OSE Immunotherapeutics: Positive Phase 2 Tedova Study in Ovarian Cancer
OSE Immunotherapeutics announced on Friday the positive results of its Phase 2 TEDOVA study evaluating Tedopi in relapsed ovarian cancer. The combination of Tedopi and pembrolizumab met the primary endpoint by statistically improving progression-free survival, a clinical success that now needs to realize the ambitions of the biotech company from Nantes.
Validated Improvement in Progression-Free Survival in a Challenging Medical Context
The TEDOVA study assessed 185 patients with platinum-sensitive relapsed ovarian cancer who had progressed after PARP inhibitors and bevacizumab treatment. Patients were randomized into three groups: standard care (control group), Tedopi monotherapy, or a combination of Tedopi and pembrolizumab. The primary endpoint was progression-free survival (PFS), comparing the latter combination to the control.
The results show a statistically significant improvement for the combination: median PFS of 4.1 months versus 2.8 months in the control group, with a hazard ratio (HR) of 0.53. This reduction in the risk of progression or death represents proof of concept for a vaccine approach in this difficult-to-treat cancer.
The addition of pembrolizumab to Tedopi alone resulted in a further 28% reduction in the risk of progression or death (HR=0.72, p=0.074). However, the combination led to an increase in the frequency of adverse effects, consistent with the mechanisms of action of immunotherapy.
Clinical Validation That Must Lead to Regulatory Steps
Professor Alexandra Leary, the principal investigator and deputy head of the oncology medicine department at Gustave Roussy, describes TEDOVA as the first positive trial in platinum-sensitive ovarian cancer in several years. She highlights that the patients targeted by the study have an unmet medical need, with a PFS of less than 3 months following platinum-based chemotherapy after failure of PARP inhibitors and bevacizumab.
Marc Le Bozec, CEO of OSE, emphasizes the observed clinical synergy and the activity of Tedopi in monotherapy. He confirms that these results reinforce the strategy to move towards Phase 3 in non-small cell lung cancer, as well as in pancreatic and ovarian cancer through academic collaborations, with results expected in 2026.
A Context of Limited Resources and Significant Cash Burn
The clinical results come in a demanding financial context. OSE recorded an operating loss of €37.5 million in 2025 (previous year: €2.7 million in revenue) and a negative free cash flow of €34 million. This significant cash consumption raises questions about the financing of the announced Phase 3 trials and the time needed before potential commercialization. The presentation of the results at the ASCO congress on May 30 and the webcast on June 10 will aim to convince investors and partners of the program's potential.
