GSK has announced positive data regarding its respiratory syncytial virus (RSV) vaccine, Arexvy, demonstrating sustained protection against RSV-related lower respiratory tract disease (LRTD) over three seasons in adults aged 60 and older. Additionally, the company reported positive results from a Phase 3 trial assessing the co-administration of Arexvy with its shingles vaccine, Shingrix.
Sustained Efficacy of Arexvy Over Three RSV Seasons
New data from the AReSVi-006 Phase 3 trial indicates that a single dose of Arexvy provides clinically meaningful protection over three full RSV seasons. The cumulative efficacy against RSV-LRTD was 62.9% (97.5% CI, 46.7-74.8), while efficacy against severe RSV-LRTD was 67.4% (95% CI, 42.4-82.7) compared to placebo. In the third season alone, the vaccine's efficacy against RSV-LRTD was 48.0% (95% CI, 8.7-72.0).
The study, which involved approximately 25,000 participants from 17 countries, showed that Arexvy's efficacy extended to different RSV subtypes and was consistent in adults aged 70-79 years and those with underlying medical conditions. Tony Wood, Chief Scientific Officer at GSK, noted that these data indicate that a single dose of Arexvy could protect millions of older adults at risk of RSV disease over three seasons.
Co-administration of Arexvy and Shingrix
In a separate development, GSK announced positive topline data from a Phase 3 trial evaluating the co-administration of Arexvy and Shingrix. The trial assessed the immunogenicity, reactogenicity, and safety of co-administering the vaccines in adults aged 50 years and older. The results demonstrated a non-inferior immune response when the vaccines were co-administered compared to when they were administered separately.
The study included 530 participants who were randomized to receive either co-administered RZV and Arexvy at visit 1 or a first dose of RZV alone (control). The control group then received Arexvy at day 31, and the second dose of RZV was given at day 61 in both groups. The co-administered vaccines were well-tolerated, with acceptable reactogenicity and safety profiles. The most common adverse events in both groups included pain at the injection site, fatigue, and myalgia.
Len Friedland, MD, Vice President of Scientific Affairs and Public Health at GSK, stated that co-administration studies help remove barriers to adult immunization by potentially reducing the number of healthcare visits. This approach could improve vaccination rates for both RSV and shingles, which pose significant health risks to older adults and those with underlying health conditions.
Implications for Public Health
These findings have significant implications for public health. RSV affects an estimated 64 million people globally each year, leading to over 465,000 hospitalizations and 33,000 deaths in adults aged 60 and older in high-income countries. Shingles, caused by the reactivation of the varicella-zoster virus (VZV), also poses a substantial health risk to adults, particularly those over 50.
By demonstrating sustained efficacy over multiple seasons and positive co-administration data, GSK is positioning Arexvy and Shingrix as essential tools in preventing respiratory and shingles-related illnesses in older adults. The company plans to submit these data to regulatory bodies for review and to inform future revaccination schedules.
