First Respiratory Syncytial Virus Vaccine Approved by FDA

The FDA has approved GSK’s Arexvy for use in the United States,¹ making it the first vaccine approved for use in older adults (≥60 years) to prevent lower respiratory tract disease (LRTD) associated with respiratory syncytial virus (RSV).

“Older adults, in particular those with underlying health conditions, such as heart or lung disease or weakened immune systems, are at high risk for severe disease caused by RSV. Today’s approval of the first RSV vaccine is an important public health achievement to prevent a disease which can be life-threatening and reflects the FDA’s continued commitment to facilitating the development of safe and effective vaccines for use in the United States,” Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, said in the FDA’s news release announcing the approval.¹

RSV is a virus that can cause infections in the lungs and breathing passages in all age groups, with circulation adhering to seasonal cycles. RSV is the cause of approximately 60,000 to 120,000 hospitalizations and 6000 to 10,000 deaths annually in adults 65 years and older in the United States, according to the CDC.

The approval of the Arexvy vaccine is based on data from a randomized, placebo-controlled clinical study that is ongoing in the United States and internationally, referred to as the AReSVi-006 phase 3 trial.² The study, which enrolled adults 60 years and older, included 12,500 participants who received a single dose of the Arexvy vaccine and 12,500 who received a placebo. The researchers found that the vaccine significantly reduced the risk of developing LRTD associated with RSV by 82.6% (96.95% CI, 57.9-94.1) and reduced the risk of developing severe LRTD associated with RSV by 94.1% (95% CI, 62.4-99.9). Efficacy was found to be 94.6% (95% CI, 65.9-99.9) in older adults who had at least 1 underlying medical condition.

Adverse effects seen during the clinical trial included injection site pain, fatigue, muscle pain, headache, and joint stiffness/pain. Atrial fibrillation was reported in 10 participants who received Arexvy and 4 participants who received the placebo within 30 days of injection.

Another 2 studies involving 2500 participants tested the safety and efficacy of the Arexvy vaccine in patients 60 years and older. Two participants developed acute disseminated encephalomyelitis (ADEM) 7 and 22 days after receiving the vaccination in 1 of the studies, in which participants received Arexvy along with an FDA-approved influenza vaccine; 1 of these participants died from this rare inflammation affecting the brain and spinal cord. A participant developed Guillain-Barre syndrome 9 days after receiving Arexvy in the second study.

A postmarketing study to assess the risk of Guillain-Barre syndrome and ADEM will be required by the FDA. The postmarketing study will also assess the risk of atrial fibrillation despite it not being required.

GSK is currently planning to conduct a clinical trial that aims to assess the safety and efficacy of the vaccine in adults aged 50 to 59 years, including those with comorbidities. These results are expected later this year. Annual revaccination schedules are also being assessed during ongoing trials.

The Advisory Committee on Immunization Practices will make recommendations for use of the vaccine in the United States in June 2023, and the vaccine will become available prior to the 2023/2024 RSV season. The United States is currently the only country to approve the Arexvy vaccine for use. However, a European regulatory decision is expected within the next few months and regulatory reviews are ongoing in other countries, including Japan.

“Today marks a turning point in our effort to reduce the significant burden of RSV. Arexvy is the first approved RSV vaccine for older adults, expanding GSK’s industry-leading vaccine portfolio, which protects millions of people from infectious diseases each year,” Tony Wood, chief scientific officer at GSK, said in the company’s news release. “Our focus now is to ensure eligible older adults in the [United States] can access the vaccine as quickly as possible and to progress regulatory review in other countries.”

References

1. FDA approves first respiratory syncytial virus (RSV) vaccine. News Release. FDA; May 3, 2023. Accessed May 3, 2023. https://www.fda.gov/news-events/press-announcements/fda-approves-first-respiratory-syncytial-virus-rsv-vaccine
2. US FDA approves GSK’s Arexvy, the world’s first respiratory syncytial virus (RSV) vaccine for older adults. News release. GSK; May 3, 2023. Accessed May 3, 2023. https://www.gsk.com/en-gb/media/press-releases/us-fda-approves-gsk-s-arexvy-the-world-s-first-respiratory-syncytial-virus-rsv-vaccine-for-older-adults/