Research & Clinical Trials
Osivax's OVX836 Falls Short of 50% Efficacy Goal in 2,850-Adult Phase 2b Trial
By News Desk ·
Key takeaways
- Osivax's Phase 2b trial of OVX836 in 2,850 European adults did not meet its pre-specified primary endpoint of 50% vaccine efficacy.
- The trial reported a 24% vaccine efficacy point estimate that was not statistically significant, with secondary endpoint estimates of 28%, 27% and 25%.
- Osivax plans combination vaccine candidates with GC Biopharma and an undisclosed global pharmaceutical partner, with a first Phase 1/2 study anticipated in Q4 2027.
Osivax said on October 15, 2026 that its Phase 2b field efficacy trial of OVX836 in 2,850 healthy European adults did not meet the pre-specified primary endpoint of 50% vaccine efficacy, reporting a 24% point estimate that was not statistically significant. The French clinical-stage biopharmaceutical company announced the results via GlobeNewswire.
Osivax's Phase 2b Trial Results and Combination Plan
The Asuniva trial evaluated a single 480 µg intramuscular dose of OVX836 versus placebo in participants aged 18 to 59 across Belgium, France, Finland and Germany. Secondary endpoints showed vaccine efficacy point estimates of 28% for CDC-defined influenza-like illness, 27% for the A/H3 subtype and 25% for A/H1N1pdm09. Osivax said the vaccine demonstrated a favorable safety profile consistent with previous clinical trials and induced robust NP-specific antibody and T-cell responses.
"While the study did not meet its primary endpoint, the consistency of the efficacy signal across influenza A subtypes, together with the observed immunogenicity and favourable safety profile, reinforces our confidence that nucleoprotein-targeted immunity can provide a complementary mechanism of protection alongside conventional seasonal influenza vaccines," said Dr Nicola Groth, Chief Medical Officer of Osivax.
Osivax is advancing a combination strategy pairing OVX836 with established seasonal influenza vaccines. Collaborations with GC Biopharma and a second, undisclosed global pharmaceutical partner will enable development of combination vaccine candidates in a single injection. GC Biopharma, a South Korean drugmaker, announced a long-term collaboration with Osivax on August 27, 2026 to develop and commercialize a combination seasonal influenza vaccine combining OVX836 with its WHO-prequalified GC FLU inactivated vaccine, according to PharmExec.
Osivax's Funding and Partnership Record
Osivax is a clinical-stage French biopharmaceutical company developing vaccines against influenza, sarbecoviruses and HPV using its oligoDOM self-assembling nanoparticle platform, according to akta.pro company records. The company has raised total funding of $89.3 million, including a $19.5 million BARDA award in August 2025 to advance OVX836 for pandemic and seasonal preparedness. In April 2026, Osivax partnered with CEPI to access the World-First Adjuvant Library to investigate dose-sparing formulations of OVX836 for pandemic response.
Osivax's Path to the Phase 2b Readout
Osivax and GC Biopharma announced a long-term collaboration on August 27, 2026 to develop and commercialize a next-generation seasonal influenza vaccine combining OVX836 with GC FLU, according to Yahoo. FierceBiotech reported the same month that Osivax licensed GC Biopharma's inactivated seasonal influenza vaccine, GC FLU, outside Japan and Korea. In December 2025, Osivax completed enrollment of 2,850 participants in the Phase 2b Asuniva trial across Belgium, France, Finland and Germany, with topline results expected mid-2026.
Osivax's Next Combination Study
The first Phase 1/2 combination study is anticipated in Q4 2027, Osivax said.