Atrogi has dosed the first participants in a human study of its lead candidate ATR‑258, marking a significant step forward for the Stockholm-based biotech as it advances its next‑generation approach to metabolic and muscle health.
The 8‑week investigator‑initiated trial, led by Associate Professor Morten Hostrup at the University of Copenhagen, will assess how ATR‑258’s highly selective β2‑adrenergic signalling affects skeletal muscle in overweight male volunteers. Participants will receive daily oral doses of the long‑acting β2‑agonist, designed to mimic key physiological effects of exercise, including fat loss, increased muscle and improved metabolic function.
Hostrup said: “This trial will allow us to rigorously interrogate targeted downstream effector signaling associated with the β2-adrenergic receptor in human skeletal muscle using a highly selective next generation modulator.
“By combining detailed muscle physiological measurements with advanced molecular readouts, we aim to better understand how biased β2-adrenergic signaling regulates muscle growth and function, and how it can potentially be harnessed to preserve, or even augment, muscle function in various conditions of muscle wasting, such as immobilization, aging, and weight loss.”
Professor Tore Bengtsson, Atrogi’s Chief Scientific Officer and Founder, explained: “Professor Hostrup is widely recognised as the leading expert in the field, and so we are excited about his commitment to investigate the muscle signaling effects of ATR-258, building on the work published in Cell in June 2025. His decision to sponsor this study speaks to the strength of our science and technology, and we look forward to sharing the results later this year.”
The trial follows the publication of landmark Cell research in 2025 validating Atrogi’s GRK2‑biased signalling approach and reporting safety data from a 69‑subject phase 1 study.
Paul Little, Atrogi’s Chief Executive Officer, said: “The initiation of this study, and dosing of the first subjects, marks an important milestone for Atrogi. With safety established in Phase 1 and a validated mechanism of action, the generation of key muscle physiology data from this trial will underpin ATR-258’s further development across metabolic and muscle-wasting conditions.”
