Sanofi’s MS Drug Tolebrutinib Faces FDA Delay Amid Extended Review
The FDA has extended the decision deadline for Sanofi's new drug application (NDA) for tolebrutinib, targeting non-relapsing, secondary progressive multiple sclerosis (nrSPMS), by three months to December 28, 20251256.
The extension was triggered by Sanofi's submission of additional analyses during the ongoing review, which the FDA classified as a major amendment, requiring a longer evaluation period1256.
Sanofi has not disclosed details of the submitted new analyses; external analysts speculate the FDA may be awaiting further safety data from the ongoing Phase III PERSEUS trial, expected to complete in November2.
Tolebrutinib is an oral, brain-penetrant Bruton's tyrosine kinase (BTK) inhibitor and was the first in its class for nrSPMS to be designated as a breakthrough therapy by the FDA14.
Key clinical evidence for tolebrutinib includes results from Phase III studies known as HERCULES, GEMINI 1, GEMINI 2, and PERSEUS23.
Sanofi continues to express confidence in the drug’s potential to slow disability progression in adult nrSPMS patients, independent of relapse activity1.
Sources:
1. https://www.sanofi.com/en/media-room/press-releases/2025/2025-09-22-05-00-00-3153624
2. https://www.biospace.com/fda/fda-action-date-for-sanofis-oral-multiple-sclerosis-drug-bumped-to-december
3. https://www.biospace.com/fda/fda-action-alert-merck-sanofi-biogen-and-more
4. https://www.sanofi.com/en/media-room/press-releases/2024/2024-12-13-06-00-00-2996609
5. https://www.empr.com/news/fda-extends-review-period-for-novel-ms-drug-tolebrutinib/