GSK Launches Phase III Bridging Clinical Trial of RSV Vaccine in China

▎Armstrong

On August 13, 2024, GSK registered a Phase III clinical trial in China for its recombinant RSV vaccine on the Clinicaltrials.gov website.

GSK's recombinant RSV vaccine was released in May last year.MonthGSK's vaccine has been approved for marketing by the FDA. The Phase III clinical trial registered in China this time is a bridging Phase III trial, planning to enroll 2,600 healthy individuals over 60 years old, with the primary endpoint follow-up expected to be completed by March 2025.

The primary endpoint of this Phase III bridging study is immunogenicity, including neutralizing antibody titers against RSV-A/B and seroconversion rates (defined as a four-fold or greater increase in neutralizing antibodies).

Summary

GSK and Pfizer's RSV vaccines were approved for marketing last year, with combined first-year sales of $2.4 billion. Moderna's RSV mRNA vaccine was approved for marketing this year.In June this year, ACIP adjusted the recommended vaccination population to those over 75 years old.OrHigh-risk populations aged 60-74 (accounting for approximately 35-40%) are expected to see an acceleration in market penetration due to the increased recommendation level, changing from physician recommendation to recommendation upon meeting eligibility criteria.In addition, the current ACIP recommendation is for a single immunization, primarily due to the lack of clinical data supporting repeated immunization.From the currently available RSV vaccines, the decline in neutralizing antibodies is relatively rapid, and the protection period may not exceed two years. In the future, as data on repeated immunization becomes available, it may shift from single-dose immunization to repeated (e.g., biennial) immunization.