Study summary

The FDA turned down tolebrutinib; European regulators backed it

Tolebrutinib decision · Regulatory decisions · December 2025 (US) and April 2026 (Europe)

What was tested

Tolebrutinib, a BTK-blocking pill, for secondary progressive MS without relapses, a form with no approved treatment in the US.

What they found

• The FDA declined to approve it in December 2025, citing the risk of severe liver injury and unclear benefit.
• In April 2026 the European Medicines Agency's committee recommended approval.
• A related trial in primary progressive MS had not met its goal.

What it means

Shows that this drug class can slow progression in some people, and that liver safety decides whether it reaches patients.