Stealth BioTherapeutics Receives Orphan Drug Designation from FDA for Elamipretide for Treatment of Duchenne Muscular Dystrophy

Stealth BioTherapeutics Corp, a clinical-stage biotechnology company focused on the discovery, development, and commercialization of novel therapies for diseases involving mitochondrial dysfunction, announced that the US Food and Drug Administration (FDA) Office of Orphan Products Development has granted Orphan Drug Designation to elamipretide for the treatment of patients with Duchenne muscular dystrophy (DMD).

The company also announced that the FDA’s Division of Neurology I has granted its request for a pre-IND meeting to discuss a development path for elamipretide in combination with products within the approved therapeutic class of exon-skipping phosphorodiamidate morpholino oligomers (PMO).  The company has previously presented data demonstrating that administration of elamipretide in combination with a PMO significantly improves dystrophin expression levels in the X-linked muscular dystrophy (mdx) mouse model.  The company also previously conducted a pre-IND meeting with the FDA’s Division of Cardiology and Nephrology during which it aligned on a potential development path for elamipretide for cardiomyopathy associated with DMD.

“We are pleased that the FDA has recognized the high unmet need for innovative treatments for DMD,” said Chief Executive Officer Reenie McCarthy. “We look forward to further discussions with the FDA regarding our development initiatives, which we hope will bring new options to patients suffering from this devastating disease.”

DMD is an X chromosome-linked genetic disorder caused by mutations in the DMD gene which encodes the dystrophin protein. DMD is a fatal disease of muscle membrane instability in which the loss of dystrophin and ensuing mitochondrial dysfunction results in a cascade of events leading to progressive loss of muscle function.  The disease, which is typically diagnosed in childhood, is associated with progressive skeletal muscle dysfunction typically starting in early childhood, progressing to loss of ambulation in early adolescence, loss of upper limb function and assisted ventilation during late adolescence into early adulthood.  Despite recent advances in treatment options for DMD, including the conditional approvals of several PMOs, most patients die in early adulthood from respiratory or, more commonly, cardiac failure.  Cellular uptake and retention of PMOs and PMO-mediated dystrophin is thought to be limited by mitochondrial dysfunction associated with DMD.

The Orphan Drug Act was enacted in 1983 to encourage development of drugs for rare diseases, which are diseases that affect 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.