Disease-modifying antirheumatic drug selection in Japanese patients with rheumatoid arthritis treated with biologics or JAK inhibitors without methotrexate: A retrospective hospital-based administrative claims database study

Abstract

Objectives: We evaluated the medication selection and clinical characteristics of rheumatoid arthritis (RA) patients who started treatment with/without methotrexate (using biologic disease-modifying antirheumatic drugs or Janus kinase inhibitors [JAKi] instead) in Japan. Methods: Using a Japanese hospital-based administrative claims database, RA patients who received treatment (abatacept, interleukin-6 receptor inhibitor [IL-6Ri], tumor necrosis factor inhibitor, or JAKi) between 1/January/2015 and 31/December/2019 were enrolled. Results: In total 19,301 patients were included (10,530 receiving methotrexate; 8,771 not receiving methotrexate within 60 days of the first treatment). Mean ages at diagnosis were 60.7 and 65.9 years in the methotrexate and non-methotrexate groups (p <0.0001). The non-methotrexate group had higher proportions of patients with Charlson Comorbidity Index ≥1 (p <0.0001), and higher comorbidity rates. Abatacept was the most frequently used drug among patients with infectious/parasitic, circulatory, and respiratory diseases at baseline. IL-6Ri had the highest use rate among patients with neoplasms; blood, gastrointestinal, and genitourinary diseases; and abnormal clinical/laboratory findings. Abatacept had the highest persistence probability from 6 months onward. Conclusions: Methotrexate is used less frequently among older Japanese RA patients or those with comorbidities. Abatacept is the most frequently used drug, followed by IL-6Ri, in patients not using methotrexate at the treatment start.