A study found that U.S. drugmaker Eli Lilly's oral obesity treatment could cut body weight by one-fifth in 72 weeks. Because oral obesity drugs allow patients to take them more comfortably, they are expected to expand the market further.
A research team led by Sean Wharton of the Wharton Medical Clinic in Canada said in the New England Journal of Medicine (NEJM) on the 16th (local time) that they administered the oral obesity drug orforglipron daily for 72 weeks to 3,127 adults and confirmed weight-loss effects ranging from 7.5% to more than 20%, depending on the dose.
Lilly acquired technology from Japan's Chugai Pharmaceutical in 2018 and developed orforglipron as an oral obesity treatment. Orforglipron is a drug that mimics the glucagon-like peptide (GLP)-1 hormone, similar to Wegovy, an injectable from Danish drugmaker Novo Nordisk.
GLP-1 is a hormone secreted by the small intestine after eating that promotes insulin secretion from the pancreas to lower blood sugar and suppresses glucagon, which raises blood sugar. It was originally developed as a diabetes treatment to lower blood sugar, then evolved into an obesity treatment after its weight-loss effect was confirmed. It reduces the rate of gastric emptying to induce satiety and suppresses appetite in the brain to produce weight loss.
Clinical trial participants were from nine countries, including the United States, China, Japan, and Spain. They had obesity with a body mass index (BMI, weight divided by height squared) over 30 and did not have diabetes. Participants took orforglipron tablets once daily at 6 mg, 12 mg, or 36 mg for 72 weeks. As a result, patients who took 6 mg of the obesity drug daily lost an average of 7.5% of their body weight. The 12 mg group saw an average 8.4% reduction, and the 36 mg group saw an average 11.2% reduction.
Among patients who took 36 mg of orforglipron daily, about 55% lost at least 10% of their body weight. Those who lost at least 15% accounted for 36%, and those who lost at least 20% accounted for 18%. Participants' waist circumference decreased, and their blood pressure and cholesterol levels improved. Some experienced mild to moderate gastrointestinal side effects.
Oral obesity drugs can be mass-produced at lower manufacturing expense than injections. The researchers said, "Patients excluded from injectable obesity drugs due to expense and accessibility issues can be treated with pills." The market is likely to grow accordingly. Orforglipron has not yet received approval from the U.S. Food and Drug Administration (FDA).
References
NEJM (2025), DOI: https://doi.org/10.1056/NEJMoa2511774