NCT07224581 · GRIN Therapeutics, Inc.
Beeline: A Phase 3 Study in GRIN-related Neurodevelopmental Disorder
What this study is about
The Phase 3 portion of Study RAD-GRIN-101 is a multinational, conducted at multiple hospitals, randomly assigned, where neither patients nor doctors know which treatment is given, compared against an inactive treatment trial followed by an where both patients and doctors know the treatment given extension to evaluate the effectiveness 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 group of participants of participants with a minimal number of countable motor seizures (with or without behavioral symptoms) (Phase 3 group of participants 1: Qualifying Seizures group of participants); and a second group of participants with disease symptoms but no seizures or fewer seizures than required for the Qualifying Seizures group of participants (Phase 3 group of participants 2: Without Qualifying Seizures Auxiliary group of participants). Participants in each group of participants will be randomly assigned 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 where both patients and doctors know the treatment given extension period (Part B) to receive radiprodil. The compared against an inactive treatment portion is expected to be approximately 16 weeks for participants in Phase 3 group of participants 1 and 28 weeks for participants in Phase 3 group of participants 2. The study will evaluate the effect of radiprodil on seizures and non-seizure symptoms and assess safety.
View original scientific description
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Part A, Participant:
- Diagnosed with GRIN-NDD with GRIN1, GRIN2A, GRIN2B, or GRIN2D gene variants known to result in GoF of the NMDA receptor
- Phase 3 Cohort 1 (Qualifying Seizures Cohort) ONLY: Experiencing at least 1 CMS per week and ≥4 CMS (generalized or focal) during screening
- With history of inadequate response to at least 2 standard antiseizure medications (ASMs)
- Phase 3 Cohort 2 (Without Qualifying Seizures Auxiliary Cohort) ONLY: With significant neurodevelopmental symptoms and a GRIN-CGI-S score ≥4
- On a stable dose of standard ASMs for at least 4 weeks prior to screening and should remain on stable doses throughout study participation
- On stable nonpharmacological treatments such as ketogenic diet and should remain stable throughout study participation Part B: \- Participant has completed Part A and is eligible to continue study participation according to the judgement of the investigator and sponsor.
Exclusion criteria
- PART A, Participant:
- Has clinically relevant medical, neurologic, or psychiatric condition and/or behavioral disorder (including those related to GRIN-NDD) that would preclude or jeopardize participant's safe participation or study drug administration or the conduct of the study according to the judgement of the investigator or sponsor.
- Is receiving \>4 standard ASMs at screening
- Has a body weight of less than 5 kg at screening Part B: \- Participant has clinically relevant medical, neurologic, or psychiatric condition and/or behavioral disorder (including those related to GRIN-NDD) that would preclude or jeopardize participant's safe participation of study drug administration or the conduct of the study according to the judgement of the investigator or sponsor.
Where
- Los Angeles, California
- Palo Alto, California
- Aurora, Colorado
- Washington D.C., District of Columbia
- Miami, Florida
- Winter Park, Florida
- Iowa City, Iowa
- Boston, Massachusetts
- Hackensack, New Jersey
- New York, New York
- Durham, North Carolina
- Cincinnati, Ohio
And 5 more locations — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 29, 2026 · Source of record for eligibility and locations