The FDA has expanded the approval of GSK’s respiratory syncytial virus (RSV) vaccine, Arexvy, to include adults aged 50-59 who are at increased risk of severe illness from the virus. Arexvy, the first FDA-approved vaccine for this demographic, was initially approved in May 2023 for adults 60 and older, who are particularly vulnerable to severe RSV cases.
RSV is responsible for thousands of hospitalizations and deaths among seniors annually, according to the CDC. However, adults aged 50 and above with chronic conditions such as asthma, diabetes, and congestive heart failure are also at significant risk of severe illness from the virus. Approximately 13 million Americans in this age group fall into the high-risk category, according to Phil Dormitzer, GSK’s head of vaccines research and development.
Dormitzer highlighted the dual benefit of the vaccine’s expanded approval: addressing the medical needs of a broader age group and simplifying vaccine administration for pharmacists. The CDC’s advisory panel is expected to vote later in June on recommendations for GSK’s vaccine, alongside competing shots from Pfizer and Moderna.
The FDA’s decision could strengthen GSK’s position in the RSV market, especially during the fall and winter seasons when the virus spreads more widely. GSK’s Arexvy generated around £1.2 billion in sales last year, surpassing Pfizer’s vaccine revenue. GSK Chief Commercial Officer Luke Miels expressed confidence that Arexvy could achieve over £3 billion in peak annual sales.
Dormitzer noted Arexvy’s strong efficacy in high-risk adults aged 50-59, consistent with results observed in older adults. In a late-stage trial, the vaccine elicited a robust immune response in the 50-59 age group, comparable to that in people aged 60 and above. A previous trial showed Arexvy to be nearly 83% effective in preventing lower respiratory tract disease caused by RSV and around 94% effective in preventing severe disease in the older age group.
Safety data for adults aged 50-59 was similar to that for adults aged 60 and above, with side effects such as fatigue, headache, and muscle pain, mostly mild to moderate. The vaccine’s efficacy in adults aged 60 and up remained strong after two RSV seasons, with 67.2% effectiveness against lower respiratory tract illness. GSK plans to test the vaccine’s efficacy over three RSV seasons to assess its long-term protection.
GSK is also conducting trials to expand Arexvy’s approval to other patient groups, including high-risk individuals aged 18-59 and adults with weakened immune systems. Additionally, regulatory agencies in Europe, Japan, and other regions are reviewing GSK’s application to expand Arexvy’s approval to high-risk adults aged 50-59.
This broader approval marks a significant step in protecting more vulnerable populations from the potentially severe impacts of RSV.
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