A Study of Soticlestat as an Add-on Therapy in Children, Teenagers, and Adults With Lennox-Gastaut Syndrome

Takeda

Status and phase: Completed; Phase 3

Conditions: Lennox Gastaut Syndrome (LGS)

Treatments: Drug: Soticlestat; Drug: Placebo

Study type: Interventional

Funder types: Industry

Identifiers

NCT04938427

2021-002481-40 (EudraCT Number)

jRCT2051210073 (Registry Identifier)

TAK-935-3002

Details and patient eligibility

About

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.

Full description

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):

1. Soticlestat
2. 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.

Enrollment: 270 patients

Sex: All

Ages: 2 to 55 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Has documented clinical diagnosis of LGS.
2. Has had ≥8 MMD seizures each month in the 3 months prior to Screening based on the historical information and has had ≥8 MMD seizures per 28 days during the 4 to 6 week prospective Baseline Period.
3. Weighs ≥10 kg at the Screening Visit (Visit 1).
4. Failure to control seizures despite appropriate trials of at least 1 ASM based on historical information, and is currently on an antiseizure therapy or other treatment options considered as standard of care (SOC).
5. Artisanal cannabidiols are allowed at a stable dose for at least 4 weeks before the screening visit (Visit 1); the dosing regimen and manufacturer should remain constant throughout the study. (Artisanal cannabidiols will not be counted as ASMs.)
6. Currently taking 0 to 3 ASMs at stable doses for at least 4 weeks before the Screening Visit (Visit 1); Fenfluramine and cannabidiol (Epidiolex) are allowed where available and counted as an ASM. ASM dosing regimen must remain constant throughout the study.

Exclusion criteria

1. Admitted to a medical facility and intubated for treatment of status epilepticus 2 or more times in the 3 months immediately before Screening (Visit 1). For the purpose of this exclusion criterion, status is defined as continuous seizure activity lasting longer than 5 minutes or repeated seizures without return to Baseline in between seizures.
2. Unstable, clinically significant neurologic (other than the disease being studied), psychiatric, cardiovascular, ophthalmologic, pulmonary, hepatic, renal, metabolic, gastrointestinal, urologic, immunologic, hematopoietic, endocrine disease, malignancy including progressive tumors, or other abnormality that may impact the ability to participate in the study or that may potentially confound the study results. It is the responsibility of the investigator to assess the clinical significance; however, consultation with the medical monitor may be warranted.
3. Considered by the investigator to be at imminent risk of suicide or injury to self, others, or property, or the participant has attempted suicide within 12 months before the Screening Visit (Visit 1). Participants who have positive answers on item numbers 4 or 5 on the Columbia suicide severity rating scale (C-SSRS) before dosing (Visit 2) are excluded. This scale will only be administered to participants aged ≥6 years.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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270 participants in 2 patient groups, including a placebo group

Placebo

Placebo Comparator group

Description:

Soticlestat placebo-matching mini-tablets or tablets, orally or via G-tube or MIC-KEY button or J-tube, BID, up to 4 weeks during titration. Participants continued to receive soticlestat placebo-matching mini-tablets or tablets for 12 weeks during maintenance. The total duration of the treatment was up to 16 weeks (Full Treatment Period). Soticlestat matching tapering was done to maintain the blind if participants decided to discontinue the treatment.

Treatment:

Drug: Placebo

Soticlestat

Experimental group

Description:

Participants weighing \<45 kg: Soticlestat, mini-tablets, at the dose of 40 mg to 200 mg, orally or via G-tube or MIC-KEY button or J-tube, BID based on body weight up to 4 weeks during titration. Participants continued to receive the dose that they were on at the end of the titration, for 12 weeks during maintenance. The total duration of the treatment was up to 16 weeks (Full Treatment Period) with the dose tapered down if participants decided to discontinue the treatment. Participants weighing ≥45 kg: Soticlestat mini-tablets or tablets with a starting dose of 100 mg BID followed by 200 mg BID and, then 300 mg BID, up to 4 weeks during titration. Participants continued to receive 300 mg BID for 12 weeks during maintenance. The total duration of the treatment was up to 16 weeks (Full Treatment Period) with the dose tapered down if participants decided to discontinue the treatment.

Treatment:

Drug: Soticlestat