Aug 11, 2026 —
Neurogene reported second-quarter 2026 financial results and highlighted continued clinical progress for NGN-401, its investigational AAV9 gene therapy for Rett syndrome.
NGN-401 is being developed as a potential one-time treatment for Rett syndrome. The therapy is designed to deliver the full-length human MECP2 gene and incorporates Neurogene’s proprietary EXACT™ transgene regulation technology, which is intended to support consistent, tightly controlled MeCP2 protein expression on a cell-by-cell basis.
The company reported positive long-term data from the Phase 1/2 trial as of a June 16, 2026 data cutoff. In the study, 100% of participants improved on the Clinical Global Impression-Improvement, or CGI-I, scale and gained at least one developmental milestone.
Across 10 participants, a total of 47 developmental milestones were gained, representing an average of 4.7 milestones per participant. Neurogene said improvements continued across follow-up through 30 months, with no plateau and no milestone loss observed as of the data cutoff.
The company also reported that milestones were gained in a progressive, stepwise sequence, suggesting a potential restart of development following treatment. Seven of 10 participants gained at least two developmental milestones and showed improvements across at least two core Rett syndrome domains. These improvements were observed in both pediatric and adolescent/adult participants.
Participants also showed clinically meaningful improvements across additional validated Rett syndrome scales, including the Rett Syndrome Gross Motor Scale and Rett Syndrome Hand Function Scale, with reported statistical significance.
NGN-401 is delivered through intracerebroventricular administration to target the brain and nervous system. The candidate is being evaluated in the Embolden™ registrational trial, in which dosing of 25 participants has been completed. Topline Embolden data are anticipated in the second half of 2027.
As of an August 10, 2026 data cutoff, NGN-401 at the 1E15 vg dose remained generally well tolerated across the Phase 1/2 trial and Embolden, with safety data reported in 35 participants.
Neurogene also initiated its Process Performance Qualification, or PPQ, campaign in July 2026 to support a planned Biologics License Application submission. Completion of PPQ runs is expected by the end of 2026.
NGN-401 has received several regulatory designations, including FDA Breakthrough Therapy, Regenerative Medicine Advanced Therapy, Fast Track, Orphan Drug, and Rare Pediatric Disease designations, as well as selection for the FDA START Pilot Program. The program has also received EMA Advanced Therapy Medicinal Product, Orphan, and PRIME designations, and U.K. Innovative Licensing and Access Pathway designation.
Neurogene strengthened its balance sheet through an oversubscribed public follow-on offering of approximately $144 million in gross proceeds. As of June 30, 2026, the company reported $225.4 million in cash, cash equivalents, and short-term investments. Including net proceeds from the July financing, Neurogene reported pro forma cash resources of approximately $360.2 million, expected to fund planned operations into the first quarter of 2029.
The update positions NGN-401 as one of the most closely watched late-stage AAV gene therapy programs in rare pediatric neurology, with key manufacturing and registrational milestones expected over the next 18 months.
