THU0666 Costs associated with switching subcutaneous tumour necrosis factor-Α inhibitor in the treatment of immune-mediated rheumatic disease
Authors: J. Dalén, A. Svedbom, K. Luttropp, S. Kachroo
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Few studies have investigated the costs associated with switching subcutaneous tumour necrosis factor-α inhibitor (SC-TNFi) in the treatment of immune-mediated rheumatic disease (IMRD; rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis),<sup>1–2</sup> and to our knowledge no studies have been performed in a European setting. <h3>Objectives</h3> The objective of this retrospective observational study was to explore costs of health care resource utilisation (HCRU) associated with switching SC-TNFi in patients with IMRD in Sweden. <h3>Methods</h3> Using data from Swedish Health Data Registers, adult, treatment naïve IMRD patients filling prescriptions between May 1st 2010 and December 31st 2015 for any of the currently available SC-TNFi (adalimumab, etanercept, certolizumab, and golimumab) were included. Prescriber specialty and department were used to exclude patients with SC-TNFi treatment unrelated to IMRD. A switch was defined as a filled prescription for a subsequent SC-TNFi within 60 days of first line discontinuation. HCRU, including non-DMARD medication, inpatient and specialised outpatient care, was captured 12 months pre- and post-treatment initiation. Eligible patients had at least 12 months follow-up, and were either persistent throughout or switched treatment during the follow-up period. The analysis was performed on a propensity score matched (PSM) cohort. <h3>Results</h3> In total, 6213 eligible patients were identified, of which 5092 were persistent with their index therapy throughout the follow-up period while 1120 patients switched SC-TNFi. The PSM cohort was derived as "Persistent" vs. "Switched" with a total of 1120 matched pairs. Patients switching therapy had higher total HCRU costs during the baseline period and maintained their average cost during the follow-up period (figure 1), whereas persistent patients decreased their average costs from the baseline period to the follow-up period. The average yearly cost during baseline and follow-up was USD 4,512 vs USD 4,690 for patients switching SC-TNFi, and USD 3,630 vs USD 2,662 for persistent patients. This corresponds to a difference in difference of USD 1,146 (p&lt;0.001). <h3>Conclusions</h3> Similar to previous findings,<sup>3–4</sup> patients switching maintained their higher costs, while persistent patients decreased their costs from baseline to the follow-up period. This further highlights the notion that persistence may not only serve as a marker for drug effectiveness, safety, and treatment satisfaction, but also for reduced HCRU and costs. <h3>References</h3> [1] Borah BJ, et al. Trends in RA patients' adherence to subcutaneous anti-TNF therapies and costs. Curr Med Res Opin2009;25(6):1365–77. [2] Cannon GW, et al. Clinical outcomes and biologic costs of switching between tumor necrosis factor inhibitors in US veterans with rheumatoid arthritis. Adv Ther2016;33(8):1347–59. [3] Dalén J, et al. Treatment persistence among patients with immune-mediated rheumatic disease newly treated with subcutaneous TNF-alpha inhibitors and costs associated with non-persistence. Rheumatol Int2016Jul;36(7):987–95. [4] Dalén J, et al. Second-line treatment persistence and costs among patients with immune-mediated rheumatic diseases treated with subcutaneous TNF-alpha inhibitors. Rheumatol Int2017;37(12):2049–58. <h3>Disclosure of Interest</h3> J. Dalén Employee of: Mapi, A. Svedbom Employee of: Mapi, K. Luttropp Employee of: Mapi, S. Kachroo Shareholder of: Merck and Co., Inc., Employee of: Merck and Co., Inc.