The Japanese Ministry of Health, Labour and Welfare (MHLW) has accepted for review GSK’s regulatory application for the use of respiratory syncytial virus (RSV) vaccine (recombinant adjuvanted), Arexvy, in high-risk adults aged 50 to 59 years.

The latest regulatory application sought an indication extension of the vaccine to prevent RSV disease in adults in this age group.

Arexvy consists of recombinant glycoprotein F stabilised in the prefusion conformation. This antigen is combined with the AS01E adjuvant of GSK.

In September 2023, the MHLW approved the vaccine to prevent RSV disease in adults aged 60 years and above.

The company filed the application based on the positive data from Phase III multi-country, observer-blind, placebo-controlled, randomised, immunogenicity clinical trial of GSK’s RSV vaccine in adults aged 50 to 59.

The study assessed the immune response and safety of a single dose of the vaccine in this patient population, including individuals at high RSV-associated lower respiratory tract disease (LRTD) risk due to underlying medical issues.

The trial compared the effects seen in these patients with those in adults aged 60 and above.

The company reported in October 2023 that its RSV vaccine trial in adults aged 50 to 59 met the primary endpoints.

Pain was the most frequently reported local adverse event, with fatigue and headache the most common systematic adverse events in the trial.

Arexvy was shown to induce an immune response in those with increased RSV risk, with the immune response non-inferior to that observed in adults aged 60 and above.

The safety and reactogenicity data of the vaccine in the trial was in line with the previously reported safety profile in the approved patient group. 

The vaccine is also indicated for use in this age group in Europe, the US, Canada, the UK and other regions for preventing RSV-associated LRTD.

Regulatory reviews for the RSV vaccine are currently underway in several countries.