Praxis Precision Medicines has decided to stop a mid-stage clinical trial of its investigational drug relutrigine earlier than planned after a data monitoring board recommended the halt due to strong efficacy results. The Boston-based biotechnology company is evaluating relutrigine, a sodium current blocker, in the Phase II EMBOLD study among patients with developmental and epileptic encephalopathies (DEE) associated with SCN8A and SCN2A mutations.
The original primary completion date for the EMBOLD trial was set for March 23, 2026. However, following the recommendation from the monitoring board, Praxis will present more detailed results on December 6 at the American Epilepsy Society conference. The company also plans to meet with the U.S. Food and Drug Administration (FDA) in the coming weeks to discuss next steps regarding relutrigine.
Truist Securities commented on Thursday that relutrigine could achieve peak U.S. sales of about $650 million by 2037. The firm added that this estimate might be “conservative,” stating: “given likely broader utilization or relutrigine in other types of DEE, once relutrigine is approved for SCN2A/8A.”
Relutrigine is an oral small molecule designed to modulate sodium channels by inhibiting persistent currents through these channels—a mechanism Praxis identifies as central to severe DEE symptoms. Previous studies have indicated that relutrigine is well-tolerated and leads to biomarker changes consistent with sodium channel modulation, along with improvements in motor seizures.
In addition to the epilepsy program update, Praxis reported it has concluded a pre-New Drug Application (pre-NDA) meeting with the FDA for its calcium channel inhibitor ulixacaltamide, intended for essential tremors (ET). The company has reached agreement with regulators on application content and expects to submit early next year.
Jefferies analysts responded positively to news of the FDA meeting: “We remain 70%+ confident in approval,” they stated Thursday, projecting that ulixacaltamide could reach “$2.5B+ peak sales,” while noting this figure could still be “conservative.” Truist offered an even higher projection for ulixacaltamide’s potential, estimating it could exceed $3 billion in U.S. sales by around 2040. Truist added that Praxis’s latest updates “further de-risks both ET and DEE programs.”
