To evaluate dose–response relationship of BGG492 as add-on therapy to 1–3 antiepileptic drugs in patients with partial-onset seizures and to investigate safety and tolerability of BGG492.
This was a 12-week, randomized, double-blind, placebo-controlled, phase II dose-titration study (core study) with a 30-week, flexible-dose, open-label extension. In the core study, patients were randomized (1:2) to placebo or BGG492 100 mg t.i.d. in cohort 1, and in cohort 2 patients were randomized (1:4) to placebo or BGG492 150 mg t.i.d. On completion of the core study, eligible patients entered the extension study. Primary outcome measures were total partial seizure frequency per 28 days (core study) and safety and tolerability (extension study).
Overall, 93 patients were randomized (150 mg [n = 44]; 100 mg [n = 24]; placebo [n = 25]), and 81 (87.1%) completed the core study. Fifty-one patients entered and 43 (84.3%) completed the extension study. In the core study, no statistically significant dose–response trend among the BGG492 treatment groups (100 and 150 mg) was observed at the 4-week double-blind maintenance period (weeks 7–10); however, there was higher percent reduction in total partial seizure frequency in the BGG492 150 mg over placebo groups (37.32%; 95% confidence interval [CI] −18.90, 66.95). Dizziness, somnolence, and fatigue were the most common adverse events (AEs), higher in the BGG492 150 mg group than in the 100 mg and placebo groups (dizziness: 14 [31.8%] vs. 3 [12.5%] and 1 [4.0%]; somnolence: 7 [15.9%] vs. 1 [4.2%] and 1 [4.0%]; fatigue: 5 [11.4%] vs. 1 [4.2%] and 1 [4.0%]). During the open-label extension study, 39 (76.5%) patients on BGG492 had AEs, and the most commonly experienced AEs were dizziness (14 [27.5%]) and somnolence (9 [17.6%]).
There was no significant dose–response trend in the BGG492 treatment groups (100 and 150 mg); however, higher percent reduction over placebo was observed in the BGG492 150 mg group. Safety and tolerability data were consistent with the known safety profile for BGG492, and no new safety risks were identified.