Michael S. Okun, MD reviewing Schapira AHV et al. JAMA Neurol 2017 Feb 1.

On time without troublesome dyskinesia was longer with safinamide than with placebo in a phase III trial. Its role relative to existing therapies remains unclear.

Safinamide is a Parkinson disease (PD) medication that acts on the dopaminergic and non-dopaminergic systems. The mechanisms of action include making dopamine more available by blocking the enzyme monoamine oxidase B (MAO-B), blocking sodium and potassium channels, and reducing glutamate release. Safinamide is not currently FDA approved (but other MAO-B drugs are).

In this double-blind, manufacturer-supported phase III study, investigators compared safinamide to placebo in 549 PD patients already on levodopa therapy and experiencing >1.5 hours per day of off time. Off time was defined as the patient perception that PD medications failed to kick in and was measured by a validated diary. PD drug regimens were optimized and held stable for 1 month before the study's start. Patients received 50 mg of safinamide or a placebo tablet once daily for 2 weeks, then escalated to 100 mg daily tolerated.

At week 24, on time without troublesome dyskinesia (the primary outcome) was 0.96 hours greater with safinamide than with placebo. Dyskinesia occurred in 15% of the active-drug group versus 6% of the placebo group.

CITATION(S):

Schapira AHV et al. Assessment of safety and efficacy of safinamide as a levodopa adjunct in patients with Parkinson Disease and motor fluctuations: A randomized clinical trial. JAMA Neurol 2017 Feb 1; 74:216.

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