Novavax crumbles after Phase III RSV failure

Novavax Inc. (NASDAQ:NVAX) plummeted $6.94 (83%) to $1.40 in early after-hours trading Thursday after its RSV F vaccine missed the primary endpoint in the Phase III Resolve trial to prevent respiratory syncytial virus (RSV) infection in elderly adults. The company said 28 of 5,921 patients treated with the vaccine reported moderate-to-severe RSV-associated lower repiratory tract disease (RSV msLRTD), compared to 26 of 5,935 receiving placebo (0.47% vs. 0.44%, p=0.78).

RSV F vaccine also missed a secondary endpoint. Novavax said 102 patients receiving the vaccine reported all symptomatic respiratory disease due to RSV (RSV ARD) vs. 117 for placebo (1.72% vs. 1.97%; p=0.32). RSV F vaccine targets RSV viral fusion F protein, and is formulated using recombinant nanoparticle technology. ...