Elecoglipron in Phase 2: What the VISTA and SOLSTICE Trials Show

What elecoglipron is

Elecoglipron, also coded AZD5004 and ECC5004, was discovered by Eccogene and is being developed by AstraZeneca, which paid for both trials. It acts on the same receptor as the injectable GLP-1 drugs, but it is a small synthetic molecule, not a peptide. Its first-in-human paper (Haggag and colleagues, Diabetes, Obesity and Metabolism, 2025) found a pharmacokinetic profile compatible with one oral dose a day. The same paper reports lab work in which it bound the human GLP-1 receptor and raised cAMP signalling without recruiting beta-arrestin-2, and a nine-month study in monkeys with dose-dependent weight changes; those are cell and animal findings. In people, single doses of 1 to 300 mg in healthy volunteers, and 28 days of 5 to 50 mg daily in type 2 diabetes, caused no serious adverse events. Both Lancet papers describe it as taken once a day with no food or fluid restrictions.

VISTA: weight loss in obesity without diabetes

VISTA (NCT06579092) randomised 310 adults with a BMI of 30 or more, or 27 or more with a weight-related condition, and no type 2 diabetes, at sites in Australia, Canada, Germany, Japan, Taiwan, the UK and the US. They took 5, 15, 50 or 75 mg once a day, or placebo, over 36 weeks of treatment; the two lowest doses started at full strength and the higher ones were reached in steps every one, two or four weeks. The average participant weighed 106.9 kg with a BMI of 38.2, and 73% were women.

The primary endpoints were read at week 26. Weight fell 2.6% on 5 mg and 10.5% on 75 mg with weekly steps, against 0.6% on placebo, and between 40.4% and 88.8% of people on elecoglipron lost at least 5% of their weight, against 15.6% on placebo. Of the 310, 288 finished the study but only 231 (75%) finished their assigned treatment. Adverse events were reported by 84% to 98% of participants on elecoglipron and by 84% on placebo, led by nausea, constipation, diarrhoea, headache and vomiting.

SOLSTICE: blood sugar in type 2 diabetes

SOLSTICE (NCT06579105), a phase 2b trial in nine countries, enrolled adults with type 2 diabetes and an HbA1c of 7.0% to 10.5% (6.5% to 10.5% in the US) who were managed by diet and exercise, or by metformin or an SGLT2 inhibitor alone. Of 406 randomised, 404 took at least one dose: fixed doses of 5, 15 or 25 mg, or doses stepped up to 50 or 75 mg, each against matched placebo. Their average HbA1c was 7.9% and their average weight 99.8 kg.

The primary endpoint was the change in HbA1c at 26 weeks. It fell by 0.91% on 5 mg and by 1.88% on 75 mg stepped up every two weeks, against 0.15% on placebo. Adverse events were reported by 63% to 87% of participants across the elecoglipron groups and by 63% on placebo, mostly gastrointestinal. The trial also had an open-label arm on oral semaglutide 14 mg, but the abstract gives no figures for it, so SOLSTICE cannot yet be read as a comparison with an approved pill.

Where it sits among oral GLP-1 drugs

Elecoglipron joins a short list of small-molecule GLP-1 tablets. Lilly's orforglipron was approved by the FDA on April 1, 2026 as Foundayo for chronic weight management. Pfizer's danuglipron went the other way: Pfizer stopped developing it in April 2025 after a phase 2b trial in which more than half of participants stopped treatment. Neither Lancet paper compares elecoglipron with either drug, and phase 2 trials in different populations, over different lengths and with different endpoints do not support ranking them.

What these results do not show

Both primary endpoints were read at 26 weeks, in dose-ranging trials whose job was to choose doses for phase 3. Neither abstract says how many people stopped because of side effects, the number that ended danuglipron. Phase 3 has started: an AstraZeneca trial in Asian adults with obesity or overweight, with or without type 2 diabetes, has been recruiting since August 21, 2026 (NCT07775404, an estimated 351 participants). Elecoglipron is not approved in any country, so outside a clinical trial there is no regulated supply of it.

One correction on this site: our ECC5004 entry described the molecule as an oral peptide in one field while the rest of the entry called it a small molecule. All three papers say small molecule, and the entry now does too.

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