Sanofi announces presentation of data on Beyfortus in RSV immunization

An immunization program implemented in Spain using Beyfortus cut infant hospitalizations due to RSV by 69.0% during the 2024-2025 RSV season compared to the 2022-2023 season, according to data presented at the 43rd Annual Meeting of the European Society for Paediatric Infectious Diseases in Bucharest, Romania. The real-world analysis also showed that a program in the UK using only the RSVpreF maternal vaccine reduced infant RSV hospitalizations in infants by 26.7% over those same RSV seasons. Sanofi’s (SNY) observational, retrospective REACH study is the first multi-country public health impact analysis of infant RSV prevention programs. These late-breaking data will be presented for the first time today during an oral session from 2:00 – 3:30 pm EEST at ESPID, which is taking place from May 26-30, 2025. Other data from Sanofi at ESPID include new durability data from the HARMONIE Phase 3b clinical study, now published in The Lancet Child & Adolescent Health, that demonstrates Beyfortus reduced RSV hospitalizations in infants by 82.7% through six months compared to no intervention, exceeding the typical length of the five-month RSV season. The high efficacy of 83.2% previously reported in the primary analysis was sustained over the longer follow-up period with no evidence of waning protection in infants born before or during the RSV season. Beyfortus maintained a favorable safety profile, consistent with clinical study results. Those results will be shared in an oral presentation on Friday, May 30 from 10:40 – 10:50 EEST.