Real-world use of biologic and targeted synthetic disease-modifying antirheumatic drugs in US patients with psoriatic arthritis: Persistence, patient characteristics associated with discontinuation, and dosing patterns.

backgroundPsoriatic arthritis (PsA) is a chronic, immune-mediated inflammatory arthropathy presenting with multiple manifestations, including peripheral arthritis, enthesitis, and skin psoriasis (PSO). Immunosuppressive/immunomodulatory therapies, including biologic/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARD), are common effective treatments for PsA; however, discontinuation is reported and contributing factors remain unclear.

objectiveTo describe the probability of persistence and time to discontinuation (including switch) of b/tsDMARD therapy in both b/tsDMARD-naive and -experienced patients with PsA within 12 months following initiation of a new b/tsDMARD. Secondary objectives included (1) describing the factors associated with b/tsDMARD persistence or nonpersistence and (2) assessing maintenance dose changes among patients with PsA initiating the anti-IL17A agents secukinumab (SEC) or ixekizumab (IXE). SEC and IXE were of particular focus owing to the variability in their dosage recommendation guidelines at the time of this study.

methodsThis observational cohort study used Merative MarketScan data and included patients initiating a new prescription of b/tsDMARD treatment for PsA, with a diagnosis of PsA between January 1, 2017, and June 30, 2021. The primary outcome was persistence, defined as days of b/tsDMARD therapy use from index date to 12 months of continuous index treatment, or first occurrence of b/tsDMARD discontinuation/switch. Associations between patient characteristics and outcomes were explored using Cox regressions, with descriptive dose analyses exploring proportions of patients with specific starting/maintenance b/tsDMARD doses.

results7,037 adult patients with PsA were included: 26.7% with PsA only and 73.3% with PsA+PSO at baseline. The 12-month probability for persistence of b/tsDMARD treatment was 51.2% (95% CI, 49.5%-52.9%), with an 8.3-month mean length of persistence. Treatment persistence probability at 12 months was 52.7% (50.8%-57.7%) for patients with PsA+PSO and 47.0% (43.7%-50.3%) for patients with PsA only. Treatment persistence probability at 12 months was 51.4% (49.6%-53.2%) for the b/tsDMARD-naive subgroup and 49.8% (45.5%-54.1%) for the b/tsDMARD-experienced group. Female sex and a baseline codiagnosis of fatigue were associated with an increased probability of nonpersistence, whereas codiagnosis of PSO was associated with decreased probability of nonpersistence. In the dosing analysis, of the patients initiating SEC therapy included in the analysis, 60.4% were prescribed a starting maintenance dose of 300 mg every 4 weeks (Q4W) and 34.1% were prescribed a starting maintenance dose of 150 mg Q4W. Of patients initiating IXE therapy included in the analysis, 84.4% were prescribed an 80-mg Q4W starting maintenance dose and 10.4% were prescribed a 160-mg Q4W starting maintenance dose.

conclusionsThe findings of this study provide relevant insights into tailoring b/tsDMARD therapy to maximize clinical benefit and potentially identify patients with the greatest unmet need.