NCT03635073

A Study of Soticlestat in Adults and Children With Rare Epilepsies

A Phase 2, Prospective, Interventional, Open-Label, Multi-Site, Extension Study to Assess the Long-Term Safety and Tolerability of Soticlestat (TAK-935) as Adjunctive Therapy in Subjects With Developmental Epileptic Encephalopathies Including Dravet Syndrome, Lennox Gastaut Syndrome, CDKL5 Deficiency Disorder, and Chromosome 15 Duplication Syndrome (ENDYMION 1)

• Status: Terminated
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 156 (actual)
• Sponsor: Takeda · Industry
• Sex: All
• Age: 2 Years
• Healthy volunteers: Not accepted

Summary

The main aim is to assess the long-term safety and tolerability of soticlestat when used along with other anti-seizure treatment. Participants will receive soticlestat twice a day. Participants will visit the study clinic every 2-6 months throughout the study. Study treatments may continue as long as the participant is receiving benefit from it.

Detailed description

The drug being tested in this study is called soticlestat (TAK-935). This global, open-label extension (OLE) study will assess the long-term safety and tolerability of soticlestat in participants with developmental and epileptic encephalopathy (DEE) who participated in previous short-term efficacy/safety studies of soticlestat. All participants will receive Soticlestat treatment. Participants who rollover from previous blinded study will undergo up to 2 weeks of Dose Optimization Period (depending on the previous study) followed by Maintenance Period. Participants who rollover from an open-label study will continue on their current dose until development is stopped by the sponsor, or the product is approved for marketing, or at any time at the discretion of the sponsor. There will be a 4-week Safety Follow-up Period after the last dose in Maintenance Period, including a 2-week dose Tapering Period.

Conditions

• Epilepsy
• Dravet Syndrome (DS)
• Lennox-Gastaut Syndrome (LGS)

Interventions

Type	Name	Description
DRUG	Soticlestat	Soticlestat tablets or mini-tablets.

Timeline

• Start date: 2018-07-19
• Primary completion: 2025-07-30
• Completion: 2025-07-30
• First posted: 2018-08-17
• Last updated: 2026-03-19
• Results posted: 2026-03-19

Locations

59 sites across 8 countries: United States, Australia, Canada, China, Israel, Poland, Portugal, Spain

Regulatory

• FDA-regulated drug study