Faculty Bibliography

High-quality placebo-controlled drug trials for focal-onset seizures in infants and children younger than 4 years have become increasingly difficult to perform because of eligibility constraints and onerous study designs. Traditional designs used in these populations require a high baseline seizure frequency, two hospitalizations for video-electroencephalography (video-EEG) monitoring, and willingness to accept potential exposure to placebo when the drugs to be tested are usually already available for off-label prescription. To address these constraints, the International League Against Epilepsy (ILAE) regulatory taskforce and the ILAE pediatric commission, in collaboration with the Pediatric Epilepsy Research Consortium (PERC), propose a novel trial design which involves seizure counting by caregivers based on previous video-EEG/video validation of specific seizure semiologies. We present a novel randomized placebo-controlled trial design intended to be used for studying new antiseizure medications (ASMs) for focal-onset seizures (FOS) in children aged one month to four years. This design uses "time to Nth seizure" as the primary outcome and incorporates a new element of variable baseline duration. This approach permits enrollment of infants with lower seizure burden, who might not have video-EEG-recorded seizures within 2-3 days of monitoring. Repeated hospitalizations for video-EEG recordings are avoided, and duration of baseline and exposure to placebo or ineffective treatment(s) are minimized. By broadening eligibility criteria, reducing risks from prolonged placebo exposure, and relying on validated recording of seizure counting by caregivers, clinical trials will be likely to be completed more efficiently than in the recent past.

There have been few studies of agreement between seizure descriptions obtained from patients and observers. We investigated 220 patients and observers who completed structured questionnaires about patients' semiological seizure features at the initial clinical visit. Inter-rater reliability was assessed using Cohen's kappa and indices of positive and negative agreement. Patients and observers had excellent agreement on the presence of memory impairment and generalized shaking and stiffness during seizures. In addition, patients under-reported seizure descriptions more easily observed externally, whereas observers under-reported change in patient location at seizure end. These findings may guide interpretation of clinical histories obtain in epilepsy care.

OBJECTIVE:To evaluate the effect of cenobamate in patients with photoparoxysmal-EEG response (PPR) to intermittent photic stimulation (IPS) as proof of principle of efficacy in patients with epilepsy. METHODS:In this multicenter, single-blind study, adults with photosensitive epilepsy, with/without concomitant antiepileptic drug therapy, underwent IPS under 3 eye conditions after a single dose of placebo (day -1, day 2) or cenobamate (day 1; 100, 250, or 400 mg). Complete suppression was a standardized photosensitivity range reduction to 0 over ≥1 time points for all eye conditions. Partial suppression was a ≥3-point reduction over ≥3 testing times vs the same time points on day -1 in ≥1 eye condition. Pharmacokinetics and safety were assessed. RESULTS:Of 6 evaluable patients, 5 reentered to receive higher doses. Cenobamate 100 mg produced partial suppression in 1 of 3 patients; 250 mg produced complete suppression in 1 of 4 and partial suppression in 4 of 4 patients; and 400 mg produced complete suppression in 1 of 4 and partial suppression in 2 of 4 patients. PPR was consistently reduced on days 1 and 2 (>24 hours after cenobamate) vs day -1 (placebo) with the 250- and 400-mg doses. Area under the plasma concentration-time curve (before dose to last measurable concentration) values between 201 and 400 μg/h/mL resulted in partial suppression in 4 of 6 (66%) patients. Most common adverse events were dizziness and somnolence. CONCLUSIONS:This proof-of-principle study demonstrated that cenobamate is a potentially effective product for epilepsy. CLINICALTRIALSGOV IDENTIFIER/UNASSIGNED:NCT00616148. CLASSIFICATION OF EVIDENCE/METHODS:This study provides Class III evidence that, for patients with photosensitive epilepsy, cenobamate suppresses IPS-induced PPR.