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.

Objectives: We evaluated the medication selection and clinical characteristics of rheumatoid arthritis patients who started treatment with/without methotrexate (MTX) (using biologic disease-modifying antirheumatic drugs or Janus kinase inhibitors instead) in Japan.

Methods: Using a Japanese hospital-based administrative claims database, rheumatoid arthritis patients who received treatment [abatacept (ABA), interleukin-6 receptor inhibitor, tumor necrosis factor inhibitor, or Janus kinase inhibitor] between 1 January 2015 and 31 December 2019 were enrolled.

Results: Overall, 19,301 patients were included (10,530 receiving MTX; 8771 not receiving MTX within 60 days of the first treatment). Mean ages at diagnosis were 60.7 and 65.9 years in the MTX and non-MTX groups, respectively (P < .0001). The non-MTX group had higher proportions of patients with Charlson Comorbidity Index ≥1 (P < .0001) and higher comorbidity rates. ABA was the most frequently used drug among patients with infectious/parasitic, circulatory, and respiratory diseases at baseline. Interleukin-6 receptor inhibitor had the highest use rate among patients with neoplasms; blood, gastrointestinal, and genitourinary diseases; and abnormal clinical/laboratory findings. ABA had the highest persistence probability from 6 months onward.

Conclusions: MTX is used less frequently among older Japanese rheumatoid arthritis patients or those with comorbidities. In such patients, ABA is the most frequently used drug, followed by interleukin-6 receptor inhibitor, when MTX is not used at treatment start.