A phase III trial investigating the GSK RSV vaccine candidate for adults aged 60 years and above exceeded its primary endpoint with no unexpected safety concerns observed, according to a pre-specified efficacy interim analysis of the AReSVi 006 phase III trial.

GSK said it will present results in a peer-reviewed publication and at an upcoming scientific meeting.

The AReSVi 006 phase III trial is a randomized, placebo-controlled, observer-blind, multi-country trial to demonstrate the efficacy of a single dose of the GSK RSV Vaccine (adjuvanted RSVPreF3 OA investigational vaccine) in adults aged 60 years and above. Approximately 25,000 participants were enrolled from 17 countries.

AReSVi 006 is part of a comprehensive RSV evidence generation programme conducted by GSK. Recent in-house results from a parallel phase III trial, AReSVi 004, investigating the immunogenicity, safety, reactogenicity, and persistence of the vaccine candidate in older adults showed that, in participants aged 60 years and above, one dose of the RSV OA investigational vaccine induced strong humoral and cellular immune responses, which remain above pre-vaccination levels up to at least the six months post-vaccination readout timepoint.

AReSVi 006 is closely monitored for safety, with safety data reviewed internally and by an external Independent Data Monitoring Committee on an ongoing basis.

The AReSVi 006 trial will continue to evaluate both an annual revaccination schedule and longer-term protection over multiple seasons following one dose of the RSV older adult (OA) vaccine candidate.

Dr Hal Barron, Chief Scientific Officer and President, R&D, GSK, said: “These data suggest our RSV vaccine candidate offers exceptional protection for older adults from the serious consequences of RSV infection. RSV remains one of the few major infectious diseases without a vaccine, and these data have the potential to meaningfully impact the treatment of RSV and may reduce the 360,000 hospitalisations and more than 24,000 deaths worldwide each year. Given the importance of these data, we plan to engage with regulators immediately and anticipate regulatory submissions in the second half of 2022.”

GSK’s RSV OA vaccine candidate contains a recombinant subunit prefusion RSV F glycoprotein antigen (RSVPreF3) combined with GSK’s proprietary AS01 adjuvant. AS01 is used with several of GSK’s established adjuvanted vaccines. The antigen plus adjuvant combination may help overcome the natural age-related decline in immunity that contributes to the challenge of protecting older adults from RSV disease.