A few months after touting its RSV vaccine’s effects on younger adults, Pfizer said a sub-study focusing on immunocompromised adults is also positive. The data could offer another boost to its efforts to reach a much broader patient population.
Pfizer didn’t release detailed data, but said Abrysvo generated a “strong neutralizing response” against RSV after a single dose.
In the MONeT trial subgroup, Pfizer evaluated two doses of Abrysvo, given one month apart, in four groups of immunocompromised people: those with non-small cell lung cancer; those on hemodialysis due to end-stage renal disease; participants with autoimmune inflammatory disorder receiving active immunomodulator therapy; and solid organ transplant recipients.
Pfizer said on Monday that this marks the first assessment from an RSV vaccine study in immunocompromised adults, and it shows its vaccine was well-tolerated.
Annaliesa Anderson“Immunocompromised adults, such as patients with cancer or autoimmune disorders, have a substantially increased risk of experiencing severe complications from RSV, yet there are currently no vaccines approved for those aged 18 to 59 in the U.S.,” Annaliesa Anderson, Pfizer’s CSO and senior VP for vaccine R&D, said in a statement. She added that the topline data “provide important evidence that Abrysvo has the potential to address a significant unmet need in this vulnerable population.”
Pfizer reported topline data from the MONeT study in April, suggesting that at-risk people aged 18 to 59 achieved neutralizing responses against both RSV-A and RSV-B that were non-inferior to those seen in Pfizer’s Phase 3 RENOIR trial in older adults. The vaccine is already approved in older adults aged 60 years and up.
Pfizer and GSK are both racing to have their RSV vaccines approved in younger populations. GSK already got an FDA label expansion in June for its vaccine Arexvy in adults aged 50 to 59. Arexvy is currently dominating the market, pulling in £1.2 billion ($1.5 billion) in 2023. Abrysvo made just $890 million last year.
GSK also expects data from trials evaluating the efficacy and safety of Arexvy in the same type of patients as Pfizer’s MONeT trial to read out in the second half of this year.