Sanofi Halts Pursuit of Regulatory Registration for Tolebrutinib in PPMS

Sanofi has announced the results of its PERSEUS phase 3 study, indicating that tolebrutinib failed to meet the primary endpoint in delaying 6-month composite confirmed disability progression in patients with primary progressive multiple sclerosis (PPMS). Consequently, Sanofi will not seek regulatory approval for PPMS treatment for this drug.

The study confirmed that tolebrutinib's safety profile aligns with previous trials, yet drug-induced liver injury remains a risk, necessitating vigilant liver function monitoring. Full results, both safety and efficacy, are pending presentation at an upcoming medical conference.

Despite the setback in PPMS, tolebrutinib is provisionally approved in the United Arab Emirates for secondary progressive multiple sclerosis and is under regulatory review in other regions. Sanofi plans to conduct an impairment test on tolebrutinib's intangible asset value, with the results to be communicated with their Q4 2025 financials.