NanoFlu Protected People Against Drifted H3N2 Influenza Strains

Novavax NanoFlu overcomes egg-adaptation and antigenic drift issues 
older man with a hat on

A Maryland based biotechnology company announced 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.

Announced by Novavax Inc. on March 24, 2020, this 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.

  • 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).

This 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

Gregory Glenn, M.D., President of Research and Development of Novavax, said in a press release, “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.

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.

NanoFlu is a recombinant hemagglutinin (HA) protein nanoparticle influenza vaccine produced by Novavax in its SF9 insect cell baculovirus system.

NanoFlu uses HA amino acid protein sequences that are the same as the recommended wild-type circulating virus HA sequences. 

The qNIV vaccine antigens were derived from A/Brisbane 02/2018 H1N1, A/Kansas 14/2017 H3N2, B/Maryland 15/2016 and B/Phuket 3073/2013. NanoFlu contains Novavax’s patented saponin-based Matrix-M adjuvant, which has demonstrated a potent and well-tolerated effect by stimulating the entry of antigen-presenting cells into the injection site and enhancing antigen presentation in local lymph nodes.

Novavax, Inc. is a late-stage biotechnology company that promotes improved health globally through the discovery, development, and commercialization of innovative vaccines to prevent serious infectious diseases.

Precision Vaccinations publishes influenza vaccine development news.