Pfizer Gets FDA Breakthrough Therapy Designation for Maternal RSV Vaccine
The FDA has granted Breakthrough Therapy designation to Pfizer’s respiratory syncytial vaccine (RSV) candidate, RSVpreF, for the prevention of RSV-associated lower respiratory tract illness in infants from birth up to six months of age by active immunization of pregnant women.
If the vaccine gets the FDA’s approval, it will be the first available to prevent RSV-associated lower respiratory tract in infants.
The FDA based its decision on positive phase 2b study results from a study in healthy pregnant women who were vaccinated in weeks 28 to 36 of gestation and their infants.
Pfizer has not yet released the clinical trial data from the study.
About RSVpreF
Pfizer’s investigational RSV vaccine candidate builds on foundational basic science discoveries including those made at the National Institutes of Health (NIH), which detailed the crystal structure of a key form of the viral fusion protein (F) that RSV uses to attack human cells, prefusion F. The NIH research showed that antibodies specific to the prefusion form were highly effective at blocking virus infection, suggesting a prefusion F-based vaccine may confer optimal protection against RSV. After this important discovery, Pfizer tested numerous versions of the viral protein, and identified those that elicited a strong anti-viral immune response in pre-clinical evaluation. The vaccine candidate is composed of two preF proteins selected to optimize protection against RSV A and B and is currently being evaluated in ongoing late-stage human trials.
March 3, 2022
