There is currently no treatment to slow down osteoarthritis (OA) progression—but if the findings of a new study hold true, that may change. An analysis of a randomized, controlled trial found that canakinumab just may hold this ability.
“Osteoarthritis is a common inflammatory disorder with no disease-modifying therapies. Whether inhibition of interleukin-1β (IL-1β) can reduce the consequences of large joint osteoarthritis is unclear,” the researchers explained.
The analysis of CANTOS (Canakinumab Anti-inflammatory Thrombosis Outcomes Study) included 10,061 patients from 1,091 clinical sites in 39 countries who were randomized to either subcutaneous canakinumab 50 mg, 150 mg, or 300 mg, or placebo once every three months. The main outcome was the time to first incident total hip replacement (THR) or total knee replacement (TKR); the secondary outcome was time to first occurrence of an OA-related adverse event (AE).
Patients were followed for a median 3.7 years. The hazard ratios (HRs) for the canakinumab groups compared to placebo patients for incident THR/TKR were: 50 mg, 0.60 (95% confidence interval [CI], 0.38 to 0.95); 150 mg, 0.53 (95% CI, 0.33 to 0.84); and 300 mg, 0.60 (95% CI, 0.38 to 0.93). In the pooled canakinumab groups compared to the placebo cohort, the researchers calculated incidence rates for THR/TKR of 0.31 and 0.54 events per 100 person-years (HR, 0.58; 95% CI, 0.42 to 0.80; P=0.001), respectively. Canakinumab patients were also less likely than placebo patients to experience OA-related AEs (HR, 0.73; 95% CI, 0.61 to 0.87). Outcomes were comparable for patients with a history of OA.
The most significant limitation of the study, however, is that CANTOS was not intended to evaluate the correlation between canakinumab and OA. The original trial, published in The New England Journal of Medicine, was designed to compare canakinumab versus placebo for cardiovascular outcomes including nonfatal myocardial infarction or stroke, or cardiovascular death. In the original study, the authors did write, “In a finding that was consistent with known effects of interleukin-1β inhibition, canakinumab resulted in significantly fewer reports of arthritis, gout, and osteoarthritis than did placebo.” (They also noted that canakinumab patients, compared to placebo patients, had significantly reduced cancer mortality.)
Still, the authors of the present analysis, which was published in Annals of Internal Medicine, wrote in their conclusion that their findings “support further investigation of IL-1β inhibition for treatment of large joint osteoarthritis.”