Abrysvo is the second RSV vaccine approved by the FDA.
The FDA has approved Pfizer’s bivalent respiratory syncytial virus (RSV) vaccine (Abrysvo) for the prevention of lower respiratory tract disease caused by RSV in adults aged 60 years or older, according to a news release.1 The approval makes Abrysvo the second RSV vaccine available for use in this patient population.
“This past RSV season demonstrated the serious consequences and potential health risks this virus poses for older adults,” said Edward E. Walsh, MD, professor of medicine at the University of Rochester Medical Center and principal investigator in the RENOIR study. “[The] FDA approval of Abrysvo recognizes significant scientific progress, and importantly helps provide older adults potential protection against RSV and an opportunity to improve community health by helping prevent the disease.”
Approval was based on data from the phase 3 RENIOR clinical trial (NCT05035212), a global, randomized, double-blind, placebo-controlled study evaluating the efficacy, immunogenicity, and safety of a single vaccine dose in older adults. The study cohort included 34,284 randomly assigned 1:1 to receive the bivalent RSV prefusion F (RSVpreF) vaccine 120 µg or placebo.
Although the RENOIR study is ongoing—efficacy data are being collected in a second RSV season—interim results were published in the New England Journal of Medicine.2 Analyses of these data demonstrated a vaccine efficacy of 66.7% and 85.7% against RSV-associated lower respiratory tract illness with at least 2 or 3 signs and symptoms, respectively; investigators identified 1.19 and 0.22 cases per 1000 person-years of observation in the vaccine group compared with 3.58 and 1.52 cases per 1000 person-years in the placebo group.
RSV-associated respiratory illness occurred in 22 and 58 participants in the vaccine and placebo groups, respectively, for a vaccine efficacy of 62.1% (95% CI, 37.1-77.9).
Adverse event rates were similar through 1 month after injection (9% and 8.5% in vaccine and placebo, respectively), with only 1.4% and 1% considered injection related. Incidences of local reactions were higher in the vaccine group (12% vs 7%), while incidences of systemic events were similar (27% and 26%).
Pfizer also recently reported positive topline results from a phase 3 study evaluating the safety and immunogenicity of Abrysvo coadministered with a seasonal inactivated influenza vaccine in adults aged 65 years and older. The company will also be initiating clinical trials evaluating the RSVpreF vaccine in healthy children aged 2 to 5 years, children aged 5 to 18 years with underlying medical conditions, adults aged 18 to 50 years at high risk due to underlying medical conditions, and immunocompromised adults aged 18 and older at high risk for RSV.
The Advisory Committee on Immunization Practices (ACIP) is scheduled to meet on June 21, 2023, to discuss recommendations around the appropriate use of RSV vaccines in older adults. Pfizer anticipates vaccine availability in Q3 of 2023, ahead of the anticipated RSV season.
“A vaccine to help prevent RSV had been an elusive public health goal for more than half a century,” said Annaliesa Anderson, PhD, senior vice president and chief scientific officer, vaccine research and development at Pfizer. “[This] approval is a monumental step forward in delivering on Pfizer’s commitment to help alleviate the significant burden of RSV in higher-risk populations, which includes older adults.”