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# Harmony Bio Granted Orphan Status for Pitolisant
- URL: https://www.fdaweb.com/harmony-bio-granted-orphan-status-for-pitolisant/
- Published: 2024-02-20T12:00:00.000Z
- Updated: 2026-09-14T14:23:25.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5156392

FDA has granted Harmony Biosciences Holdings an orphan drug designation for pitolisant and its use in treating Prader-Willi syndrome (PWS). The company says about 20,000 people in the U.S. have PWS, and the majority experience behavioral symptoms and more than half suffer from excessive daytime sleepiness.

The orphan designation follows a positive end-of-phase 2 meeting with the agency, according to the company. Harmony’s Phase 2 pitolisant study with individuals with PWS showed overall improvement in daytime sleepiness on the ESS-CHAD Parent/Caregiver Version by 3.7 to 5.5 points, it says.

Harmony is planning a Phase 3 registrational study called TEMPO that is expected to start before April. The randomized, double-blind, placebo-controlled trial will evaluate the drug in patients six years and older with PWS.