Favorable Ph I/IIa for Novavax' pandemic flu vaccine program

Maryland, USA-based Novavax has announced favorable results from the second stage a Phase I/IIa human clinical trial of its pandemic influenza virus-like particle vaccine candidate. The vaccine, which does not contain an adjuvant, induced robust neutralizing antibody responses. Novavax' VLP candidate is directed against the H5N1 A/Indonesia/05/2005 avian influenza strain. Avian influenza emerged in humans in Indonesia in 2005 and has caused 135 documented human cases, 81% of which have been fatal.

In this study, the vaccine demonstrated strong neutralizing antibody titers across all three doses tested, exhibiting increasing antibody titers with the escalation of the dose. The study evaluated individuals who received two injections of 15mcg, 45mcg, 90mcg or placebo. Among those individuals in the 15mcg arm, 72% had a neutralizing antibody titer of 1:20 or greater (four-fold rise from baseline) against the H5N1 A/Indonesia strain as did 73% of subjects in the 45mcg arm and 94% of subjects in the 90 mcg arm.

All subjects tested negative for neutralizing antibodies to the H5N1 A/Indonesia strain before vaccination and no responses were observed among individuals who received a placebo. Novavax' proprietary VLPs contain the surface proteins (hemagglutinin [HA] and neuraminidase [NA]) and matrix protein (M1) of the H5N1 A/Indonesia strain. Additional immunological responses induced by each of the components of the vaccine are being evaluated including responses against HA, NA and the M1 proteins.