Recruiting

Phase 3

RadiprodilBeeline: A Phase 3 Study in GRIN-related Neurodevelopmental Disorder

Sponsor:

GRIN Therapeutics, Inc.

Code:

NCT07224581

Conditions

GRIN-related Neurodevelopmental Disorder

Eligibility Criteria

Sex: All

Age: 0 - 18

Healthy Volunteers: Not accepted

Interventions

Radiprodil

Placebo

Study Details

Brief summary:

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.

Conditions

GRIN-related Neurodevelopmental Disorder

Study ID

NCT07224581

Start date

Jan 5, 2026

Status verified date

Jul, 2026

Completion date

Jul, 2028

Anticipated

Primary completion date

May, 2027

Anticipated

Eligibility Criteria

Sex: All

Age: 0 - 18

Healthy Volunteers: Not accepted

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.

Study Design

Enrollment

100 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Radiprodil

Liquid suspension of radiprodil, at varying concentrations depending on participant's weight.

The following dose-escalation regimen (twice daily \[BID\]) will be used:

Titration Period Visit 1 (Visit T1): Dose 1, Visit T2: Dose 2, Visit T3: Dose 3, Visit T4: Maintenance Dose.

placebo comparator: Placebo

Liquid suspension of placebo matching radiprodil oral suspension and dose-escalation regimen.

Interventions

Radiprodil

Radiprodil oral suspension

Placebo

Placebo-to-match radiprodil oral suspension

Primary outcome measure

Part A - Phase 3 Cohort 1 (Qualifying Seizures Cohort): Countable motor seizures (CMS) [ Time Frame: 12 weeks ]
Part A - Phase 3 Cohort 2 (Without Qualifying Seizures Auxiliary Cohort): Adverse events (AEs), serious adverse events (SAEs), and adverse drug reactions (ADRs) [ Time Frame: 24 weeks ]
Part B - Open-Label Extension: Adverse events (AEs), serious adverse events (SAEs), and adverse drug reactions (ADRs) [ Time Frame: Average of 2 years ]

Central Contacts and Locations

Central contacts

Clinical Operations

+1-877-225-0014 ClinicalTrials@GrinTherapeutics.com

Locations

UCLA Health - Ronald Reagan UCLA Medical Center

Recruiting

Los Angeles, California, United States, 90095

Contacts

Angela Martinez

310-968-8942 AngelaMartinez@mednet.ucla.edu

Lucile Packard Children's Hospital

Recruiting

Palo Alto, California, United States, 94304

Contacts

650-721-1458

Children's Hospital Colorado - Anschutz Medical Campus

Recruiting

Aurora, Colorado, United States, 80045

Children's National Hospital

Recruiting

Washington D.C., District of Columbia, United States, 20010

Contacts

Chloe Hooker

202-476-4809 chooker@childrensnational.org

Nicklaus Children's Hospital

Recruiting

Miami, Florida, United States, 33155

Contacts

Dainelys Pena Rodriquez

786-624-3547 dainelys.penarodriguez@nicklaushealth.org

Pediatric Neurology and Epilepsy

Recruiting

Winter Park, Florida, United States, 32789

Contacts

Denise Hubert

407-293-1122 dhubert@pediatricneurologyandepilepsy.com

Iowa Health Care - Pediatric Neurology & Specialty Clinic

Recruiting

Iowa City, Iowa, United States, 52242

Boston Children's Hospital

Recruiting

Boston, Massachusetts, United States, 02115

Contacts

Helen Olson

Helen.Olson@childrens.harvard.edu

Northeast Regional Epilepsy Group (NEREG) - Hackensack

Recruiting

Hackensack, New Jersey, United States, 07601

Contacts

Hardik A Rana, MBBS

551-497-5000 hrana@epilepsygroup.com

Columbia University - Harkness

Recruiting

New York, New York, United States, 10032

Contacts

Jaimie Gowatsky

917-838-6514 jg2917@cumc.columbia.edu

Duke Health-Duke Children's Hospital & Health Center

Recruiting

Durham, North Carolina, United States, 27705

Contacts

Gloria Pinero

919-613-0767 gloria.pinero@duke.edu

Children's Hospital of Philadelphia

Recruiting

Philadelphia, Pennsylvania, United States, 19104

Contacts

Jennie Minnick

MINNICK@chop.edu

Child Neurology Consultants of Austin - South Austin

Recruiting

Austin, Texas, United States, 78757

The University of Texas Southwestern Medical Center (UTSW)

Recruiting

Dallas, Texas, United States, 75390

UTHealth Houston

Recruiting

Houston, Texas, United States, 77030

Contacts

Annette Frenk, MSc

713-500-7164 Annette.C.FrenkOquendo@uth.tmc.edu

Seattle Children's Hospital

Recruiting

Seattle, Washington, United States, 98105

More Information

Sponsor

GRIN Therapeutics, Inc.

Last update posted

Jul 17, 2026

Last verified

Jul, 2026

Keywords

Beeline
GRIN1
GRIN2A
GRIN2B
GRIN2D
GRIN-NDD

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by GRIN Therapeutics, Inc. on 2026-07-17.