Stealth BioTherapeutics announced 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 Leber's hereditary optic neuropathy (LHON).
LHON is an inherited mitochondrial disease that causes loss of central vision due to damage to neurons in the retina, called retinal ganglion cells. The disease, which affects approximately 10,000 people in the United States, can lead to legal blindness, and there are no FDA-approved therapies to address it.
Orphan Drug Designation provides various benefits for an investigational drug, including seven-year exclusivity after marketing approval is received. Elamipretide has also been granted Orphan Drug Designation for the treatment of primary mitochondrial myopathy and Barth syndrome, two other rare primary mitochondrial diseases.
"This designation further underscores our commitment to develop potential therapies for patients suffering from rare mitochondrial diseases," said Reenie McCarthy, Stealth's chief executive officer. "This third Orphan Drug Designation for elamipretide highlights our significant progress within our present rare disease focus, as we continue to advance our longer-term strategy of developing therapies for age-related diseases."
In December 2017, Stealth was also granted Fast Track designation for elamipretide for the treatment of LHON. Stealth is currently evaluating the safety, tolerability and efficacy of topical eye drop delivery of elamipretide in patients with LHON in ReSIGHT, a phase 2, prospective, double-masked, vehicle-controlled clinical study initiated in 2016. Top-line results from the study are expected later this year.