GSK Seeks Expanded Use Approval from FDA for RSV Vaccine Arexvy

Science laboratory test tubes, laboratory equipment | Image Credit: © BillionPhotos.com - © BillionPhotos.com - stock.adobe.com

GSK announced on July 14, 2025, that FDA has accepted the company’s application to extend the indication for respiratory syncytial virus vaccine, adjuvanted (Arexvy), GSK’s respiratory syncytial virus (RSV) vaccine, to adults aged 18–49 who are at increased risk. The vaccine is approved in the United States to prevent lower respiratory tract disease (LRTD) caused by RSV in adults older than 60 years. It is also approved to treat people aged 50–59 who have increased risk for LRTD caused by RSV.

A Phase IIIb trial evaluated the immune response and safety of Arexvy in adults aged 18–49 at increased risk, and results showed that the safety and reactogenicity data were consistent with those from a Phase III program from the original vaccine approval in the US.

Arexvy contains recombinant RSV glycoprotein F stabilized in the prefusion conformation (RSVPreF3) and is combined with AS01E adjuvant, which includes the QS-21 adjuvant that is licensed by the Agenus subsidiary, Antigenics. It has been approved to prevent RSV-LRTD in adults older than 60 years in more than 60 countries and is approved for adults aged 50–59 who are at increased risk in more than 50 markets.

RSV, a contagious virus that impacts the lungs and breathing passages, affects approximately 64 million people globally, according to a press release from GSK (1), and an estimated 21 million people have at least one risk factor for severe RSV infection. Diseases such as asthma, chronic obstructive pulmonary disease, and heart conditions may put adults at increased risk for RSV, and RSV may make these conditions worse, causing hospitalization or death.

Risk of Guillain-Barré syndrome

Risk for Guillain-Barré syndrome (GBS) is increased during the 42 days after vaccination with Arexvy, according to postmarketing data. A diminished immune response may be seen in immunocompromised people. Adverse events associated with the vaccine include injection site pain, fatigue, myalgia, headache, arthralgia, erythema, and swelling.

In January 2025, FDA issued a requirement for a GBS warning in the prescribing information for Arexvy. The rare disorder damages nerve cells and can cause weakness and paralysis. The warning came after an evaluation of Medicare claims data that suggested an increase of GBS but evidence was insufficient to establish a causal relationship (2).

FDA’s decision on the expanded indication is expected in the first half of 2026. GSK is also seeking expanded indications for the vaccine in the European Economic Area and Japan.

Earlier FDA approvals for RSV vaccines

In October 2024, FDA approved another RSV vaccine, a bivalent RSV prefusion F vaccine, Abrysvo, from Pfizer with a broad indication for adults aged 18–59 years at increased risk as well as those older than 60 years. The vaccine was also approved in the European Union in August 2023 (3).

“Immunocompromised adults, such as patients with cancer or autoimmune disorders, have a substantially increased risk of experiencing severe complications from RSV, yet there are currently no vaccines approved for those aged 18 to 59 in the [United States],” said Annaliesa Anderson, Pfizer senior vice president and chief scientific officer for vaccine research and development, in an August 2024 press release about the results (4). “We are encouraged by the positive top-line data from this study, which provide important evidence that Abrysvo has the potential to address a significant unmet need in this vulnerable population.”

References

1. GSK. US FDA Accepts Application to Review Expanded Use of GSK’s RSV Vaccine, Arexvy, for Adults 18-49 At Increased Risk. Press Release. July 14, 2025. https://us.gsk.com/en-us/media/press-releases/fda-accepts-application-to-review-expanded-use-of-gsk-s-rsv-vaccine-arexvy/

2. FDA. FDA Requires Guillain-Barré Syndrome (GBS) Warning in the Prescribing Information for RSV Vaccines Abrysvo and Arexvy. FDA.gov. Jan. 7, 2025. https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/fda-requires-guillain-barre-syndrome-gbs-warning-prescribing-information-rsv-vaccines-abrysvo-and

3. Haigney, S. RSV Vaccine Approved for Adults 18–59, PharmTech.com. Oct. 23, 2024. https://www.biopharminternational.com/view/rsv-vaccine-approved-for-adults-18-59

4. Pfizer. Pfizer Announces Top-Line Results of Abrysvo for RSV in Immunocompromised Adults. Press Release. Aug. 12, 2024.