Chondroitin sulfate as effective as celecoxib for symptomatic knee osteoarthritis
The SYSADOA* chondroitin sulfate was as effective as the NSAID** celecoxib and superior to placebo in reducing pain and improving function for over 6 months in patients with symptomatic knee osteoarthritis (OA), according to the CONCEPT*** trial.
In this prospective, multicentre, double-blind trial, 604 patients with primary knee OA were randomized to receive chondroitin sulfate 800 mg (n=199), celecoxib 200 mg (n=200), or placebo (n=205) once daily for 6 months. Participants were evaluated using the Visual Analogue Scale (VAS) and Lequesne Index (LI) and followed for 182 days. [Ann Rheum Dis 2017;76:1537-1543]
Analysis of VAS and LI scores revealed significant improvement across all treatment arms compared with baseline as early as day 30 (p<0.001 for all).
At day 182, improvement in VAS and LI persisted in the chondroitin sulfate (-42.6 mm; p=0.001 and -4.7; p=0.023, respectively) and celecoxib arms (-39.5 mm; p=0.009 and -4.6; p=0.015, respectively) compared with placebo (-33.3 mm and -3.7, respectively).
Of note was the decrease in LI observed in the celecoxib arm at day 30, which only became apparent in the chondroitin sulfate arm at day 91 (p=0.045 and 0.050, respectively, compared with placebo). “[T]his observation may be related to an intrinsic difference in the mechanism of action of the molecules [of the two active drugs],” said the researchers.
Despite significant improvement in pain and function across all treatment arms as early as one month into treatment, the parallel findings between chondroitin sulfate and celecoxib at treatment end highlight the former’s excellent efficacy profile, noted the researchers.
Abdominal pain/discomfort was the most frequent adverse event across all treatment arms (2.5, 4.5, and 2.9 percent in the chondroitin sulfate, celecoxib, and placebo arms, respectively). Apart from one case of thrombocytopenia and one of leukopenia in the placebo group, no significant toxicities were reported in the chondroitin sulfate group, reflecting its safety, noted the researchers.
“[The combined] therapeutic effect and well-documented safety and tolerability explain why recent guidelines recommend SYSADOAs, including pharmaceutical-grade [chondroitin sulfate], as a first-line treatment in the management of knee OA … especially in [the] older population requiring long-term treatment,” said the researchers.
Furthermore, SYSADOAs counter the clinical risks associated with chronic acetaminophen and NSAID use despite their proven efficacy for OA, [Semin Arthritis Rheum 2016;45(4 Suppl):S3-S11; Ann Rheum Dis 2016;75:552-559; Lancet 2016;387:2093-2105] with previous findings showing a higher effect size for pain with chondroitin sulfate vs acetaminophen (0.35 vs 0.14). [Semin Arthritis Rheum 2014;44:253-263]
The researchers acknowledged the need for future clinical guidelines on the pharmacological management of knee OA, which warrants significant attention given the associated functional impairment that may eventually lead to disability. [Best Pract Res Clin Rheumatol 2006;20:3-25; Br Med Bull 2013;105:185-199]