A major clinical trial testing a vaccine against E. coli has been discontinued following an interim analysis that showed insufficient efficacy, pharmaceutical companies Sanofi and Johnson & Johnson announced today in Paris.
The phase 3 E.mbrace study, which began in June 2021, was evaluating a vaccine candidate’s ability to prevent invasive E. coli disease, including sepsis and blood infections, in adults aged 60 and older with a history of urinary tract infections. The trial spanned more than 250 sites across five continents.
The majority of E. coli strains are not harmful and play a crucial role in maintaining a healthy gut ecosystem by assisting in breaking down the food, contributing to the production of essential vitamins, and acting as a defense mechanism against more dangerous microorganisms.
However, not all E. coli are benign. Certain strains can cause a range of health issues in humans, including gastrointestinal distress resulting in diarrhea, infections of the urinary tract, respiratory ailments like pneumonia, and even severe systemic infections such as sepsis, a dangerous condition where the body responds improperly to an infection. Symptoms generally appear two to five days after exposure but can emerge anywhere from one to eight days later. Most people recover within 5-10 days.
An independent data monitoring committee conducted a scheduled review of the trial data and determined that the vaccine candidate did not demonstrate adequate effectiveness compared to placebo in preventing invasive E. coli disease. However, no safety concerns related to the vaccine were identified during the study, and participants who developed infections received prompt medical care.
The trial’s termination affects a significant collaboration between Sanofi and Johnson & Johnson’s Janssen Pharmaceuticals division, established in October 2023. Under their agreement, Sanofi had committed $250 million in upfront and development milestone payments, with both companies sharing research and development costs.
In a statement, Jean-François Toussaint, Global Head of Research and Development Vaccines at Sanofi, expressed disappointment in the results while emphasizing the company’s dedication to understanding the factors behind the trial’s outcome. “E. coli sepsis is a devastating disease and there are no preventative measures available to date.” Toussaint added that the company plans to conduct further analysis of the trial data.
The E.mbrace study was designed as a randomized, double-blind, placebo-controlled trial testing a single dose of the vaccine. Janssen Research & Development, LLC, which serves as the trial sponsor, will continue monitoring currently enrolled participants for safety follow-up.
Commenting on this article, the nation’s leading E. coli lawyer said, “This unfortunate development is a setback in the hunt for preventive measures against invasive E. coli disease. With luck, the lessons learned from this trial will better enable future vaccine efforts.”
