Stealth BioTherapeutics announced that the U.S. Food and Drug Administration (FDA) Office of Orphan Products Development has granted Orphan Drug Designation to Stealth's investigational drug candidate, elamipretide, for the treatment of patients with Barth syndrome.
"There are currently no FDA-approved therapies for patients with Barth syndrome, a debilitating condition characterized by heart and skeletal muscle weakness," said Reenie McCarthy, Stealth's chief executive officer. "We believe elamipretide represents a promising, novel approach with the potential to offer hope for patients with Barth syndrome, and we are very pleased to have received Orphan Drug Designation for this indication."
The Orphan Drug Act, enacted in 1983, encourages development of therapies for rare diseases. A disease is considered rare if it affects fewer than 200,000 persons in the United States. Once granted, Orphan Drug Designation provides various development benefits for an investigational drug, including seven-year exclusivity after marketing approval is received.
In March 2018, Stealth announced the completion of enrollment in the TAZPOWER clinical trial, a phase 2/3 crossover study evaluating the effects of daily treatment with elamipretide in 12 patients with genetically confirmed Barth syndrome followed by an open-label treatment extension. The primary endpoints include change in distance walked during the six-minute walk test and change in total fatigue as measured by a patient-reported outcome measure, the Barth Syndrome Symptom Assessment. Secondary endpoints include additional functional assessments, patient-reported outcomes and safety. Data from the TAZPOWER trial are expected later this year.