Sanofi Shares Slide After Trials of Potential Breast Cancer Drug Halted

By Scott Kanowsky 

Investing.com -- Sanofi SA (EPA:SASY) shares slid on Wednesday after the French drugmaker announced that it will halt trials of a new treatment for patients battling advanced breast cancer.

In a statement, the company said it would stop global clinical development of the medicine, known as amcenestrant, after a phase 3 study showed it was not effective enough to warrant further research.

All other studies of amcenestrant, including in early-stage breast cancer, will also be discontinued, Sanofi added.

“While we are disappointed by this outcome, our research will further the scientific understanding of endocrine therapies in people with breast cancer," said John Reed, global head of research and development at Sanofi.

In a note, analysts at Morgan Stanley called the decision a "setback for the innovation narrative" put forward by Sanofi, saying that amcenestrant had been flagged as a potentially lucrative piece in the group's drug pipeline.

The end of Sanofi's amcenestrant trials is expected to lead to a 6% negative impact on the company's estimated discounted cash flow, according to the Morgan Stanley analysts.

The decision could also have a knock-on effect on studies being conducted on similar breast cancer drugs from Sanofi rivals Roche (SIX:ROG) and AstraZeneca PLC (LON:AZN), the analysts added.