The aims of the study are:
- to learn if soticlestat, when given as add-on therapy, reduces the number of major motor drop seizures in children, teenagers, and adults with Lennox-Gastaut Syndrome.
- to assess the safety profile of soticlestat when given in combination with other therapies.
Participants will receive their standard antiseizure therapy, plus either tablets of soticlestat or placebo. A placebo looks just like soticlestat but will not have any medicine in it. Participants will take soticlestat or placebo for 16 weeks, followed by a gradual dose reduction for 1 week. Then, participants will be followed up for 2 weeks.
A Multicenter, Randomized, Double-Blind, Placebo-Controlled, Parallel Group Study to Evaluate the Efficacy, Safety, and Tolerability of Soticlestat as Adjunctive Therapy in Pediatric and Adult Subjects With Lennox-Gastaut Syndrome (LGS)
The drug being tested in this study is called soticlestat (TAK-935). Soticlestat will be assessed for efficacy, safety, and tolerability in pediatric and adult participants with LGS.
The study will enroll approximately 234 patients. Participants will be randomly assigned (by chance, like flipping a coin) in a 1:1 ratio to receive standard of care (SOC) plus one of the following adjunctive therapies which will remain undisclosed to the participant and study doctor during the study (unless there is an urgent medical need):
- Placebo (dummy inactive pill - this is a tablet/mini-tablet that looks like the study drug but has no active ingredient)
Participants will receive soticlestat or matching placebo based on their weight in the 4-week Titration Period. Following the Titration Period, participants will continue to receive the same dose in the 12-week Maintenance Period. The dose will then be down-tapered if participants decide to discontinue the treatment and/or are not deemed eligible to continue in Open-label extension (OLE).
This multi-center trial will be conducted worldwide. The overall time to participate in the study will be from 22-25 weeks. At the end of the treatment period, participants have the option to either complete the study and taper off the investigational product or to enter the OLE if they meet eligibility requirements. If participants discontinue, they will be followed-up on phone call approximately 14 days after the last dose of study drug for safety.