The European Medicines Agency (EMA) has accepted GSK’s regulatory application seeking expansion of its adjuvanted recombinant respiratory syncytial virus (RSV) vaccine, Arexvy, to include adults aged 50 to 59 years.

If approved, the vaccine would become the first to be available for protecting this age group against RSV.

Arexvy is currently indicated for use in individuals aged 60 years and above to prevent RSV-associated lower respiratory tract disease in Europe.

The application is based on positive data from a Phase III trial, which demonstrated non-inferior immune responses in adults aged 50 to 59 compared to those aged 60 and above.

This observer-blind, placebo-controlled, randomised study analysed immune responses in participants aged 50 to 59 without pre-defined chronic diseases compared with those of adults aged 60 and older. 

The trial's primary endpoints were RSV-A and RSV-B neutralisation titres [levels in the bloodstream] one-month post-vaccination in the 50-59 age group versus the older cohort.

The study met these endpoints, indicating a comparable immune response between the two age groups.

A decision from the European regulatory authority is anticipated in the second half of 2024.

The vaccine, which includes the recombinant glycoprotein F stabilised in the prefusion conformation, is combined with AS01E adjuvant.

It has already received approval in Japan, the US, the UK and Canada for the same indication. Reviews for regulatory approval in additional countries are ongoing.

GSK is the first company to seek regulatory approval for an RSV vaccine in the 50-59 year demographic.

The expansion could provide significant protection for adults in this age range who are at an increased risk of severe RSV disease due to underlying health conditions.

The latest development comes after the company agreed to acquire asthma drug specialist Aiolos Bio in a $1.4bn deal to bolster its respiratory and inflammatory asset pipeline.