Cenobamate Continuation for Over 6 Years Represents Long-Term Efficacy and Safety

In the long-term open-label extension of a randomized double-blind placebo-controlled study of adjunctive treatment for epilepsy with cenobamate (Xcopri; SK LIfe Science, Paramus, NJ)treatment duration averaged 6.25 years (200 mg median modal daily dose, range 50 to 400 mg). Initial enrollment was 149 adults who completed an earlier 12-week study, and as of July 2019, 57% (85/149) of participants continued being treated with cenobamate.

"In this long-term evaluation with cenobamate, we observed high retention rates beyond 6 years in a real-life clinical setting in which patients received individualized doses of both cenobamate and other antiseizure medications (ASMs)," said Jaqueline French, MD, professor of Neurology, NYU Langone Comprehensive Epilepsy Center, director, Epilepsy Study Consortium, and chief medical and innovation officer, Epilepsy Foundation. "Because refractory epilepsy is a chronic, difficult to manage condition requiring ongoing treatment, the long-term retention rates represent an important and encouraging clinical outcome reflecting the safety, tolerability and effectiveness of cenobamate."

At the completion of the 12-week period, 149 participants entered the extension treated with cenobamate along with 1 to 3 additional ASMs. The probability of continuing cenobamate for 6 years was 59%; among those who remained on cenobamate for at least 12 months (n=107), the probability of continuing for 6 years was 79%. The 54% (80/149) of participants who took cenobamate were able to discontinue 1 or more concomitant ASMs.

The most common emergent adverse events were dizziness (33%), headache (27%), and somnolence (22%). The adverse events that lead to discontinuation in >1% of participants were fatigue (1%, 2/149), ataxia (1%, 2/149), and memory impairment or amnesia (1%, 2/149).