Merck, a leading science and technology company, today announced the U.S. Food and Drug Administration (FDA) has placed a partial clinical hold on the initiation of new patients on evobrutinib and patients with less than 70 days exposure to study medication in the U.S. The ongoing, fully-enrolled Phase III EVOLUTION clinical trial program of evobrutinib in relapsing multiple sclerosis (RMS) will continue as planned with all participants remaining on treatment as all are beyond 70 days exposure to study medication.

The Phase III clinical trial program of evobrutinib is on schedule to read out in the fourth quarter of 2023.

The FDA action was based on their assessment of two recently reported cases of laboratory values suggestive of drug-induced liver injury that have been identified during the Phase III studies. Importantly, both patients were asymptomatic, did not require any medical intervention or hospitalization for this condition and their liver enzymes fully normalized after discontinuation of the study medication.

The Phase III EVOLUTION clinical trial program of evobrutinib has been closely monitored by an Independent Data Monitoring Committee, including hepatologists, since initiation. In close collaboration with external experts as well as the Independent Data Monitoring Committee for the trials, Merck is assessing the potential contributory role of predisposing factors to the liver injury.

Merck is working closely with the FDA to establish the best path forward for the benefit of patients in current and future trials with evobrutinib.