The Retention Rate and Safety of JAK Inhibitors in Rheumatoid Arthritis: Real Word Data from a Monocentric Cohort

Background/Objectives: To date, the literature concerning real-world data on the retention rate and safety of Janus kinase inhibitors (JAKis) is limited. To retrospectively evaluate the overall drug retention rate (DRR) of different JAKis in a monocentric cohort of patients with rheumatoid arthritis (RA). Methods: Patients diagnosed with RA and treated with JAKis who were evaluated at our outpatient clinic from March 2017 to December 2023 were included in the study. Demographic, clinical characteristics, and comorbidities were recorded. The DRR was evaluated as the time to drug discontinuation, and baseline predictors of drug discontinuation were investigated through Cox regression after adjusting for baseline confounders. Results: The global DRR for JAKis was 51.3%. The DRR was 37.5% for tofacitinib, 46.6% for baricitinib, 69.4% for upadacitinib, and 53.5% for filgotinib. Considering all JAKis, the only significant predictor of drug discontinuation was the use of JAKis as a first-line treatment (HR 95% CI [0.25 (0.13-0.46)]. When considering each JAKi individually, a longer disease duration predicted TOF discontinuation (HR95% CI [1.05 (1.01-1.09)], while seropositivity protected against TOF being withdrawn (HR95% CI [0.41 (0.17-0.97)]. No independent predictors emerged for other JAKis. Conclusions: the use of JAKis as a first-line treatment as well as disease duration and serology may impact the DRR of JAKis, which may inform tailored treatment strategies in clinical practice.