Objective:

This investigator-initiated study examined discontinuations and dose reductions of concomitant ASMs following cenobamate initiation in patients with epilepsy treated at MetroHealth (Cleveland, OH).

Background:

The treatment goal for people with epilepsy who receive polytherapy is 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.

Design/Methods:

Adults with focal epilepsy who started adjunctive cenobamate between 9/2020 and 5/2022 were analyzed by retrospective chart review (target enrollment n=75). Data on concomitant ASMs and doses were collected.

Results:

Eighty-one patients received cenobamate as of 5/2022. Two discontinued because of side effects. Seventy-nine continued on cenobamate as of the data cutoff (mean [range] age, 44.1 [19-74] years; 48% women). Seventy-five started cenobamate because of uncontrolled seizures. Four other patients were seizure-free but started cenobamate to taper off their current ASMs, which were causing intolerable side effects. Among those continuing cenobamate, 34.2% (27/79) discontinued concomitant ASMs, including clobazam (n=15), levetiracetam (n=5), phenytoin (n=3), lacosamide (n=2), lamotrigine (n=1), and oxcarbazepine (n=1). Nine patients achieved cenobamate monotherapy, and 15.2% (12/79) of patients were in the process of tapering off concomitant ASMs, including phenytoin (n=8) and clobazam (n=4). Divalproex sodium dose reductions occurred in 4 patients. At data cutoff, 34.2% (27/79) of patients were seizure-free ≥3 months (range, 3-10 months), including all 4 patients who were seizure-free prior to starting cenobamate and 23 patients with uncontrolled seizures prior to cenobamate. No patients had worsening seizure frequency on cenobamate.

Conclusions:

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