GSK said a dose of its RSV vaccine protected against illness over three years, according to new data presented at the CHEST 2024 Annual Meeting.
In the Phase 3 trial, called AReSVi-006, a dose of Arexvy was 62.9% effective over three disease seasons, measured on the shot’s ability to prevent lower respiratory infections. It was 67.4% effective at preventing severe disease caused by respiratory syncytial virus, or RSV.
RSV cases begin to rise in the fall and run through the winter, a period lasting several months that accounts for the “season.”
“This is the only RSV vaccine with efficacy and safety data available through three full seasons,” GSK’s CSO Tony Wood said in a statement. “We will continue to provide data on longer term follow-up to help recommending bodies determine future revaccination schedules.”
Protection did wane slightly by the third season, when efficacy fell to 48%.
Arexvy was the first RSV vaccine to be approved and has taken around 60% of the retail market share, followed by Pfizer and Moderna’s vaccines. But according to analyst reports released last week, the vaccines have seen a slower uptake this season, and weekly Arexvy prescriptions were down more than half compared with last year.
“Every 3-year revaccination is consistent with our base case, and longer-term demonstrates a perhaps differentiated value of Arexvy vs competitors,” Jefferies analysts wrote in a Tuesday note. “However, near-term [consensus] sales likely need to be cut.”
GSK has said it expects the vaccine to reach £3 billion ($3.93 billion) or more in peak revenue. Sales last year were £1.2 billion ($1.6 billion).