Abstracts

Rationale: Many people with epilepsy require medication changes due to inadequate efficacy or tolerability. For patients who receive polytherapy, the goal of treatment is to achieve seizure control with the lowest possible drug load (lowest numbers and doses). Cenobamate is an antiseizure medication (ASM) approved in the US and EU for uncontrolled focal seizures. We present interim results of an ongoing investigator-initiated study examining discontinuations and dose reductions of concomitant ASMs following initiation of cenobamate in patients with epilepsy treated at MetroHealth (Cleveland, OH).

Methods: Adults with focal epilepsy who started adjunctive cenobamate treatment between 9/2020 and 5/2022 were analyzed by retrospective chart review. Data on concomitant ASMs and doses were collected. Target enrollment was 75 patients.

Results: Eighty-one patients received cenobamate as of 05/2022. Two patients discontinued cenobamate due to side effects. Seventy-nine patients continue to receive cenobamate as of the data cutoff (mean age 44.1 years [range: 19-74]; 48% women). Cenobamate was started in 75 patients because of uncontrolled seizures. Four other patients were seizure-free but having intolerable side effects to their current ASMs and were started on cenobamate to taper off those ASMs. Among the patients continuing cenobamate, discontinuation of concomitant ASMs occurred in 34.2% (27/79), including clobazam (n=15), levetiracetam (n=5), phenytoin (n=3), lacosamide (n=2), lamotrigine (n=1), and oxcarbazepine (n=1). Monotherapy with cenobamate was achieved in 9 patients. An additional 15.2% (12/79) of patients were in the process of tapering off concomitant ASMs, including phenytoin (n=8) and clobazam (n=4). Reductions in divalproex sodium dose occurred in 4 patients. At data cutoff, 34.2% (27/79) of patients were seizure-free for ≥ 3 months (range 3-10 months). This includes all 4 patients who were seizure-free prior to starting cenobamate in addition to 23 patients with uncontrolled seizures prior to starting cenobamate. No patients had worsening seizure frequency after starting cenobamate.

Conclusions: Initiation of cenobamate lead to a reduction in concomitant ASM drug load (either discontinuation or dose reduction) in 53.1% (43/81) of patients in this analysis, and some patients were able to transition to monotherapy with cenobamate. Seizure control was maintained or improved during cenobamate treatment. These data suggest that cenobamate therapy may allow a reduction or elimination of polytherapy in some patients.

Funding: Medical writing support was funded by SK Life Science, Inc.