BOSTON, June 29, 2026
Praxis Precision Medicines announced that the U.S. Food and Drug Administration (FDA) has extended the review period for its New Drug Application (NDA) for relutrigine, an investigational therapy for SCN2A and SCN8A developmental and epileptic encephalopathies (DEEs). The FDA has assigned a new Prescription Drug User Fee Act (PDUFA) target action date of December 27, 2026, extending the original review deadline of September 27, 2026 by three months.
The extension follows the company’s submission of additional sensitivity analyses of existing clinical data, which the FDA classified as a major amendment, requiring additional review time. Importantly, the agency did not request any new clinical studies and identified no safety or manufacturing concerns, allowing the regulatory review to continue without interruption. The decision keeps relutrigine on track as a potential first approved treatment specifically targeting patients with SCN2A and SCN8A DEEs, two rare and severe forms of childhood epilepsy with significant unmet medical need.
FDA Review Continues Without Safety Concerns
According to Praxis Precision Medicines, the review extension is strictly related to the FDA’s evaluation of the additional clinical analyses submitted during the NDA review process and should not be interpreted as a negative regulatory outcome. The company emphasized that relutrigine’s application remains active, with the FDA continuing its comprehensive assessment of efficacy and clinical benefit. Praxis also confirmed that regulators did not raise manufacturing deficiencies, quality concerns, or new safety issues, reinforcing confidence in the existing development program.
Company President and Chief Executive Officer Marcio Souza stated that Praxis remains confident in the overall strength of the clinical data package supporting relutrigine and will continue working closely with the FDA throughout the remainder of the review process. At the same time, the company is advancing commercial launch preparations to ensure readiness should regulatory approval be granted later this year.
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Relutrigine Targets Serious Genetic Epilepsies
Relutrigine is being developed as a precision therapy for SCN2A and SCN8A developmental and epileptic encephalopathies, devastating rare genetic neurological disorders caused by mutations affecting sodium channel function in the brain. These conditions often begin during infancy or early childhood and are characterized by frequent treatment-resistant seizures, developmental delays, intellectual disability, and lifelong neurological impairment.
Currently, no FDA-approved therapies specifically target SCN2A or SCN8A DEEs, leaving patients dependent on broad anti-seizure medications that frequently provide inadequate seizure control. Praxis believes relutrigine’s differentiated mechanism has demonstrated a compelling clinical profile capable of addressing this significant unmet need, potentially offering a precision medicine approach for these genetically defined epilepsies if approved by the FDA.
Precision Neuroscience Pipeline Continues to Expand
The relutrigine program represents an important component of Praxis Precision Medicines’ broader strategy of developing precision neuroscience therapies using genetic insights to treat disorders involving abnormal neuronal excitation and inhibition. Through its proprietary Cerebrum™ small molecule platform and Solidus™ antisense oligonucleotide (ASO) platform, the company is building a diversified pipeline across epilepsy, movement disorders, and other central nervous system diseases.
Praxis currently has multiple late-stage clinical programs aimed at addressing serious neurological disorders with limited treatment options. While the FDA review timeline for relutrigine has been extended, the absence of additional clinical trial requests or regulatory safety concerns suggests the application remains on a standard review path toward the updated December 27, 2026 PDUFA date. Investors, clinicians, and rare disease advocates will closely monitor the FDA’s final decision, which could introduce the first targeted treatment option for patients with SCN2A and SCN8A developmental and epileptic encephalopathies.
Source: Praxis Precision Medicines, press release
