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:
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.
Medscape invited two researchers and two outside experts to discuss this research 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.
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," King, of the department of medicine at the University of Toronto, said in an email.
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.
"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," Gudbergsen, a physician and associate professor at The Parker Institute, University of Copenhagen, Denmark, told Medscape in an email.
"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 lb) prior to randomization, and the subsequent weight loss with liraglutide was about 2.8 kg (6 lb; 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," 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 write, 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 write.
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."
Berenbaum is a professor of rheumatology at Sorbonne University and director of the department of rheumatology at AP-HP Saint-Antoine Hospital in Paris, France. He is also co-founder and CEO of 4Moving Biotech (a subsidiary of 4P Pharma, an innovator accelerator biotech company), which is testing liraglutide for KOA.
In their 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 Medscape in an email. "In order to get the direct effect of liraglutide, it should be injected intraarticularly," he said.
Observational Study of Patients With Diabetes and KOA
Zhu and colleagues recently published results of the first clinical investigation of long-term effects of GLP-1 receptor agonists on KOA in patients with comorbid type 2 diabetes.
They analyzed data from a subset of patients with KOA and type 2 diabetes from the Shanghai Osteoarthritis Cohort, including 233 patients who received a GLP-1 receptor agonist (semaglutide, liraglutide, or dulaglutide [Trulicity]) for at least 2 years and 1574 patients who did not receive this therapy.
The patients had a mean weight of 66 kg (145 lb), a mean BMI of 27 kg/m2, and a mean A1C of 7.3%.
"According to conventional wisdom, a weight change greater than 5% is considered clinically relevant for KOA," the researchers write. They found that patients had substantial weight loss after GLP-1 receptor agonist therapy.
The primary outcome, the incidence of knee surgery, was lower in the patients who received a GLP-1 receptor agonist than in the other patients (1.7% vs. 5.9%; adjusted P = .014).
Patients who received a GLP-1 receptor agonist also had greater improvements in secondary outcomes than did other patients, including pain subscale scores and cartilage-loss velocity of the medial femorotibial joint in patients with predominantly lateral OA.
"The effects of GLP-1 receptor agonists on arthritic knees were largely mediated by weight loss instead of glycemic control," Zhu and colleagues report.
They conclude that with long-enough treatment, "GLP-1 receptor agonist therapies might be disease-modifying for KOA patients with comorbid [type 2 diabetes mellitus]."
They call for further research to elucidate the effects of GLP-1 receptor agonists on the disease process, joint structure, and patient-reported outcomes of OA.
Garvey noted that "whether your BMI is 30 or 40, if there are complications, that tells you that degree of adiposity is sufficient to impair health." So, if a patient in southeast China has a BMI of 27 kg/m2 and has osteoarthritis, he or she could still benefit from weight loss, he said.
Liraglutide and Pain-Related Behavior in Mouse Models of OA
Berenbaum and colleagues reported that liraglutide alleviated pain-related behavior in sodium monoiodoacetate mouse models of KOA.
In addition, liraglutide had anti-inflammatory and anti-catabolic effects in synovial fluid from the knees of six patients with OA of varying severity.
The researchers analyzed generic liraglutide (from Hybio Pharmaceuticals, Shenzhen, China) and nongeneric liraglutide (from Novo Nordisk, Bagsværd, Denmark).
They found that "when injected intra-articularly, liraglutide blunts the inflammatory process that is present in OA synovial tissue, explaining the acute analgesic effect," Berenbaum said.
"Liraglutide could be a game-changer," he said, "by demonstrating not only an effect on joint structures like synovial tissue and cartilage, but also on symptoms in a short-term period."
Garvey said the symptom improvements after intrasynovial infusion of liraglutide in this trial were "impressive." This study "adds credence to the hypothesis that these GLP-1 receptor agonists could have effects above and beyond weight loss," he said.
Two Trials Near Completion, One Is Upcoming
Phase 1 and 2 Trials of 4P-004
"We are now in a phase 1 clinical trial [of 4P-004/liraglutide] in patients suffering from knee OA and should start a large phase 2 trial next year," said Berenbaum.
The phase 1 LASARE trial, sponsored by 4Moving Biotech, planned to enroll 32 patients with KOA.
The primary outcome is safety and tolerability of single IA administration of 4P-004 at escalating doses in patients with KOA. Secondary outcomes include plasma concentration of liraglutide when administered this way.
Phase 3 Trial of Semaglutide for KOA
Novo Nordisk is performing a phase 3 study, "Effect of Subcutaneous Semaglutide 2.4 mg Once-weekly Compared to Placebo in Subjects With Obesity and Knee Osteoarthritis," with an expected enrollment of 407 patients with KOA and estimated trial completion in September.
Eligible patients were aged 18 and older, with BMI > 30 kg/m2 and KOA with Kellgren-Lawrence grades 2 or 3. The co-primary outcomes are change in body weight and change in WOMAC pain score, from baseline to 68 weeks.
The LOSEIT trial was supported by Novo Nordisk and the Cambridge Weight Plan. The observational study in China was supported by the Shanghai Shen Kang Hospital Development Centre, the Clinical Research Plan of SHDC, and the National Natural Science Foundation of China. The preclinical trial was supported by 4P Pharma/4Moving Biotech.
Berenbaum is CEO of 4Moving Biotech and chair of the scientific advisory board of 4P Pharma. He has received personal fees from 4P Pharma as well as numerous other pharmaceutical companies. Garvey has reported being a consultant to Boehringer Ingelheim, Novo Nordisk, Eli Lilly, Merck, Fractyl Health, and Alnylam Pharmaceuticals, and reported being an investigator for studies sponsored by Novo Nordisk, Eli Lilly, Pfizer, and Epitomee. Gudbergsen, King, and Zhu report no relevant financial relationships.
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Cite this: Could GLP-1 Receptor Agonists Ease Knee Osteoarthritis Pain, Slow Progression? - Medscape - Jul 24, 2023.