Pfizer Gains FDA Nod for RSV Vaccine in More Adults

Pfizer's Abrysvo has become the first respiratory syncytial virus (RSV) vaccine available for adults under 50 years of age. The FDA has granted approval for this vaccine to be used in adults aged 18 to 59 who are at higher risk of RSV-related lower respiratory tract disease (LRTD). This marks a significant milestone as Abrysvo is now the only RSV vaccine that can be administered to such a broad age range in adults.

This expansion is particularly important for younger adults with underlying chronic conditions like diabetes or obesity. In the United States, approximately 9.5% of adults between 18 and 49 years old have these conditions, making them more vulnerable to severe RSV LRTD and potential hospitalizations. Aamir Malik, Pfizer's Chief U.S. Commercial Officer, expressed the company's pride in achieving this FDA approval, noting the serious threat RSV poses to younger adults with certain chronic health issues. Additionally, Abrysvo continues to be the sole vaccine option for pregnant women between 32 and 36 weeks of gestation, aiming to protect infants from birth through six months.

The recent label expansion for Abrysvo was backed by the inferred efficacy demonstrated in the Phase III MONeT trial. In April 2024, Pfizer announced that Abrysvo had met its primary efficacy endpoint in this trial. Although specific data were not disclosed at the time, Pfizer indicated that they would later submit the findings for publication in a peer-reviewed journal and presentation at an upcoming conference.

The broadened use of Abrysvo follows changes in the RSV vaccination guidelines by the U.S. Centers for Disease Control and Prevention (CDC). In June 2024, the CDC's Advisory Committee on Immunization Practices (ACIP) recommended RSV vaccinations for all seniors aged 75 and older. For adults aged 60 to 74, the committee advised that vaccines be administered only to those at risk of severe disease. The decision on the use of RSV vaccines for adults aged 50 to 59 was postponed.

Despite this smaller target demographic, the expanded approval could enhance Pfizer's market position for Abrysvo, helping it compete more effectively with GSK's RSV vaccine, Arexvy. GSK gained a head start by obtaining FDA approval for Arexvy a month earlier. Arexvy is recommended for adults aged 60 and above, as well as for those aged 50 to 59 who are at risk of RSV LRTD. GSK's early entry into the market has been challenging for competitors to match. In December 2023, GSK CEO Emma Walmsley reported that Arexvy had dominated the majority of retail vaccinations in the U.S., positioning it to become a blockbuster product for the company.

In summary, Pfizer's Abrysvo approval for younger adults at high risk of RSV-related LRTD offers a new preventive measure for a significant segment of the population. This advancement underscores the importance of addressing RSV's impact on vulnerable groups and highlights the ongoing competition within the pharmaceutical industry to provide effective vaccines against this virus.