Stealth BioTherapeutics Reports Positive Results for Primary Mitochondrial Myopathy Trial

Trial evaluating treatment with elamipretide in rare disease meets efficacy and safety endpoints

Data to be presented at Mitochondrial Medicine 2016 on Friday, June 17 at 8:10 a.m. PT

BOSTON – June 6, 2016 – Stealth BioTherapeutics (Stealth), a clinical-stage biopharmaceutical company developing investigational drugs to treat mitochondrial dysfunction, today announced positive results from MMPOWER, a Phase 2 trial evaluating the systemic delivery of elamipretide for the treatment of primary mitochondrial myopathy, or muscle weakness, in patients with a genetically confirmed mitochondrial disease.

Data from the MMPOWER trial will be presented at , the United Mitochondrial Disease Foundation (UMDF) symposium, on Friday, June 17 at 8:10 a.m. PT.

In January 2016, the U.S. Food and Drug Administration (FDA) granted Fast Track designation for elamipretide for the treatment of primary mitochondrial myopathy, characterized by muscle weakness, in patients with genetic mitochondrial diseases. In the second half of this year, the Company will initiate the MMPOWER-2 study in patients who participated in MMPOWER.

Additionally, Stealth will present today at the at the BIO International Convention at the Moscone Center in San Francisco. The Company will participate in the Mitochondrial Disease Forum from 1:00 – 5:00 p.m. PT, where speakers will discuss the challenges and opportunities in research for genetic mitochondrial disease, the current drug development landscape and the potential of mitochondrial research for other diseases and aging. Stealth’s Chief Scientific Officer Mark Bamberger will present during the “Drug Development for Mitochondrial Disease: Examining the Current Landscape and Scientific/Regulatory Gaps” session from 2:00 – 3:30 p.m. PT.

“Mitochondrial medicine has the potential to address numerous rare and common diseases, and as a leader in the space, we are thrilled to participate in these meetings to help bring this conversation to the broader healthcare community and to share updates with those already in the field,” said Stealth’s Chief Executive Officer Reenie McCarthy. “We especially look forward to presenting positive results from the MMPOWER trial and our ongoing development plans for elamipretide in rare mitochondrial diseases, for which there are currently no FDA-approved treatments.”

For additional information on MMPOWER or elamipretide, please refer to Stealth’s website or


MMPOWER was a double-blind, placebo-controlled study to evaluate the safety, tolerability and efficacy of elamipretide to treat primary mitochondrial myopathy in patients with genetically confirmed mitochondrial disease. Genetic mitochondrial diseases are a diverse group of rare inherited disorders characterized by systemic mitochondrial dysfunction that impairs patient health and well-being. The trial evaluated 36 patients ages 16-65 in three dose cohorts.

About Elamipretide

Stealth’s lead candidate, elamipretide, is an investigational drug with the potential to modify disease by preserving energetics and restoring normal energy production in mitochondria, while decreasing oxidative stress. The energetics from mitochondria maintain healthy physiology and prevent disease. This mitochondria-targeted candidate is being developed for both rare and common diseases.

Stealth BioTherapeutics: Leading Mitochondrial Medicine

Stealth BioTherapeutics is a privately held biopharmaceutical company committed to bringing mitochondrial therapies to patients to treat both rare and common diseases. Stealth’s clinical development program is focused along several core therapeutic areas, including orphan mitochondrial diseases, cardiorenal diseases and ophthalmic disorders. More information regarding Stealth and its pipeline is available at


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