Dive Brief:
- Pfizer on Monday said its RSV vaccine Abrysvo led to strong immune responses in immunocompromised adults given the shot in a late-stage study.
- The results came from a substudy of a Pfizer-run Phase 3 trial testing two doses of Abrysvo in adults at risk of severe lower respiratory tract disease associated with respiratory syncytial virus, or RSV. Vaccination was well-tolerated, Pfizer said, and led to a “strong neutralizing response” against RSV subtypes A and B.
- The data add to evidence of the effectiveness of Abrysvo, which faces competition from GSK’s rival vaccine Arexvy and Moderna’s mResvia, which gained Food and Drug Administration approval in May.
Dive Insight:
Pfizer, GSK and Moderna all aim to widen labeling for their respective RSV shots.
Currently, Abrysvo is approved in the U.S. for adults 60 years and older as well as for maternal use. In June, GSK gained an expanded age indication for Arexvy to also include adults aged 50 to 59 who are at increased risk of RSV infection, possibly helping to expand its already dominant market position. Moderna’s mResvia is only for adults 60 years and older.
Pfizer recently asked regulators for an expanded approval of its shot in at-risk adults older than 18 based on results from a portion of the MONeT study that enrolled people with chronic conditions. According to data released in April, vaccination led to an immune response equivalent to that reported among older adults in the trial that supported Abrysvo’s initial clearance.
Monday’s data also comes from MONeT, but from a smaller part that involved 203 immunocompromised adults. Participants included people who previously received an organ transplant, were on hemodialysis due to end-stage kidney disease, had lung cancer or were on immune-modulating treatment for an autoimmune disorder.
About half of the adults enrolled were between the ages of 18 to 59, while the other half were 60 years or older.
Immunocompromised people, as well as infants and the elderly, are at a higher risk of contracting severe disease from RSV, which can make underlying conditions worse.
Pfizer says it plans to present the data from the MONeT trial at an upcoming scientific conference and publish results in a peer-reviewed scientific journal. The company will also submit the data to regulatory agencies.
