Stealth BioTherapeutics announces presentation of elamipretide data at ACC

Trial results support further study of elamipretide in heart failure

BOSTON – April 3, 2016 – Stealth BioTherapeutics (Stealth), a clinical-stage biopharmaceutical company developing investigational drugs for treating mitochondrial dysfunction, announced promising results from the Phase 1 PREVIEW trial evaluating elamipretide (formerly known as Bendavia) in heart failure patients with reduced ejection fraction. The results showed elamipretide to be safe and well tolerated with demonstrated improvements in key secondary efficacy measures. The data were presented today at the American College of Cardiology’s 65th Annual Scientific Session (ACC.16) in Chicago during the Novel Therapies in Heart Failure moderated poster session, South Hall A1, from 12:30-1:45 PM CT.

Heart failure affects approximately six million people in the U.S. and continues to be the leading cause of hospitalization, despite available therapies.

“The heart requires a significant amount of energy to both contract and relax, and targeting the mitochondrial dysfunction affecting the heart’s energy supply in this population is a new approach to treating the disease,” said Melissa Daubert, M.D., Duke University Health System and the trial’s primary investigator for echocardiography. “Based on the improvement in heart function seen after just one high-dose treatment, we are very excited to explore the benefits of elamipretide after repeated dosing.”

PREVIEW was a randomized, double-blind, ascending dose, placebo-controlled study. Thirty-six patients with ejection fraction less than or equal to 35 percent and stable symptoms of New York Heart Association (NYHA) Class II-III heart failure were randomized to a single four-hour infusion of elamipretide in three ascending, weight-adjusted doses (0.005, 0.05 or 0.25 mg/kg/hr) or saline. The primary endpoints were the safety and tolerability of elamipretide. Secondary endpoints were improvement in cardiac function measured by echocardiography.

The study demonstrated elamipretide significantly reduced left ventricular volume, or the amount of blood remaining in the left ventricle following a heartbeat, at the end of the four-hour infusion in patients in the highest-dose group. In other long-term studies of patients with heart failure, this reduction in volume has been associated with better outcomes.

Trends toward improvement in other echocardiography parameters were also seen in the highest-dose group. The two lower doses showed no significant improvement compared with placebo. Elamipretide was also well tolerated with no serious adverse events in any treatment group; blood pressure and heart rate remained stable in all patients.

“The promising findings in the PREVIEW trial support our ongoing development of elamipretide for heart failure patients with significant unmet treatment needs,” said Chief Executive Officer Reenie McCarthy. “These findings compel us to study this investigational drug in additional heart failure trials in the coming months for patients with either reduced or preserved ejection fraction, including a study for patients hospitalized due to worsening heart failure. These trials will help further our understanding of elamipretide’s potential to treat the failing heart.”

For additional information on this study or elamipretide, please refer to Stealth’s website and