GlaxoSmithKline (GSK) has announced that the US Food and Drug Administration (FDA) has accepted for review its application to expand the use of its respiratory syncytial virus (RSV) vaccine, Arexvy (adjuvanted), to include adults aged 18–49 who are at increased risk.

Arexvy is currently approved in over 60 countries, including the US, for the prevention of lower respiratory tract disease (LRTD) caused by RSV in adults aged 60 and above. It is also approved for at-risk individuals aged 50–59 in more than 50 markets, including the US, Japan, and countries across Europe.

RSV is a common contagious virus that affects the lungs and respiratory passages, impacting an estimated 64 million people of all ages globally each year. It can worsen underlying medical conditions and, in severe cases, lead to hospitalisation or death.  

In the US, over 125 million adults are under the age of 50, with approximately 21 million of them having at least one diagnosed risk factor for severe RSV illness—such as asthma, chronic obstructive pulmonary disease (COPD), congestive heart failure, or coronary heart disease.    

The current regulatory submission is backed by data from a Phase IIIb clinical trial assessing the immune response and safety profile of Arexvy in adults aged 18–49 with increased risk, compared to those aged 60 and older.

The safety and reactogenicity findings were consistent with the Phase III data that supported the vaccine’s initial US approval.  

A final decision from the FDA on this submission is expected in the first half of 2026.

GSK also continues to pursue additional regulatory approvals to extend the vaccine’s indication in other regions, including the European Economic Area and Japan.