Persistence, switching, and discontinuation patterns of b/tsDMARDs in patients with rheumatoid arthritis: a single-center retrospective cohort study from Saudi Arabia.

OBJECTIVE: To characterize real-world treatment patterns, including persistence, switching, and discontinuation, of biologic and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in patients with rheumatoid arthritis (RA) in Saudi Arabia. METHODS: This retrospective cohort study was conducted at Dammam Medical Complex in Saudi Arabia. Adult RA patients naïve to b/tsDMARDs who initiated therapy between January 1, 2013, and January 31, 2023, were included. Treatment patterns were summarized using descriptive statistics. Drug survival was assessed with Kaplan-Meier curves and Cox proportional hazards models. RESULTS: Among 175 eligible patients, first-line therapy was a tumor necrosis factor inhibitor (TNFI) in 109 (62.3%), a non-TNFI in 47 (26.9%), and tofacitinib in 19 (10.9%). Estimated drug survival probabilities at 5 years were 0.47 (95% CI: 0.37-0.59) for TNFIs, 0.51 (95% CI: 0.38-0.68) for non-TNFIs, and 0.68 (95% CI: 0.48-0.97) for tofacitinib. At 10 years, survival was 0.33 (95% CI: 0.23-0.48) for TNFIs and 0.27 (95% CI: 0.16-0.45) for non-TNFIs. Kaplan-Meier analysis showed no significant difference across classes (log-rank p = 0.68). Adjusted hazard ratios for switching or discontinuation (reference: TNFIs) were 1.10 (95% CI: 0.69-1.74, p = 0.68) for non-TNFIs and 0.68 (95% CI: 0.27-1.72, p = 0.42) for tofacitinib. The primary reason for switching was lack/loss of efficacy, while pregnancy and non-adherence were the most frequent causes of discontinuation. CONCLUSION: Tumor necrosis factor inhibitors were the most commonly initiated first-line b/tsDMARD in this Saudi cohort. Persistence appeared comparable across classes, although the small sample size limits definitive conclusions. These findings provide initial real-world insights into the utilization of advanced RA therapies at a single tertiary center in Saudi Arabia.