Sanofi shares fall on twin trouble for experimental multiple scleroris drug

Dec 15 (Reuters) - ‌Shares of French pharmaceutical group Sanofi fell 4% on Monday ‍after ‌it flagged another delay to a U.S. regulatory decision for its ⁠experimental multiple sclerosis drug and ‌disappointing results from a late-stage study.

Shares initially fell 5% to the bottom of the SBF 120 index of Paris' most traded stocks before paring losses.

Sanofi said ⁠that the U.S. Food and Drug Administration's decision on its tolebrutinib drug to treat ​non-relapsing secondary progressive multiple sclerosis will likely be ‌delayed until the first quarter ⁠of 2026.

It is the second delay to a decision that was initially expected in September before being pushed to December 28.

Sanofi also ​said that tolebrutinib failed to slow disability progression in a late-stage trial in patients with primary progressive multiple sclerosis, a form of the disease that accounts for about 10% of cases.

"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, Sanofi's head of research and development.

Jefferies analysts called the trial results a negative surprise, but said the bigger commercial opportunity remained in patients with non-relapsing secondary ⁠progressive multiple sclerosis.

The drug was granted breakthrough therapy designation by the FDA in December last year ​and is also under regulatory review in the European Union.

Tolebrutinib was provisionally approved in the United Arab Emirates in July to treat non-relapsing secondary progressive multiple sclerosis and to slow ‌disability accumulation independent of relapse activity in adults.

(Reporting by Mathias de Rozario in Gdansk and Bhanvi Satija in London, editing by Milla Nissi-Prussak)