To characterize the efficacy and safety of soticlestat (TAK-935/OV935) in children with Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) in the ELEKTRA study (NCT03650452).

DS and LGS are rare childhood epilepsies that are often resistant to current treatment. Soticlestat has demonstrated efficacy in preclinical seizure models, including significant reductions in spontaneous seizures in a murine DS model.

The modified-intent-to-treat population included 139 participants who received ≥1 dose of study drug and had ≥1 efficacy assessment (DS, n=51; LGS, n=88). Overall, children treated with soticlestat (DS and LGS combined) showed a median placebo-adjusted seizure frequency reduction of 25.1% (p=0.0024) during the 20-week treatment period, with children in the DS cohort demonstrating a median placebo-adjusted seizure frequency reduction of 46.0% (p=0.0007), and children in the LGS cohort demonstrating a median placebo-adjusted seizure frequency reduction of 14.8% (p=0.1279). The incidence of treatment-emergent adverse events (TEAEs) was similar between the soticlestat and placebo groups (80.3% vs 74.3%). Serious adverse events were reported in 15.5% of participants receiving soticlestat and 18.6% of participants receiving placebo. No deaths were reported. The most frequent TEAEs reported in soticlestat-treated patients with at least 5% difference from placebo were lethargy and constipation.

Soticlestat treatment resulted in a statistically significant reduction in median placebo-adjusted seizure frequency from baseline in children with DS, and in a directional reduction in seizure frequency in patients with LGS. Soticlestat appears to be generally well-tolerated.

Study funded by Takeda Pharmaceutical Company Limited and Ovid Therapeutics Inc.