Atrogi announces first subjects dosed in human trial for lead candidate ATR-258

  • First-in-class oral therapy ATR-258 mimics the effects of exercise – driving fat loss, increasing muscle, and improving metabolism – with broad potential as a novel treatment for muscle-sparing weight loss
  • Study led by Associate Professor Morten Hostrup, a leading authority on β2-adrenergic receptor signaling in skeletal muscle at the University of Copenhagen, to evaluate muscle physiological aspects of ATR-258’s highly selective β2-adrenergic signaling
  • Atrogi’s breakthrough technology, validated by publication of landmark research in Cell in June 2025, enables, for the first time, development of next-generation, highly selective β2-agonists for chronic use

Stockholm, Sweden, March 18, 2026 – Atrogi AB, a clinical stage biotech company pioneering novel GPCR pathway-signalling modulators to transform metabolic and muscle health, today announces that the first subjects have been dosed in a human trial for its lead candidate, ATR-258, evaluating the muscle physiological effects of its highly selective GRK-targeted β2-adrenergic signaling pathway.

The 8-week, investigator-initiated, interventional study will examine biased β2-adrenergic receptor (β2-AR) signaling in human skeletal muscle, in overweight male volunteers, who will receive daily oral dosing of ATR-258, Atrogi’s GRK-selective long-acting β2-agonist. The study aims to measure the extent to which ATR-258 recapitulates the muscle physiological effects of classic β2 agonists, as well as its potential across a range of muscle atrophic conditions.

Morten Hostrup, Associate Professor at the University of Copenhagen and Principal Investigator of the study, 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, Chief Scientific Officer and Founder of Atrogi, added: “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.”

This trial builds on the strong momentum at Atrogi, following the publication of a landmark study in Cell in June 2025 which validated Atrogi’s novel GRK2-biased signaling pathway approach, unlocking the therapeutic potential of muscle-targeted β2-agonists while avoiding the cardiovascular side effects typically associated with this approach. The paper also detailed first-in-human trial data from a 69-subject Phase 1 trial, demonstrating the safety and tolerability of ATR-258 in both healthy volunteers and patients with type 2 diabetes.

Paul Little, Chief Executive Officer at Atrogi, commented: “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.”

Additional information on the  study for ATR-258 can be found on www.clinicaltrials.gov, NCT identifier NCT07421024.

Ends

For media or partnership inquiries, please contact:

Paul Little, CEO, Atrogi AB

info@atrogi.com

Optimum Strategic Communications

Mary Clark, Isabelle Abdou, Joshua Evans

+44 20 3357 0618

atrogi@optimumcomms.com

Notes to Editors

About Atrogi

Atrogi AB is a Stockholm-based, clinical-stage biotech pioneering novel GPCR pathway-signalling modulators to transform metabolic and muscle health. Its lead candidate, ATR-258, is a first-in-class oral GRK2-biased β2-agonist designed to safely stimulate muscle metabolism and preserve lean mass, offering a novel approach to treating diabetes, obesity, and muscle loss.

Atrogi’s proprietary compound library, developed under the scientific leadership of Professor Tore Bengtsson, serves as the foundation for a broader platform aimed at discovering selective GPCR modulators across multiple disease areas. Learn more at www.atrogi.com and on LinkedIn.

Meet us at the Endocrine Metabolic GPCRs conference in Liverpool

We are excited to share that Professor Tore Bengtsson and  Dr. Hamza Bokhari will be attending Endocrine Metabolic GPCRs 2026 in Liverpool (9–10 Feb)!

Hamza will be presenting our latest research:

“A GRK-Biased β₂-Adrenergic Receptor Agonist Induces Coordinated Fat Loss and Muscle Gain via Pathway-Selective Signaling.”

Our work underscores how pathway-selective GPCR modulation can drive favorable metabolic outcomes while minimizing adverse effects, which has exciting implications for metabolic diseases and muscle wasting.

Looking forward to engaging discussions and new collaborations at EMGPCRs2026!

