Argues new weight-loss drugs may reduce knee pain

Participants taking the highest dose of 12 milligrams per week lost about one-quarter of their body weight on average.

Approximately two-thirds of patients on the drug achieved at least a 50 percent reduction in knee pain, compared with 38 percent of participants receiving a placebo. The research, funded by drug manufacturer Eli Lilly and Company, included more than 1,000 men and women across studies that featured a Phase 3 trial named TRIUMPH-1-OA.

The findings were also the subject of a segment on NBC’s TODAY on Nov. 9, where medical contributor Akshay Syal discussed the implications of the data.

“These trials confirm that powerful weight-loss drugs such as the GLP-1s can give people with knee osteoarthritis and obesity pain relief at least as good as our best current medicines,” said Jay Karri, an assistant professor of neurology and orthopedics at the University of Maryland School of Medicine, who was not involved in the experiments.

Patients administered doses of 4 milligrams or 12 milligrams per week reported substantially less knee pain by the end of the trial period, which lasted at least 68 weeks.

Participants also demonstrated improved physical function, including a greater ease in rising from the floor or using the stairs, alongside metabolic markers such as lower blood pressure and reduced systemic inflammation. Unlike some other treatments, the drug is not associated with gastrointestinal problems or the loss of muscle mass, which is critical for knee stabilization.

“The drug was very effective for both outcomes,” said Thomas Schnitzer, a rheumatologist at Northwestern University, who led the study.

Approximately 5 percent of the U.S. population, or 15 million people, live with painful knee osteoarthritis. Current standard treatments range from physical therapy and non-steroidal oral drugs like ibuprofen and Voltaren to corticosteroid injections and opioids, which often provide only short-term benefit.

Eli Lilly is expected to apply for U.S. Food and Drug Administration approval early next year. The company is studying retatrutide, a triple-hormone-receptor-agonist drug, as a potential treatment for people with obesity and painful knee osteoarthritis.

Investors remain attentive to the company’s pipeline, with some analysts estimating a fair share value of $1,477.03 compared to the recent closing price of $1,364.73. While the firm maintains a strong growth outlook, market participants warn that the Eli Lilly narrative could shift if obesity pricing pressure intensifies or if future safety data impacts confidence in pipeline assets.

Retatrutide is an investigational triple-hormone-receptor-agonist injection that mimics three hormones involved in weight regulation, including glucagon-like peptide 1. The drug is developed by Eli Lilly and Company.

The research involved more than 1,000 men and women with obesity and knee osteoarthritis. Patients requiring a joint replacement were excluded from the study, and researchers have noted that future investigation is required to determine if the drug benefits individuals who are not overweight.

While previous research indicates that losing 5 to 10 percent of body weight through lifestyle changes can reduce osteoarthritis symptoms, people taking the drug lost as much as 24 percent of their body weight. Schnitzer noted that achieving weight loss beyond 10 percent through diet and exercise alone is difficult for those already experiencing significant knee pain.