What are the key takeaways from this Beyond Biotech episode?

Key insights include: **GLP-1 muscle loss scale:** GLP-1 drugs cause a meaningful proportion of total weight loss to come from muscle mass, not fat. Adults over 50 already lose roughly 1% of muscle annually, so combining GLP-1-driven muscle loss with age-related sarcopenia creates compounding functional decline — reduced walking pace, impaired ability to rise from a chair, and increased mortality risk.; **ATR258 phase one results:** In an eight-week proof-of-mechanism study, ATR258 produced a 13% improvement in lower extremity muscle power from baseline, a 1.1kg reduction in fat mass, and a 0.8kg increase in lean mass — all in participants not instructed to change diet or exercise habits, with results deemed statistically significant.; **Biased GPCR signaling as a design principle:** ATR258 selectively activates the GRK2 intracellular pathway through the beta-2 receptor while avoiding the beta-arrestin pathway. Blocking beta-arrestin prevents receptor desensitization, eliminating the dose-escalation cycle that historically caused cardiovascular side effects in older beta-2 agonists like clenbuterol.

What did Paul Little discuss on Beyond Biotech?

Paul Little, CEO of Swedish biotech Atrogi, discusses ATR258, a first-in-class oral beta-2 agonist designed to counter GLP-1-driven muscle loss. Phase one data from 69 participants shows simultaneous fat loss and functional muscle gain, with phase two trials planned for 2027 across three potential indications. Key topics include: **GLP-1 muscle loss scale:** GLP-1 drugs cause a meaningful proportion of total weight loss to come from muscle mass, not fat. Adults over 50 already lose roughly 1% of muscle annually, so combining GLP-1-driven muscle loss with age-related sarcopenia creates compounding functional decline — reduced walking pace, impaired ability to rise from a chair, and increased mortality risk.; **ATR258 phase one results:** In an eight-week proof-of-mechanism study, ATR258 produced a 13% improvement in lower extremity muscle power from baseline, a 1.1kg reduction in fat mass, and a 0.8kg increase in lean mass — all in participants not instructed to change diet or exercise habits, with results deemed statistically significant..

How long is this episode of Beyond Biotech?

This episode is 28 minutes long. SignalCast provides an AI-generated summary so you can get the key insights in about 3 minutes.

Beyond Biotech

GLP-1 muscle loss: the next battleground in obesity treatment (Part 2 of 3)

October 23, 2026

28 min episode · 2 min read

Paul Little

Episode

28 min

Read time

2 min

Topics

Productivity, Health & Wellness, Relationships

AI-Generated Summary

Published Oct 23, 2026

Key Takeaways

✓GLP-1 muscle loss scale: GLP-1 drugs cause a meaningful proportion of total weight loss to come from muscle mass, not fat. Adults over 50 already lose roughly 1% of muscle annually, so combining GLP-1-driven muscle loss with age-related sarcopenia creates compounding functional decline — reduced walking pace, impaired ability to rise from a chair, and increased mortality risk.
✓ATR258 phase one results: In an eight-week proof-of-mechanism study, ATR258 produced a 13% improvement in lower extremity muscle power from baseline, a 1.1kg reduction in fat mass, and a 0.8kg increase in lean mass — all in participants not instructed to change diet or exercise habits, with results deemed statistically significant.
✓Biased GPCR signaling as a design principle: ATR258 selectively activates the GRK2 intracellular pathway through the beta-2 receptor while avoiding the beta-arrestin pathway. Blocking beta-arrestin prevents receptor desensitization, eliminating the dose-escalation cycle that historically caused cardiovascular side effects in older beta-2 agonists like clenbuterol.
✓Functional gain benchmark: The 13% lower-limb power improvement observed in eight weeks is approximately twice the functional gain expected from resistance training over the same period, according to trial lead Morten Høstrup. Little frames this as potentially equivalent to reversing four to five years of sarcopenic decline in older populations.
✓Three phase two pathways: Atrogi is evaluating three phase two directions: co-therapy with GLP-1s to offset muscle loss, a standalone sarcopenia indication targeting adults over 50 with excess weight and low limb function, and a rare muscle-wasting disease indication. The company targets a phase two start in 2027 and is actively pursuing partnership with larger pharma.

