Shares of Praxis Precision Medicines, Inc. (NASDAQ:PRAX) fell about 7% in after-hours trading on Monday after the company disclosed that the U.S. Food and Drug Administration extended the review period for its New Drug Application for relutrigine by three months.
The FDA reset the PDUFA target action date to December 27, 2026, moving it from the previously scheduled date of September 27, 2026. Praxis said the delay followed the company’s submission of additional sensitivity analyses of existing clinical data, a filing the agency classified as a "major amendment."
Relutrigine is under review as a potential treatment for SCN2A and SCN8A developmental and epileptic encephalopathies. According to Praxis, the FDA did not request any new clinical studies in connection with the amendment and did not raise concerns related to safety or manufacturing. The company described the review as active and ongoing.
Marcio Souza, president and chief executive officer of Praxis, said the company remains confident in the strength of the data package and will continue to work with the FDA review team. Praxis also said it is continuing preparations aimed at delivering relutrigine to patients with SCN2A and SCN8A encephalopathies, which the company notes currently lack FDA-approved treatment options.
Market reaction to regulatory schedule shifts can be swift for small-cap biotechnology firms, and Praxis’s after-hours decline reflects investor sensitivity to timeline uncertainty even when an agency classifies a submission as a major amendment rather than requesting additional trials. Praxis’s statement emphasizes that the agency did not flag safety or manufacturing issues and that its review remains in progress.
Investors and other stakeholders will be watching communications between Praxis and the FDA and any subsequent updates to the regulatory timeline. For now, the company is maintaining preparations related to relutrigine's potential commercial availability should the review conclude in a favorable decision.