Real-World Utilization of Biologic and Targeted Synthetic Disease-Modifying Anti-rheumatic Drugs in Psoriatic Arthritis and Axial Spondyloarthritis: Insights from Sweden and Germany.

Introduction: Real-world data on patient characteristics and dosing patterns for psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA) are limited. This study assessed characteristics and dosing patterns in patients initiating a biologic or targeted synthetic disease-modifying anti-rheumatic drug (b/tsDMARD).

Methods: This cohort study included adult patients with PsA and axSpA newly initiating b/tsDMARDs, identified in the Swedish National Registers (2017-2021) and a German insurance claims database (2018-2021) from two regions (Saxony and Thuringia). Patient characteristics and dosing patterns were analyzed descriptively.

Results: Overall, 9414 (Sweden) and 2045 (Germany) patients with PsA and 7763 (Sweden) and 1756 (Germany) patients with axSpA were included. Patients with PsA were generally older and more often female than the patients with axSpA. Swedish patients were generally younger with fewer co-diagnoses than German patients. The most common co-diagnoses were psoriasis, hypertension, and joint pain. Most patients were b/tsDMARD-naïve and had prior nonsteroidal anti-inflammatory drug or corticosteroid use. Anti-tumor necrosis factor agents were most commonly used (Sweden: PsA 71.22%, axSpA 86.42%; Germany: PsA 41.66%, axSpA 79.67%). Secukinumab was the most frequently prescribed treatment with recommended dose escalation, followed by ixekizumab and guselkumab. For secukinumab, German patients typically received higher maintenance doses (300 mg vs 150 mg/month) than those in Sweden, especially in those without psoriasis. For ixekizumab, while all patients in Sweden received an 80 mg/month maintenance dose, some patients in Germany received a 160 mg/month maintenance dose. For guselkumab, some patients in Germany received higher-than-recommended maintenance doses; this pattern was not observed in Sweden.

Conclusion: Differences between patient characteristics and dosing patterns were observed between patients with PsA and axSpA in Sweden and Germany. Treatment variations may reflect high prevalences of co-diagnoses, like psoriasis, or unmet therapeutic needs. This work serves as a first step towards future research for personalized treatment approaches to optimize treatment outcomes.