The FDA has delayed a decision on the approval of Praxis Precision Medicine’s rare epilepsy prospect by three months. TD Cowen analysts said they “strongly believe FDA bandwidth constraints from last year’s agency downsizing likely contributed to the delay.”
FDA officials accepted the drug candidate, relutrigine, for priority review in March. The acceptance set Praxis up to receive a decision on the sodium channel modulator for the treatment of SCN2A and SCN8A developmental and epileptic encephalopathies by Sept. 27. Relutrigine was “progressing incredibly well with the FDA,” Praxis CEO Marcio Souza said three weeks ago at a Goldman Sachs event.
Now, the smoothly progressing program has hit a bump in the road. After receiving additional sensitivity analyses, the FDA has concluded that it needs three more months to review the filing. While the agency didn’t request new clinical studies or cite any safety or manufacturing concerns, the delay pushes the decision date back to Dec. 27.
TD Cowen analysts provided details of the additional analysis in a note to investors. Praxis characterized its submission as “simple” and “limited to minor sensitivity analyses and data reformatting/presentation changes,” the analysts said.
But the FDA classed Praxis’ submission as a major amendment, triggering the three-month delay. The setback is “consistent with the nature of review extensions seen across many NDAs recently,” the analysts said, naming Rhythm Pharmaceuticals’ Imcivree and KalVista Pharmaceuticals’ sebetralstat as examples of programs that have experienced similar delays.
Rhythm won approval for Imcivree in hypothalamic obesity three months later than planned after the FDA classed additional sensitivity analyses of existing clinical data as a major amendment. The FDA blamed “heavy workload and limited resources” for the delayed sebetralstat decision, KalVista said at the time.
KalVista suffered its delay about two months after the FDA began laying off 3,500 people in April 2025. Rhythm learned of its extension in November. The FDA has continued to extend reviews in 2026, with AstraZeneca, Beren Therapeutics, Eisai and Biogen, and Orca Bio among the companies to face delays. It is unclear whether the FDA’s downsizing was a factor, as TD Cowen analysts believe in the case of Praxis.
The analysts predict that, like KalVista and Rhythm before it, Praxis will bounce back from the delay and win FDA approval. Relutrigine has already been through a “benign” mid-cycle review meeting at the FDA and is supported by strong clinical data, the analysts said. Praxis reported a 53% placebo-adjusted drop in seizures at Week 16 of its confirmatory, registrational clinical trial cohort.