Structure Therapeutics Inc. (NASDAQ:GPCR) is still months away from seeking approval for its experimental weight-loss pill, but the company is already bracing for a challenge that has plagued the obesity drug market: compounded copycat versions.
Structure Therapeutics is advancing the oral small molecule aleniglipron that resembles Eli Lilly and Co.'s (NYSE:LLY) orforglipron but with a shorter half-life.
Details
In December 2025, Structure shared topline data from the ACCESS clinical program of aleniglipron, including 36-week data from the core Phase 2b ACCESS study and the ongoing exploratory ACCESS II study, and interim data from the ongoing Body Composition study and the ACCESS open-label extension study.
In the core Phase 2b ACCESS study, aleniglipron achieved a clinically meaningful and statistically significant placebo-adjusted mean weight loss of 11.3% at the 120 mg dose at 36 weeks, and across all active arms had a 10.4% adverse event (AE)-related treatment discontinuation rate.
In the exploratory ACCESS II study, aleniglipron achieved a placebo-adjusted mean weight loss of up to 15.3%, with a 240 mg dose at 36 weeks.
Structure Therapeutics is also conducting three new aleniglipron clinical studies as planned, which will generate additional data to competitively position aleniglipron and further support the design of the Phase 3 program.
In December 2025, Structure Therapeutics initiated a first-in-human Phase 1 clinical study of ACCG-2671, the company's lead oral small molecule amylin receptor agonist for obesity.
CEO Raymond Stevens warned that the rise of unapproved alternatives could undermine new entrants even before they reach patients.
"It's the thing I fear the most," Bloomberg noted, citing Stevens' interview at the JPMorgan Healthcare Conference on Wednesday. "We've really got to get this compounding issue under control."
Patients increasingly turned to compounded obesity drugs when demand for branded treatments far outstripped supply. Even though those supply constraints have largely eased, compounded drugs have continued to circulate.
What Are Other Drugmakers Saying?
Novo Nordisk A/S' (NYSE:NVO) CEO Mike Doustdar recently estimated that up to 1.5 million patients in the U.S. may still be using compounded weight-loss drugs, largely because they are cheaper than branded options.
Lower-cost alternatives could limit the adoption of newly approved drugs and pressure pricing across the sector.
Bloomberg highlighted that Stevens believes Structure may have some protection. Aleniglipron is a small-molecule drug, which typically requires a more complex manufacturing process. By contrast, popular injectable drugs such as Lilly's Zepbound and Novo's Wegovy are peptides, which Stevens said are generally easier to replicate.
Even so, drugmakers broadly agree that regulatory oversight has fallen short. Companies argue the U.S. Food and Drug Administration has not done enough to curb the continued production and sale of compounded versions now that shortages have ended.
GPCR Price Action: Structure Therapeutics shares were down 0.80% at $83.65 at the time of publication on Thursday, according to Benzinga Pro data.
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