Structure Therapeutics begins Phase 3 testing of oral GLP-1 pill aleniglipron
Structure Therapeutics has begun Phase 3 testing of its daily GLP-1 pill aleniglipron, but the weight-loss figures reported so far come from an extension study with no placebo group [1].
Structure Therapeutics has begun enrolling adults in the Phase 3 ACCOMPLISH program for aleniglipron, an experimental GLP-1 pill taken once a day, the company said in a release dated Sept. 8, 2026 [1]. The program started in August 2026 and consists of two randomized, double-blind, placebo-controlled trials [1].
ACCOMPLISH-1 (NCT07654361) is signing up as many as 3,600 adults who have obesity or are overweight with at least one related health condition [1]. ACCOMPLISH-2 (NCT07654374) is enrolling up to 1,100 adults with obesity or overweight plus type 2 diabetes [1]. Participants in both studies will receive placebo or one of three aleniglipron doses [1]. The company expects results in the second half of 2028. It did not say how many people have been dosed or how far enrollment has progressed [1].
Aleniglipron is a non-peptide small molecule that activates the GLP-1 receptor, the company said [1].
72-week results from an extension study
Alongside the Phase 3 news, Structure reported 72-week data from ACCESS, an extension that followed participants after a 36-week Phase 2b trial [1]. Of those who finished the first 36 weeks, 87% joined the extension [1].
Participants who had been assigned to 45 mg, 90 mg or 120 mg in the earlier phase and then moved up to 180 mg lost 11.6%, 14.4% and 16.2% of their starting weight, respectively [1]. Weight loss had not leveled off at the two highest doses, according to the company [1]. More than a third of people in the 90 mg and 120 mg groups dropped more than 20% of their body weight, with average absolute losses of 35.9 pounds and 40.5 pounds [1].
People who had received placebo during the first 36 weeks crossed over to aleniglipron, began at 2.5 mg, and lost an average of 9.0%, or 22.7 pounds, over the next 36 weeks [1].
Structure noted that the 180 mg dose was only reached after Week 60, so most participants had limited time at the top dose by Week 72 [1]. The extension had no placebo group, so the 72-week figures are not a randomized comparison [1].
Fewer than 5% of extension participants discontinued because of adverse events, the company said [1]. No cases of drug-induced liver injury were reported, and liver enzyme elevations that occurred resolved without anyone stopping treatment [1]. Those who began at 2.5 mg and stepped up every four weeks had better gastrointestinal tolerability than people who started at 5 mg in the earlier phase [1].
A second pill aimed at a different target
Structure also released first-in-human data for ACCG-2671, an oral small molecule that acts on amylin and calcitonin receptors, a different pathway from GLP-1 [1]. Thirty-one healthy adults without obesity received a single dose of 1, 2, 5 or 10 mg, or placebo [1]. The drug stayed in the body for about six days, and no serious adverse events occurred [1]. Six people who received 10 mg lost an average of 3.3% of body weight by Day 24 [1]. Nausea and vomiting appeared at the 5 mg and 10 mg doses [1]. A 12-week multiple-dose phase in people with obesity is now enrolling, with results expected in the first half of 2027 [1].
Why it matters for patients
Aleniglipron is being developed as a once-daily tablet rather than an injection [1]. It remains investigational, and no approval decision has been disclosed.
The weight-loss numbers reported so far come from an extension study with no placebo arm, and averages from a trial group do not predict what any one person will experience [1]. The Phase 3 results expected in 2028 will be the main evidence regulators weigh.
The release does not include head-to-head comparisons with approved GLP-1 medicines or with other oral candidates in late-stage development, so how aleniglipron compares has not yet been reported [1]. Results in people with type 2 diabetes also have not been reported; that group is being studied separately in ACCOMPLISH-2 [1].
What happens next
- First half of 2027: results from the multiple-dose portion of the ACCG-2671 study [1].
- Second half of 2028: results from ACCOMPLISH-1 and ACCOMPLISH-2 [1].
The release did not give a timeline for seeking FDA approval or say which uses the company would pursue [1].
Sources
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