FRI0450 Tumor Necrosis Factor Inhibitor Treatment in Psoriatic Arthritis: Need for Co-Medication?
Authors: B. Michelsen, D.M. Soldal, A. Kavanaugh, D.L. Boyle, G. Haugeberg
Journal: Annals of the Rheumatic Diseases (2016)

<h3>Background</h3> Different than for rheumatoid arthritis, the potential benefits of conventional synthetic disease modifying drug (csDMARD) co-medication among psoriatic arthritis (PsA) patients receiving tumor necrosis factor inhibitors (TNFi) remain unclear.<sup>1</sup> <h3>Objectives</h3> This study aimed to investigate the role of concomitant csDMARDs on survival of subcutaneous TNFi in Norwegian PsA outpatients between 2000 and 2015. <h3>Methods</h3> We included all the PsA patients who initiated first time treatment with adalimumab, etanercept, golimumab and certolizumab in the years 2000–2015 in a Norwegian outpatient clinic. Baseline characteristics and drug survival were compared between patients with and without csDMARD co-medication. The <i>X</i><sup>2</sup> test, independent t-test and Mann-Whitney U test were applied as appropriate for group comparisons. Drug survival was explored by Kaplan-Meier analysis, and patients receiving versus not receiving co-medication were compared using the log rank test. Additional analyses for each of the TNFi were performed. Univariable and multivariable Cox regression analysis were used to identify predictors of discontinuation. <h3>Results</h3> Among 371 PsA patients being treated with TNFi, 145 received csDMARD co-medication; 58/118 with etanercept, 48/106 with adalimumab, 21/47 with certolizumab and 18/47 with golimumab, respectively. Mean (SD) age was 54.0 (11.5) years, disease duration 13.1 (9.1) years, years of education 12.9 (3.4), body mass index (BMI) 27.1 (4.3) kg/m<sup>2</sup>, baseline DAS28 4.1 (1.4), 45.7% were female. Baseline characteristics were similar for patients with and without co-medication, except for a higher percentage of first time TNFi users (67.6%) compared to previous TNFi users (32.4%) in the co-medication group, p=0.001. Drug survival of TNFi was similar for patients receiving versus not receiving concomitant csDMARDs (log rank test p=0,181, figure). In the Cox regression analysis identified predictors for TNFi discontinuation were previous use of TNFi (HR 1.68, 95% CI 1.25–2.26, p&lt;0.001) and TNFi type (p&lt;0.001). Separate analyses for first time TNFi users did not change the primary outcome. Separate analyses for different TNFi types showed similar drug survival with and without co-medication, except for certolizumab for which a trend toward better drug survival with co-medication was seen. <h3>Conclusions</h3> In our population of TNFi treated PsA patients, we found similar drug survival for patients with and without csDMARD co-medication. Identified predictors for TNFi discontinuation were previous use of TNFi and TNFi type. <h3>References</h3> Behrens F et al. Tumour necrosis factor inhibitor monotherapy vs combination with MTX in the treatment of PsA: a systematic review of the literature. Rheumatology. 2015; 54: 915–26. <h3>Disclosure of Interest</h3> B. Michelsen: None declared, D. Soldal: None declared, A. Kavanaugh: None declared, D. Boyle: None declared, G. Haugeberg Grant/research support from: Pfizer