Neurogene Inc. announced the dosing of the first two female pediatric patients with Rett syndrome in its ongoing Phase 1/2 trial of NGN-401. Rett syndrome is a debilitating, X-linked, neurodevelopmental disorder with significant unmet medical need. In non-clinical studies with NGN-401 at clinically relevant doses, cardiac features of Rett syndrome were ameliorated, and no overexpression toxicity was observed.

These data were part of the robust non-clinical package that supported the U.S. Food and Drug Administration's (FDA) decision to allow Neurogene to proceed directly into a pediatric population for its first-in-human study. NGN-401 has also been granted Orphan Drug Designation, Rare Pediatric Disease Designation, and Fast Track Designation by the FDA. The first-in-human, open-label, single-arm, multi-center Phase 1/2 clinical trial (NCT05898620) is evaluating NGN-401 at a dose of 1x1015 total vector genomes to assess the safety and tolerability of NGN-401 in female pediatric patients ages 4-10 with Rett syndrome.

The first two patients were dosed sequentially in the third and fourth quarter of 2023 at Texas Children's Hospital, an internationally recognized pediatric research center affiliated with Baylor College of Medicine, and the first clinical trial site to be opened in the U.S. for this study. The company remain on track to report preliminary clinical data from the first cohort of patients in this trial in the fourth quarter of 2024, with additional data from an expanded number of patients expected in the second half of 2025. Females with Rett syndrome typically have normal development until 6-18 months of age, followed by a progressive deterioration of acquired skills such as gross and fine motor skills, purposeful hand function and communication.

They subsequently develop stereotypic hand movements such as hand-wringing. Forward-looking statements in this communication include, but are not limited to, statements regarding the expected enrollment of and timing of data from Neurogene's Phase 1/2 clinical trial; statements regarding the potential of, and expectations regarding, Neurogene's programs, including NGN-101, NGN-401 and its research stage opportunities; the expected dosing of additional patients in Neurogene's Phase1/2 clinical trial; statements by Neurogene's Founder and Chief Executive Officer. Neurogene's limited experience in designing clinical trials and lack of experience in conducting clinical trials; the ability to identify and pivot to other programs, product candidates, or indications that may be more profitable or successful than Neurogene's current product candidates; expectations regarding the market and potential for Neurogene's current product candidate; the substantial competition Neurogene faces in discovering, developing, or commercializing products; expectations regarding the substantial competition Neurogene face in discovering, developing, or Commercializing products; expectations regarding the potential of, and expected to be in the U.S.