A respiratory syncytial virus F-protein (RSV F) nanoparticle vaccine (Novavax, Inc.) has failed to demonstrate clinical efficacy in a phase 3 study involving adults 60 years of age and older.
The randomized, observer-blinded, placebo-controlled trial was conducted at 60 sites in the United States. The study’s primary objective was to demonstrate the efficacy of an unadjuvanted, 135-mcg dose of the RSV F vaccine in the prevention of moderate-to-severe RSV-associated lower respiratory tract disease (RSV msLRTD) compared with placebo. The study’s secondary objective was to demonstrate the efficacy of the RSV F vaccine in reducing the incidence of symptomatic respiratory disease due to RSV (RSV ARD). The trial also evaluated the vaccine’s safety compared with that of placebo.
RSV msLRTD occurred in 0.47% (28/5,921) of the vaccine group and in 0.44% (26/5,935) of the placebo group (P = 0.78). Similarly, RSV ARD occurred in 1.72% (102/5,921) of the vaccine group and in 1.97% (117/5,935) of the placebo group (P = 0.32).
Novavax shares cratered after the news was announced, according to a report from FierceBiotech. The Maryland-based company saw its stock plummet by more than 83%––decimating its share price from $8.34 to $1.40 in a few hours.
RSV is a respiratory infectious disease that causes serious infection of the respiratory tract, similar to influenza. For some people, RSV may progress in severity and lead to hospitalization or even death. The spread of RSV occurs annually, with an incidence rate of 2.5 million infections per year in the U.S. Each year, RSV is responsible for approximately 207,000 hospitalizations and 16,000 deaths among adults older than 65 years of age. Currently, no approved RSV vaccines are available.
Sources: Novavax; September 15, 2016; and FierceBiotech; September 16, 2016.