Breakthrough Therapy designation granted based on interim NGN-401 Phase 1/2 data demonstrating clinically meaningful, durable and multidomain functional improvements
On track to complete dosing in Embolden™ registrational trial of NGN-401 in second quarter of 2026
Plans to present additional interim Phase 1/2 clinical data in mid-2026
Neurogene Inc. (Nasdaq: NGNE), a clinical-stage company founded to bring life-changing genetic medicines to patients and families affected by rare neurological diseases, today announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy designation to NGN-401, an investigational gene therapy in late-stage clinical development as a potential best-in-class treatment for Rett syndrome.
The Breakthrough Therapy designation was based on the FDA’s review of interim efficacy and safety data from the Phase 1/2 trial as of the data cutoff date of October 30, 2025, including patient-level data and supporting video documentation, demonstrating clinically meaningful and durable functional improvements across multiple Rett syndrome domains with continued skill acquisition over time.
NGN-401 is being evaluated as a one-time treatment for Rett syndrome and is designed to deliver the full-length human MECP2 gene under the control of Neurogene’s proprietary EXACT™ transgene regulation technology. It is delivered through intracerebroventricular administration to achieve the broadest targeting directly to the brain and nervous system based on nonclinical biodistribution data. NGN-401 is currently being evaluated in the Embolden™ registrational clinical trial, with completion of dosing expected in the second quarter of 2026.
“The FDA’s decision to grant Breakthrough Therapy designation validates the clinically meaningful, durable and multidomain functional improvements observed with NGN-401, including continued skill acquisition observed over time, and underscores the significant unmet medical need of those living with Rett syndrome,” stated Rachel McMinn, Ph.D., Founder and Chief Executive Officer of Neurogene. “We appreciate the Agency’s continued engagement, including through our participation in the START Pilot Program and now our Breakthrough Therapy designation, to support the rapid advancement of NGN-401.”
Breakthrough Therapy designation is intended to expedite the development and review of medicines for the treatment of serious conditions which have shown preliminary clinical evidence indicating the potential for substantial improvement over available therapies on a clinically significant endpoint. The benefits of Breakthrough Therapy designation include eligibility for Priority Review, rolling submission of sections of the Biologics License Application and FDA’s organizational commitment to help determine an efficient route to approval.
This designation for NGN-401 is the latest of several regulatory designations granted by FDA, including Regenerative Medicine Advanced Therapy (RMAT) and Rare Pediatric Disease designations, and selection for FDA’s Support for Clinical Trials Advancing Rare Disease Therapeutics (START) Pilot Program.
