.
BioVaxys highlighted one patient in the platinum-sensitive cohort who remains in complete response more than three years after starting treatment, with an immune response lasting nearly four years. Across the study, MVP-S triggered survivin-specific immune responses in 62% of tested patients, which were linked to disease control in the majority of cases.
The study was led by Amit Oza, MD, at Princess Margaret Cancer Centre in Toronto. Patients were followed for up to two years after vaccination, and efficacy was measured using RECIST 1.1 criteria.
“The combination of MVP-S, pembrolizumab and low dose cyclophosphamide in epithelial ovarian cancer demonstrated promising and sustained clinical activity with good tolerability,” said Kenneth Kovan, President and Chief Operating Officer of BioVaxys. “Other studies suggest that anti-PD1 enhances the robust antigen-specific, cytotoxic immune response already induced by MVP-S. These findings reinforce survivin as a viable target for immunotherapy in ovarian cancer, together with checkpoint inhibitors such as anti PD-1.”
Epithelial ovarian cancer is typically diagnosed late and is marked by repeated relapse and treatment resistance, limiting long-term survival. While immune checkpoint inhibitors alone have shown limited benefit in this setting, BioVaxys said the PESCO data support further development of vaccine-checkpoint combinations targeting survivin, a tumor-associated antigen highly expressed in ovarian cancer but largely absent from healthy tissue.
MVP-S is built on BioVaxys’ proprietary DPX™ antigen-delivery platform, which is designed to generate a durable, targeted T-cell immune response. The company said the results add to growing clinical evidence supporting MVP-S across multiple cancer indications and underpin its ongoing Phase IIB development programs in platinum-resistant ovarian cancer and relapsed-refractory diffuse large B-cell lymphoma.