High disease relapse after bDMARD spacing in psoriatic arthritis compared to rheumatoid arthritis and axial spondyloarthritis patients: real-life data from BIOPURE registry

The objective is to evaluate the effectiveness of a spacing strategy of bDMARDs in a cohort of selected patients in disease remission or low-disease activity (LDA) without glucocorticoids affected with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA). This was a single-centre study carried out on patients prospectively enrolled in the biologic Apulian registry. Patients whose disease was in remission or LDA without taking glucocorticoids during the previous 6 months and who had agreed to increase the time interval between bDMARD doses were included in this study. Demographic and clinical characteristics were recorded at baseline and at 3, 6 and 12 months of follow-up. Endpoint of the study was the survival of spacing doses in the time lag of the study. Failure of spacing was defined as the first flare of disease. Thirty-seven RA, 28 PsA and 20 axSpA patients underwent bDMARD spacing according to a local strategy. During the follow-up, 5 RA, 6 PsA and 4 axSpA patients had a joint flare, but further 5 PsA patients manifested a skin relapse. Global persistence was 86.5% for RA (MST = 41 (95% CI: 37–45) months) and 80% for axSpA patients (MST = 36 (95% CI: 31–42) months). PsA patients showed a lower persistence, being of 60.7% (MST = 30 (95% CI: 23–36) months) (log-rank test, p = 0.03). Dose reduction by spacing bDMARD doses may be a feasible approach in patients with persistent remission/LDA activity. However, PsA patients might have greater odds of spacing failure because of skin psoriasis relapse.Key Points• Spacing of bDMARDs may be a feasible strategy for some patients with rheumatoid arthritis, psoriatic arthritis and axial spondyloarthritis who achieve the target and withdrawn glucocorticoids.• Psoriatic arthritis patients showed lower persistence because of both articular and skin relapses.