More about the conference: https://www.endocrinology.org/events/endocrine-metabolic-gpcrs/endocrine-metabolic-gpcrs-2026

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BioStock interview: Atrogi’s new CEO on the next growth phase

Meet us at London Life Science Week and the LSX Investival Showcase 17th of November

The future of obesity treatment isn’t just about weight loss; it’s about the quality and durability of that loss. 17th of November, Atrogi will be at the London Life Sciences Week and the LSX Investival Showcase and will be represented by Dr. Hamza Bokhari to discuss how we are leading this new paradigm.

Atrogi is now a Phase 2-ready company with a differentiated platform of oral beta-2 agonists. While the field has made incredible strides, the challenges of muscle loss and weight regain remain. Our lead asset is designed to solve this. It is a foundational oral therapy that delivers high-quality, muscle-preserving weight loss, both as a standalone treatment and as a crucial add-on to any potent appetite suppressant.

Furthermore, our platform’s focus on muscle biology is highly translatable. We believe this creates a significant opportunity to address other diseases where muscle wasting is a core problem, including high-value rare disease indications.
We are keen to connect with investors and potential pharma partners who share our vision for defining the next generation of metabolic and muscular health. Please contact us to schedule a meeting.

Atrogi Appoints Paul Little, PhD, as Chief Executive Officer to Accelerate Growth and Advance Next Phase

Stockholm, Sweden 3 of November

Atrogi AB, a phase II ready biotech company developing next generation oral muscle metabolism and obesity therapeutics, today announced the appointment of Dr. Paul Little as its new Chief Executive Officer, effective immediately.

Paul Little brings over 25 years of international experience spanning drug discovery, clinical development, and biotech investment. He previously served as CEO of Vesper Bio, where he successfully advanced programs from discovery to clinical Phase II, and as Operating Partner at the Lundbeck Foundation, supporting and building high-impact life science ventures. He also held board positions at several innovative biotech companies, including Folium. 

Atrogi is currently preparing for its next stage of clinical and corporate development, advancing its lead candidate ATR-258, an orally available β₂-receptor agonist designed to improve metabolism while preserving muscle mass. With Phase I data published in Cell and a strong proprietary pipeline, Atrogi is now well positioned to lead a new generation of metabolic therapies that go beyond GLP-1 analogues.  

“Paul’s proven leadership, deep scientific background, and experience scaling biotech companies from early discovery to clinical validation make him an ideal leader for Atrogi’s next phase,” said Anders Ekblom, Chair of the Board. “We are confident he will accelerate our path toward bringing transformative treatments in metabolic health to patients worldwide.” 

“Atrogi has built a unique GPCR Discovery Platform with over 1,000 proprietary compounds designed to fine-tune β₂ signalling with minimal desensitization, enabling applications across muscle and metabolism-related diseases. A platform that holds the potential to fundamentally change how we treat metabolic and muscle-related diseases,” said Paul Little, CEO of Atrogi. “I’m thrilled to join the team at this pivotal moment. Our biology is validated, our assets are strong, and our path is clear. We are now executing an accelerated plan to advance ATR-258 into Phase II and to engage investors and partners to capture the full potential of our technology.”  

About Atrogi   

Atrogi is a phase II ready Stockholm-based biotech company focused on revolutionizing oral treatments for metabolic diseases. The company has developed a proprietary screening platform to identify and validate pharmaceutical candidates targeting key cell-signalling pathways, with several potential molecules showing promising data in treating conditions beyond metabolic disorders. Our research focus on selective stimulation of the β₂-adrenergic receptor, which improves metabolism in fat and skeletal muscle cells, without causing muscle loss or cardiovascular strain. This approach has led to the development of ATR-258, a first-in-class oral β₂-agonist now advancing toward phase II evaluation in patients.  

 

Contact

Meet us at BIO Europe 3-5 November

Looking forward to BIO Europe in Vienna next week! Our focus will be the future of high-quality weight loss.
The success of incretins has created a critical unmet need for a solution to the muscle loss and subsequent weight regain that follows. We have developed a Phase II ready, oral therapy designed to solve this. Our approach, built on a validated GPCR platform, is to deliver a foundational muscle-preserving treatment that can be used as a standalone or as a crucial add-on to current appetite suppressants.

We are keen to connect with investors and potential partners who share our vision for defining the next generation of metabolic therapeutics. Message us to schedule a meeting!

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