Neurogene (NGNE) TD Cowen 45th Annual Healthcare Conference summary

Unmet need and disease overview

• Rett syndrome is a rare neurodevelopmental disorder with a global prevalence of about 1 in 10,000 adults, characterized by severe impairments in hand function, communication, gross motor function, autonomic disturbances, and seizures.

• Current approved treatments do not address core symptoms such as mood, hand function, and communication, leaving significant unmet needs.

• No existing therapies substantially alter the disease course.

Gene therapy platform and approach

• The Exact platform enables precise control of transgene expression in AAV vectors, critical for diseases like Rett syndrome where both under- and overexpression are harmful.

• The platform uses co-expressed microRNA to regulate transgene levels on a cell-by-cell basis, aiming for consistent therapeutic protein delivery.

• NGN-401 is the lead program utilizing this technology.

Clinical trial data and patient outcomes

• Interim phase 1/2 data from November 2024 showed consistent, durable, and time-dependent improvements in all four patients, with two having over 12 months of follow-up.

• All patients demonstrated at least a two-point improvement on the CGII scale, which is considered clinically meaningful.

• Notable gains included new skills in hand function, gross motor abilities, and communication, such as using utensils, climbing stairs, and speaking meaningful words.

• Improvements were also observed in autonomic domains, including resolution of constipation and dysphagia, as measured by standard clinical scales.

• All girls in the study showed time-dependent deepening of responses, regardless of baseline presentation.