Sanofi Halts ExPEC Vaccine Trial: Implications for the Vaccine Market

Sanofi, in collaboration with Janssen Pharmaceuticals, has announced the discontinuation of the E.mbrace phase 3 study for its vaccine candidate against extraintestinal pathogenic E. coli (ExPEC). The interim analysis conducted by an independent data monitoring committee (IDMC) determined that the vaccine candidate did not demonstrate sufficient efficacy in preventing invasive E. coli disease (IED) compared to placebo. This setback has significant implications for the global vaccines market and Sanofi's vaccine portfolio.



The E.mbrace study was a randomized, double-blind, placebo-controlled, multicenter, interventional phase 3 study evaluating the efficacy, safety, and immunogenicity of a single dose of the vaccine candidate compared to a placebo in the prevention of IED, which includes sepsis and bacteremia (blood infections). The study was initiated in June 2021, enrolling adults aged 60 years or older in stable health with a history of urinary tract infection in the past two years. The study was conducted at over 250 sites across five continents.

The failure of the E.mbrace study to demonstrate sufficient efficacy in preventing IED may impact Sanofi's plans to expand its vaccine portfolio with a first-in-class product for ExPEC. However, the company remains committed to driving innovation in R&D by developing first and best-in-class vaccines in areas of high unmet need. Sanofi's vaccine portfolio includes a wide range of products, such as influenza, pneumococcal, meningococcal, and human papillomavirus (HPV) vaccines, among others. The company will likely continue to invest in research and development to maintain its position as a leader in the global vaccines market.

The discontinuation of the E.mbrace phase 3 study has resulted in an impairment charge before tax of $250 million for Sanofi in the Q4 2024 IFRS results. This adjustment impacts negatively the full-year IFRS EPS reported in the Q4 2024 results press release on January 30, 2025, by €0.15 from €4.59 previously to €4.44 now. However, there is no impact to the business net income / business EPS, which remains unchanged respectively at €8,912 million / €7.12 (non-IFRS). There is no change to the financial guidance for 2025.

In the long term, the implications of the E.mbrace study's discontinuation for Sanofi's vaccine portfolio and the global vaccines market remain to be seen. The company will likely continue to invest in research and development to maintain its position as a leader in the global vaccines market. As the global vaccines market continues to evolve, companies like Sanofi will need to adapt and innovate to stay competitive in the face of changing market dynamics and emerging infectious diseases.

Jean-François Toussaint, Global Head of Research and Development Vaccines at Sanofi, stated, "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 IDMC's finding and to share further analysis once available. We are grateful to the participants, families, and healthcare professionals involved in this development program. While disappointed by this outcome, we remain steadfast in our commitment to drive innovation in R&D by developing first and best-in-class vaccines in areas of high unmet need."

In conclusion, the discontinuation of the E.mbrace phase 3 study for Sanofi's ExPEC vaccine candidate has significant implications for the global vaccines market and Sanofi's vaccine portfolio. The company will need to adapt and innovate to maintain its position as a leader in the global vaccines market in the face of changing market dynamics and emerging infectious diseases.