VIENNA — The glucagon-like peptide 1 (GLP-1) receptor agonist semaglutide (Wegovy) not only induced weight loss but also improved knee pain in people with knee osteoarthritis (OA) and obesity, according to results from the STEP 9 study reported at the Osteoarthritis Research Society International (OARSI) 2024 World Congress.
From baseline to week 68, the mean change in knee pain assessed using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score was a reduction of 41.7 points for semaglutide and a decrease of 27.5 points for a matching placebo. The estimated treatment difference of 14.1 points between the groups was statistically significant (P < .001).
As for weight loss, this also fell by a significantly greater amount in the people treated with semaglutide vs those given placebo, with respective reductions of 13.7% and 3.2% from baseline, with an estimated 10.5% greater weight loss with semaglutide.
Sara Freeman/Medscape Medical News
Dr. Henning Bliddal
“The interesting thing is whether there’s a specific action of GLP-1 receptor agonists on the joint, not through the weight loss but by itself,” principal study investigator Henning Bliddal, MD, DMSc, told this news organization ahead of reporting the results at OARSI 2024.
Weight loss is “obviously good” because “the knees suffer from the weight. But whether it’s good for the knee or just for the health or the well-being of the person is another matter,” said Dr. Bliddal, who is director of the Parker Institute at Bispebjerg Frederiksberg Hospital in Copenhagen, Denmark.
Not Approved in OA
Semaglutide and other potentially weight loss-inducing drugs are not currently indicated for use specifically in OA, Tonia Vincent, MBBS, PhD, told this news organization, and so “I think we have to be very cautious,” she said.
“Weight loss is one of the few things that has been shown to be successful in clinical trials,” said Dr. Vincent, who is a professor of musculoskeletal biology and an honorary rheumatologist at the Kennedy Institute of Rheumatology at Oxford University in Oxford, England.
“People always feel better too when they lose weight, so that helps manage pain. So, I’d be very surprised if there isn’t a benefit,” she added.
“I just think we need to know more about the long-term use of these drugs, whether the healthcare system can afford them, and how we would ration them.”
Previous Work
The STEP 9 study is not the first time that Dr. Bliddal has investigated the effects of a GLP-1 receptor agonist in people with knee OA, but it is the first to have shown a significant effect on knee pain.
Previously, results from the LOSEIT trial with liraglutide demonstrated that, after an 8-week dietary intervention run-in phase, people who were treated with the GLP-1 receptor agonist lost an average of 2.8 kg in body weight over a period of 1 year, vs a 1.2 kg gain in the placebo group. Knee injury and Osteoarthritis Outcome Scores, however, were largely unaffected.
“The study was more or less negative for knee pain because at that time we had to pretreat patients with some kind of weight loss before they were allowed to have the liraglutide,” Dr. Bliddal said.
“There’s so many different considerations with diets and the different ways that [dietary modification] is performed, that could be part of the explanation why some people didn’t find the pain relief,” Dr. Bliddal suggested.