GRIN Therapeutics to Present on Global Phase 3 Beeline Clinical Trial of Radiprodil at American Epilepsy Society Annual Meeting

Presentation highlights novel methodologies for measuring clinical outcomes, including seizure frequency and behavioral changes, in currently recruiting Phase 3 study in GRIN-related neurodevelopmental disorder (GRIN-NDD)

NEW YORK, Dec. 3, 2025 /PRNewswire/ -- GRIN Therapeutics, Inc., a leader in the development of targeted disease-specific therapies to treat serious neurodevelopmental disorders, today announced that it will present insights on the development of novel rating scales for GRIN-related neurodevelopmental disorder (GRIN-NDD) in a poster presentation at the American Epilepsy Society (AES) Annual Meeting being held December 5-9, 2025, in Atlanta, GA. These include the newly developed Clinical Global Impression of Severity (CGI-S) and Change (CGI-C) scales, which measure changes in symptoms and impacts reported to be most meaningful to patients and caregivers affected by GRIN-NDD.

These customized outcome measures will be used to evaluate the company's investigational therapy radiprodil in the planned global Phase 3 Beeline clinical trial, including its impact on core aspects of GRIN-NDD such as seizures, behavioral dysfunction and neurodevelopment.

Presentation Details:
Title: Development of Novel Clinical Global Impression Scales Specific to the Common Signs and Symptoms of GRIN-Related Neurodevelopmental Disorder
Presenter: Russell L. Chin, MD, Medical Director, GRIN Therapeutics
Session date/time: Tuesday, December 9, 2025, 12:00-1:45 p.m. EST

Additional information about the meeting can be found on the AES website.

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 that 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 planned global Phase 3 trial for radiprodil in eligible patients with GRIN-NDD will aim to evaluate the impact of a targeted disease-specific treatment on core aspects of the disease, including seizures, behavioral abnormalities and functional outcomes. Radiprodil is also being developed 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. Late last year, 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 a global pivotal Phase 3 trial. The company has an additional ongoing clinical trial to evaluate radiprodil for the potential treatment of tuberous sclerosis complex (TSC) and focal cortical dysplasia (FCD) type II. 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]

SOURCE GRIN Therapeutics Inc.