Neurogene (NGNE) investor relations material

Program overview and clinical progress

• Lead program NGN-401 targets Rett syndrome, a severe neurological disorder with significant unmet need and a multi-billion dollar market opportunity in the US and Europe.

• Embolden registrational trial is ongoing, with enrollment and dosing expected to complete in Q2 2024; a 12-month+ data update is anticipated midyear.

• Phase I/II data showed multiple functional skill gains in pediatric patients, supporting recent Breakthrough Therapy designation.

• Durable improvements observed over up to two years of follow-up, with no plateau in functional gains.

• NGN-401 uses full-length MECP2 gene and ICV delivery, aiming for durable, transformative outcomes.

Commercial and regulatory strategy

• Manufacturing is in-house at a Houston facility, supporting clinical and future commercial supply without major new CapEx.

• US is the primary target market; Europe is under consideration with PRIME designation and ongoing regulatory engagement.

• No immediate plans for significant European infrastructure buildout; pricing strategy will prioritize US value.

• Approximately 20 US centers of excellence will serve as initial treatment hubs, with advocacy efforts to expand capacity.

• Families and clinicians will drive adoption, focusing on long-term outcomes and peer experiences.

Clinical endpoints, patient selection, and adoption

• FDA requires a 12-month primary endpoint for gene therapy approval in Rett syndrome; six months is not considered sufficient.

• ICV administration is routine for neurosurgeons and not seen as a barrier to adoption; efficacy is the main driver.

• Prior experience with DAYBUE (trofinetide) does not preclude gene therapy eligibility, except during immunosuppression.

• Disease variability is high, but benefit has been observed across severity and genotype; standard of care differs by geography but disease is fundamentally similar worldwide.

• Market ramp will be gradual due to limited centers and the complexity of gene therapy delivery.