04:37 PM EST, 11/11/2024 (MT Newswires) -- Neurogene ( NGNE ) said Monday it likely will not move forward with its NGN-101 CLN5 Batten disease gene therapy program after the US Food and Drug Administration denied a Regenerative Medicine Advance Therapy application for the program.

Neurogene ( NGNE ) shares were falling 35% in recent after-hours trading.

"Given the rarity of the disease, continued investment in the program was predicated on alignment on a streamlined registrational pathway with FDA," the company said, adding the regulator denied the RMAT application.

Neurogene ( NGNE ) said it's "evaluating options for the program."

Neurogene ( NGNE ) also said Monday it has seen "positive" interim results in the first four participants in the low-dose group of a phase 1/2 trial assessing NGN-401 gene therapy to treat female pediatric patients with Rett syndrome, a neurodevelopmental disease.

The company said it expects to provide an update of registrational trial design in H1 2025 and will release more interim phase 1/2 results in H2 2025.