Structure Therapeutics reports first clinical data for an oral small-molecule amylin agonist

Structure Therapeutics, a San Francisco biotech traded as NASDAQ: GPCR, said on September 8, 2026, that it has produced the first reported clinical data for an oral, non-peptide amylin receptor agonist, a pill called ACCG-2671. The company also released 72-week results for its oral GLP-1 pill, aleniglipron, which is now in Phase 3 testing.^[1]

ACCG-2671 was tested in 31 healthy adults without obesity who did not have obesity, in single doses of 1, 2, 5, or 10 milligrams or placebo. The drug had a roughly six-day half-life, a finding the company says could support once-weekly dosing. There were no serious side effects and no signs of liver injury. A single 10 mg dose was linked to a 3.3% average drop in body weight by day 24 in six participants, along with a roughly 60% drop by day two in a marker of bone breakdown called CTX-1. Nausea and vomiting rose with dose: none was reported at 1 mg or 2 mg, but 4 of 5 participants had nausea and 3 of 5 had vomiting at 5 mg, and all 6 participants at 10 mg had nausea.^[1]

Based on those early results, Structure has started a longer, 84-day study of ACCG-2671 in people with obesity, testing different doses and dosing schedules, including one group that will take the pill alongside an existing injectable GLP-1 drug. Results from this next stage are expected in the first half of 2027.^[1]

For aleniglipron, an oral small-molecule GLP-1 drug, the company reported 72-week data from an open-label extension of its earlier Phase 2b study. Participants who had started on 45 mg, 90 mg, or 120 mg doses and were later raised to 180 mg lost an average of 11.6%, 14.4%, and 16.2% of body weight, respectively, with no sign that weight loss had leveled off in the two higher-dose groups. More than a third of people in the 90 mg and 120 mg groups lost more than 20% of their body weight, averaging about 36 to 40 pounds lost. A separate group that had originally received placebo and then switched to aleniglipron starting at a lower 2.5 mg dose lost 9.0% of body weight, or about 22.7 pounds, over 36 weeks. Fewer than 5% of participants across the extension study stopped treatment because of side effects, and there were no cases of drug-induced liver injury.^[1]

Why it matters for patients

Both drugs are still years away from being available, if they reach the market at all. ACCG-2671 has only been tested in a small, short study in people without obesity, so its weight-loss effect, long-term safety, and effect in people who actually have obesity are not yet known. The bone marker changes are described by the company as encouraging, but what they mean for real-world bone health has not been established.^[1]

For aleniglipron, the appeal for patients is that it is a once-daily pill rather than an injection, and the 72-week data suggest weight loss can continue past a year without leveling off at higher doses. The company also reports that starting at a lower 2.5 mg dose, rather than 5 mg, improved stomach-related side effects, which is often the reason people stop taking GLP-1 drugs. Still, this is an extension of an earlier mid-stage study, not the larger Phase 3 trial that regulators will use to decide on approval.^[1]

What happens next

Structure's Phase 3 ACCOMPLISH program for aleniglipron includes two ongoing trials: ACCOMPLISH-1, enrolling up to 3,600 adults with obesity or overweight and at least one weight-related health condition, and ACCOMPLISH-2, enrolling up to 1,100 adults with obesity or overweight and type 2 diabetes. Topline results from these trials are expected in the second half of 2028. The next data readout for ACCG-2671, from the ongoing multi-dose study in people with obesity, is expected in the first half of 2027.^[1]