Randomized, Double-blind, Placebo-controlled, Comparative Study of Human Anti-TNF Antibody Adalimumab in Combination with Methotrexate and Methotrexate Alone in Taiwanese Patients with Active Rheumatoid Arthritis

Background/Purpose: Adalimumab is a fully humanized monoclonal antibody that blocks tumor necrosis factor (TNF)-alpha, which is effective in the treatment of patients with rheumatoid arthritis (RA). The purpose of this study was to compare the efficacy and safety of adalimumab plus methotrexate (MTX) and MTX alone in Taiwanese patients with active RA. Methods: Forty-seven patients with active RA who were maintained on MTX therapy at a stable dose of 10-15 mg/week for 4 weeks were randomized blindly to receive adalimumab 40 mg (n = 35) or placebo (n = 12) by subcutaneous injection every other week over a period of 12 weeks. The primary endpoint was a reduction in tender and swollen joint counts of 20% (ACR20), 50% (ACR50) and 70% (ACR70), as determined by the American College of Rheumatology criteria in week 12. The occurrence of treatment-emergent adverse events (TEAEs) was the primary safety variable. Results: Addition of adalimumab to MTX resulted in a significant reduction in the number of swollen joints (12.6 vs. 5.6; p = 0.011), patients' global assessment of disease activity (18.0 vs. 4.8; p = 0.040), pain visual analog scale (18.3 vs. 1.3; p = 0.015), and disability indices of the Health Assessment Questionnaire (0.6 vs. 0.2; p = 0.031), compared with MTX alone after 12 weeks of therapy. Overall improvement in disease activity was assessed by ACR20 (54.3% vs. 33.3%), ACR50 (34.3% vs. 16.7%) and ACR70 (14.3% vs. 0%), and all favored the adalimumab plus MTX group. TEAEs were comparable between the treatment groups, except for a slightly higher incidence of severe infection in the adalimumab plus MTX group. Conclusion: Adalimumab in combination with MTX is well tolerated and provides significantly more clinical benefits than MTX alone in Taiwanese patients with active RA. [J Formos Med Assoc 2009;108(4): 310-319]