Sanofi reports disappointing regulatory updates for MS treatment, shares fall

(Sharecast News) - Sanofi's stock was in the red on Monday after the pharma group gave two disappointing updates regarding its tolebrutinib treatment for multiple sclerosis. Firstly, the company said results from a phase 3 study showed that tolebrutinib did not meet its primary endpoint in delaying the time to onset of so-called "six-month composite confirmed disability progression (cCDP) in participants with primary progressive multiple sclerosis (PPMS).

Six-month cCDP refers to the significant worsening of neurological functions, measured over a six-month period.

Due to the results, Sanofi said it would not pursue regulatory registration for PPMS, which represents around 10% of the overall MS patient population.

"We are disappointed by today's results; however, we do believe that these results will improve our understanding of the underlying disease biology of multiple sclerosis," said Houman Ashrafian, executive vice president, head of R&D at Sanofi.

Sanofi also announced that the review process for tolebrutinib in non-relapsing secondary progressive multiple sclerosis (nrSPMS) is expected to be delayed by the Food and Drug Administration in the US.

The company said that that the review "will extend beyond the previously communicated US target action date of December 28, 2025, and expects further guidance from the FDA by the end of the first quarter of 2026".

Sanofi shares were down 1.8% at €81.83 by 1127 GMT, having dropped more than 6% early on.