Osivax’s bet on a universal influenza vaccine has failed its largest test. The French company’s phase 2b Asuniva trial of OVX836, a nucleoprotein based influenza A vaccine, randomised 2,850 healthy adults across four European countries to a single 480 microgram dose or placebo, and produced a vaccine efficacy point estimate of 24 percent against a prespecified primary target of 50 percent, without statistical significance.
Secondary estimates were consistent but modest, at 28 percent against CDC defined influenza like illness, 27 percent against A/H3 and 25 percent against A/H1N1pdm09, and the company reported robust nucleoprotein specific antibody and T cell responses with a favourable safety profile. The result did not reproduce the 84 percent preliminary efficacy the same vaccine had shown in a much smaller phase 2a study.
Osivax is responding by abandoning the standalone ambition. Development will focus on combinations with conventional seasonal vaccines, building on an August licence for GC Biopharma’s inactivated seasonal flu vaccine and a second, undisclosed global pharmaceutical partner. The logic is that strain specific antibodies from a standard vaccine plus the broad cellular immunity OVX836 induces could protect better than either alone, which is now the claim the company has to prove.