E. Coli Vaccine Candidate Fails to Demonstrate Efficacy in Phase 3 Trial
Investigators note there were no safety signals related to the vaccine candidate, and participants who developed E. coli disease received treatment and care.
A vaccine candidate for Escherichia coli was not sufficiently effective at preventing E. coli disease (IED) compared to placebo in a phase 3 trial. Investigators noted that there were no safety signals related to the vaccine candidate, and participants who developed IED received treatment and care.1
The investigational vaccine was a 9-valent candidate in development for the immunization against IED in adults aged 60 years and older. | Image Credit: Ezume Images | stock.adobe.com
“E. coli sepsis is a devastating disease, and there are no preventative measures available to date. Driven by our ambition to transform the practice of medicine, we entered this ambitious, although challenging field. We are disappointed to see that the vaccine was not associated with sufficient efficacy to support the trial continuation, and we will work tirelessly to understand the factors behind the [independent data monitoring committee’s] finding and to share further analysis once available,” Jean-François Toussaint, global head of research and development vaccine at Sanofi, said in a release.1
The E.mbrace (NCT04899336) study was a randomized, double-blind, placebo-controlled phase 3 trial that evaluated the safety, efficacy, and immunogenicity of a single dose of the vaccine candidate compared with the placebo. Investigators started enrollment in June 2021, with adults aged 60 years or older with a history of urinary tract infection in the past 2 years. As a result of the analysis, the study will be discontinued. Safety follow-ups will also be conducted for the currently enrolled individuals, and a more detailed analysis will be shared.1,2
The investigational vaccine was a 9-valent candidate in development for the immunization against IED in adults aged 60 years and older. In the study, patients underwent a screening phase, randomization of treatment, vaccine phase, and a follow-up phase 4 years post-vaccination. The total study duration was estimated to be about 6 years and 9 months. The primary end point included the number of individuals with the first invasive extraintestinal pathogenic IED event up to 9 years.
Secondary end points included the number of individuals with the first IED event, the number of all IED, the number of individuals with the first hospitalization due to IED even, the number of individuals with the first IED-related sepsis, the bacteremic IED event, the first pyelonephritis, the first urinary tract infection, all urinary tract infection, the first IED event caused by E. coli, and E. coli-related pyelonephritis and urinary tract infection. Further, safety end points included the number of solicited systemic adverse events (AEs), the number of unsolicited AEs, the number of serious AEs, and the number of serious AEs related to the study vaccine or procedure.3
E. coli can be found in the environment, foods, water, and intestines of animals and people. Although most E. coli are harmless, some bacteria can cause diarrhea, urinary tract infections, pneumonia, sepsis, and other illnesses. According to the CDC, people most at risk are children younger than 5, adults 65 years and older, patients with weakened immune systems, and those who travel internationally.4
