In The News: FDA Panel Endorses mAb to Prevent RSV in Infants

Medpage Today reported on the early June vote of approval by the Antimicrobial Drugs Advisory Committee in favor of nirsevimab, a monoclonal antibody against RSV. The vote was unanimous for its use in prevention of lower respiratory tract disease in neonates and infants born during or entering their first RSV season. In kids up to 24 months of age who would still be vulnerable to severe RSV in their second season, 19 of 21 members voted in favor.

Committee members overall found the data “robust” in the younger age group, though some expressed they were “uncomfortable” on the question of risk-benefit assessment in at-risk children up to 24 months of age due to extrapolated data. Further study and additional data, however, could negate that ‘uncomfortable’ expression.

AstraZeneca developed nirsevimab as a long-acting RSV fusion protein inhibitor monoclonal antibody delivered via intramuscular injection. It joins Pfizer’s RSV vaccine for pregnant persons in the second or third trimester of pregnancy to prevent RSV in infants, which recently received a vote of approval by an FDA advisory committee. There is also the previously approved palivizumab for prevention of severe lower respiratory tract disease due to RSV in certain high-risk infants and children. It is administered monthly whereas nirsevimab would be a single dose prior to RSV season.

Data resulted from two trials in infants entering their first RSV season and a trial in high-risk infants over two RSV seasons. A fourth trial had to be paused due to the COVID-19 pandemic.

Two PIDS members are also committee members and quoted in the story. Michael Green said, “I’ve been taking care of kids with RSV for more than 40 years, and I’m excited about this.” Fellow member Karen Klotoff is quoted on her vote in favor, “I think that there is a very well-characterized burden of severe disease that needs to be prevented…[AstraZeneca] addressed a diversity of relevant risk groups and demographic groups, and [studies] were very well conducted…I also think that implementation especially with a lot of variance these days in seasonality will be challenging, and will have to be considered very carefully.”