Stealth BioTherapeutics Reports Elamipretide Improved Skeletal Muscle Bioenergetics in the Elderly

Trial evaluating treatment with investigational drug, elamipretide, demonstrated improved mitochondrial function by increasing energy production after single treatment

BOSTON – September 19, 2016 – Stealth BioTherapeutics (Stealth), a clinical-stage biopharmaceutical company developing investigational drugs to treat mitochondrial dysfunction, today announced results from the MOTION Trial. This clinical trial evaluated the systemic delivery of elamipretide on skeletal muscle function in elderly subjects with reduced mitochondrial function, and demonstrated improved mitochondrial energy production after treatment. This increase in mitochondrial bioenergetics was comparable to the improvement resulting from six months of exercise training, shown in a similar patient population in other trials.

The data from this trial were presented at the Late Breaker Poster Session of the Heart Failure Society of America Annual Scientific Meeting in Orlando, Florida on Saturday, September 17.

MOTION was a Phase 2 randomized, double-blind, placebo-controlled study that evaluated 40 patients ages 60-85 with demonstrated mitochondrial dysfunction to determine the effect of elamipretide on skeletal muscle energetics and performance. The primary endpoint showed improved mitochondrial energy production (ATPmax) which increased by 30% over baseline as compared to a 10% change in the placebo group (p=0.055). The improved bioenergetics were associated with greater skeletal muscle function (p=0.004).  Furthermore elamipretide was well tolerated with no treatment-emergent adverse events (TEAEs) identified.

“Fatigue and exercise intolerance are commonly experienced by elderly patients.  This is especially prominent in certain disease states such as heart failure.  In both cases dysfunctional mitochondria and reduced bioenergetics appear to be centrally involved,” said Dr. Kevin Conley, trial investigator, and Professor, Physiology & BioPhysics, Bioengineering at the Translational Center for Metabolic Imaging at University of Washington. “It is apparent that treatment with elamipretide significantly improved energy production in this patient set. This change is comparable to the improvement seen in my previous studies of endurance training, exercising three times a week for six months, providing hope for patients and their potential for improved muscle function.”

“The encouraging findings in the MOTION trial indicate that muscle function can be improved by restoring bioenergetics,” said Stealth’s Chief Executive Officer Reenie McCarthy. “Our ongoing trials in heart failure and other diseases of aging support the potential for treating mitochondrial dysfunction with elamipretide “

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

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 primary mitochondrial diseases, cardiorenal diseases and ophthalmic disorders. More information regarding Stealth and its pipeline is available at


Media Relations
dna Communications
Kate Contreras, 617-520-7088

Investor Relations
Stern IR
Beth DelGiacco, 212-362-1200