MitoRx Therapeutics advances next-generation obesity therapy

MitoRx Therapeutics Ltd, a pioneering biotech company developing novel mitochondrial-targeted therapies for obesity, has announced the successful completion of a £5.5m (USD7.2m) pre-Series A funding round, led by Oshen Holdings SA. The investment will accelerate the development of Myo‑004, a first-in-class small molecule designed to promote weight loss without loss of lean muscle mass, a significant advancement over existing GLP-1 receptor agonists.

A new class of obesity drug

Unlike peptide-based GLP-1 agonists, Myo‑004 is a small molecule that operates via a mitochondrial mechanism, specifically modifying persulfides. This mitochondrial-targeted action restores disrupted sulfidic signaling, improving cellular metabolism and enabling effective weight reduction. Preclinical studies in murine models demonstrated significant fat loss while preserving both muscle and bone mass, highlighting a critical advantage over current GLP-1 therapies.

Myo‑004 has also shown synergistic effects when combined with semaglutide, further enhancing fat reduction without compromising lean mass. These findings were presented at major scientific conferences, including the 32nd European Conference on Obesity and the American Diabetes Association’s 2025 Scientific Sessions, where data confirmed improvements in insulin sensitivity, muscle fiber size, and liver-fat clearance in diet-induced obesity models.

Targeting energy expenditure, not appetite

MitoRx positions Myo‑004 within a new class of “energy-expenditure” therapies, which achieve weight loss through metabolic modulation rather than appetite suppression. According to MitoRx, Myo‑004 represents an “entirely new category of weight loss drug”, designed to deliver sustainable, high-quality fat loss while safeguarding lean mass.

Investor confidence and strategic growth

The pre-Series A round will support MitoRx’s clinical candidate selection and ongoing oral program development within its proprietary Candidate Engine platform, which identifies and profiles next-generation mitochondrial-targeted molecules.

“Investors clearly recognize that preservation of lean mass is key to effective weight loss therapy,” said Jon Rees, CEO and Co-founder of MitoRx. “Our small molecules drive fat loss while preserving muscle through a unique mechanism, providing a better-quality outcome than GLP-1 receptor agonists. This funding enables us to build a comprehensive data package demonstrating safety, efficacy, and tolerability for people living with obesity.”

Justin Cahill, Managing Partner at Oshen Holdings SA, added: “While GLP-1 therapies have been a major step forward, the data show they are not the long-term solution. MitoRx’s Myo‑004 offers sustainable weight control, muscle preservation, and broader metabolic benefits, positioning the company at the forefront of next-generation obesity treatments.”

As part of the funding round, Didier Cowling of Oshen Holdings SA joins MitoRx’s Board of Directors, enhancing the strategic leadership as the company advances its promising therapies.