Objective: Adalimumab is a fully human, monoclonal, antitumour necrosis factor antibody approved for the treatment of rheumatoid arthritis (RA) in more than 60 countries. We investigated the efficacy and safety of 40 mg every-other-week (eow) subcutaneous injections of adalimumab with methotrexate (MTX) versus placebo with MTX in Korean patients with RA with insufficient responses to MTX.
Methods: This was a 24-week, randomized, double-blind, placebo-controlled, phase III study conducted at six sites in Korea. The primary efficacy endpoint was a 20% improvement in the American College of Rheumatology response criteria (ACR20) at week 24. Secondary endpoints included ACR50, ACR70, and individual ACR components. Beginning at week 18, non-responders (< 20% reduction in swollen and tender joint counts) could switch to rescue therapy with open-label adalimumab 40 mg eow.
Results: Of the 128 patients enrolled, 65 received adalimumab and 63 received placebo. An ACR20 response at week 24 was achieved by 61.5% of patients receiving adalimumab versus 36.5% receiving placebo (P < 0.01). ACR50 and ACR70 responses were achieved by 43.1% and 21.5% of adalimumab patients versus 14.3% and 7.9% of placebo patients (P < 0.001 and P < 0.05, respectively). Adalimumab significantly improved all seven ACR core components. Statistically significant improvements in ACR20 were observed with adalimumab as early as week 2. Adalimumab was generally well tolerated; there were no significant differences in incidences of adverse events between groups.
Conclusions: In Korean patients with RA with insufficient responses to MTX, combination therapy with adalimumab and MTX was more efficacious than placebo and MTX in reducing RA signs and symptoms.