RSV Vaccine Arexvy Wins FDA Approval for Older Adults

The Food and Drug Administration (FDA) has approved Arexvy (respiratory syncytial virus vaccine, adjuvanted) for the prevention of lower respiratory tract disease (LRTD) caused by respiratory syncytial virus (RSV) in individuals 60 years of age and older.

The approval was based on data from the ongoing randomized, placebo-controlled, observer-blind phase 3 AReSVi 006 trial (ClinicalTrials.gov Identifier: NCT04886596), which included approximately 25,000 adults 60 years of age and older. The efficacy of Arexvy in the prevention of a first episode of confirmed RSV-A and/or B-associated LRTD during the first season was the study’s primary endpoint.

Vaccine efficacy was reported to be 82.6% (96.95% CI, 57.9-94.1), with 7 cases in the vaccine arm compared with 40 cases in the placebo arm. The median follow-up time was 6.7 months for both study groups. Vaccine efficacy against RSV A-associated LRTD cases and RSV B-associated LRTD cases was 84.6% (95% CI, 32.1-98.3) and 80.9% (95% CI, 49.4-94.3), respectively. Compared with placebo, Arexvy significantly reduced the risk of developing severe RSV-associated LRTD by 94.1% (95% CI, 62.4-99.9).

In participants 70 years of age and older, Arexvy significantly reduced the risk of developing RSV-associated LRTD by 84.4% (95% CI, 46.9-97.0), compared with placebo. Due to the low number of cases in patients 80 years of age and older, vaccine efficacy in this population could not be concluded.

Concomitant administration of Arexvy with Fluarix Quadrivalent showed no interference in the immune response to any of the antigens contained in the vaccines, according to phase 3 data (ClinicalTrials.gov Identifier: NCT04841577).

The most commonly reported adverse events were injection site pain, fatigue, myalgia, headache, and joint stiffness/pain. Within 30 days after vaccination, atrial fibrillation was reported in 10 participants who received Arexvy and 4 participants who received placebo. Additionally, 2 cases of acute disseminated encephalomyelitis and 1 case of Guillain-Barré syndrome were observed during clinical development. The FDA is requiring a postmarketing study to assess these safety signals. While not required by the agency, GlaxoSmithKline will also evaluate atrial fibrillation risk in the postmarketing study.

Arexvy is supplied as 2 components: a single-dose vial of lyophilized antigen component (powder) and a single-dose vial of adjuvant suspension component (liquid) (packaged without syringes or needles). Following reconstitution, the vaccine should be administered by intramuscular injection. A single dose after reconstitution is 0.5mL.

Arexvy is expected to be available for the 2023-2024 RSV season.