Objective: To evaluate the efficacy and safety of adding intramuscular (IM) gold to the treatment regimen of patients with rheumatoid arthritis (RA) who have a suboptimal response to methotrexate (MTX).
Methods: A randomized, double-blind, double-observer, placebo-controlled multicenter trial of 48 weeks was conducted. Sixty-five RA patients who had a suboptimal response to >/=12 weeks of MTX therapy were randomly assigned to receive weekly IM gold or placebo in addition to MTX. Gold was administered according to a standard protocol developed for the study. The primary outcome measure was the percentage of patients who met the American College of Rheumatology (ACR) 20% improvement criteria (achieved an ACR20 response) at week 48. Secondary outcomes included the percentages of patients achieving ACR50 and ACR70 responses, the individual criteria that make up the primary outcome, quality of life, direct and indirect health care costs, intraarticular steroid use, and adverse events, among other measures. Statistical analyses were based on an intent-to-treat strategy.
Results: Sixty-one percent of patients receiving gold achieved an ACR20 response compared with 30% of patients receiving placebo (chi(2) = 6.04, P = 0.014; logistic regression odds ratio 3.64 [95% confidence interval 1.3, 10.4], P = 0.016). Twenty-six percent of patients receiving gold achieved an ACR50 response compared with 4% of patients receiving placebo (P = 0.017), and 21% of patients receiving gold achieved an ACR70 response compared with 0% of patients receiving placebo (P = 0.011). From both clinical and cost-effectiveness perspectives, gold was the preferred and dominant strategy. Study treatment was discontinued in 23 patients (14 in the placebo group compared with 9 in the gold group; P = 0.022) due to loss to followup, adverse events, or lack of efficacy.
Conclusion: In RA patients with a suboptimal response to MTX, adding weekly IM gold causes significant clinical improvement. Adverse events were minor, and IM gold-related adverse events led to discontinuation in only 11% of the gold group over 48 weeks.