• ATR-258, a first-in-class oral medication, mimics exercise-induced benefits—promoting fat reduction, muscle growth, and metabolic enhancement—offering significant potential as a new therapy for weight loss that preserves muscle mass.
• The study is directed by Associate Professor Morten Hostrup of the University of Copenhagen, a preeminent expert in β2-adrenergic receptor signaling within skeletal muscle, to assess the physiological muscle impacts of ATR-258’s highly selective β2-adrenergic signaling.
• Atrogi’s innovative technology, supported by pivotal research published in Cell in June 2025, facilitates the development of next-generation, highly selective β2-agonists suitable for chronic treatment for the first time.

(SeaPRwire) –   STOCKHOLM, March 18, 2026 — Clinical-stage biotechnology firm Atrogi AB, which specializes in developing GPCR pathway-signaling modulators to improve metabolic and muscular health, announced today that the initial subjects have received doses of its primary candidate, ATR-258, in a human clinical trial investigating the muscle physiological effects of its highly selective GRK-targeted β2-adrenergic signaling pathway.

This 8-week, investigator-led interventional trial will evaluate biased β2-adrenergic receptor (β2-AR) signaling in the skeletal muscle of overweight male participants, who will be administered daily oral doses of ATR-258, the company’s GRK-selective, long-acting β2-agonist. The research aims to determine how effectively ATR-258 replicates the muscle physiological benefits of traditional β2-agonists and its potential utility in treating various muscle-atrophy conditions.

Morten Hostrup, Associate Professor at the University of Copenhagen and the study’s Principal Investigator, stated: “This trial provides an opportunity to precisely examine the targeted downstream effector signaling linked to the β2-adrenergic receptor in human skeletal muscle using a highly selective, next-generation modulator. By integrating comprehensive muscle physiological assessments with advanced molecular analysis, we intend to gain a deeper understanding of how biased β2-adrenergic signaling influences muscle development and function, and how this mechanism might be utilized to maintain or enhance muscle performance in scenarios involving muscle wasting, such as aging, immobilization, and weight loss.”

Professor Tore Bengtsson, Founder and Chief Scientific Officer at Atrogi, added: “Professor Hostrup is widely acknowledged as a leading authority in this field, and we are thrilled by his dedication to exploring the muscle signaling properties of ATR-258, building upon our findings published in Cell in June 2025. His commitment to leading this study underscores the robustness of our scientific approach, and we look forward to presenting the findings later this year.”

This trial follows a period of significant progress for Atrogi, following the June 2025 publication of a landmark study in Cell that validated the company’s unique GRK2-biased signaling pathway. This approach unlocks the therapeutic potential of muscle-targeted β2-agonists while mitigating the cardiovascular risks typically associated with such treatments. The publication also highlighted data from a 69-subject Phase 1 trial, which confirmed the safety and tolerability of ATR-258 in both patients with type 2 diabetes and healthy volunteers.

Paul Little, Chief Executive Officer at Atrogi, commented: “The launch of this study and the dosing of the first participants represent a major milestone for Atrogi. With the safety profile confirmed in Phase 1 and a validated mechanism of action, the acquisition of essential muscle physiology data from this trial will support the continued development of ATR-258 for metabolic and muscle-wasting disorders.”

Further details regarding the ATR-258 study are available at www.clinicaltrials.gov, under the NCT identifier NCT07421024.

About Atrogi

Atrogi AB is a Stockholm-based, clinical-stage biotech company focused on developing novel GPCR pathway-signaling modulators to improve metabolic and muscle health. Its lead candidate, ATR-258, is a first-in-class oral GRK2-biased β2-agonist engineered to safely stimulate muscle metabolism and maintain lean mass, providing a new strategy for addressing obesity, diabetes, and muscle loss.

Atrogi’s proprietary compound library, created under the guidance of Professor Tore Bengtsson, forms the basis of a broader platform dedicated to identifying selective GPCR modulators for a variety of disease indications. More information is available at www.atrogi.com and on LinkedIn.