Stealth BioTherapeutics Initiates Phase 1/2 Trial of SBT-20 at CHDR in Patients With Early Stage Huntington's Disease

BOSTON, May 2, 2017 /PRNewswire/ -- Stealth BioTherapeutics Inc. (Stealth), a clinical-stage biopharmaceutical company developing therapeutics to treat mitochondrial dysfunction, today announced the initiation of CHALLENGE-HD, a Phase 1/2 trial evaluating SBT-20 in patients with early stage Huntington's disease. SBT-20 is an investigational tetrapeptide aimed at improving mitochondrial function by restoring the physical and biochemical properties of dysfunctional mitochondria.

The press release 

"Huntington's disease is a fatal genetic disorder in which nerve cells in the brain deteriorate over time, causing patients to have progressively limited physical and mental abilities. Research shows that mitochondrial dysfunction may play a central role in this deterioration, making the mitochondria a prime target for study," said Stealth's Chief Clinical Development Officer Jim Carr. "This trial examines the safety and tolerability of SBT-20 at various doses, and begins to explore the possible benefit of the compound in addressing mitochondrial dysfunction in Huntington's disease."

CHALLENGE-HD is a two-part, randomized, double-blind, placebo-controlled trial being conducted at a single clinical site, the Centre for Human Drug Research (CHDR) in the Netherlands. The trial is evaluating the safety, tolerability and efficacy of daily subcutaneous injections of SBT-20 in adult patients with early stage Huntington's disease (genetically confirmed disease with Unified Huntington's Disease Rating Scale [UHDRS] Total Motor Score of five or more and Total Functional Capacity Score of seven or more). During part one, patients are administered SBT-20 subcutaneously for seven days at one of three ascending doses (5, 15 and 25 mg). The findings will be used to select a dose for the second part of the trial, in which SBT-20 will be administered subcutaneously for 28 days. The trial aims to enroll 24 patients, all of whom will participate in both part one and part two of the trial. The trial's primary endpoints are safety and tolerability, and secondary endpoints will measure the effect of SBT-20 on mitochondrial and motor function as well as its pharmacokinetic profile.

"The initiation of CHALLENGE-HD is a significant milestone for Stealth as our second drug candidate enters human trials in a new therapeutic area. As a leader in mitochondrial medicine, we want to pursue the full potential of mitochondria-targeted therapies, in rare primary mitochondrial diseases, common diseases of aging and now in neurodegenerative disorders. We plan to use the results from this trial to better inform our SBT-20 pipeline development plan and the broader potential of our platform in neurodegenerative disorders," said Stealth's Chief Executive Officer Reenie McCarthy.

For additional information on CHALLENGE-HD and SBT-20, please refer to Stealth's website.

About Huntington's Disease

Huntington's disease is an inherited disorder that causes degeneration of brain cells, called neurons, in regions of the brain that control muscle movement, as well as other areas. Symptoms of the disease, which gets progressively worse over time, include uncontrolled movements (called chorea), cognitive deficits and psychiatric disturbances. There are no FDA-approved treatments that can stop or reverse the course of Huntington's disease.

About SBT-20

SBT-20 is Stealth's second pipeline candidate and is being developed for the treatment of neurodegenerative diseases. SBT-20 is an investigational tetrapeptide with the potential to slow neuronal degeneration and disease progression in Huntington's disease by improving mitochondrial function. In preclinical studies, SBT-20 has demonstrated an enhanced ability to target the central nervous system by achieving higher concentrations and extended stability in the cerebrospinal fluid compared with elamipretide.

About Stealth BioTherapeutics

We are a privately held clinical-stage biotechnology company focused on the development of therapeutics for diseases involving mitochondrial dysfunction. We believe there is a strong rationale for our lead product candidate, elamipretide, in indications in these diseases based on encouraging preclinical and early clinical data. We are investigating elamipretide in three primary mitochondrial diseases – mitochondrial myopathy (MM), Barth syndrome and Leber's hereditary optic neuropathy (LHON) – as well as in heart failure, Fuchs' corneal dystrophy and dry age-related macular degeneration. We received Fast Track designation for elamipretide for the treatment of primary mitochondrial myopathy from the FDA in December 2016. We are developing our second product candidate, SBT-20, for neurodegenerative disorders. Our mission is to be the leader in mitochondrial medicine. To learn more information about us and our pipeline, visit