Aiming to challenge flu shot market leader Sanofi, Vaxart put up phase 2 data for an oral flu vaccine candidate that the biotech says provided participants both mucosal and systemic immune responses.
Vaxart’s oral flu vaccine tablet provided a 39% reduction in flu cases in the challenge study compared with placebo, versus a 27% reduction for Fluzone over placebo. The Sanofi vaccine is a flu shot covering four strains of the influenza virus, while Vaxart’s vaccine is a tablet.
Vaxart's room temperature-stable tablet also appeared to beef up the immune response in mucous membranes, the body's first line of defense against a flu infection. The vaccine significantly expanded the number of mucosal homing receptor β7+ plasmablasts, Vaxart Chief Scientific Officer Sean Tucker, Ph.D., said in a statement. The company believes those plasmablasts “are a key indicator of a protective mucosal immune response and a unique feature of our oral recombinant vaccines.”
Vaxart CEO Wouter Latour, M.D., said the mucosal response in study participants “clearly differentiates our oral vaccines from conventional injectable vaccines, and strongly suggests" vaccines developed on the company’s platform “could be optimal to protect against mucosal pathogens” such as flu and RSV.
Vaxart believes its tablet vaccines will be easier to distribute and administer than traditional shots, which require refrigeration. That could boost vaccination rates, the company figures.
Vaxart, which merged with Aviragen last year, is also testing candidates against norovirus, RSV and HPV. Vaxart’s shares have climbed about 78% since the flu results were announced on Friday.
The U.S. Department of Health and Human Services’ BARDA funded the trial through a $13.9 million grant awarded in 2015. Last year, the agency bumped the grant amount up to $15.7 million.