Clinical trials

The Phase 3 portion of Study RAD-GRIN-101 is a multinational, multicenter, randomized, double-blind, placebo-controlled trial followed by an open-label extension to evaluate the efficacy and safety of radiprodil in participants with GRIN-related neurodevelopmental disorder (GRIN-NDD) with a gain-of-function (GoF) genetic variant. This study will enroll two cohorts: one cohort of participants with a minimal number of countable motor seizures (with or without behavioral symptoms) (Phase 3 Cohort 1: Qualifying Seizures Cohort); and a second cohort with disease symptoms but no seizures or fewer seizures than required for the Qualifying Seizures Cohort (Phase 3 Cohort 2: Without Qualifying Seizures Auxiliary Cohort). Participants in each cohort will be randomized 1:1 to receive active drug (radiprodil) or matching placebo (Part A). Following completion of Part A, all eligible participants (including those previously on placebo) may continue into the open-label extension period (Part B) to receive radiprodil. The placebo-controlled portion is expected to be approximately 16 weeks for participants in Phase 3 Cohort 1 and 28 weeks for participants in Phase 3 Cohort 2. The study will evaluate the effect of radiprodil on seizures and non-seizure symptoms and assess safety.

This Phase 1, open-label study will evaluate the pharmacokinetics (PK), safety, and tolerability of a single oral dose of radiprodil in adults with varying degrees of hepatic impairment compared with healthy participants. Radiprodil is being developed as a potential treatment for GRIN-related neurodevelopmental disorders, tuberous sclerosis complex, and focal cortical dysplasia. Approximately 40 adults aged 18 to 75 years will be enrolled into five cohorts based on liver function (mild, moderate, or severe hepatic impairment) or healthy status. Participants will receive a single 15 mg oral dose of radiprodil and remain in the clinical research unit for intensive PK and safety monitoring through Day 6. The primary objective is to characterize the PK profile of radiprodil in participants with hepatic impairment compared with healthy participants. Safety and tolerability will also be assessed. Results from this study will help determine whether dose adjustments are needed in individuals with impaired liver function.