Could glucagon-like peptide-1 receptor agonists, such as liraglutide and semaglutide, also be potential disease-modifying treatments for knee osteoarthritis (KOA)?
Weight loss is recommended for patients with KOA, and GLP-1 receptor agonists are approved for weight loss. New early research suggests these drugs might have a disease-modifying effect for KOA.
Three recently published studies investigated this:
- The LOSEIT phase 4, randomized controlled trial of liraglutide vs. placebo in patients with obesity/overweight and KOA.
- A large observational study out of China in patients with KOA and type 2 diabetes.
- A preclinical trial of liraglutide in mouse models of KOA.
The preclinical trial and the observational study report promising results, and the lack of KOA pain relief in patients in the phase 4 trial may be explained by the trial design. Three other trials are in the works.
This news organization invited two researchers and two outside experts to discuss these studies and potential future treatment of KOA with GLP-1 receptor agonists.
The big picture, as seen by two experts
The GLP-1 receptor agonists liraglutide (Victoza) and semaglutide (Ozempic) are approved for type 2 diabetes, and, in higher doses, liraglutide (Saxenda) and semaglutide (Wegovy) are approved for weight loss in patients with obesity (or overweight with comorbidities), and given as weekly injections.
ljubaphoto/E+/Getty Images
Victoza and Saxenda are expected to come off patent in December 2023, and in 2026, respectively.
Lauren King, MD, PhD, a rheumatologist and clinician scientist who was not involved with the recent investigational studies of GLP-1 receptor agonists for KOA, noted that obesity is the most important, guideline-recommended, modifiable risk factor for KOA.
“In people with overweight and obesity, losing weight can improve knee osteoarthritis symptoms, and some evidence supports that it may also slow joint structural changes,” Dr. King, of the department of medicine at the University of Toronto, said in an interview.
Large trials of GLP-1 receptor agonists in people with overweight and obesity, such as the STEP trials of semaglutide, she noted, “provide evidence that these medications are safe and effective, facilitating clinically relevant and sustained weight loss.”
Further research is needed, she said, to better understand disease-modifying effects of GLP-1 receptor agonists in patients with KOA.
Similarly, W. Timothy Garvey, MD, professor in the department of nutrition sciences at the University of Alabama at Birmingham and director of the UAB Diabetes Research Center, who was not involved with this research, noted that weight loss improves KOA symptoms.
Dr. Garvey was lead investigator in the STEP 5 trial of semaglutide and lead author of the American Association of Clinical Endocrinologists 2016 Obesity Management guidelines.
“The question is whether these GLP-1 receptor agonists have anything to offer over and above weight loss per se, and we don’t know for sure,” he said.
They “do have anti-inflammatory actions,” and “there are GLP-1 receptors in locations where you think GLP-1 receptor agonism may help inflammation in the knee, in joints, and in other tissues,” he noted.
He looks forward to results of the phase 3 trial of semaglutide in patients with KOA, expected this fall.
Three published studies
LOSEIT: RCT of liraglutide for pain and weight control in KOA
Henrik Rindel Gudbergsen, MD, PhD, and colleagues published results of the only randomized controlled trial of a GLP-1 receptor agonist (liraglutide, Saxenda) vs. placebo in patients with overweight/obesity and KOA, the LOSEIT trial.
All patients first entered an 8-week, pre-randomization phase where they had strict caloric restriction (and ate meal replacements) and lost at least 5% of their initial weight. They also had less knee pain at the end of this phase.
Then they were randomly assigned to receive 3 mg liraglutide or placebo daily injections for 1 year.
From randomization until week 52, the liraglutide group had greater mean weight loss than the placebo group (but this was < 5% of their weight). They did not have greater reduction in knee pain than patients in the placebo group.
“Our interpretation was that dieting results in weight loss and diminishes knee pain (which we knew), and that the impact of liraglutide following severe calorie restriction and weight loss and improvement of pain was limited,” Dr. Gudbergsen, a physician and associate professor at The Parker Institute, University of Copenhagen, told this news organization.
“That was the surprise for us as investigators,” he said, “and, I assume, why Novo Nordisk is now pursuing the investigation of semaglutide for KOA, as this is expected to create a larger effect on body weight and knee symptoms.”
The weight loss was about 12.5 kg (27.5 pounds) prior to randomization, and the subsequent weight loss with liraglutide was about 2.8 kg (6 pounds; about 4% of their weight). “Thus, it could seem that the participants’ potential for weight loss as well as symptom reduction was fully exploited in the pre–random assignment dietary intervention period,” according to the researchers.
“It seems highly relevant to use liraglutide or semaglutide for patients impacted by obesity and KOA, as it is in line with guidelines suggesting weight loss for this group,” Dr. Gudbergsen said. “However, whether liraglutide and/or semaglutide, acting via an anti-inflammatory effect, for example, has an added positive impact on cartilage quality remains to be clarified,” he said.
Others who were not involved in this study suggest that the lack of pain-reduction benefit with liraglutide vs. placebo can be explained by the short-term use of liraglutide (1 year), small weight loss (< 5%), and systemic rather than intraarticular injection.
The LOSEIT trial design “is problematic and could not provide a confirmative conclusion,” Hongyi Zhu, MD, PhD, Shanghai Sixth People’s Hospital, China, and colleagues wrote in their observational study. The small weight loss of < 5% in the liraglutide group may explain why the pain relief was not better than with placebo. A longer study duration with significant weight loss/maintenance may be needed, they noted.
Francis Berenbaum, MD, PhD, senior author of a preclinical study of liraglutide, said that in the LOSEIT trial, “daily systemic injections of liraglutide did not ameliorate OA-related pain, probably because of poor access and hence poor local concentrations of liraglutide in the knee joint.”
Dr. Berenbaum is professor of rheumatology at Sorbonne University and director of the department of rheumatology at AP-HP Saint-Antoine Hospital in Paris. He is cofounder and CEO of 4Moving Biotech (a subsidiary of 4P Pharma, an innovator accelerator biotech company), which is testing liraglutide for KOA.
In experiments in mice, systemic injections of liraglutide did not lead to high enough concentration in synovial fluid to show efficacy for pain relief, he told this news organization. “In order to get the direct effect of liraglutide, it should be injected intraarticularly,” he said.