GRIN Therapeutics Inc, a developer of precision therapeutics for neurodevelopmental disorders, announced on Friday 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.

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. According to GRIN, 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.

The 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.