Reneo Pharmaceuticals announced the U.S. Food and Drug Administration (FDA) Office of Orphan Products Development has granted Orphan Drug Designation to the company's lead drug candidate, REN001, for the treatment of primary mitochondrial myopathies (PMM). The company also announced positive preliminary results from a recently completed clinical study for REN001 in patients with PMM.

REN001 is a selective PPAR delta agonist in clinical development as a treatment for genetic myopathies, including PMM. PMM is a group of life-threatening diseases caused by genetic mutations impairing mitochondrial function. PMM patients often have reduced muscle function adversely impacting daily functions and are faced with decreased life expectancy. There are no FDA approved drugs for the treatment of PMM.

"Patients with primary mitochondrial myopathies have many aspects of their lives impacted," said Niall O'Donnell, Ph.D., CEO of Reneo Pharmaceuticals. "The preliminary safety data and exploratory endpoint results from our first PMM clinical study has driven us to move forward, into a large, global clinical trial in PMM. We hope this will result in a great stride forward for patients with PMM."

Reneo completed a 12-week clinical study in PMM patients with mitochondrial gene defects and a history of myopathy. Patients received REN001 orally, once-a-day, with a majority electing to enter an additional 36-week open-label extension study. The study looked at outcomes from walk tests and several symptom questionnaires. Safety data from the study suggests that REN001 was safe and well tolerated in PMM patients. Preliminary walk test data from this study is aiding in the design of a 200-patient clinical trial, which is expected to start in early 2021.

Last year, Reneo received FDA Orphan Drug Designation for REN001 for the treatment of fatty acid oxidation disorders. REN001 is also in clinical development for glycogen storage disease type V, also known as McArdle disease.

Orphan designation is granted by the FDA Office of Orphan Products Development to novel drugs or biologics that treat a rare disease or condition affecting fewer than 200,000 patients in the United States. The designation qualifies the sponsor for various development incentives of the Orphan Drug Act including tax credits for clinical research costs to advance the evaluation and development of products that demonstrate promise for the treatment of rare diseases. Orphan Drug Designation also conveys up to seven years of market exclusivity upon approval of the drug, as well as the ability to apply for annual federal grants and the waiver of filing fees through the Prescription Drug User Fee Act (PDUFA).