Dose Adjustment of Methotrexate Administered Concomitantly with Golimumab for Rheumatoid Arthritis in Japanese Real-World Clinical Settings

Abstract

Introduction: The combination of methotrexate (MTX) with biological disease-modifying antirheumatic drugs (bDMARDs) is a recommended treatment option for rheumatoid arthritis (RA) patients showing an inadequate response to MTX monotherapy. However, the adequate dose of MTX, especially in long-term treatment with bDMARDs/MTX combination therapy, remains under-addressed. Since RA patients require long-term treatment, we examined the effects of using golimumab (GLM) in the long run as well as its persistency and associated factors. Methods: We used the Japan Medical Data Center Inc. (JMDC) administrative claims data of 489 patients receiving GLM therapy for calculating the persistency in patients with constant, reduced, or escalated MTX dosing. The factors associated with GLM persistency were assessed using Cox proportional hazard modeling, controlling for the dose adjustment of concomitant MTX, age, sex, RA disease period, and the initial dose of GLM or concomitant MTX during GLM/MTX combination therapy. Results: During GLM/MTX combination therapy, up to 52% of patients were reported to experience dose adjustments of concomitant MTX treatment (i.e., dose reduction and escalation in 34% and 18% of patients, respectively). Persistency was similar in the MTX dose-reduction patients and the MTX dose-constant patients. In the Cox proportional hazard model, no significant differences were observed in association with GLM persistency, including with respect to MTX dose adjustment. Conclusions: GLM prescription was continued in 80% or more (1 year) and 50% or more (3 years) of RA patients receiving reduced concomitant MTX dosing, suggesting that MTX dose adjustment (including MTX reduction) could be considered in GLM/MTX combination therapy.