Patients receiving interleukin-1£] (IL-1£]) inhibitors had lower rates of total hip or total knee replacements over an average follow up of 3.7 years, according to an exploratory analysis of data from the CANTOS (Canakinumab Anti-inflammatory Thrombosis Outcomes Study), which is a randomized double-blind, placebo-controlled trial.
These findings are important, as no treatments currently exist that can either prevent or slow progression of osteoarthritis.In the CANTOS trial, more than 10,000 patients with elevated high-sensitivity C-reactive protein (hs-CRP) levels and a history of myocardial infarction were randomly assigned canakinumab or placebo injections every 3 months for up to 5 years to determine the cardiovascular effects.
The reduction in joint replacements among patients who received canakinumab versus the placebo group became apparent after only one year of treatment and remained statistically significant when CANTOS participants with a history of crystalline or inflammatory arthritis were excluded.
However, the authors provide a cautionary note that the number of women in the trial was relatively low, while knee osteoarthritis is a disease that predominates in older women.
According to the authors of an accompanying editorial from the UC Davis Health, the results of this analysis are both unexpected and exciting. The investigators used elevated hs-CRP level as an entry criterion, and may have identified a subgroup of persons with osteoarthritis in whom inflammatory cytokines activate pathways that accelerate joint degeneration.
The authors also note that joint replacement is a robust endpoint and one that might be adapted by the U.S. Food and Drug Administration for evaluating disease-modifying osteoarthritis drugs.