Pfizer Inc. (NYSE: PFE) today announced that the U.S. Food and Drug Administration (FDA) accepted for priority review a Biologics License Application (BLA) for its respiratory syncytial virus (RSV) vaccine candidate, PF-06928316 or RSVpreF, as submitted for the prevention of lower respiratory tract disease caused by RSV in individuals 60 years of age and older.
Priority Review designation by the FDA reduces the standard BLA review period by four months. The Prescription Drug User Fee Act (PDUFA) goal date for a decision by the FDA on the RSVpreF application is in May 2023. This decision follows the FDA's Breakthrough Therapy Designation of RSVpreF in older adults in March 2022.
"With no RSV vaccines currently available, older adults remain at-risk for RSV disease and potential severe outcomes, including serious respiratory symptoms, hospitalization, and in some cases, even death," said Annaliesa Anderson, Ph.D., Senior Vice President and Chief Scientific Officer, Vaccine Research & Development, Pfizer. "The FDA's acceptance of the BLA for our RSV vaccine candidate is an important regulatory milestone in Pfizer's efforts to help protect older adults against RSV and demonstrates additional progress toward what has been an elusive public health goal - reducing the overall burden associated with this infectious disease."
The regulatory submission is supported by results of the Phase 3 clinical trial (NCT05035212) RENOIR (RSV vaccine Efficacy study iNOlder adults Immunized against RSV disease). RENOIR is a global, randomized, double-blind, placebo-controlled study designed to assess the efficacy, immunogenicity, and safety of a single dose of RSVpreF in adults 60 years of age and older. RENOIR has enrolled approximately 37,000 participants, randomized to receive RSVpreF 120 μg or placebo in a 1:1 ratio. In August 2022, Pfizer announced positive top-line results of an interim efficacy analysis for RENOIR.
Burden of RSV
RSV is a contagious virus and a common cause of respiratory illness.1 The virus can affect the lungs and breathing passages of an infected individual and can potentially cause severe illness in young infants, older adults, and individuals with certain chronic medical conditions. 2,3,4 In the United States alone, among older adults, RSV infections account for approximately 60,000-120,000 hospitalizations and 6,000-14,000 deaths each year.5,6,7,8 Among children younger than five years old in the U.S., RSV infections account for approximately 2.1 million outpatient visits and 58,000-80,000 hospitalizations occur each year.9,10,11 RSV incidence can vary dramatically from one year to the next, and this year there has been a large resurgence in cases following an evolution of masking and isolation measures.
RSV is a disease for which there are currently no prophylactic, therapeutic, or vaccine options for older adults and the medical community is limited to offering only supportive care for adults with the illness.
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 prefusion F, a key form of the viral fusion protein (F) that RSV uses to enter human cells. 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 a stabilized prefusion F protein and identified a candidate that elicited a strong anti-viral immune response in pre-clinical evaluations. The bivalent vaccine candidate is composed of equal amounts of recombinant RSV prefusion F from subgroups A and B.
Pfizer is currently the only company with an investigational vaccine being prepared for regulatory applications for both infants through maternal immunization and older adults to help protect against RSV. In November 2022, Pfizer announced a positive interim analysis of its Phase 3 clinical trial (NCT04424316) MATISSE (MATernal Immunization Study for Safety and Efficacy) investigating its bivalent RSV prefusion vaccine candidate, RSVpreF or PF-06928316, when administered to pregnant participants to help protect their infants from RSV disease after birth.
