Praxis Precision Medicines Inc. (NASDAQ: PRAX) announced that its Phase 2/3 POWER1 study of vormatrigine for focal onset seizures failed to meet its primary endpoint, prompting the company to pause enrollment in a second study while it reassesses the program.

The POWER1 study evaluated vormatrigine in adults with focal onset seizures who were taking one to three anti-seizure medications. Patients received either 20 mg daily for six weeks followed by 30 mg daily for six weeks, or placebo for 12 weeks. The primary endpoint measured the percent change in monthly seizure frequency from baseline.

While the study did not meet its primary success measure, the company reported that a secondary measure, the 50% response rate, was achieved. Seizure reduction was more pronounced during the second half of the study when patients received the higher 30 mg dose.

The treatment showed a safety profile with adverse event-related discontinuations below 10%. Approximately 90% of patients from the vormatrigine treatment group transitioned to an open-label extension study.

"While the results for POWER1 were not what we hoped for, we are encouraged by the signal we saw on the higher dose arm, the low discontinuation rate and solid safety profile," said Marcio Souza, President and Chief Executive Officer of Praxis.

The company is pausing enrollment in its POWER2 study to review the vormatrigine program and determine potential modifications. Praxis stated it will continue focusing on preparing for planned launches of relutrigine and ulixacaltamide.

Vormatrigine is designed as a once-daily oral treatment targeting sodium channels in the brain for adult focal onset seizures and generalized epilepsy. The drug candidate aims to selectively target hyperexcitable sodium channels associated with disease states.