Structure Therapeutics Reports Positive Topline Data from Phase 2 ACCESS II Trial with Once-Daily Oral Small Molecule GLP-1 Receptor Agonist, Aleniglipron
March 16, 2026
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Placebo-adjusted mean weight loss of 16.3% (39 lbs) at 180 mg and 16.0% (37 lbs) at 240 mg at 44 weeks with no evidence of weight loss plateau in ACCESS II, demonstrating highest efficacy among oral GLP-1RAs and comparable efficacy to injectable GLP1-RAs
Continued weight loss up to 16.2% (40.5 lbs) observed with 120 mg dose in the ACCESS Open Label Extension (OLE) study at 56 weeks, with no evidence of weight loss plateau
Updated interim data from ACCESS OLE and Body Composition studies continue to support improved tolerability and low (2.0 – 3.4%) study drug discontinuations due to adverse events with the lower 2.5 mg starting dose
End-of-Phase 2 meeting with FDA scheduled in the second quarter of 2026;
Phase 3 initiation remains on track for 2H 2026
Company to host conference call today at 8:30 a.m. Eastern Time
SAN FRANCISCO, March 16, 2026 (GLOBE NEWSWIRE) – Structure Therapeutics Inc. (NASDAQ: GPCR), a clinical-stage global biopharmaceutical company developing novel oral small molecule therapeutics for metabolic diseases, with a focus on obesity, today announced positive topline data from the ACCESS clinical program of aleniglipron for the treatment of people living with obesity and/or overweight with at least one weight related co-morbidity. This includes 44-week data from the Phase 2 ACCESS II study and interim data from the ongoing body composition study and the ACCESS open label extension (OLE) study. Aleniglipron is an investigational orally-available, once-daily, nonpeptide small molecule agonist of the glucagon-like-peptide-1 (GLP-1) receptor designed to address patient needs and accessibility.
In the Phase 2 ACCESS II study, aleniglipron achieved clinically meaningful and statistically significant placebo-adjusted mean weight loss of 16.3% (39 lbs; p<0.0001) at the 180 mg dose and 16.0% (37 lbs; p<0.0001) at the 240 mg dose at 44 weeks. In the ACCESS OLE study, aleniglipron achieved continued weight loss from 36 weeks, up to 16.2% (40.5 lbs) with 120 mg at 56 weeks. Both studies continue to demonstrate no evidence of weight loss plateau.
Aleniglipron continues to demonstrate a tolerability profile that is consistent with the GLP-1 receptor agonist class and a compelling safety profile with no off-target events. In ACCESS II, across all active arms in participants who reached doses 120 mg or higher from 28 to 44 weeks, there was only one (3.7%) adverse event (AE)-related treatment discontinuation.
With a median follow-up of 20 weeks, the tolerability data as of the February 20, 2026 cutoff date from the interim analyses of the OLE and the body composition studies provide further support that the use of 2.5 mg as a lower starting dose very meaningfully reduces the rate of AE-related discontinuations during the titration phase. In the OLE, with a median follow-up of 20 weeks, there was an overall AE-related discontinuation rate of 2%. In the body composition study, with a median follow-up of 20 weeks, there was an overall AE-related discontinuation rate of 3.4% in the aleniglipron arm.
Together, these positive efficacy, tolerability and safety findings continue to support the advancement of aleniglipron into Phase 3 clinical development, with initiation anticipated in the second half of 2026.
“The totality of efficacy and tolerability data across the Phase 2 program continue to demonstrate clear differentiation of aleniglipron, with the highest weight loss observed for an oral GLP-1RA to date and a safety profile appropriate for chronic use in a disease that impacts millions of people,” said Raymond Stevens, Ph.D., CEO of Structure Therapeutics. “The consistent weight loss observed across multiple studies to date reaffirms aleniglipron’s potential to be a best-in-class oral GLP-1, with injectable-like efficacy that could become a backbone oral small molecule therapy for obesity.”
“The weight-lowering data from these ACCESS studies, without apparent plateau by Week 56, are encouraging—particularly the weight loss from baseline of up to -15.3% vs +1.1% at 180mg in ACCESS II that hopefully will be confirmed in larger, longer-term studies,” said Julio Rosenstock, MD, Chair of the ACCESS program Steering Committee and Clinical Professor of Medicine, Univ. of Texas, Southwestern Medical Center. “In addition, the tolerability profile of starting at a low dose of 2.5 mg and the slow titration, positions the program ready for Phase 3 studies.”
ACCESS II Study - Evaluating higher doses up to 240 mg
ACCESS II is a randomized, double-blind, placebo-controlled, clinical study of aleniglipron that enrolled 85 adult participants living with obesity or overweight (defined as a BMI of greater than 25 kg/m2) with at least one weight-related comorbidity. The 44-week study was designed to evaluate two higher doses of aleniglipron. Participants started at 5 mg of aleniglipron (or placebo) and followed a 4-week titration schedule up to target doses of 120 mg, 180 mg and 240 mg.
As reported in December 2025, at 36 weeks, each of the three dose cohorts in the ACCESS II study met statistical significance compared to placebo.
Results from the primary efficacy estimandi at 44 weeks are as follows:
Aleniglipron 120 mg Aleniglipron 180 mg Aleniglipron 240 mg Placebo
Mean percent change in body weight at 44 weeks compared to baseline
-13.6 -15.3 -15.0 +1.1
Placebo-adjusted mean percent change in body weight at 44 weeks compared to baseline
-14.7 -16.3 -16.0 -
P-value p<0.0001 p<0.0001 p<0.000
Aleniglipron demonstrated a tolerability profile consistent with the GLP-1 receptor agonist class following repeated, once-daily dosing of up to 240 mg. As expected for the GLP-1 receptor agonist drug class, the most common AEs were gastrointestinal (GI)-related, and the two most common AEs in the titration phase were nausea and vomiting.
