Neurogene is a clinical-stage biotech developing gene therapies for rare neurological diseases. The company's sole clinical program is NGN-401, a gene therapy for Rett syndrome — a rare, progressive neurodevelopmental disorder caused by mutations in the MECP2 gene, affecting roughly 15,000–20,000 patients in the U.S., EU, and UK. There are no currently approved disease-modifying treatments for Rett syndrome. NGN-401 delivers a functional copy of the MECP2 gene via a one-time injection directly into the fluid surrounding the brain and spinal cord. The core design challenge is that both too little and too much MeCP2 protein causes serious disease, creating a narrow therapeutic window. Neurogene addresses this with its proprietary EXACT technology, a microRNA-based genetic circuit that self-regulates protein expression on a cell-by-cell basis, preventing overexpression toxicity while supplying enough protein to deficient cells. NGN-401 is in a Phase 3 registrational trial; enrollment is complete and dosing is expected to finish in Q2 2026. Neurogene owns its cGMP manufacturing facility in Houston, and the commercial manufacturing scale matches the clinical scale, avoiding costly comparability studies. If approved, NGN-401 would be a one-time treatment sold at high price to a small patient population — the typical rare disease gene therapy model. Neurogene is pre-revenue and funds operations through equity financing.