Neurogene Announces Positive Regulatory Update for NGN-401 Gene Therapy in Rett Syndrome with Plans to Initiate Dosing in Embolden Registrational Trial in Q4 2025

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 the Company has completed discussions with the U.S. Food and Drug Administration (FDA) on its Embolden registrational trial protocol and plans to initiate dosing in the fourth quarter of 2025. In response to strong interest from the Rett syndrome community, the trial is expected to enroll across 13 sites.

“In preparation for the Embolden registrational trial, we expanded our clinical trial footprint and have more than doubled our presence in the United States and plan to initiate dosing this quarter,” said Rachel McMinn, Ph.D., Founder and Chief Executive Officer of Neurogene. “Being part of the FDA’s START pilot program and having RMAT designation, we are well-positioned to engage in early discussions with the FDA with the goal of an expedited BLA submission.”

Neurogene also announced new preclinical data from nonhuman primates (NHPs) demonstrating that intracerebroventricular (ICV) delivery of NGN-401 achieves superior AAV biodistribution across brain regions relevant to Rett syndrome, compared to intrathecal lumbar (IT-L) delivery. These findings are consistent with preclinical data generated by other independent laboratories, reinforcing a growing body of evidence that supports ICV delivery for achieving greater expression in the brain. Neurogene’s results further validate and recapitulate this consensus, underscoring the robustness of the approach.

Dr. McMinn continued, “Feedback from the Rett syndrome community and KOLs reinforce that the decision to undergo gene therapy treatment is driven by a single critical factor: the potential for meaningful improvement. The route of administration data presented at the ESGCT Congress this week provide a potential rationale for the global improvement and multi-domain skill acquisition observed in our previously reported¹ NGN-401 Phase 1/2 efficacy data. Importantly, the comparable systemic exposure between ICV and IT-L confirms there is no liver-sparing benefit to IT-L administration, consistent with clinical data from intra-CSF administered products.”