With no vaccines currently approved for RSV, Pfizer and GSK are neck-and-neck to be first on the market with their vaccines. Last month, GSK similarly gained priority review from the FDA for its BLA with a decision date also set as May.
Both vaccines are for use in older adults; while Pfizer is also working on a maternal RSV candidate (which is in Phase 3 trials).
Elusive public health goal
Pfizer’s RSV vaccine candidate, PF-06928316 or RSVpreF, has been submitted for prevention of lower respiratory tract disease caused by RSV in individuals 60 years of age and older.
Priority review designation from the FDA reduces the standard BLA review period by four months: with the Prescription Drug User Fee Act (PDUFA) goal date for a decision by the FDA in May 2023.
RSV is a contagious virus and common cause of respiratory illness: with the potential to cause severe illness in young infants, older adults and individuals with certain chronic medical conditions. In the US, RSV infections account for up to 120,000 hospitalizations and 6,000 – 14,000 deaths a year.
Last month, the Centers for Disease Control and Prevention (CDC) warned that there has been an increase in RSV cases and RSV associated emergency department visits and hospitalizations in almost all of its regions: already reaching the typical December and January seasonal peak highs in some areas.
“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.”
Pfizer's regulatory submission is supported by results of the Phase 3 Renoir trial: 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.
The vaccine gained FDA Breakthrough Therapy Designation in March 2022.
Pfizer Phase 3 trial for RSV vaccine candidate in older adults
- In data published in August, Pfizer reported vaccine efficacy of 85.7% in participants aged 60+ with more severe disease primary endpoint of lower respiratory tract illness (LRTI-RSV) defined by analysis of three or more RSV-associated symptoms. The vaccine was ‘well-tolerated with no safety concerns’.
- The bivalent vaccine candidate is composed of two preF proteins selected to optimize protection against RSV A and B strains.
- In the US, the vaccine has a PDUFA goal date of May, 2023.
GSK Phase 3 trial for RSV vaccine candidate in older adults
- In data published in October, GSK reported overall vaccine efficacy of 82.6% for its vaccine, with consistent efficacy against RSV A and B strains. The vaccine has a ‘favorable safety profile’.
- This candidate contains a recombinant subunit prefusion RSV F glycoprotein antigen (RSVPreF3) combined with GSK’s proprietary AS01E adjuvant.
- In the US, the vaccine has a PDUFA goal date of May, 2023.
- In the EU, the European Medicines Agency has accepted the vaccine’s marketing authorisation application under accelerated assessment, with a decision anticipated in Q3 2023. A new drug application has also been accepted by the Japanese Ministry of Health, Labour and Welfare.
Meanwhile, Moderna’s mRNA candidate mRNA-1345 entered Phase 3 trials for adults aged 60+ in February, with the FDA having granted Fast Track designation for the vaccine. Bavarian Nordic’s candidate entered Phase 3 trials in April while Johnson & Johnson’s candidate (which has FDA Breakthrough Therapy Designation) announced its Phase 3 trial in September last year.