Sanofi provides update on tolebrutinib regulatory submission in non-relapsing secondary progressive multiple sclerosis Paris, December 24, 2025. The US Food and Drug Administration (FDA) has issued a complete response letter (CRL) for the new drug application of tolebrutinib to treat non-relapsing secondary progressive multiple sclerosis (nrSPMS) in adult patients. On December 15, 2025, Sanofi provided an update on the ongoing review which stated that: (i) FDA was expecting the review to go beyond the previ ...