Praxis' sodium channel blocker reduces seizures in 2 types of epilepsy in phase 2

Praxis Precision Medicines has scored another midphase win in epilepsy this year, with its sodium channel inhibitor shown to reduce seizures in children with two specific types of the neurological disorder.

The EMBOLD study enrolled 16 individuals aged between 2 and 18 years who had been diagnosed with early-onset SCN2A-DEE or SCN8A-DEE—forms of epilepsy for which there are no approved treatments. These patients either received placebo or relutrigine, which inhibits persistent sodium current, a key driver of seizure symptoms in SCN2A-DEE and SCN8A-DEE.

Participants who received relutrigine saw an average 46% reduction in their seizures during the double-blind part of the study, Praxis said in a Sept. 3 release. Disrupted movement improved by 23% based on a clinician’s assessment at Week 16, while communication improved by 31% and seizure severity and intensity by 62%.

Five patients receiving relutrigine went for 28 days without a seizure, compared to none in the placebo cohort, the biotech noted.

The primary endpoint of the trial was the drug’s safety, and Praxis reported that no patients discontinued their treatment due to an adverse event. Relutrigine was “generally safe and well tolerated,” the company said, with seven patients increasing their daily dose from 0.5 mg/kg to 1 mg/kg during the trial.

The most common adverse events were infections, vomiting, pyrexia, somnolence and constipation, the biotech said.

“When comparing to the baseline rates, patients in EMBOLD had over 2,000 fewer seizures since the beginning of the study,” Praxis CEO Marcio Souza said in the release.

“Seizure freedom is the ultimate goal for patients, and we were humbled by the progress made with relutrigine during the EMBOLD study with over 30% of patients achieving this life-altering milestone,” Souza added.

Praxis scored another midphase epilepsy win back in March when a high dose of its next-generation NaV blocker PRAX-628 was linked to a 100% complete response rate in epilepsy patients with photoparoxysmal response, a form of photosensitivity.