What It Covers

Paul Little, CEO of Swedish biotech Atrogi, discusses ATR258, a first-in-class oral beta-2 agonist designed to counter GLP-1-driven muscle loss. Phase one data from 69 participants shows simultaneous fat loss and functional muscle gain, with phase two trials planned for 2027 across three potential indications.

Key Questions Answered

•GLP-1 muscle loss scale: GLP-1 drugs cause a meaningful proportion of total weight loss to come from muscle mass, not fat. Adults over 50 already lose roughly 1% of muscle annually, so combining GLP-1-driven muscle loss with age-related sarcopenia creates compounding functional decline — reduced walking pace, impaired ability to rise from a chair, and increased mortality risk.
•ATR258 phase one results: In an eight-week proof-of-mechanism study, ATR258 produced a 13% improvement in lower extremity muscle power from baseline, a 1.1kg reduction in fat mass, and a 0.8kg increase in lean mass — all in participants not instructed to change diet or exercise habits, with results deemed statistically significant.
•Biased GPCR signaling as a design principle: ATR258 selectively activates the GRK2 intracellular pathway through the beta-2 receptor while avoiding the beta-arrestin pathway. Blocking beta-arrestin prevents receptor desensitization, eliminating the dose-escalation cycle that historically caused cardiovascular side effects in older beta-2 agonists like clenbuterol.
•Functional gain benchmark: The 13% lower-limb power improvement observed in eight weeks is approximately twice the functional gain expected from resistance training over the same period, according to trial lead Morten Høstrup. Little frames this as potentially equivalent to reversing four to five years of sarcopenic decline in older populations.
•Three phase two pathways: Atrogi is evaluating three phase two directions: co-therapy with GLP-1s to offset muscle loss, a standalone sarcopenia indication targeting adults over 50 with excess weight and low limb function, and a rare muscle-wasting disease indication. The company targets a phase two start in 2027 and is actively pursuing partnership with larger pharma.

Notable Moment

Little notes that building muscle through ATR258 may provide a structural buffer against post-GLP-1 weight rebound — because greater muscle mass absorbs excess blood glucose before it converts to fat, potentially addressing one of the most persistent unsolved problems in obesity pharmacotherapy.

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Episode Transcript

Welcome to Beyond Biotech, and part two of our three part series on GLP-1s and the future of metabolic health. A series we're calling The Metabolic Moment. In just a few years, GLP-1s have become a phenomenon. They've transformed how we treat diabetes and obesity, created one of the biggest markets in pharma, and sparked a cultural conversation that reaches far beyond the clinic. Now that market is shifting, cheaper alternatives are coming, new mechanisms are entering trials, and some companies are aiming for something closer to a cure. So what happens next for patients, for the companies leading the field, and for the startups hoping to overtake them? Across three conversations, we'll follow the money, the science, and the people behind this metabolic moment. GLP-one drugs have transformed obesity care, but they come with a catch. A meaningful share of the weight people lose is muscle, and that matters especially for older patients. So what if a drug could help the body burn fat while protecting or even building muscle? That's the idea behind Atrogi, a Swedish biotech developing ATR258. It's a first in class oral therapy designed to mimic some of the effects of exercise. The aim is to keep the metabolic benefits while avoiding the cardiovascular side effects linked to older beta-two agonists. The company has completed a 69 person phase one trial, and now has new proof of mechanism data showing gains in muscle power. Phase two is planned for 2027. Joining me today is Paul Little, CEO of Atrogi. We talk about what GLP-one's left unsolved, the science behind ATR258, and how a small company competes in a market led by giants. Paul, welcome to Beyond Biotech. Nice to be here. Thanks for having me. Paul, you're the CEO of Atrogi. You have been since November 2025. But before that, you were CEO of Vesper Bio. You had some programs in clinical trials. You've had a PhD in organic chemistry. I mean, you've been in the industry now for a quarter century. How does this shape what you're doing? How does it shape the work that you're doing in drug discovery? Well, it's a great question. Guess when you reflect back, I've seen a fair few things happen over the twenty five years. And I think the first thing that I've seen that is interesting for today's conversation is I went through one of the first attempts to get an obesity drug on the market in the zeros, and at that point we were arguing quite a lot with investors and pharma companies about whether there's actually a market in obesity. I think we've now answered that question finally. I think some of the other things we've worked out is how to outsource and work with collaborators across broad geographies to leverage smaller teams in a cash efficient way. We've understood what our customers are looking for and that's an ever changing landscape of desires and needs of course. But I think the most important …

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