Biotech Values

[DewDiligence]

SNY’s Nirsevimab—an anti-RSV mAb—reduced infant hospitalization by 83% in 8,000-patient registry study:

https://www.globenewswire.com/news-release/2023/05/12/2667568/0/en/Press-Release-Nirsevimab-delivers-83-reduction-in-RSV-infant-hospitalizations-in-a-real-world-clinical-trial-setting.html

Nirsevimab (similar to its predecessor Synagis) is a prophylactic antibody, not a vaccine; i.e. Nirsevimab is effective at preventing clinically meaningful RSV infections while the drug remains active, but it does not train the immune system to thwart future RSV infections, nor does it treat patients who already have RSV infection.

The main difference between Nirsevimab and Synagis (which was FDA-approved way back in 1998) is that Nirsevimab has much better efficacy, so that it makes sense to use Nirsevimab for the general infant population during the RSV season. Synagis, on the other hand, was used only for high-risk infants such as those born prematurely.

The efficacy of Nirsevimab is roughly similar to PFE’s maternal RSV vaccine, which has an Aug 2023 PDUFA date (#msg-171260623).

Nirsevimab is a joint project of SNY and AZN, but SNY has the commercial rights in the US.