Structure Therapeutics' obesity drug shows 16% weight loss in trials

Structure Therapeutics has announced strong results from phase 2 trials of aleniglipron, its oral obesity treatment. The drug demonstrated significant weight loss in patients, with effects lasting up to 56 weeks. Investors responded positively, pushing the company's stock up by 8% in early trading on Monday.

The latest data comes from three studies: the 44-week ACCESS II trial, an interim body composition study, and an open-label extension. In ACCESS II, patients on 180 mg and 240 mg doses of aleniglipron lost an average of 16.3% and 16% of their body weight, respectively, compared to placebo. These results were measured at 44 weeks.

In the open-label extension, participants taking a 120 mg dose saw continued weight reduction, reaching up to 16.2% at 56 weeks. Researchers noted no sign of a weight loss plateau in either study, suggesting sustained effectiveness over time.

The company now plans to move forward with phase 3 trials in the second half of the year. This follows a strong year for Structure Therapeutics, whose stock has risen 184% since January. Shares currently trade around $63.38, down from a peak of nearly $94.90 in early 2026.

With phase 2 results showing consistent weight loss and no plateau, Structure Therapeutics is advancing aleniglipron into late-stage testing. The drug's performance has already boosted investor confidence, reflected in the company's stock gains. Phase 3 trials will determine whether these benefits hold in larger patient groups over a longer period.