Sanofi stock slumps after two setbacks on multiple-sclerosis drug

By Steve Goldstein

Sanofi shares were under pressure on Monday.

Shares of Sanofi slumped on Monday as the French drugmaker said a U.S. regulatory review of its multiple-sclerosis drug won't be completed by the end of the year and that a trial for a different form of MS didn't succeed.

Sanofi said the review of what's called tolebrutinib, to treat non-relapsing secondary progressive multiple sclerosis, will extend beyond Dec. 28, and that it expects further guidance by the U.S. Food and Drug Administration by the end of the first quarter.

It said the same drug didn't meet its primary endpoint in delaying disease progression in primary progressive multiple sclerosis in a late-stage Phase 3 trial.

The net effect of the two announcements was to send the stock (FR:SAN) (SNY) down 4% in Paris trade.

Analysts at Jefferies said the bigger commercial opportunity is in secondary MS and that the drug wasn't "done."

"The market may well write the asset off, but that seems a bit premature. We wonder if more share price pressure will mean more pressure on management," they said.

-Steve Goldstein

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12-15-25 0443ET