NEW YORK, Jan. 9, 2026 /PRNewswire/ — GRIN Therapeutics, Inc., a leader in the development of targeted disease-specific therapies for serious neurodevelopmental disorders, today announced that it has dosed the first patient in its global Phase 3 Beeline trial of investigational radiprodil in individuals with GRIN-related neurodevelopmental disorder (GRIN-NDD) with gain-of-function variants (ClinicalTrials.gov identifier: NCT07224581).

Radiprodil is a selective negative allosteric modulator of the NMDA receptor GluN2B subunit and is designed to address the underlying biology of GRIN-NDD, and not just the symptoms. Because of radiprodil’s direct mechanism of action impacting the underlying biology of the NMDA receptor, there is an opportunity to have impact on all resulting manifestations of the dysregulation caused by receptor overactivation. This offers potential advantages over existing non-targeted anticonvulsant therapies.

“This study reflects a truly collaborative effort between investigators, patient communities, and industry partners,” said Kristen Park, M.D., pediatric epileptologist in the Division of Neurology at Children’s Hospital Colorado and Principal Investigator for the Phase 3 Beeline trial at the Children’s Hospital Colorado trial site. “GRIN-NDD is one of the most complex neurodevelopmental disorders with limited treatment options today. The Beeline trial gives us the opportunity to further evaluate whether radiprodil can address not only seizures but also the cognitive and behavioral aspects of the disease and provide the kind of treatment option that patients and families have been hoping for. We are proud to be a part of this important trial at Children’s Hospital Colorado.”

“With the first patient dosed, the Beeline trial marks a pivotal moment for GRIN Therapeutics and the community. For the first time, through the Phase 3 Beeline trial, patients have the opportunity to receive a drug that specifically targets the abnormal receptor leading to their condition – a drug that aims to address the underlying biology of GRIN-NDD, potentially modifying the course of disease,” said Michael Panzara, M.D., MPH, Chief Medical Officer of GRIN Therapeutics. “In four years, we have advanced from company inception to a global Phase 3 program built around deep scientific understanding of the disease and engagement with key stakeholders, including families and global regulatory authorities. This milestone represents what can be achieved when the right team with the right background and experience, the right resources, and the right collaborators align to drive clinical development.”

The Beeline trial (NCT07224581) is a global Phase 3 study designed to evaluate the efficacy and safety of investigational radiprodil in patients with GRIN-NDD who have confirmed gain-of-function variants. The trial incorporates a disease-specific endpoint, the GRIN-specific Clinical Global Impression (GRIN-CGI) scale developed in collaboration with caregivers, as well as traditional clinical outcome assessments and measures of seizure reduction.

This study builds on results from the Phase 1b/2a open-label Honeycomb trial, in which patients with countable motor seizures (CMS) who received investigational radiprodil experienced a median reduction of 86% in CMS frequency compared to baseline. During the trial period, 71% of patients achieved more than 50% reduction in CMS and six of seven were seizure-free on at least 80% of days during the eight-week maintenance period. Clinicians and caregivers generally assessed patients as improved clinically over the course of the study regardless of the occurrence of seizures, as measured by Clinician and Caregiver Global Impressions of Change (CGI-C and CaGI-C) and the Aberrant Behavior Checklist – Community (ABC-C). The most common adverse events observed were those associated with infections or the underlying disease. Serious adverse events (SAEs) were similarly associated with infections or the underlying disease, and all were assessed as unrelated to radiprodil.

The Phase 3 Beeline trial is being conducted across multiple regions globally. GRIN Therapeutics’ collaboration with Angelini Pharma outside of North America will support future accessibility if approved for patients in Europe and other regions.

About Radiprodil

Radiprodil is an investigational, potent negative allosteric modulator that selectively targets the GluN2B subunit of the N-methyl-D-aspartate (NMDA) receptor and is being assessed for the treatment of GRIN-related neurodevelopmental disorder (GRIN-NDD). It has been awarded Breakthrough Therapy, Orphan Drug and Rare Pediatric Disease designations by the U.S. Food and Drug Administration as well as Priority Medicines (PRIME) designation by the European Medicines Agency (EMA) and a positive opinion for orphan designation from the EMA Committee for Medicinal Products for Human Use (CHMP). The global Phase 3 Beeline trial for radiprodil in patients with GRIN-NDD gain-of-function variants is designed to evaluate the impact of a targeted disease-specific treatment on core aspects of the disease, including seizures, behavioral manifestations, and functional outcomes. Radiprodil is also being assessed for the treatment of tuberous sclerosis complex (TSC) and focal cortical dysplasia (FCD) type II, two disorders associated with NMDA receptor overexpression. The Astroscape trial (ClinicalTrials.gov identifier: NCT06392009) is an ongoing, open-label Phase 1b/2a clinical trial assessing the safety, tolerability, pharmacokinetics (PK), and potential efficacy of radiprodil in patients with TSC or FCD type II.

About GRIN Therapeutics

GRIN Therapeutics, Inc. is dedicated to the research and development of precision therapeutics for neurodevelopmental disorders with the goal of bringing hope to patients and caregivers. In late 2024, GRIN Therapeutics reported promising topline data from a Phase 1b/2a clinical trial (the Honeycomb Trial, ClinicalTrials.gov identifier: NCT05818943) evaluating investigational radiprodil in GRIN-related neurodevelopmental disorder (GRIN-NDD) in patients with gain-of-function (GoF) variants, leading to the decision to advance to the global pivotal Phase 3 Beeline trial (ClinicalTrials.gov identifier: NCT07224581). The company has an additional ongoing clinical trial to evaluate radiprodil for the potential treatment of tuberous sclerosis complex (TSC) and focal cortical dysplasia type II (FCDII). GRIN Therapeutics is an affiliate of Neurvati Neurosciences, a portfolio company of Blackstone Life Sciences. For more information, please visit www.grintherapeutics.com.

About Neurvati Neurosciences

Neurvati Neurosciences is the neuroscience development platform of Blackstone Life Sciences, created to bridge the gap that has long constrained progress in the field. Neurvati identifies and advances high-potential neuroscience assets through a disciplined, scalable model that establishes and funds fit-for-purpose affiliate companies—each designed to drive development with precision, dedicated capital, and experienced leadership. By addressing the challenges that have historically impeded neuroscience drug development, Neurvati offers a differentiated solution that creates durable value across the neuroscience ecosystem and accelerates the delivery of new therapies for patients with complex neurological and psychiatric disorders.

About Blackstone Life Sciences

Blackstone Life Sciences is an industry-leading private investment platform with capabilities to invest across the life cycle of companies and products within key life science sectors. By combining scale investments and hands-on operational leadership, Blackstone Life Sciences helps bring to market promising new medicines and medical technologies that improve patients’ lives and currently has more than $12 billion in assets under management.

Corporate Contact
Elliott Ruiz
+1 201.674.5417
[email protected]

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