Praxis Precision Medicines Reports Promising Results in Epilepsy Drug Trial

Praxis Precision Medicines has announced encouraging results from its midphase trial of vormatrigine, a sodium-channel modulator designed to treat focal onset seizures. The study, known as Radiant, demonstrated a significant reduction in seizure frequency among patients, prompting the company to advance its plans for a larger phase 2/3 trial.

Trial Results and Efficacy

The Radiant study, which involved 37 patients with focal onset seizures, reported a median 56.3% reduction in seizure frequency from baseline over an eight-week period. Notably, 60% of patients who completed the trial experienced at least a 50% reduction in seizure frequency.

Praxis observed early improvements, with 54% of patients reaching the 50% reduction threshold in the first week of treatment. The efficacy appeared to deepen over time, with 22% of patients achieving a 100% reduction in seizure frequency during the final month of the study.

Dr. Steven Petrou, Chief Scientific Officer at Praxis, highlighted the consistency of efficacy across different patient subgroups, regardless of their background therapies. "This level of consistency, in both efficacy and tolerability, across different treatment backgrounds speaks to vormatrigine's versatility," Petrou stated. "It reinforces the idea that this is a therapy with broad applicability."

Safety and Discontinuation Rates

While the drug was generally well-tolerated, the trial faced a significant 23% discontinuation rate. Praxis attributed many of these dropouts to a lack of background therapy dose adjustment, despite protocol guidance. The company noted that adverse events and discontinuations "were avoided entirely" in six instances where investigators proactively reduced background treatment.

This high discontinuation rate may have contributed to the tepid investor response, with Praxis shares declining nearly 14% to $46.68 in Monday trading following the announcement.

Future Plans and Market Implications

Despite the challenges, Praxis remains optimistic about vormatrigine's potential. CEO Marcio Souza suggested that the drug's efficacy was not impacted by the reduction of other medications, supporting the possibility of vormatrigine becoming a standalone therapy.

"I think what we established is that the background therapy is not doing anything but causing side effects, and vormatrigine is getting these patients better," Souza explained. "So a monotherapy study, or a switch to monotherapy, makes a lot of sense."

Praxis is now planning to initiate a monotherapy trial in the first half of 2026. In the nearer term, the company will launch a follow-up to the Radiant study, enrolling a larger patient population to receive either a placebo or one of three doses of vormatrigine.

As the epilepsy treatment landscape continues to evolve, with drugs like SK Life Science's Xcopri gaining widespread adoption, Praxis's vormatrigine represents a potential new option for patients with focal onset seizures. The upcoming larger trials will be crucial in determining whether this promising candidate can overcome its initial hurdles and establish itself as a significant player in the epilepsy market.