The regulatory application was supported by positive results from a phase III trial (https://www.clinicaltrials.gov/study/NCT05590403 ) evaluating the immune response and safety of GSK’s RSV vaccine in adults aged 50-59, including those at increased risk for RSV-LRTD due to certain underlying medical conditions.
ACIP will presumably endorse this change at its meeting on Jun 26-27, making GSK the first RSV-vaccine company with a recommendation for the 50-59 group.
The clinical trial referenced above was a “bridging study” rather than an efficacy study. I.e., the trial showed that adults age 50-59 given Arexvy had a non-inferior safety profile and immune response compared to adults age 60+ in a separate arm of same trial.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”