Novavax published positive top-line results of its pivotal Phase 3 clinical trial of NanoFlu, its recombinant quadrivalent seasonal influenza vaccine candidate with its proprietary Matrix-M adjuvant, in adults aged 65 and older.
Using the Food and Drug Administration’s (FDA) criteria for accelerated approval of seasonal influenza vaccines, the trial evaluated the immunogenicity and safety of NanoFlu compared to Fluzone Quadrivalent, a U.S.-licensed quadrivalent influenza vaccine, Novavax said.
NanoFlu Phase 3 Primary Objectives
The trial’s primary objectives were to demonstrate non-inferior immunogenicity of NanoFlu compared to Fluzone Quadrivalent using the day 28 ratio of geometric mean titers (GMT) and the difference in seroconversion rates (SCR), as well as the overall safety of NanoFlu. Immunogenicity was measured by hemagglutination inhibition (HAI) assays using egg-derived reagents.
NanoFlu achieved the primary endpoints, both GMT and SCR, for all four strains included in the vaccine, Novavax said, adding that NanoFlu was well-tolerated and had a safety profile comparable to Fluzone Quadrivalent with a modest increase in local adverse events (AEs).
With these data, Novavax now has a clear path forward to licensure with our differentiated recombinant influenza vaccine, said Stanley C. Erck, President and Chief Executive Officer of Novavax.
“These strong Phase 3 results align with and validate our previous clinical trials, in which NanoFlu showed higher HAI antibody responses than the leading flu vaccine for older adults. We expect that both Fast Track designation and the accelerated approval pathway from the FDA will help Novavax bring NanoFlu to market as quickly as possible to address the serious public health threat of influenza.”
NanoFlu Phase 3 Secondary Objectives
The trial’s key secondary endpoints assessed GMT and SCR, but with an HAI assay based on wild-type reagents, which are expected to provide a more accurate assessment of clinically relevant HAI antibody responses against circulating wild-type viruses.
NanoFlu demonstrated significantly higher GMT and SCR than Fluzone Quadrivalent across all four strains included in the vaccine.
24%-66% higher GMT responses; and
11.4-20.4 higher SCR percentage points.
NanoFlu also demonstrated significantly higher GMT and SCR than Fluzone Quadrivalent for four tested drifted H3N2 strains not included in the vaccine but circulating this year.
34%-41% higher GMT responses; and
14.1-16.8 higher SCR percentage points
“In addition to meeting the primary objectives, we are very pleased to report that NanoFlu also met or exceeded its secondary endpoints for all four strains using our proprietary HAI assay based upon wild-type reagents,” said Gregory Glenn, M.D., President of Research and Development of Novavax. “NanoFlu demonstrated significant improvement against four drifted H3N2 strains that are co-circulating this year. These data, similar to what was shown in our Phase 2 clinical trial, demonstrate that NanoFlu overcomes issues related to egg-adaptation and antigenic drift. We extend our sincere appreciation to those who volunteered for this important study and to our clinical partners who worked so quickly and diligently on this trial.”