Praxis Precision Medicines said positive efficacy data have prompted the independent data monitoring committee to recommend an early stop to the registrational EMBOLD trial evaluating relutrigine in developmental and epileptic encephalopathies (DEE). The study, which enrolled children with SCN2A-DEE or SCN8A-DEE, met its primary endpoints, triggering the early-halt recommendation on ethical grounds. Relutrigine is a first-in-class small molecule that selectively modulates persistent sodium current to reduce NaV channel hyperexcitability, a key driver of severe DEEs. Praxis said the results mark a potential milestone, as no approved therapies currently target SCN2A- or SCN8A-driven disease.
A meeting with the US FDA has been scheduled to discuss next steps. Praxis will determine the timing of a New Drug Application submission following the meeting. EMBOLD topline results will be presented at the American Epilepsy Society Annual Meeting on December 6, 2025.
DEE landscape
DEEs are early-onset epilepsies characterized by drug-resistant seizures and developmental impairment. Standard therapies, including sodium channel blockers, often fail to achieve seizure control or impact neurodevelopment, particularly in genetically driven channelopathies.
- UCB: fenfluramine is approved for Dravet syndrome and Lennox-Gastaut syndrome and is being explored in multiple DEE and genetic epilepsy settings.
- Lundbeck/Longboard Pharmaceuticals: LP352 (bexicaserin), a next-generation serotonin receptor agonist, is in Phase 1/2 and Phase 3 development for DEE, Dravet syndrome and Lennox-Gastaut syndrome.
- Takeda: soticlestat development in Dravet and Lennox-Gastaut was discontinued in early 2025 after Phase 3 trials failed primary seizure-reduction endpoints.