GSK Presents Phase III Data for RSV, Shingles Combo Shots

GSK has announced promising Phase III trial results for the combined administration of its RSV vaccine, Arexvy, and its shingles vaccine, Shingrix. According to the company, the co-administration of these vaccines generates an immune response comparable to when the vaccines are administered separately. GSK stated that this combo vaccination was well-tolerated with an acceptable safety profile, although specific details on side effects were not disclosed.

Led Friedland, GSK's vice president of scientific affairs and public health, remarked that co-administering these vaccines could reduce the number of healthcare visits required, thereby removing barriers to adult immunization. The company plans to use these Phase III results to seek regulatory approval from the FDA and the European Medicines Agency for the combined use of Arexvy and Shingrix. If successful, this could potentially increase the sales of both vaccines.

Arexvy has established itself as a leading RSV vaccine, having been the first to receive approval in May 2023, ahead of Pfizer’s Abrysvo. According to GSK’s third-quarter 2023 earnings report, Arexvy accounted for two-thirds of retail RSV vaccinations in the U.S., generating $859 million in its first full commercial quarter. GSK's CEO, Emma Walmsley, projected that Arexvy would achieve blockbuster status, buoyed by the FDA’s approval for its use in individuals aged 50 to 59 years, granted in June 2024.

Despite these gains, Arexvy faces potential growth challenges. In June 2024, the CDC’s Advisory Committee on Immunization Practices revised its RSV vaccination guidelines, recommending the vaccine primarily for individuals aged 75 and older. For those aged 60 to 74, only those at high risk for severe disease are advised to receive the shot. These updated guidelines could hinder further expansion of Arexvy’s market.

On the other hand, Shingrix, GSK’s shingles vaccine, has already surpassed the blockbuster threshold, generating over $4.3 billion in 2023. This significant revenue contributed to a 25% growth in GSK’s vaccine business. However, Shingrix has also experienced a slowdown in sales. In the second quarter of the current year, GSK reported a 4% year-over-year decline in Shingrix sales. The decrease was attributed largely to a new Medicare rule affecting how pharmacies process reimbursements.

The company believes that the combined administration of Arexvy and Shingrix could provide a more convenient vaccination schedule, potentially boosting sales for both vaccines. If regulatory approval is secured, GSK could enhance its market position by simplifying the vaccination process for patients, thereby encouraging higher uptake rates. The company's strategy aims to leverage its scientific and technological capabilities to improve adult immunization rates and address public health challenges related to RSV and shingles.

Ultimately, GSK's efforts to combine these two vaccines into a single regimen reflect its broader ambition to innovate in the field of immunization, making it more accessible and effective for adults. This approach could not only improve public health outcomes but also strengthen GSK’s commercial performance in the competitive vaccine market.