Osivax Reports Mixed Results for Influenza Vaccine Candidate OVX836

Osivax, a clinical-stage biopharmaceutical company based in Lyon, France and Liège, Belgium, has reported results from its Phase 2b field efficacy trial for its influenza A vaccine candidate, OVX836. The trial, known as Asuniva, evaluated the efficacy, safety, and immunogenicity of a single intramuscular dose of OVX836 (480 µg) versus placebo in 2,850 healthy adults across Europe. The study did not meet its pre-specified primary endpoint of 50% vaccine efficacy, with a point estimate of 24% (not statistically significant). However, secondary endpoints showed an emerging pattern of a preliminary efficacy signal, with point estimates of 28% (CDC), 27% (A/H3), and 25% (A/H1N1pdm09) for the different influenza A subtypes.

The vaccine demonstrated a favorable safety profile consistent with previous clinical trials and induced robust NP-specific antibody and T-cell responses. According to Osivax, 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.

Osivax is advancing a combination strategy to harness the potential synergistic effects of influenza vaccines targeting different influenza antigens. This strategy combines the broad cellular immunity induced by OVX836 with the strain-specific protection provided by established seasonal influenza vaccines. The company has recently established strategic collaborations with GC Biopharma and a second, undisclosed global pharmaceutical partner to develop combination vaccine candidates in a single injection. This approach has the potential to substantially improve overall vaccine efficacy.

The first Phase 1/2 combination study is anticipated in Q4 2027. OVX836, a first-in-class influenza A vaccine candidate that targets the nucleoprotein (NP), a highly conserved internal antigen, has been tested in seven clinical trials with over 4,000 participants and has shown promising safety, immunogenicity, and efficacy read-outs. The Asuniva trial, a randomized, double-blind, placebo-controlled, multicenter Phase 2b trial, was 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.

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, visit www.osivax.com.