Stealth BioTherapeutics Announces EMBRACE Results: A Phase 2 Clinical Study of Bendavia in Acute Coronary Syndrome

Promising heart failure results support strategic focus of Stealth’s cardio-renal program

Boston, MA — March 15, 2015 — Stealth BioTherapeutics (Stealth), a clinical-stage biopharmaceutical company developing drug candidates for the treatment of diseases involving mitochondrial dysfunction, today announced its EMBRACE results. EMBRACE is a Phase 2 multinational clinical study evaluating Bendavia in patients with acute coronary syndrome (ACS). The results were presented at the American College of Cardiology 64th Annual Scientific Session in San Diego, California, during the Late-Breaking Clinical Trials (LBCT) session, Main Tent, from 8:00 AM to 9:15 AM PT.

EMBRACE evaluated the effects of Bendavia on reducing myocardial damage in ACS patients with an acute ST-segment elevation myocardial infarction (MI). The study’s primary endpoint was area-under-the-curve (AUC) for creatine kinase MB (CK-MB), an enzyme used to estimate cardiac damage from an MI. CK-MB AUC in Bendavia-treated patients was lower than placebo (5570 ± 486 versus 5785 ± 426 ng*h/mL with maximum CK-MB values of 217 versus 267 ng/mL), although the difference did not achieve significance in the primary analysis population (PAP) of 118 patients. EMBRACE showed no significant differences in clinical safety, patient tolerability or adverse events among groups for the intent-to-treat population (n=297), consistent with prior Phase 1 and 2 clinical studies of Bendavia.

In the PAP, there was a significant imbalance (p=0.02) among Bendavia and placebo patients with preexisting hypertension (38% versus 60%). Given this imbalance, a non-prespecified analysis of patients with hypertension showed significantly lower infarct volumes with Bendavia (35.8 mL versus 52.6 mL for placebo, p=0.03), consistent with reduced cardiac damage for treated patients. This analysis of hypertensive patients also demonstrated improved ST-segment resolution with Bendavia versus placebo (p=0.05) by 24 hours post-MI.

Although EMBRACE was not designed to show a difference in PAP clinical outcomes, a non-prespecified analysis demonstrated a trend toward reduction in new onset heart failure during Bendavia treatment (14% [8/58] versus 25% [15/60] for placebo, p=0.16).

“When blood flow to the heart is reintroduced after a blockage, the rapid restoration of oxygen and nutrients can result in irreversible damage. Most of our cardiovascular and heart attack strategies have focused on opening arteries, but not on preventing this damage,” said Dr. C. Michael Gibson, EMBRACE’s chairman, and an interventional cardiologist and Chief of Clinical Research in the Cardiovascular Division at Beth Israel Deaconess Medical Center, an affiliate of Harvard Medical School. “We’ve done a lot to improve ACS care, but patients are still left with a heart that does not function well, and they often progress to heart failure. The trend toward reducing the incidence of heart failure during Bendavia treatment supports its ongoing development for these patients.”

“A strategic focus for Stealth’s cardio-renal program is heart failure, and EMBRACE provided us with encouraging results here,” said Chief Executive Officer Travis Wilson. “Based on promising findings from this study and those recently reported in our renal trial, we are progressing Bendavia’s development for heart failure patients with kidney disease as a comorbidity, an underserved population with significant unmet treatment needs.”


EMBRACE (Evaluation of the Myocardial effects of Bendavia for reducing Reperfusion injury in patients with Acute Coronary Events) is a Phase 2 study across more than 20 sites within the United States and Europe. This multinational, double-blind, placebo-controlled clinical study evaluated Bendavia’s potential to improve cardiac function and preserve viable myocardium in ACS patients by restoring their mitochondrial function and energetics.

Mitochondria, The Cell’s Powerhouse

Mitochondria are the cell’s powerhouse, responsible for more than 90% of the energy our bodies need to sustain life and support growth. The energetics from mitochondria maintain healthy physiology and prevent disease. In many common and rare diseases, dysfunctional mitochondria are a key component of disease progression.

About Bendavia™ and Ocuvia™

Stealth’s lead candidates, Bendavia and Ocuvia, are investigational drugs with the potential to modify disease through mitoprotection — the ability to preserve energetics and restore normal energy production in mitochondria, while decreasing oxidative stress. These clinical candidates are being developed for both common and rare diseases including mitochondrial diseases where there are no FDA-approved treatments. The underlying science of Bendavia and Ocuvia is supported by more than 100 independent, peer-reviewed publications and abstracts. These mitochondrial-targeted candidates represent a novel therapeutic approach with the potential to address a wide variety of diseases having unmet treatment needs.

Stealth BioTherapeutics: Leading Mitochondrial Medicine

Stealth BioTherapeutics is a privately held biopharmaceutical company committed to bringing mitochondria therapies to patients to treat both common and rare diseases. As a key common element in a variety of serious, debilitating diseases, mitochondria — the cell’s energy source — offer a promising, and yet untapped, target to modify diseases with significant unmet treatment needs. Stealth is expanding its clinical development program to additional therapeutic areas, including cardio-renal diseases, ophthalmic disorders and orphan mitochondrial diseases. By defining the broad potential of its mitochondrial platform and therapies, Stealth is leading mitochondrial medicine.

More information regarding Stealth and its pipeline is available at

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