Cycle versus swap strategy after TNFi discontinuation in psoriatic arthritis and axial spondyloarthritis: a quasi-experimental study

OBJECTIVES: To compare a bDMARD mode of action cycle vs swap treatment strategy in patients with psoriatic arthritis (PsA) or axial spondyloarthritis (axSpA) after first tumour necrosis factor inhibitor (TNFi) discontinuation. METHODS: In December 2019, our local treatment protocol for PsA and axSpA changed from a cycle strategy (first TNFi to second TNFi) to a swap strategy (first TNFi to IL-17i). We performed a retrospective comparison of the 3-year drug retention rate using multivariable Cox regression (ref: cycle group) and disease activity (DAS28-CRP for PsA, BASDAI for axSpA) in patients with a clinical diagnosis of PsA and axSpA. For subgroup analyses, Cox regression models were stratified by sex, reason of first TNFi discontinuation, and (non-)radiographic status in axSpA. RESULTS: In PsA patients (n=406), there was no overall significant difference in drug retention between strategies (HR: 1.17 (95% CI: 0.87 to 1.58), p=0.29), but male PsA patients had a significant higher risk for treatment discontinuation following a swap strategy. In axSpA patients (n=335), the swap strategy was overall associated with a higher risk of treatment discontinuation (HR: 1.46 (95% CI: 1.03 to 2.07), p=0.04). Patients who discontinued their first TNFi due to inefficacy and patients diagnosed with radiographic axSpA were at significant higher risk for treatment discontinuation following a swap strategy. No significant differences in disease activity were found for treatment strategies in PsA or axSpA. CONCLUSION: In PsA, the cycle and swap treatment strategy performed similarly, while in axSpA, the cycle strategy was associated with a significant higher drug retention rate.