FRI0127 Open-label non-mandatory transitioning from originator etanercept to biosimilar sb4: 6-month results from a controlled cohort study
Authors: L. Tweehuysen, V.J.B. Huiskes, B.J.F. van den Bemt, J.E. Vriezekolk, S. Teerenstra, F.H.J. van den Hoogen, C.H. van den Ende, A.A. den Broeder
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Open-label mandatory transitioning to a biosimilar has no impact on disease activity in inflammatory rheumatic diseases.<sup>1</sup> In light of shared treatment decision-making between patients and physicians, non-mandatory transitioning might be preferable above mandatory transitioning. First attempts with non-mandatory transitioning unfortunately showed suboptimal acceptance and persistence rates to a biosimilar.<sup>2</sup> <h3>Objectives</h3> To evaluate the effects of non-mandatory transitioning from originator etanercept (ENB) to biosimilar etanercept (SB4) on drug survival and effectiveness in a controlled cohort study of patients with an inflammatory rheumatic disease. <h3>Methods</h3> In 2016, 642 ENB treated patients were asked to transition to SB4 by a structured communication strategy with opt-out option. Consenting patients were eligible for the current study [BIO-SPAN]. ENB treated patients in 2014 were recruited as historical cohort. Drug survival was compared by Cox regression analyses adjusting for age, gender, diagnosis, ENB treatment duration, ENB dose interval, csDMARD and CRP, using a robust variance estimator to account for repeated subjects. Adjusted differences in CRP, DAS28-CRP and BASDAI change over 6 months were assessed. <h3>Results</h3> 635 (99%) patients agreed to transition to SB4 of whom 625 patients (433 RA, 128 PsA, 64 axSpA) were included in the transition cohort. Additionally, 600 patients were included in the historical cohort. Crude 6 months retention rates of SB4 in the transition cohort and ENB in the historical cohort were: 90% (95%CI 88%–93%) vs 92% (95%CI 90%–94%). The transition cohort had a significantly higher relative risk of discontinuation (adjusted HR 1.57, 95% CI 1.05–2.36). Reasons for discontinuing SB4 (n=60) and ENB (n=46) were: lack of effect (43% vs 61%), adverse events (47% vs 28%), malignancy (3% vs 4%), pregnancy (4% vs 4%), other (3% vs 3%). In the transition cohort, 17 patients restarted ENB, 32 patients switched to another biologic and 11 patients maintained biologic-free. DAS28-CRP, BASDAI and CRP were similar between baseline and month 6. Compared with the historical cohort, the transition cohort had a smaller decrease in CRP (adjusted diff 1.8 (95%CI 0.3–3.2)) and DAS28-CRP (adjusted diff 0.15 (95%CI 0.05–0.25)) over 6 months. <h3>Conclusions</h3> Open-label non-mandatory transitioning from ENB to SB4 using a structured communication strategy showed a slightly lower persistence rate and smaller decreases in disease activity compared with a historical cohort, but these differences were considered as not being clinically relevant. The acceptance and persistence rates of SB4 in our transition cohort were similar to those of mandatory transitioning. Since mandatory transitioning is not acceptable in many countries, the use of a communication strategy which might optimise acceptance and persistence rates of non-mandatory transitioning seems attractive. <h3>References</h3> [1] Glintborg B, et al. Ann Rheum Dis2017. [2] Tweehuysen L, et al. Arthritis Rheumatol2017. <h3>Disclosure of Interest</h3> L. Tweehuysen: None declared, V. J. Huiskes: None declared, B. J. van den Bemt Speakers bureau: Pfizer, Abbvie, Sandoz, UCB, J. Vriezekolk: None declared, S. Teerenstra: None declared, F. H. van den Hoogen Consultant for: Celltrion, Sandoz, Mundipharma, Biogen, Speakers bureau: Celltrion, Sandoz, Janssen, Egis, C. van den Ende: None declared, A. den Broeder Grant/research support from: CZ, Menzis, ZonMw, Consultant for: Amgen, Boehringer Ingelheim, Speakers bureau: Bristol-Myers Squibb, Pfizer