Structure Therapeutics doses the first patients in the Phase 3 ACCOMPLISH program

Structure Therapeutics started its Phase 3 ACCOMPLISH program for aleniglipron, an oral, non-peptide small molecule GLP-1 receptor agonist, in August 2026 ^[1]. The San Francisco company confirmed the launch in a September 8, 2026 release that also reported 72-week weight-loss data from an earlier trial and first-in-human results for a second obesity drug candidate ^[1].

What the Phase 3 program looks like

ACCOMPLISH is made up of two randomized, double-blind, placebo-controlled trials. ACCOMPLISH-1 (NCT07654361) is enrolling up to 3,600 adults living with obesity, or overweight with at least one weight-related health condition. ACCOMPLISH-2 (NCT07654374) is enrolling up to 1,100 adults with obesity or overweight plus type 2 diabetes. In both trials, participants receive placebo or one of three aleniglipron doses ^[1]. The specific doses being tested in Phase 3 are cut off in the available source text, so they are not confirmed here.

Enrollment is ongoing and topline data are expected in the second half of 2028 ^[1]. That timeline means aleniglipron would not be positioned for a regulatory filing until after those results.

The data behind the decision

The Phase 3 program follows a 36-week open-label extension (OLE) of the Phase 2b ACCESS trial (NCT06693843), which tracked participants out to 72 weeks of treatment. Eighty-seven percent of eligible participants who finished the double-blind portion entered the extension ^[1].

Participants originally randomized to 45 mg, 90 mg and 120 mg who continued into the extension and were titrated up to 180 mg lost 11.6%, 14.4% and 16.2% of body weight respectively at 72 weeks, with no sign of a plateau in the two top doses ^[1]. More than one-third of participants in the 90 mg and 120 mg groups lost more than 20% of body weight, with mean absolute losses of 35.9 and 40.5 pounds ^[1]. The company noted an important caveat: participants were only titrated to the top 180 mg dose after Week 60, so exposure to that dose was limited by Week 72 ^[1].

People originally on placebo crossed over to aleniglipron at Week 36 starting at a lower 2.5 mg dose, with titration every four weeks. They lost 9.0% of body weight, or 22.7 pounds, after 36 weeks of treatment, and the company said the lower starting dose produced better gastrointestinal tolerability than the 5 mg start used in the double-blind phase ^[1].

Fewer than 5% of participants in the extension stopped treatment because of treatment-emergent adverse events ^[1]. There were no cases of drug-induced liver injury, and all liver-enzyme elevations resolved without stopping treatment ^[1].

Separately, Structure reported first clinical data for ACCG-2671, an oral small molecule amylin and calcitonin receptor agonist. In a 31-person single-ascending-dose study in healthy adults without obesity, the drug had a roughly 6-day half-life and no serious adverse events. A single 10 mg dose was tied to a 3.3% mean weight reduction at Day 24, but nausea and vomiting appeared at the 5 mg and 10 mg doses — all six participants at 10 mg had gastrointestinal events ^[1]. A 12-week multiple-ascending-dose portion in people with obesity has begun, with topline data expected in the first half of 2027 ^[1].

Why it matters for patients

Aleniglipron is a pill, not an injection, and it is a small molecule rather than a peptide like semaglutide (Ozempic, Wegovy, Rybelsus). CEO Raymond Stevens framed the appeal as "greater convenience with scalable and cost-effective manufacturing" that could "broaden access and choices" ^[1]. Whether that translates into lower prices for US patients is not addressed in the company's release.

Nothing here changes what is available today. Aleniglipron is investigational, has not been reviewed by the FDA, and the 72-week numbers come from an open-label extension — meaning participants and investigators knew who was getting the drug, which is a weaker design than a blinded comparison. The Phase 3 trials are the test that regulators will weigh.

What happens next

ACCOMPLISH-1 and ACCOMPLISH-2 continue enrolling, with topline results due in the second half of 2028 ^[1]. ACCG-2671 multiple-dose data are expected in the first half of 2027 ^[1]. The company's release does not compare aleniglipron head-to-head with other oral GLP-1 candidates, and competitor timelines are not covered in the source material.