Sanofi's Multiple Sclerosis Drug Candidate Hits Roadblock in US

MT Newswires · 2d ago
01:36 AM EST, 12/24/2025 (MT Newswires) -- Sanofi (SAN.PA) received a complete response letter from the US Food and Drug Administration regarding the new drug application for tolebrutinib, a treatment for non-relapsing secondary progressive multiple sclerosis, or nrSPMS. The target action date for the FDA's review was previously pushed back, and an updated guidance from the regulator on the drug candidate was expected by the end of the first quarter of 2026, according to a Wednesday release. Further, upon the FDA's request, Sanofi had submitted an expanded access protocol for tolebrutinib in nrSPMS. The drug, which previously won breakthrough therapy designation from the FDA, has received approval in the United Arab Emirates for the same indication and is under regulatory review in the European Union and other global jurisdictions, the company noted. Sanofi Head of Research and Development Houman Ashrafian said the company will continue working with the regulator to "find a path forward for tolebrutinib."