GSK’s Arexvy RSV Vaccine Shows Promise in Younger Adults, Following Pfizer’s Approval

GSK's Response to Pfizer's Approval:
GSK has released preliminary data for its RSV vaccine, Arexvy, indicating potential protection for adults aged 18-49 at increased risk of lower respiratory tract disease (LRTD) caused by RSV.

Expanded Age Indication:
The US FDA has approved Arexvy for the prevention of RSV-LRTD in adults aged 50-59 who are at increased risk, in addition to its previous approval for adults aged 60 and older.

Clinical Trial Results:
A phase 3b trial showed that a single dose of Arexvy triggered strong immune responses in adults aged 18-49 at elevated risk for RSV-LRTD, meeting the trial's co-primary endpoints.

Competitive Landscape:
Pfizer's RSV vaccine, ABRYSVO, has been approved for adults aged 18-59 at increased risk, making it the first and only RSV vaccine indicated for adults younger than 50.

Long-term Efficacy:
GSK's Arexvy has demonstrated cumulative efficacy over three full RSV seasons, with a clinically meaningful efficacy of 62.9% against RSV-LRTD and 67.4% against severe RSV-LRTD.

Regulatory Reviews:
GSK has filed regulatory submissions to extend the use of its RSV vaccine to adults aged 50-59 at increased risk in Europe, Japan, and other geographies, with reviews ongoing.

Market Impact:
The approval and data releases from both GSK and Pfizer highlight the growing competition in the RSV vaccine market, with multiple options now available for different age groups.