A randomized,double‐blind,placebo‐controlled,phase III study of the human anti‐tumor necrosis factor antibody adalimumab administered as subcutaneous injections in Korean rheumatoid arthritis patients treated with methotrexate

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.