A Phase 2 Study of Radiprodil in Subjects With Drug-resistant Infantile Spasms (IS)

An Open-label Adaptive Study for the Assessment of Safety, Tolerability, Pharmacokinetics, and Efficacy of Multiple Doses of Radiprodil in Subjects With Drug-resistant Infantile Spasms

The purpose of the study is to evaluate the safety and tolerability, the pharmacokinetics and the efficacy of radiprodil in abolishing clinical spasms in subjects with drug-resistant infantile spasms

The study is divided into 3 parts:

Part A - exploratory, Part B - confirmatory, Part C - open label extension

Inclusion Criteria:

Part A and B:

• Subject is male or female between 2 and 14 months of age
• The diagnosis of infantile spasms (IS)
• Subject has drug-resistant IS

Part C:

• Subject participated in EP0078 Part A and received 2 radiprodil treatment cycles
• Subject experienced a relapse of spasms during the down taper or within 5 half-lives (3 days) discontinuation of radiprodil treatment in Cycle 2 of Part A
• Electroencephalogram (EEG) on baseline Part C is compatible with the diagnosis of infantile spasms

Exclusion Criteria:

Part A and B:

• More than 6 months have passed since the diagnosis of Infantile Spasms (IS)
• Current treatment with cannabinoids
• Subject has hematocrit greater than 60
• Subject has any medical condition that, in the opinion of the Investigator, could jeopardize or would compromise the subject's ability to participate in this study
• Subject has a history or current condition predisposing to respiratory dysfunction
• Current treatment with felbamate
• Current treatment with perampanel
• Ketogenic diet
• Clinically significant lab abnormalities
• Clinically significant abnormality on ECG that, in the opinion of the Investigator, increases the safety risks of participating in the study
• Subject has a lethal or potentially lethal condition other than IS, with a significant risk of death before 18 months of age such as non-ketotic hyperglycinemia
• Body weight is below 4 kg
• Known history of severe anaphylactic reaction secondary to medication intake or serious blood dyscrasias

Part C:

• Subject experienced any acute tolerability issues in either treatment cycle in Part A which the investigator and the sponsor medical monitor consider a risk for further participation
• Subject met any withdrawal criteria in Part A
• Subject has experienced any adverse effects or developed any new medical conditions since enrollment in Part A which the investigator considers could significantly increase the safety risks of participating in Part C