Praxis Precision Medicines’ epilepsy pipeline has suffered a setback after a next-gen NaV blocker failed to sufficiently reduce seizures in a phase 2/3 study.
The Boston-based biotech had been evaluating the drug, called vormatrigine, among patients with focal onset seizures (FOS) who were also taking between one and three other anti-seizure medications. Patients either received a 20 mg daily dose of vormatrigine for six weeks followed by a 30 mg dose for another six weeks, or placebo.
The study, dubbed POWER1, missed its primary endpoint of demonstrating a reduction in monthly frequency of seizures against baseline, Praxis disclosed in a June 1 release.
However, the biotech pointed out that the study was able to hit a secondary endpoint of demonstrating a 50% response rate. A reduction of seizures was also “more pronounced” once patients migrated across to the 30 mg dose regimen, added Praxis, which also noted that less than 10% of patients discontinued their treatment because of adverse events.
Praxis had already launched a separate phase 3 study for vormatrigine in FOS, dubbed POWER2, and a readout had been pencilled in for 2027. But the biotech said today that it is pausing enrollment in that trial so it can “reassess the vormatrigine program and determine potential modifications.”
“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,” Praxis CEO Marcio Souza said in the release.
“We will take some time to review these results to ensure we have the best path forward for developing vormatrigine and the ongoing POWER2 study,” Souza added.
In the meantime, the company will “continue to focus on preparing for the planned launches” of relutrigine and ulixacaltamide. The FDA is due to make a call in September on approving relutrigine, a sodium channel inhibitor, to treat severe, early-onset genetic epilepsies caused by mutations in genes encoding voltage-gated sodium channels.
The agency is also scheduled to decide on whether to approve the T-type calcium channel inhibitor ulixacaltamide to treat essential tremor in January 2027.
