Objectives: To confirm the safety and effectiveness of adalimumab and to evaluate the influence of the concomitant use of methotrexate (MTX).
Methods: Postmarketing surveillance of 7740 Japanese rheumatoid arthritis (RA) patients was performed. All patients who received adalimumab in the registration period were followed for 28 weeks after starting treatment for safety and 24 weeks for effectiveness. Effectiveness was measured by duration of morning stiffness, swollen and tender joint counts (28 joints), patient global assessment of disease activity, erythrocyte sedimentation rate and serum C-reactive protein.
Results: Comparable rates of adverse drug reactions (ADRs) were reported in this study and in the interim analysis. Age, pulmonary disease history or comorbidity, co-existing diabetes mellitus, concomitant MTX at doses of > 8 mg/week and concomitant glucocorticoids at doses of > 5 mg/day were risk factors for infections. All mean values of effectiveness measurements improved. Relatively lower disease activity at baseline, biologic-naïve, concomitant MTX use and early RA stage/low functional class were background factors contributing to the effectiveness. The combination of adalimumab with MTX improved the response to adalimumab treatment.
Conclusion: Adalimumab, especially with concomitant use of MTX, provided significant improvement in disease activity, without any unexpected ADRs in Japanese RA patients.
Trial registration: ClinicalTrials.gov NCT01076959.