Persistence and Use of Ixekizumab in Patients with Psoriatic Arthritis in Real-World Practice in Spain. The PRO-STIP Study

INTRODUCTION: Ixekizumab (IXE) is an IgG4-type monoclonal antibody targeting IL-17A indicated alone or in combination with methotrexate, for the treatment of active psoriatic arthritis (PsA) in adult patients with insufficient response or with intolerance to one or more disease-modifying anti-rheumatic drug (DMARD) therapy. The PRO-STIP study aimed to describe persistence, patient characteristics, treatment patterns, and effectiveness in patients with PsA receiving IXE in a real-world clinical setting in Spain. METHODS: This was an observational, multicentric, retrospective, longitudinal study in adult PsA patients who started IXE between January 2019 and December 2020, with at least 24 weeks of follow-up. A descriptive analysis of patient characteristics and treatment patterns was performed. The primary objective, treatment persistence, was estimated by Kaplan–Meier survival curve. Effectiveness was evaluated by Disease Activity in Psoriatic Arthritis (DAPSA) scores at baseline and at 12 and 24 weeks. RESULTS: Eighty-nine patients met the selection criteria (55.1% women and mean age 51.5 years). The median time from PsA diagnosis to starting IXE was 7.7 years (IQR 3.4–14.6). Prior to IXE, 95.5% patients had been treated with at least one biologic or targeted synthetic DMARD (b/tsDMARD). The observed persistence rates were 95.5%, 84.3% and 68.5% at 24, 48, and 104 weeks, respectively. The median persistence was not reached in the study period (mean persistence, 86.9 [95% CI 80.6–93.2] weeks). Twenty-eight (31.5%) patients discontinued IXE, 19 patients (21.3%) due to loss of effectiveness and two patients (2.2%) due to adverse events. In patients receiving treatment and with available effectiveness assessment (n = 24), DAPSA decreased significantly from baseline 23.7 (95% CI 19.5–27.9) to 14.8 (95% CI 10.5–19.2) at 12 weeks (p = 0.005) and 14.3 (95% CI 11.1–17.4) at 24 weeks (p = 0.004). CONCLUSIONS: PsA patients treated with IXE in a real-world setting show high treatment persistence through 104 weeks and improvements in disease activity after treatment initiation. This suggests that IXE could be an effective treatment for patients with PsA. RETROSPECTIVELY REGISTERED: Date of registration: 25th May 2021.