Sanofi and J&J Halt E. coli Vaccine Trial After Insufficient Efficacy

An independent review found the experimental vaccine failed to meet effectiveness thresholds, though no safety concerns were identified.

The E.mbrace Phase 3 trial for the experimental E. coli vaccine ExPEC9V has been discontinued due to insufficient efficacy.
An independent data monitoring committee determined the vaccine was not effective enough in preventing invasive E. coli disease (IED) compared to a placebo.
No safety issues were identified during the trial, and follow-up care for enrolled participants is ongoing.
The trial, launched in June 2021, involved over 250 sites across five continents and targeted adults aged 60+ with a history of urinary tract infections.
Sanofi recorded a $250 million financial charge related to the halted trial but stated this would not impact its 2025 revenue forecast.