ASC39: An Oral Amylin Pill Aiming to Match Injectable Amylin Drugs (July 30, 2026)
Table of Contents
Why an oral amylin drug matters
Amylin has quietly become one of the hottest targets in obesity medicine. It is a hormone the pancreas releases alongside insulin, and it curbs appetite, slows the stomach's emptying, and - crucially - tends to take off fat while sparing muscle, which is exactly the 'quality weight loss' the field is chasing. The catch is that today's leading amylin drugs are all injections: Novo Nordisk's cagrilintide, Zealand/Roche's petrelintide, and Eli Lilly's selective agonist eloralintide are peptides given under the skin. A pill that could match them would be far easier to take and to combine. ASC39, from the Chinese biotech Ascletis Pharma, is a bid to be exactly that - a once-daily oral small molecule that behaves like an injectable amylin peptide.
What Ascletis has shown so far
Ascletis has released head-to-head preclinical data comparing ASC39 directly with eloralintide, and the numbers are close. In cell-based cyclic-AMP assays, ASC39 activated the human amylin 1 receptor with an EC50 of 21.4 picomolar, essentially identical to eloralintide's 21.2 picomolar. At the calcitonin receptor - the one blamed for much of amylin's nausea - ASC39 was weaker (EC50 846 picomolar) than at the amylin receptor, and actually a touch more selective than eloralintide (1,351 picomolar). In diet-induced obese rats given the drug by mouth, ASC39 produced 6.6% placebo-adjusted weight loss versus 5.6% for eloralintide in the same experiment. The company presented these findings at the American Diabetes Association's 2026 Scientific Sessions in New Orleans in June, alongside human data for its oral GLP-1 pill ASC30 and preclinical data for its triple agonist ASC37.
The receptor selectivity story
Amylin does not act through a single receptor. It signals through the calcitonin receptor (CTR) and through the amylin receptors AMY1, AMY2 and AMY3, which are the calcitonin receptor teamed up with small helper proteins called RAMPs. A recurring theme in 2026 - shared by injectable candidates like Alveus's AMY3-selective ALV-200 - is that amylin's benefits and its side effects may split across these receptors, with the calcitonin receptor tied more closely to nausea and food aversion. ASC39's reported profile fits that thesis: strong activity at the amylin receptor and much weaker activity at the calcitonin receptor. Whether that translates into better real-world tolerability can only be settled in human trials, which have not yet begun.
The combination play: ASC30_39
ASC39 is not just a standalone pill; it is half of a combination. Ascletis has selected a fixed-dose combination called ASC30_39, which packs ASC39 together with ASC30 - the company's once-daily oral GLP-1 receptor agonist that is Phase III-ready and has reported about half the vomiting of orforglipron under weekly titration - into a single tablet. In a head-to-head dog study, the combination tablet showed excellent oral bioavailability, high drug exposure and a half-life of up to 12 hours, plus good stability at room temperature and a small pill size. The strategy mirrors the injectable GLP-1-plus-amylin combinations CagriSema and MariTide, but aims to deliver both mechanisms in one convenient once-daily pill.
Where it sits in the pipeline
ASC39 was named a clinical development candidate in early 2026, and Ascletis says it plans to file a U.S. FDA Investigational New Drug (IND) application for ASC39 oral tablets in obesity in the third quarter of 2026, with an IND for the ASC30_39 combination on the same timeline. That puts ASC39 among a growing wave of oral obesity assets - from orforglipron and other GLP-1 pills to oral amylin efforts - that are trying to break the injection-only mold. It is worth being clear-eyed about the stage, though: everything reported so far is preclinical, in cells, rats and dogs. The eloralintide-matching potency is encouraging as a proof of concept, but potency in an assay is not the same as safe, durable weight loss in people.
What to watch next
The near-term milestones are regulatory and clinical: whether the ASC39 and ASC30_39 INDs clear the FDA in the second half of 2026, and whether first-in-human dosing follows. From there, the questions are the ones preclinical data cannot answer - how much weight ASC39 takes off in humans, how well it is tolerated (the whole selling point of amylin selectivity), how much lean mass it preserves, and whether the oral combination with ASC30 can rival injectable GLP-1-plus-amylin regimens. If the human data hold up anywhere near the preclinical comparison with eloralintide, ASC39 would be one of the more interesting oral entrants in the amylin field.
Safety and status note
ASC39 is an investigational small molecule in preclinical, IND-enabling development. It has not entered human trials, is not approved anywhere, and is not a supplement, research chemical or compounding-eligible peptide. Any product marketed as 'ASC39' by a vendor is unverified and should be treated with caution. This article is for informational purposes and is not medical advice.
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Citations
- [1] Ascletis - Oral Small Molecule Amylin Receptor Agonist ASC39 Demonstrated Eloralintide-like Amylin Selectivity and Efficacy in Preclinical Models (Mar 17, 2026) Source
- [2] Ascletis Announces Fixed-Dose Combination of ASC30 (oral GLP-1R agonist) and ASC39 (oral amylin-selective agonist) for Clinical Development (Apr 7, 2026) Source
- [3] Ascletis Reinforces Its Differentiated Obesity Portfolio at ADA 2026 (ASC30 clinical data; ASC37 and ASC39 preclinical) (June 2026) Source
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