Mighty Therapeutics Initiates IND-Enabling Studies of MYTX-255: a Mitochondrial-Targeted Therapeutic Candidate

New data presented in long-chain fatty acid oxidation disorders at INFORM 2026 support development of Company's third mitochondrial-targeted candidate

NEEDHAM, Mass., Sept. 9, 2026 /PRNewswire/ -- Mighty Therapeutics (the "Company" or "Mighty"), a commercial-stage biotechnology company pioneering development of a new class of medicines that directly target mitochondrial dysfunction in rare and age-related diseases, today announced the initiation of IND-enabling studies of MYTX-255, a novel investigational mitochondrial-targeted therapeutic candidate. The Company plans to submit an Investigational New Drug (IND) application for MYTX-255 by year-end 2027.

"We are thrilled to advance our third mitochondria-targeted therapeutic toward the clinic, furthering our pioneering work in mitochondrial medicine across a range of serious diseases," said David A. Brown, PhD, Chief Scientific Officer at Mighty Therapeutics. "Based on the compelling data we recently presented at the INFORM Annual Meeting, we intend to develop MYTX-255 for fatty acid oxidation disorders, which are life-threatening genetic conditions that leave patients unable to generate the energy they need from fats, often leading to severe metabolic crises, muscle breakdown, and organ damage. We believe MYTX-255 has the potential to improve energy production, metabolic resilience, and mitochondrial function across multiple fatty acid oxidation disorders."

Mighty presented a study demonstrating beneficial effects of MYTX-255 in cells derived from patients with long-chain fatty acid oxidation disorders (LC-FAODs) at the INFORM Annual Meeting, held August 23-24, 2026, in Helsinki, Finland. In the study, fibroblasts from people with four genetically distinct LC-FAODs showed impaired mitochondrial function. Treatment with MYTX-255 significantly improved mitochondrial energy-producing capacity across all four types of LC-FAODs, as measured by two independent tests of mitochondrial function. These findings support further investigation of MYTX-255 as a potential therapeutic approach for multiple forms of LC-FAODs.

MYTX-255 has also demonstrated potential in several different models of cardiac and muscle myopathy including hypertrophic cardiomyopathy, idiopathic cardiomyopathy, and aging cardiac and skeletal muscle.

Mighty is advancing a robust clinical and preclinical pipeline across a range of diseases, including ocular diseases such as dry age-related macular degeneration; neurodegenerative diseases such as Parkinson's disease, Leigh syndrome, and Friedreich's ataxia; diseases of aging; and rare diseases associated with mitochondrial dysfunction such as POLG disease and Barth syndrome.

About Mighty Therapeutics

Mighty Therapeutics, together with its wholly owned operating subsidiary, Stealth BioTherapeutics Inc., is advancing novel therapies for people living with diseases involving mitochondrial dysfunction. Grounded in rigorous science and inspired by meaningful patient partnerships, the company is building a proprietary pipeline to directly address bioenergetic deficits at the source.

In September 2025, Mighty marked a historic milestone with the U.S. Food and Drug Administration (FDA) approval of its first commercial therapy, establishing both the first FDA-approved treatment for Barth syndrome and the first FDA-approved therapy to directly target mitochondria.

Today, Mighty's development portfolio encompasses rare and age-related diseases. Mighty continues to develop elamipretide in Barth syndrome and polymerase gamma related mitochondrial disease. Mighty's Phase 3 ReNEW clinical trial of elamipretide in dry age-related macular degeneration is fully enrolled, with data expected late 2027, and Mighty is progressing its next-generation clinical candidate, bevemipretide, into a Phase 2/3 clinical trial in dry age-related macular degeneration by year-end. Mighty is also developing systemic bevemipretide for Parkinson's disease and continues to develop preclinical assets MYTX-255 and MYTX-589 for rare mitochondrial disorders. For more information, visit www.mightytx.com.

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SOURCE Mighty Therapeutics