Will MRI Be a Primary Endpoint for Regulatory Approval of Future MS Therapeutics?

Regulatory agencies require primary clinical endpoints (i.e., relapse rates or sustained disability progression) for phase III trials of therapeutic medications for multiple sclerosis (MS). Magnetic resonance imaging (MRI) is allowed as a secondary or tertiary outcome to corroborate the mechanism of action and clinical effect. Now, investigators have examined whether MRI can be used as an effective surrogate measure of clinical outcomes, based on the wealth of available trial information from the past 30 years of MS drug development.

The authors compiled relapse and MRI data from 31 randomized, controlled clinical trials in relapsing MS that included almost 19,000 patients. These trials involved all the FDA-approved disease-modifying therapi…