A large phase 3 study conducted over GSK’s RSV vaccine Arexvy has shown how the vaccine’s efficacy varies and wanes over seasons. The study enrolled around 25,0000 people from 17 different countries and compared the treatment to a placebo at different intervals to reveal that against RSV-caused lower respiratory tract disease, Arexvy demonstrated an efficacy of 83% in the first season.
In the subsequent seasons, the efficacy dropped from 56% in the second to less than 50% in the third. Results from the trial are to be shared at the CHEST 2024 Annual Meeting, with regulatory agencies and will also be published in peer-reviewed journals.
The trials played an important role in generating continued support for the approval of Arexvy as the first RSV shot to gain approval in the U.S. and the safety profile from these trial results has been consistent with previous ones.
Since its approval last year, Arexvy has been joined by Pfizer’s Abrysvo and most recently Moderna’s mResvia in the market, although it still holds the most market share. The evidence from the study is only expected to bolster GSK’s position in the market.
Over the summer, recommendations were made by advisors to the CDC as a result of which it was decided that vaccine regimes would be tightened for adults, with a focus on those aged 75 years or older, and those at high risk of the disease. To discuss these measures further in detail, another meeting is scheduled for later this month.
Peter Welford a Jefferies analyst in a note to clients hinted at the fact that the meeting could include discussions on GSK’s trial results for Arexvy. He said that although it is difficult to say anything for sure there is a low possibility that a two-year vaccination schedule be considered for the vaccine.
Investors have keenly been following any recommendations made to the agency since any changes suggested to the vaccine schedule are bound to cause changes in the uptake of the vaccine. Presently those who have already received a vaccination are not advised to get another shot and that has resulted in sales tracking lower than last year.
RSV is a common respiratory infection that becomes widespread during the winter. Each year in the U.S. alone it results in the hospitalization of 100,000 to 160,000 older adults.
