Sanofi says that it anticipates that the FDA review process for its oral, brain-penetrant Bruton’s tyrosine kinase inhibitor, tolebrutinib, in non-relapsing secondary progressive multiple sclerosis (nrSPMS) will extend beyond the previously communicated U.S target action date of December 28, 2025.
Secondary progressive multiple sclerosis typically refers to people with a previous diagnosis of relapsing MS who have stopped experiencing relapses but continue to experience disability accumulation, in the absence of relapses. Addressing disability accumulation remains a significant unmet need in MS.
According to Sanofi, in response to an FDA request, the drugmaker has submitted an expanded access protocol for tolebrutinib in nrSPMS, underscoring the company's commitment to providing eligible patients with access to the investigational therapy.
This is the second time the FDA has delayed its decision about tolebrutinib. Originally, the agency had accepted the drug for priority review with a decision date of September 28, 2025. However, regulators then determined that additional analyses during the review required a major amendment to the NDA and pushed the target action date to December 28.
Now, Sanofi says it expects further guidance from the FDA by the end of the first quarter of 2026.
At the same time, Sanofi revealed in a second press release that the phase 3 PERSEUS study showed that tolebrutinib did not meet its primary endpoint in delaying time to 6-month composite confirmed disability progression (cCDP) in participants with primary progressive multiple sclerosis (PPMS), which represents 10% of the overall multiple sclerosis patient population. Based on these results, Sanofi will not pursue approval for PPMS.