GSK says EU heath regulator reviewing expansion of RSV vaccine

GSK's application to expand the use of its RSV vaccine, Arexvy, to adults aged 18 and above has been accepted by the European Medicines Agency, potentially intensifying competition with Merck's mRESVIA and Pfizer's Abrysvo following recent U.S. approvals for similar expanded use; the decision on the EU approval is expected in the first half of 2026 as GSK seeks to revive falling Arexvy sales, which were down 57% in the first quarter to 0.1 billion pounds, missing market expectations despite initial blockbuster projections.

Analysis

The European Medicines Agency's acceptance of GSK's application to expand the use of its Respiratory Syncytial Virus (RSV) vaccine, Arexvy, to adults aged 18 and above represents a potential avenue for market expansion, although a final regulatory decision is not anticipated until the first half of 2026. This strategic move aims to enhance GSK's competitive standing against rivals such as Merck, whose mRESVIA recently secured U.S. approval for adults aged 18 to 59, and Pfizer's Abrysvo. Despite this regulatory progression, Arexvy's commercial performance has been a significant concern; first-quarter sales for the vaccine dropped sharply by 57% to 0.1 billion pounds, falling considerably short of market expectations and GSK's initial blockbuster projection of 3 billion pounds in peak annual sales. This underperformance is reflected in the negative sentiment score of -0.3 for GSK. An eventual EU approval for the expanded indication could be vital for GSK to revitalize Arexvy's sales and more effectively navigate the increasingly competitive RSV vaccine market, where Merck currently holds a positive sentiment (0.7) following its recent U.S. regulatory success.

Key Decisions for Investors

• Investors should consider the EMA's review of Arexvy's expanded use as a potential long-term catalyst for GSK, but temper expectations with caution due to the vaccine's current significant sales decline and the extended H1 2026 timeline for a European decision.
• The intensified competition within the RSV vaccine market, notably from Merck's mRESVIA following its U.S. approval, necessitates careful monitoring as it poses a risk to Arexvy's market penetration and pricing power.
• Closely track GSK's upcoming quarterly reports for any signs of stabilization or recovery in Arexvy sales, alongside further regulatory milestones and competitive product developments from Pfizer and Merck to gauge the evolving market dynamics.