Real-world effectiveness and safety of upadacitinib in Japanese patients with rheumatoid arthritis: impact of age, renal function, and low-dose therapy

OBJECTIVES: Upadacitinib (UPA) is an important therapeutic option for rheumatoid arthritis (RA), but evidence in older adults and patients with renal impairment remains limited. This study evaluated the real-world effectiveness and safety of UPA in Japanese patients with RA, including older adults and those with renal impairment. PATIENTS AND METHODS: This multicenter retrospective study included 112 patients with RA who received UPA (7.5 or 15 mg/day), with clinical outcomes assessed up to 52 weeks based on medical record review. Effectiveness was assessed using the Disease Activity Score 28–erythrocyte sedimentation rate (DAS28-ESR), Clinical Disease Activity Index (CDAI), and Health Assessment Questionnaire–Disability Index (HAQ-DI). Safety was evaluated based on adverse events and laboratory findings. Predictors of response were explored using multivariable regression, and prespecified subgroup analyses were performed by age (≥ 75 vs.