Time lag between the initiation of adalimumab after methotrexate correlates with the efficacy of adalimumab in rheumatoid arthritis patients

Objectives: To evaluate the efficacy and safety of adalimumab (ADA) and methotrexate (MTX) in patients with rheumatoid arthritis (RA) and investigate critical factors associated with efficacy. Methods: In this retrospective cohort study, patients received ADA at a single facility. Clinical outcome was retrospectively evaluated using the Disease Activity Score in 28 joints with Erythrocyte Sedimentation Rate (DAS28-ESR). Results: Of the 122 patients undergoing treatment with ADA between July 2008 and April 2014, DAS28-ESR data after 6 months of treatment were available for 103 and 87 (84.5%) were treated with a combination of ADA and MTX. For combination therapy, time lag between MTX and the initiation of ADA significantly correlated with efficacy of ADA at 6 months, as well as prior use of biologics, but not disease duration. Conclusions: Clinical outcomes were correlated with the time lag between MTX and the initiation of ADA, not disease duration. Early initiation of ADA after MTX might improve clinical outcomes.