ResVax is a vaccine candidate composed of recombinant RSV F nanoparticles adsorbed to aluminum phosphate. The F protein is essential to RSV infectivity and is the target of palivizumab.
ResVax is indicated to prevent severe RSV disease. Protecting infants as early as birth and during the first months of life when they are most at risk for hospitalization.
ResVax is administered to the maternal participant as an intramuscular (IM) Injection of RSV F Vaccine at 28-36 weeks Estimated Gestational Age (EGA).
Clinical Trial NCT02624947: A Study to Determine the Safety and Efficacy of the RSV F Vaccine to Protect Infants Via Maternal Immunization
- March 1, 2019, Novavax announced the Prepare™ Phase 3 clinical trial failed to meet its main goal of preventing medically significant RSV lower respiratory tract infection.
- June 10, 2019, Novavax issued a press release:
- The U.S. Food & Drug Administration (FDA) has recommended that Novavax conduct an additional Phase 3 clinical trial to confirm efficacy against 'medically significant' RSV disease in infants born to mothers vaccinated with ResVax.
- Novavax has recently held meetings with several European national regulatory agencies to solicit input on the Prepare trial and possible pathways to licensure in Europe. The next step will be to seek formal scientific advice this fall from the European Medicines Authority, the agency responsible for licensing vaccines for the European Union.
This Phase 3 Study is a randomized, observer-blind, placebo-controlled trial enrolling third-trimester pregnant women in the Northern and Southern hemispheres, for up to four consecutive RSV seasons in each hemisphere.
The trial enrolled 4636 third-trimester pregnant subjects. Women in the third trimester of a singleton uncomplicated pregnancy and 18 to 40 years of age (inclusive) will be enrolled and randomized in a 1:1 ratio into one of two treatment groups, active or placebo, over approximately the three months prior to peak RSV season.
After the first global season of enrollment, the randomization scheme will be changed to a 2:1 (active/placebo) ratio to enable more efficient accrual of the safety database.
All maternal subjects will receive a single intramuscular (IM) injection on Day 0 with the assigned test article, the RSV F vaccine or placebo. Study participation for maternal subjects will span approximately nine (9) months from the first dose, ending six (6) months post-delivery. Study follow-up for infant subjects who are consented will span approximately one (1) year post-delivery.