Praxis Precision Medicines Reports Positive EMBOLD Study Results for Relutrigine in Rare Epileptic Encephalopathies
Key Insights
Praxis Precision Medicines announced positive results from the EMBOLD study of relutrigine for SCN2A and SCN8A developmental and epileptic encephalopathies (search), with the Data Monitoring Committee recommending early study termination for efficacy.
The first-in-class sodium channel (search) modulator represents a potential breakthrough for devastating pediatric conditions that currently have no approved treatment options and carry extremely high mortality rates.
The FDA has confirmed an upcoming meeting to review the data and discuss the New Drug Application pathway, with topline results to be presented at the American Epilepsy Society Annual Meeting on December 6, 2025.
Praxis Precision Medicines announced positive results from the registrational cohort of its EMBOLD study evaluating relutrigine for the treatment of patients with SCN2A and SCN8A developmental and epileptic encephalopathies (search) (DEEs). The Data Monitoring Committee recommended stopping the study early for efficacy following a successful interim analysis.
"SCN2A and SCN8A DEEs are devastating conditions with extremely high mortality due to the debilitating seizure burden they impose on patients, and there are currently no approved treatment options," said Marcio Souza, president and chief executive officer of Praxis. "Our progress represents an important milestone towards delivering the first therapy ever designed for these children and their families."
Regulatory Pathway and Next Steps
The FDA has confirmed a meeting to review the data and discuss next steps in the coming weeks. Praxis will make a determination on the timing for filing a New Drug Application (NDA) for relutrigine after the meeting. The EMBOLD topline results will be presented at the American Epilepsy Society Annual Meeting at the Georgia World Congress Center on Saturday, December 6, 2025.
Drug Profile and Mechanism of Action
Relutrigine (PRAX-562) is a first-in-class small molecule in development for the treatment of developmental and epileptic encephalopathies as a preferential inhibitor of persistent sodium current (search), shown to be a key driver of seizure symptoms in severe DEEs. The drug's mechanism of precision sodium channel (search) (NaV) modulation is consistent with superior selectivity for disease-state NaV channel (search) hyperexcitability.
In vivo studies of relutrigine have demonstrated dose-dependent inhibition of seizures up to complete control of seizure activity in SCN2A, SCN8A and other DEE mouse models. The drug has been generally well-tolerated in three Phase 1 studies and has demonstrated biomarker changes indicative of NaV channel (search) modulation.
Previous Clinical Data
Data from cohort 1 of the Phase 2 EMBOLD study demonstrated a well-tolerated safety profile with robust, short- and long-term improvement in motor seizures in a heavily pre-treated population, alongside maintained seizure freedom in some patients with SCN2A- and SCN8A-DEE.
Regulatory Designations
Relutrigine has received multiple regulatory designations recognizing its potential to address unmet medical needs. The FDA has granted Orphan Drug Designation (ODD) and Rare Pediatric Disease Designation for the treatment of SCN2A-DEE, SCN8A-DEE and Dravet syndrome (search). The European Medicines Agency has awarded Breakthrough Therapy Designation (BTD) and ODD for the treatment of SCN2A-DEE and SCN8A-DEE.
Company Overview
Praxis Precision Medicines is a clinical-stage biopharmaceutical company translating insights from genetic epilepsies into the development of therapies for CNS disorders characterized by neuronal excitation-inhibition imbalance. The company applies genetic insights to the discovery and development of therapies for rare and more prevalent neurological disorders through its proprietary small molecule platform, Cerebrum™, and antisense oligonucleotide (ASO) platform, Solidus™. Praxis has established a diversified, multimodal CNS portfolio including multiple programs across movement disorders and epilepsy, with four clinical-stage product candidates.