Sanofi Multiple Sclerosis Drug Hit by Double Setback

By Adria Calatayud

Sanofi said a U.S. regulatory decision on its tolebrutinib experimental treatment for a type of multiple sclerosis would be delayed again, and that a late-stage trial for a different form of the disease didn't hit its main goal.

The French pharmaceutical company said Monday that talks with the U.S. Food and Drug Administration had indicated a regulatory review for tolebrutinib in nonrelapsing secondary progressive multiple sclerosis would extend beyond a target action date of Dec. 28. The company expects further guidance from the FDA by the end of the first quarter of 2026, it said.

Sanofi in September said that the FDA extended its review of tolebrutinib by three months.

The company said it submitted an expanded access protocol for tolebrutinib in response to an FDA request, allowing eligible patients who didn't participate in clinical trials to access the therapy, and that it strongly believes in the risk-benefit profile of the drug.

Separately, Sanofi said results from a late-stage study of tolebrutinib in primary progressive multiple sclerosis didn't meet the primary goal in delaying the onset of disability progression.

As a result, the company said it wouldn't pursue regulatory registration in primary progressive multiple sclerosis and would assess whether it needs to book an impairment charge on the value of tolebrutinib. Sanofi said its 2025 guidance remains unchanged.

Write to Adria Calatayud at adria.calatayud@wsj.com

(END) Dow Jones Newswires

December 15, 2025 01:49 ET (06:49 GMT)