Prevalence and predictors of TNF-inhibitor persistence in psoriatic arthritis

18 Apr 2018

Objectives: To evaluate TNF-α inhibitor (TNFi) persistence when used as first- or second-line biologic therapy for the management of PsA, and to determine baseline clinical and laboratory parameters associated with TNFi persistence. Methods: A retrospective single-centre cohort study was performed on all patients with PsA initiated on TNFi therapy between 2003-2015. Demographic, clinical and laboratory characteristics were compared with TNFi persistence, using Kaplan-Meier survival and Cox proportional hazards models. Results: 188 patients with PsA were prescribed TNFi therapy as first-line biologic therapy over a period of 635 person-years (46% male, mean age 47.3 [S.D. 11.4] years; median disease duration 11(interquartile range, [IQR] 7-16 years). At 12 months of follow-up 79% of patients persisted with TNFi therapy, and 73% at 24 months. Of those discontinuing TNFi, 35% stopped due to primary inefficacy, 22% secondary inefficacy, and 43% adverse events. Multivariable analysis identified female sex (hazard ratio, HR 2.57; 95%CI 1.26, 5.24;p=0.01) and the presence of metabolic syndrome-related co-morbidities (HR 2.65; 95%CI 1.24, 5.69;p=0.01) as predictors of lower persistence. Of 32 cases treated with a second TNFi, persistence at 12 months was 56%. TNFi persistence was two-fold less likely in these 32 cases compared with firstline TNFi users (HR 2.02; 95%CI 1.20, 3.42;p=0.01). Conclusion: Patients with PsA who are female and have metabolic syndrome-related co-morbidities have lower TNFi persistence. Although persistence was lower in patients who had switched to a second TNFi, a substantial proportion of these cases responded, advocating switching to a secondTNFi as a valid therapeutic strategy.