FDA hits Praxis with 3-month delay for epilepsy drug verdict

 

The delay is largely “benign” for Praxis Precision Medicines, according to Jefferies, which emphasized that the FDA did not flag safety or manufacturing issues.

Praxis Precision Medicines will have to wait up to three more months for the FDA’s decision on its epilepsy therapy.

Monday, the Boston biotech announced that the agency has delayed its target decision date for the investigational sodium channel blocker relutrigine after classifying data from additional analyses as a major amendment to the original application. Relutrigine’s original target action date of Sept. 27 has now been pushed back to Dec. 27. The company is seeking approval for relutrigine in patients with developmental epileptic encephalopathies (DEE) linked to SCN8A and SCN2A mutations.

The FDA hasn’t asked for any additional trials, nor did it point out any safety or manufacturing concerns, according to Praxis’ Monday announcement.

Jefferies took this lack of flags as good news, calling the review extension a “fairly benign delay” in a Monday note.

“Importantly, the FDA did not cite any safety or manufacturing concerns, and no new clinical studies were requested, so we continue to believe approval prospects are favorable,” the analysts wrote. “Said another way, the FDA could have issued a CRL [complete response letter] if it was not inclined to approve.” Jefferies’ historical analysis of review extensions indicates that more than 80% end up getting the regulator’s greenlight.

Relutrigine is an oral drug that blocks the persistent flow of current across sodium channels, which when otherwise left unchecked is a key driver of seizures in patients with DEE. In December 2025, Praxis announced that a mid-stage study for relutrigine in this indication would be terminated ahead of schedule because of the drug’s strong performance, in accordance with the recommendations of an independent data committee.

Data released that same month showed a 53% placebo-adjusted reduction in seizures over 16 weeks. Treated patients also saw 66% more motor seizure-free days. Jefferies called these results “impressive” in its Monday note, “especially given the lack of effective options” for the DEE population.

Praxis “is comfortable with relutrigine reaching $1B+ peak sales in SCN2A/8A alone,” the analysts added.

Outside of relutrigine, Praxis is also advancing the antisense oligonucleotide elsunersen to reduce seizures in SCN2A DEE. The FDA granted the asset breakthrough therapy designation last week. Elsunersen is in the pivotal single-arm EMBRAVE3 trial, which is currently enrolling patients.

https://www.biospace.com/fda/fda-hits-praxis-with-3-month-delay-for-epilepsy-drug-verdict