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# Phelan-McDermid Therapy Given Rare Disease Status
- URL: https://www.fdaweb.com/phelan-mcdermid-therapy-given-rare-disease-status/
- Published: 2024-07-19T12:00:00.000Z
- Updated: 2026-09-14T14:35:55.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5157394

FDA has granted Neuren Pharmaceuticals a rare pediatric disease designation for its drug candidate NNZ-2591 and its use in treating Phelan-McDermid syndrome. The designation may qualify Neuren for a priority review voucher if its therapy gains approval.

The designation is based on recent data from a Phase 2 trial of NNZ-2591, a treatment for children with Pitt Hopkins syndrome, a neurodevelopmental disorder caused by mutations in the TCF4 gene on chromosome 18\. The trial showed that NNZ-2591 led to improvements as assessed by clinicians and caregivers, Neuren says, adding that it is preparing for an end-of-Phase 2 meeting with FDA in the third quarter to further discuss the therapy’s development program.