Objectives: A multicenter, randomized, double-blind, placebo-controlled study of the oral calcineurin inhibitor tacrolimus was performed in patients with early rheumatoid arthritis who had responded poorly to disease-modifying antirheumatic drugs (DMARDs), and factors related to suppression of joint destruction were investigated.
Methods: The change in the total Sharp score (∆TSS) was assessed by univariate analysis in patients with X-ray films to identify the main determinant of a ∆TSS of <0.5 in week 52. Patients with this factor were then investigated further.
Results: Univariate analysis showed that a baseline C-reactive protein (CRP) level of <1.5 mg/dL was the major determinant of ∆TSS <0.5 at week 52 in the tacrolimus group. Detailed analysis of patients with a baseline CRP of <1.5 mg/dL revealed no significant differences in background factors between the two groups. In week 52, ∆TSS was significantly smaller in the tacrolimus group than in the placebo group (2.67 ± 5.40 vs. 8.05 ± 10.32, respectively, p = 0.017). Both groups had a similar incidence of adverse reactions.
Conclusions: Adding tacrolimus to DMARDs significantly suppressed disease activity and joint destruction in patients with early rheumatoid arthritis, a disease duration ≤3 years, a CRP <1.5 mg/dL, and a poor response to oral DMARDs.