Structure Therapeutics stock jumps 8% after obesity drug's phase 2 success

Structure Therapeutics has seen its stock climb by around 8% in Monday trading. The rise follows strong phase 2 results for its obesity treatment, alenigliptin. Investors reacted positively to data showing significant weight loss in clinical trials.

The latest findings come from the 44-week ACCESS II study and ongoing body composition research. In ACCESS II, patients on 180 mg and 240 mg doses lost an average of 16.3% and 16% of their body weight, respectively. These results were adjusted against a placebo group.

An open-label extension study also showed promising outcomes. Participants taking a 120 mg dose maintained steady weight loss, reaching up to 16.2% at 56 weeks. Neither study indicated a weight loss plateau during treatment. The company's stock has seen major growth over the past year. After positive phase 2 data in December 2025, shares jumped from about $13.22 to the mid-$80s range—a 184% increase. Though it later dipped to around $63–89, the stock had previously peaked near $94.90. With these results, Structure Therapeutics now plans to launch phase 3 trials in the second half of the year.

The phase 2 data highlights alenigliptin's potential as an obesity treatment. Phase 3 trials will further test its long-term effectiveness and safety. The company's stock movement reflects investor confidence in the drug's progress.