Two early-phase study trials suggest that GSK’s RSV vaccine, Arexvy, may benefit certain high-risk subgroups of younger adults and could potentially serve a broader population. This news comes shortly after the FDA approved Pfizer’s RSV vaccine, formerly known as Abrysvo, for adults aged 18 to 59 who are at higher risk of developing lower respiratory tract disease (LRTD), making Abrysvo the first vaccine to protect all adults at risk. The FDA had previously approved Arexvy for use in patients aged 60 and above, as well as those aged 50 to 59 with conditions predisposing them to severe RSV disease.
A new trial of Arexvy showed that one dose initiated a robust immune response among adults aged 18 to 49 with at least one comorbidity that increased their LRTD risk. The trial findings indicate that the immune response in this group was equivalent to or better than that of 417 adults over 60 years of age in a parallel control group, allowing the trial to meet its primary objectives.
This trial included subjects with impaired immune responses, such as individuals who had received kidney or lung transplants. In a group of 131 participants, a single dose of Arexvy led to a strong immune response. Among those who received a second dose, results were comparable to those observed in 125 healthy older adults who received only one dose. These initial findings will be presented at the CDC’s next Advisory Committee on Immunization Practices meeting, with final results to be shared at other medical conferences and regulatory reviews for potential label updates.
While the FDA recently approved both Pfizer’s and GSK’s RSV vaccines, the CDC has yet to issue comprehensive guidance for RSV vaccination in adults. Previously, in April, the CDC updated its guidelines to recommend RSV vaccines only for adults over 75 or for those aged 60 to 75 with comorbidities, revising an earlier recommendation that all adults over 60 should consult their doctors about RSV vaccination.
Pfizer’s Abrysvo achieved $890 million in sales last year, while GSK recorded £1.2 billion (about $1.5 billion) in Arexvy sales. Following the CDC’s narrowed recommendations, GSK adjusted its 2024 sales forecast from a high single-digit increase to a low to mid-single-digit figure. Besides Pfizer’s Abrysvo and GSK’s Arexvy, Moderna recently received FDA clearance for its RSV vaccine, mRESVIA, for adults aged 60 and above, adding another option to the lineup of RSV vaccines for adults.
GSK Responds to Pfizer’s RSV Approval with Data Aiming for Similar Approval in Younger Adults
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