Updated Data for Arexvy Show Vaccine Efficacy Across Multiple RSV Seasons

A single dose of respiratory syncytial virus (RSV) vaccine, adjuvanted (Arexvy; GSK) produced efficacy against lower respiratory tract disease (LRTD) caused by RSV in adults 60 years of age and older across multiple RSV seasons and following an annual revaccination, according to data from the AReSVi-006 (Adult Respiratory Syncytial Virus) phase III trial. The findings indicate that a single dose of Arexvy is effective preventing RSV-LRTD and severe LRTD across 2 full RSV seasons, according to GSK.

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The FDA approved Arexvy on May 3, 2023, to prevent LRTD caused by RSV in individuals 60 years of age and older.

“Our goal is to provide a high level of protection for older adults most at risk from RSV,” Tony Wood, chief scientific officer, GSK, said in a press release. “These data show the efficacy of a single dose of our vaccine over two RSV seasons against RSV-LRTD, including in the populations most at risk due to age or underlying medical conditions. This reinforces our confidence in its potential to make a significant public health impact. We look forward to discussing these results with regulators and vaccine recommending bodies and to collecting more data from the ongoing clinical development program.”

Arexvy contains a recombinant subunit prefusion RSV F glycoprotein antigen (RSVPreF3) combined with GSK’s proprietary AS01E adjuvant. RSV develops in between 3% and 7% of healthy older adults in the United States and Europe each year, with an estimated 177,000 hospitalizations and 14,000 deaths each year in the United States. RSV can be especially severe in older adults, with approximately 18% admitted to an intensive care unit, 31% receiving home health services at discharge, and 26% dying within 1 year post admission.

In older adults, the virus is a common cause of LRTD, which affects the lungs and can cause life-threatening pneumonia and bronchiolitis. The CDC has found that on an annual basis, RSV leads to approximately 60,000-120,000 hospitalizations and 6000-10,000 deaths among adults 65 years of age and older.

According to the study investigators, a similar pattern of vaccine efficacy was demonstrated across 2 seasons in adults with underlying comorbidities and in advancing age, which supports the impact Arexvy could have on individuals with the greatest risk of severe RSV outcomes.

A confirmatory secondary endpoint of the trial was efficacy after an annual revaccination schedule. The results showed that cumulative efficacy across 2 seasons in those administered a second dose of the vaccine was 67.1% (97.5% CI, 48.1-80.0, 30 of 12,469 vs 139 of 12,498). This indicates that revaccination after 12 months does not confer an additional benefit for the overall population, according to the study. Investigators will continue analyzing longer term follow up data and the optimal timing for potential revaccination, according to GSK.

Safety and reactogenicity data were found to be consistent with prior observations from the phase III program, according to the study investigators. The most commonly reported adverse effects in patients administered Arexvy during clinical trials were injection site pain, fatigue, muscle pain, headache, and joint stiffness/pain. Among all clinical trial participants, atrial fibrillation within 30 days of vaccination was reported in 10 participants administered Arexvy and 4 participants administered the placebo.

These updated findings will be presented at the US Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices meeting with data from a pair of influenza co-administration trials (quadrivalent high dose and quadrivalent adjuvanted) and will be submitted to the FDA for review.

Reference

GSK shares positive data for Arexvy, its respiratory syncytial virus (RSV) older adult vaccine, indicating protection over two RSV seasons. GSK. News release. June 21, 2023. https://www.gsk.com/en-gb/media/press-releases/gsk-shares-positive-data-for-arexvy-its-respiratory-syncytial-virus-older-adult-vaccine-indicating-protection-over-two-rsv-seasons/