Novavax, Inc. announced positive top-line results of its pivotal Phase III 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 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.
NanoFlu Phase III 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. NanoFlu was well-tolerated and had a safety profile comparable to Fluzone Quadrivalent with a modest increase in local adverse events (AEs).
NanoFlu Phase III 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 II 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.”
About Phase III Clinical Trial: The trial enrolled 2,652 healthy older adults across 19 U.S. clinical sites. Trial participants received either NanoFlu or the comparator, both of which were formulated with the four influenza strains recommended for the 2019-2020 Northern hemisphere influenza season. Participants will be followed for approximately one year after injection, with primary immunogenicity analyses of the Day 28 sera samples.