- Phase 2b study provides first consistent efficacy signal for a monovalent nucleoprotein-based influenza vaccine across both major influenza A subtypes
- OVX836 did not meet its pre-specified primary endpoint of 50% vaccine efficacy
- Results support development of OVX836 in combination with traditional seasonal influenza vaccines to provide a complementary layer of protection
- Strategic collaborations with GC Biopharma and a second, undisclosed global pharmaceutical partner enable next phase of combination vaccine development
Lyon, France and Liège, Belgium - 15 October 2026 - Osivax, a clinical-stage biopharmaceutical company developing differentiated influenza vaccines designed to generate broad-spectrum immune responses, today announced results from its sponsored Phase 2b field efficacy trial of OVX836 and outlined the next phase of development for its next-generation seasonal influenza vaccine strategy.
The Phase 2b field efficacy trial evaluated the efficacy, safety and immunogenicity of OVX836 (480 µg) versus placebo in 2,850 healthy adults in Europe. The trial did not achieve its pre-specified primary endpoint of 50% vaccine efficacy (VE), while a point estimate VE of 24% (not statistically significant) was reported. Secondary endpoints of VE, such as the CDC-defined influenza-like illness and the strain-specific VE showed an emerging pattern for a preliminary VE signal with VE point estimates of 28% (CDC), 27% (A/H3) and 25% (A/H1N1pdm09), respectively. The vaccine also demonstrated a favorable safety profile consistent with previous clinical trials and induced robust NP-specific antibody and T-cell responses. To Osivax’s knowledge, these findings represent the first consistent efficacy signal for a monovalent nucleoprotein-based influenza vaccine across both major influenza A subtypes in a field efficacy trial.
In parallel to the development of OVX836 as a standalone vaccine candidate, Osivax has been advancing a combination strategy to harness the potential synergistic effects of influenza vaccines targeting different influenza antigens. The Phase 2b results further support this strategy, which combines the broad cellular immunity induced by OVX836 with the strain-specific protection provided by established seasonal influenza vaccines. Recently established collaborations with GC Biopharma and a second, undisclosed global pharmaceutical partner will enable the development of combination vaccine candidates in a single injection. This approach has the potential to substantially improve overall vaccine efficacy.
“Large efficacy studies are designed not only to evaluate clinical benefit, but also to deepen our understanding of novel immune mechanisms under real-world conditions," said Dr Nicola Groth, Chief Medical Officer of Osivax. "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.”
“These results provide a clear direction for the future development of OVX836. Rather than replacing existing seasonal influenza vaccines, we believe the greatest opportunity lies in complementing them” said Alexandre Le Vert, CEO and Co-Founder of Osivax. “By combining strain-specific antibody protection with the broad cellular immunity induced by OVX836, we aim to develop next-generation influenza vaccines capable of delivering broader and more durable protection against seasonal influenza.”
The two collaborations provide access to established seasonal influenza vaccines for the development of combination vaccine candidates. Securing distinct agreements with two established leaders in influenza vaccines represents a significant milestone for Osivax and a strong external validation of its combination strategy. The first Phase 1/2 combination study is anticipated in Q4 2027.
About OVX836
OVX836 is a first-in-class influenza A vaccine candidate that targets the nucleoprotein (NP), a highly conserved internal antigen. Unlike surface antigens, the NP is much less likely to mutate, providing a broader and more universal immune response. Osivax’ oligoDOMTM technology enables the design and production of a recombinant version of the NP, which self-assembles into a nanoparticle, thus triggering powerful T- and B-cell immune responses. OVX836 has been tested in 7 clinical trials with over 4,000 participants so far, and has shown promising safety, immunogenicity, and efficacy read-outs.
About OXV836-005 – Asuniva
Asuniva is a randomized, double-blind, placebo-controlled, multicenter Phase 2b trial conducted in Belgium, France, Finland and Germany, to assess the safety, immunogenicity, and efficacy of a single intramuscular dose of OVX836 (480 µg) in 2,850 participants aged 18–59 years. Asuniva is the first large, field efficacy study with OVX836 which generated the clinical evidence needed to advance the vaccine toward late-stage development. Further information can be found at clinicaltrials.gov.
About Osivax
Osivax is a clinical-stage biopharmaceutical company developing a portfolio of differentiated influenza vaccines generating superior T-cell responses in addition to strong and sustained B-cell responses, thanks to its novel, self-assembling nanoparticle platform technology, oligoDOMTM. The company’s lead candidate, OVX836, is a broad-spectrum influenza A vaccine candidate currently in Phase 2b clinical trials with over 4,000 volunteers tested and encouraging first signal of vaccine efficacy data. By combining OVX836 with standard flu vaccines, Osivax is advancing toward a best-in-class seasonal flu vaccine to prevent all strains of influenza. Osivax collaborates with leading global health agencies, including US based BARDA and NIH, and European-based institutions and top-tier pharmaceutical companies, reinforcing its mission to prevent all types of seasonal and pandemic influenza. The company will expand into other infectious disease indications through combinations and collaborations worldwide. For further information: www.osivax.com
Contact
| Alexandre LE VERT, CEO contact@osivax.com +33 (0)9 70 30 13 80 | For Media Inquiries Trophic Communications Anja Heuer - osivax@trophic.eu +49 (0) 151 106 199 05 |
Attachment
