Structure Therapeutics Aleniglipron Results

Structure Therapeutics Inc. (GPCR) said in a press release on March 16, 2026, that positive Phase 2 ACCESS II topline data for aleniglipron support advancing the program toward Phase 3.

ACCESS II Efficacy and Safety Results

The 44-week ACCESS II trial showed mean body-weight reductions from baseline of −13.6% for the 120 mg dose (placebo-adjusted −14.7%; p<0.0001), −15.3% for 180 mg (placebo-adjusted −16.3%; p<0.0001), and −15.0% for 240 mg (placebo-adjusted −16.0%; p<0.0001), while placebo participants gained 1.1%. Aleniglipron is an orally available once-daily non-peptide small-molecule GLP-1 receptor agonist (oral GLP-1RA).

The company said the 180 mg placebo-adjusted result corresponded to about 39 pounds lost, and the 240 mg dose to about 37 pounds. It described these as the highest reported efficacy among oral agents and comparable to injectable GLP-1 therapies, noting these are cross-trial comparisons rather than head-to-head data.

An interim analysis of an open-label extension after a median 20 weeks of additional follow-up (56 weeks total) showed continued weight loss with no plateau. Patients previously on active drug and titrated to 120 mg in the extension reached up to 16.2% weight loss (about 40.5 pounds) from baseline.

A separate body-composition and titration study, with a data cutoff of Feb. 20, 2026, examined a 2.5 mg starting dose with slow uptitration. After about 20 weeks, it reported roughly 6.8% weight loss and a 3.4% adverse-event-related discontinuation rate in the aleniglipron arm.

More than 625 participants have received aleniglipron across ACCESS, ACCESS II, the open-label extension, and the body-composition study. Adverse-event discontinuation rates were low: among participants reaching doses of 120 mg or higher between weeks 28 and 44 in ACCESS II, one discontinued due to adverse events (3.7% in that subgroup). The open-label extension interim analysis showed a 2% overall adverse-event discontinuation rate.

The company described the tolerability profile as consistent with the GLP-1 receptor agonist class, with gastrointestinal complaints—mainly nausea and vomiting—most common during titration. Across all studies, no drug-induced liver injury, persistent liver-enzyme elevations, or QTc prolongation have been reported.

Regulatory Path and Pipeline Positioning

Structure Therapeutics is a clinical-stage biotechnology company focused on orally available small-molecule therapies for metabolic diseases, led by aleniglipron for obesity and overweight. Its pipeline also includes oral amylin receptor agonists and combination small-molecule GLP-1 candidates incorporating GIP, glucagon, and apelin mechanisms, developed on a structure-based G-protein-coupled receptor (GPCR) discovery platform aimed at addressing scalability and access limitations of biologics and peptides.

Management described aleniglipron as a potential best-in-class oral GLP-1 and a possible backbone oral therapy for obesity. The company emphasized that topline and interim Phase 2 findings are early and may not predict Phase 3 or commercial outcomes. It noted that comparative claims are based on cross-trial data and require confirmation in larger, longer-term studies.

Structure has a Type B End-of-Phase 2 meeting with the U.S. Food and Drug Administration scheduled for the second quarter of 2026. The company anticipates initiating a Phase 3 program in the second half of 2026. The planned Phase 3 design includes a 2.5 mg starting titration dose and evaluation of multiple once-daily doses up to 240 mg.