Atrogi Doses First Patients in Trial of Novel Muscle-Enhancing Therapy ATR-258

Stockholm, Sweden – March 19, 2026 – Atrogi AB, a clinical-stage biotech company, has initiated a human trial evaluating its lead candidate, ATR-258, a novel therapy designed to mimic the effects of exercise and combat muscle wasting.¹ The first subjects have been dosed in the 8-week, investigator-initiated study, marking a significant milestone for the company.

What is ATR-258?

ATR-258 is a first-in-class oral therapy that aims to drive fat loss, increase muscle mass, and improve metabolism.¹ It functions as a highly selective β2-adrenergic receptor agonist, targeting a pathway crucial for muscle health. The therapy’s potential extends to treating muscle-sparing weight loss and various muscle atrophic conditions.

The Clinical Trial Design

The trial, led by Associate Professor Morten Hostrup at the University of Copenhagen, will examine the effects of ATR-258 on human skeletal muscle.¹ Overweight male volunteers will receive daily oral doses of the drug, allowing researchers to assess its impact on muscle physiology. The study will focus on biased β2-adrenergic receptor (β2-AR) signaling and its role in muscle growth and function. Researchers aim to determine if ATR-258 can replicate the beneficial effects of traditional β2 agonists without the associated cardiovascular side effects.

Mechanism of Action: Targeting GRK-Selective Signaling

Atrogi’s breakthrough technology, validated by research published in Cell in June 2025, enables the development of next-generation, highly selective β2-agonists for chronic apply.¹ ATR-258 selectively targets the GRK (G protein-coupled receptor kinase) pathway, modulating β2-adrenergic signaling. This unique approach aims to overcome the limitations of conventional β-agonists, such as receptor desensitization and undesirable side effects.³ By activating the β₂-adrenergic receptor through a unique signaling pathway, the technology unlocks the potential for chronic treatment of metabolic disease.³

Previous Trial Data & Safety Profile

Prior to this trial, a phase 1 study involving 69 participants demonstrated the safety and tolerability of ATR-258 in both healthy volunteers and individuals with type 2 diabetes.¹ This established a foundation for further investigation into the drug’s efficacy and potential applications.

Expert Perspectives

“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,” said Morten Hostrup, Associate Professor at the University of Copenhagen and Principal Investigator of the study.¹

Professor Tore Bengtsson, Chief Scientific Officer and Founder of Atrogi, added, “Professor Hostrup is widely recognised…in the field, and we are excited about his commitment to investigate the muscle signalling effects of ATR-258. We look forward to sharing the results later this year.”¹

Looking Ahead

Atrogi anticipates sharing the results of this trial later in 2026. The data generated will be crucial in guiding the further development of ATR-258 for a range of metabolic and muscle-wasting conditions.¹ The company’s pipeline also includes research into treatments for type 2 diabetes and obesity.²

References

1. Atrogi Announces First Subjects Dosed in Human Trial for Lead Candidate ATR-258. PRNewswire. March 18, 2026.
2. Our Pipeline – Atrogi. Accessed March 19, 2026.
3. Our Science – Atrogi. Accessed March 19, 2026.