New Phase III Data of RSV Vaccine Arexvy Shows Efficacy Through Three Full Seasons

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GSK has shared positive Phase III data from its AReSVi-006 trial of Arexvy, a respiratory syncytial virus (RSV) vaccine for adults. The study evaluated the efficacy of a single dose of Arexvy against lower respiratory tract disease (LRTD) caused by RSV in adults aged 60 years and older, including those at increased risk over three full RSV seasons.¹

Newly released results from the trial show that after a single dose of the vaccine, cumulative efficacy over three full RSV seasons was clinically meaningful at 62.9% against RSV-LRTD and 67.4% against severe RSV-LRTD compared to placebo. The vaccine’s efficacy was 48% against RSV-LRTD in the third full RSV season.

In a press release, Tony Wood, chief scientific officer, GSK, said, “We are excited by these new data which show that a single dose of Arexvy could help protect millions of older adults at risk of RSV disease over three seasons to benefit public health. This is the only RSV vaccine with efficacy and safety data available through three full seasons. We will continue to provide data on longer term follow-up to help recommending bodies determine future revaccination schedules.”

AReSVi-006 (NCT04886596) is a randomized, placebo-controlled, double-blind, multi-country trial. According to GSK, about 25,000 were enrolled across 17 countries. The study’s primary endpoint was vaccine efficacy against RSV-LRTD after one RSV season. Following one season, 12,469 participants in the vaccine arm were re-randomized to receive either the vaccine or placebo and were monitored for occurrence of RSV-LRTD after two and three seasons.

In June 2024, the FDA approved Arexvy for the prevention of RSV-LRTD in adults aged 50-59 who are at increased risk.²

“Today's approval reflects the importance of broadening the benefits of RSV immunization to adults aged 50-59 who are at increased risk,” said Wood in a press release from the time. “For those with underlying medical conditions, RSV can have serious consequences, so we are proud to be the first to help protect them from RSV-LRTD.”

The approval was supported by positive data from a Phase III study of Arexvy evaluating the immune response and safety of the vaccine in adults aged 50-59, including those at an increased risk for RSV-LRTD due to certain underlying medical conditions. The trial, NCT05590403, was a placebo-controlled, observer-blind, randomized, multi-country immunogenicity study. Its primary endpoints were RSV-A and RSV-B neutralization titers at one month after vaccine administration.

In the same press release, Professor Ann R. Falsey, University of Rochester School of Medicine, added, “I am thrilled that GSK’s RSV vaccine is now approved for adults aged 50-59 at increased risk of RSV-LRTD. When it comes to the risks associated with RSV, age is just a number, an important number, but not the only factor to consider. Many adults in this age group have underlying health conditions that place them at increased risk for serious illness with RSV infection compared with those without these conditions. Now there is a vaccine approved that can help protect them.”

References

1. GSK presents positive data for Arexvy, its respiratory syncytial virus (RSV) vaccine, indicating protection over three RSV seasons. News release. GSK. October 8, 2024. Accessed October 10, 2024. https://www.gsk.com/en-gb/media/press-releases/gsk-presents-positive-data-for-arexvy-its-rsv-vaccine-indicating-protection-over-three-rsv-seasons/

2. US FDA approves expanded age indication for GSK’s AREXVY, the first respiratory syncytial virus (RSV) vaccine for adults aged 50-59 at increased risk. News release. GSK. June 7, 2024. Accessed October 10, 2024. https://us.gsk.com/en-us/media/press-releases/us-fda-approves-expanded-age-indication-for-gsk-s-arexvy-the-first-respiratory-syncytial-virus-rsv-vaccine-for-adults-aged-50-59-at-increased-risk/