Lacosamide safe, efficacious for long-term seizure control in idiopathic generalized epilepsy

In patients with idiopathic generalized epilepsy, adjunctive lacosamide treatment in the long term may safely reduce the frequency of generalized onset tonic–clonic seizures (GTCS), as shown in the open-label extension EP0012 trial.

EP0012 included 239 patients (mean age 27.9 years, 56.1 percent female, 18.4 percent children) who participated in the phase III SP0982. These patients had ≥3 GTCS during the 16-week baseline and were on a stable dose of 1–2 antiseizure medications (with or without one benzodiazepine) for ≥28 days before visit 1 and throughout the study period.

During EP0012, the patients were transitioned to age- and weight-based lacosamide dosing. The doses were increased or reduced in weekly steps at the investigator’s discretion to optimize tolerability and seizure reduction for each patient. Doses could be increased up to a maximum of 12 mg/kg/day (oral solution) for children weighing <50 kg, 600 mg/day (tablets) for children weighing ≥50 kg, and 800 mg/day (tablets) for adults. Minimum doses were 4 mg/kg/day or 200 mg/day.

Of the patients, 157 (65.7 percent) completed the trial, with the median treatment duration being 3.2 years. The most common reason for discontinuation (≥10 percent) was withdrawn consent (12.6 percent). Based on Kaplan–Meier estimates, the retention rate was 87 percent at 1 year, 72 percent at 3 years, and 60 percent at 5 years.

Treatment-emergent adverse events (TEAEs) occurred in 222 (92.9 percent) patients. TEAEs led to treatment discontinuation in 19 patients (7.9 percent).

Only a few patients experienced an increase in number of days with absence or myoclonic seizures or had new absence or myoclonic seizures. From the combined baseline, the median percent change in GTCS frequency per 28 days was −88.6 percent. Post hoc analyses showed small numerical differences in GTCS frequency according to antiseizure medications used (1, 2, or ≥3).