Real‐World Safety and Retention of Tofacitinib in Elderly Versus Non‐elderly Patients With Rheumatoid Arthritis: A Retrospective Cohort Study in Taiwan

OBJECTIVES: Tofacitinib, the first approved oral small-molecule Janus kinase inhibitor (JAKi), is widely used for treating rheumatoid arthritis (RA). This study aims to compare the drug retention rates of tofacitinib between elderly (≥ 65 years) and nonelderly (< 65 years) RA patients in a real-world clinical setting in Taiwan and to identify clinical factors associated with treatment discontinuation. METHODS: We conducted a retrospective cohort study of RA patients receiving tofacitinib between 2015 and 2020, with follow-up until December 31, 2021. Patients were categorized into an elderly group (≥ 65 years, n = 82) and a nonelderly group (< 65 years, n = 224). Drug discontinuation was defined as the cessation of tofacitinib during follow-up. Primary outcomes included retention rates, reasons for discontinuation, and the incidence of adverse events. Kaplan-Meier analysis and multivariate Cox proportional hazards models were used to identify independent factors for discontinuation. RESULTS: A total of 306 RA patients were included (mean age: 56.97 ± 12.44 years). The elderly group had a significantly higher prevalence of comorbidities, including hypertension, diabetes, hyperlipidemia, and osteoporosis. There was no significant difference in mean treatment duration (2.70 ± 1.73 vs. 2.61 ± 1.69 years, p = 0.7049). Kaplan-Meier analysis showed no statistically significant difference in retention rates (Log-rank test, p = 0.425). Multivariate analysis revealed that age was not an independent risk factor for discontinuation (adjusted HR = 1.086, 95% CI: 0.729-1.618, p = 0.685). Among 40 patients who discontinued due to adverse events, serious infection was the leading cause (35.0%), comprising 10 non-fatal serious infection events and 4 infection-related deaths. Major adverse cardiovascular events (MACE) occurred only in the elderly group (15.8%). CONCLUSIONS: In real-world practice, the drug retention of tofacitinib in elderly RA patients is comparable to that in nonelderly patients. Despite a higher comorbidity burden, age itself is not an independent risk factor for treatment discontinuation. However, the risk of MACE is higher in elderly patients, necessitating careful cardiovascular assessment and monitoring before tofacitinib treatment. These findings suggest that tofacitinib is a viable option for elderly RA patients, provided individualized risk assessment is performed. Notably, discontinuation due to adverse events was substantially less frequent than discontinuation due to lack of efficacy, supporting the overall favorable tolerability of tofacitinib in this population.