FDA extends review of Sanofi’s tolebrutinib for progressive multiple sclerosis

The American medicines regulator has delayed its decision on Sanofi’s (Euronext: SAN) tolebrutinib, an oral Bruton's tyrosine kinase inhibitor in development for non-relapsing secondary progressive multiple sclerosis. The US Food and Drug Administration (FDA) extended the target action date by three months to December 28, 2025, after receiving additional analyses it deemed a major amendment.

Sanofi said it is confident in the drug’s potential and continues to work closely with the agency. Tolebrutinib is the first brain-penetrant BTK inhibitor in this indication to be awarded breakthrough therapy designation.

Its application is supported by data from the HERCULES Phase III trial in nrSPMS and the GEMINI Phase III studies in relapsing MS, while the PERSEUS trial in primary progressive MS is ongoing with results due in the second half of 2025.