For Patients & Providers

At Stealth BioTherapeutics, our work is personal. We believe strongly in the potential of our science to deliver new treatment solutions and improve quality of life for patients with diseases involving mitochondrial dysfunction. Many of the diseases we are targeting currently have no FDA-approved treatments, presenting a significant unmet medical need that we hope to help address.

Our team works closely with patients and healthcare professionals to achieve our mission of developing therapies for rare and common age-related diseases involving mitochondrial dysfunction. We collaborate closely with patient advocacy to understand how these diseases impact the daily lives of patients and to better inform our clinical development efforts. We also partner with leading institutions, physicians and scientists to develop our mitochondrial therapies.

In preclinical studies, elamipretide has been shown to restore mitochondrial function at the cellular level with resulting improvement in the function of organ systems such as skeletal muscle, eye, brain, heart and kidney.^14-19

Our hope is that this investigational therapy will help improve the prognosis and quality of life for patients and families whose lives are touched by mitochondrial disease.

Mitochondria & Disease

Mitochondria, often described as the “powerhouse of the cell”, are responsible for approximately 90% of energy production in human cells.¹ These “powerhouses” are found in all human cells other than red blood cells.² Mitochondria produce energy through the conversion of food into adenosine triphosphate, or ATP.²This happens through a series of reactions, controlled by the electron transport chain, within the inner folds of the mitochondria.² In normal mitochondria, the inner mitochondrial membrane is highly folded, creating curves, called cristae.³ The cristae house the electron transport chain, which is composed of five protein complexes responsible for mitochondrial ATP production.³ Cardiolipin, a phospholipid found only in the inner mitochondrial membrane, is responsible for establishing the cristae architecture and optimizing the function of the electron transport chain for ATP generation.⁴

Dysfunctional mitochondria produce less ATP and increased unhealthy levels of reactive oxygen species, or ROS, which leads to oxidative stress.² Although low levels of ROS are normal and important for the cell, high levels of ROS can damage cardiolipin, thereby disrupting the structure of the inner mitochondrial membrane and triggering a cycle of increasing ROS generation that can lead to the inflammation, fibrosis, senescence and cell death implicated in many human diseases.⁵

Mitochondrial dysfunction characterizes numerous inherited rare diseases – collectively known as primary mitochondrial diseases – that arise from over 250 different genetic mutations.⁶ These include primary mitochondrial myopathy, Barth syndrome, and Leber’s hereditary optic neuropathy.^7-8 Mitochondrial dysfunction is also involved in a wide range of common age-related diseases, such as dry age related macular degeneration.^9-10

As the body’s main source of energy production, mitochondria are critical for normal organ function, particularly with respect to high energy demanding organ systems such as skeletal muscle, eye, brain, heart and kidney.^10-12 Patients with mitochondrial disease often experience functional deficit in three or more of these organ systems.^11-12

Mitochondrial Diseases

The term mitochondrial disease or disorder generally refers to a defect which exists somewhere along the energy building pathway.^2,12,35 Mitochondrial diseases are typically classified and named either after the specific genetic defect (e.g. POLG mutation) or the cluster of symptoms associated with the disease (e.g. MELAS: Mitochondrial Encephalopathy, lactic acidosis, stroke, or LHON: Leber’s hereditary optic neuropathy).^2,12,35 Some mitochondrial disorders are named after the clinician who first identified the disease (i.e. Leigh syndrome, Barth syndrome).^36-37 Regardless of the name, the term mitochondrial disease is an umbrella term that encompasses many specific conditions caused by mitochondrial defects.^2,12,35

Inherited Rare Diseases

Primary (inherited) mitochondrial myopathy, or PMM, is characterized by debilitating skeletal muscle weakness and exercise intolerance.¹² We estimate that approximately 70,000 individuals in the United States are diagnosed with this syndrome.²⁰ There are no therapies approved by the U.S. Food and Drug Administration (FDA) or the European Medicines Agency (EMA) for the treatment of primary mitochondrial myopathy.¹²

Barth syndrome, or Barth, is characterized by skeletal muscle weakness, delayed growth, fatigue, varying degrees of physical disability, heart muscle weakness, or cardiomyopathy, low white blood cell count, or neutropenia (which may lead to an increased risk for bacterial infections), and methylglutaconic aciduria (which is an increase in an organic acid that results in abnormal mitochondria function).^22-24 We believe that the incidence of Barth to be between one in 300,000 to 400,000 births.²²

Leber’s hereditary optic neuropathy, or LHON, is characterized by central vision loss.²⁶ We estimate that approximately 10,000 individuals in the United States are diagnosed with LHON.²⁷ There are no therapies approved by the FDA for the treatment of LHON.²⁸

Common Diseases of Aging

Dry age-related macular degeneration, or dry AMD, the leading cause of blindness among older adults in the developed world, is characterized by symptoms such as distorted vision, reduction in low luminance visual acuity, reduced overall visual acuity and blurred vision.^30-31 We estimate that dry AMD impacts more than 1.7 million individuals in the United States.^30–33 There are no FDA or EMA approved treatments for the treatment of dry AMD.³¹

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Community

We work closely with key advocacy organizations and their stakeholders to better understand the needs of people impacted by diseases involving mitochondrial dysfunction. Advocacy organizations play a vital role in helping patients, families and caregivers navigate the difficult path from diagnosis to living with diseases that are debilitating and for which there are no widely understood standards of diagnosis or care.

We collaborate with leading mitochondrial disease patient advocacy organizations to progress our closely aligned missions, by:

Supporting their efforts to improve patients’ lives
Advocating for relevant events and initiatives
Fostering strong relationships in the rare disease and mitochondrial disease community
Positively impacting the mitochondrial disease patient community