RSV Vaccine Candidate Flops in Phase Three Study

Bavarian Nordic A/S recently announced that its Phase 3 clinical trial of MVA-BN® RSV, a respiratory syncytial virus (RSV) vaccine candidate for adults ≥60 years of age, did not meet all the primary endpoints of preventing lower respiratory tract disease (LRTD) from RSV.

Based on this outcome, Bavarian Nordic will discontinue its RSV program, including its partnership with Nuance Pharma to develop and launch the vaccine for selected Asian markets.

“We are disappointed that our RSV vaccine candidate was not successful in this pivotal trial,” said Paul Chaplin, President and Chief Executive Officer of Bavarian Nordic, in a press release on July 22, 2023. 

The final study results showed that the vaccine candidate had a 59% efficacy in preventing at least two pre-defined LRTD symptoms meeting one of the efficacy criteria of the study.

However, when measuring more severe LRTD based on at least three pre-defined symptoms, the vaccine candidate only demonstrated a 42.9% efficacy and missed the co-primary endpoint of the study.

As of July 24, 2023, there are two approved RSV vaccines in the U.S. and several late-stage vaccine candidates conducting research.