Sanofi's
FDA Extends Review Period of Sanofi's Multiple Sclerosis Drug Filing
SNY's NDA for tolebrutinib in nrSPMS is under FDA priority review with a decision pushed to Dec. 28, 2025. Extension follows submission of new analyses, deemed a major amendment to SNY's application by the FDA.
In phase III studies, tolebrutinib delayed confirmed disability progression versus placebo and Aubagio. Sanofi (SNY Quick QuoteSNY - Free Report) announced that the FDA has extended the target action date for its new drug application (NDA) for tolebrutinib by three months. The NDA is seeking approval of tolebrutinib, an oral and brain-penetrant investigational Bruton's tyrosine kinase (BTK) inhibitor, to treat non-relapsing, secondary progressive multiple sclerosis (nrSPMS).
The FDA’s decision follows Sanofi’s submission of additional analyses during the review process, which the agency deemed a major amendment to the NDA. As a result, the decision date has been moved to Dec. 28, 2025, from Sept. 28, 2025.
The FDA accepted Sanofi’s tolebrutinib NDA for the nrSPMS indication in March 2025 under its priority review pathway. The filing is supported by data from three late-stage studies — one (HERCULES) in nrSPMS and two (GEMINI 1 and 2) in relapsing MS (RMS). Data from HERCULES showed that patients treated with tolebrutinib delayed the time to onset of six-month confirmed disability progression when compared to placebo, and data from GEMINI 1 and 2 showed that patients treated with tolebrutinib delayed the time to onset of six-month confirmed disability worsening when compared to Aubagio (teriflunomide). A similar regulatory filing for the drug is currently under review in the EU.
Year to date, shares of Sanofi have lost 2.5% against the industry’s 0.9% growth.
Per Sanofi, tolebrutinib is the first and only brain-penetrant BTK inhibitor to treat both nrSPMS and RMS. MS is a chronic neurodegenerative disease that causes disability accumulation over time, which is not properly addressed by the currently available therapies that are designed to primarily address peripheral inflammation. There are no approved therapies to treat nrSPMS at present.
If approved, tolebrutinib will also be the first therapy designed to target smoldering neuroinflammation, a key driver of disability accumulation in MS. By showing a clinically meaningful benefit in disability accumulation, tolebrutinib holds the potential to address a significant unmet need in MS.
Besides nrSPMS and RMS, Sanofi is also evaluating the drug in the phase III PERSEUS study in patients with primary progressive MS. Data from this study is expected to be released by the end of 2025. Tolebrutinib was added to Sanofi’s portfolio with the acquisition of Principia in 2020. It enjoys the FDA’s Breakthrough Therapy designation in the United States for the nrSPMS indication.
