AB1279 Efficacious transition from reference product infliximab to the biosimilar in daily practice
Authors: Z. Layegh, J. Ruwaard, R.C. Hebing, M.J. L`Ami, W. van der Weele, M.T. Nurmohamed, G. Wolbink, C. Krieckaert
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> The biosimilar of infliximab, approved in September 2013 for the treatment of rheumatic diseases. The biosimilar is non-inferior to the reference product of infliximab based on safety, quality and efficacy.<sup>1</sup> In order to enable health care cost saving and efficient treatment, a transition to the biosimilar was deemed necessary. <h3>Objectives</h3> To evaluate the transition from the reference product to the biosimilar in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA). <h3>Methods</h3> Consecutive patients treated with reference product were switched to the biosimilar in the period July 2015 to June 2016 at the Amsterdam Rheumatology and immunology Center, Reade. Patients were informed by a letter about the transition to the biosimilar and were subsequently contacted by a nurse or the pharmacist for additional questions and whether they agreed upon the switch. Patients were advised to contact their treating rheumatologist when in doubt. Once agreed, the biosimilar was administered at the same dosage and interval as previous treatment with the reference product. Patients were followed until January 2018. The primary outcome was to evaluate the transition from the reference product to the biosimilar, secondary outcome was the change in disease activity measured with the Disease Activity Score in 28 joints using erythrocyte sedimentation rate (DAS28-ESR). Last available DAS28-ESR before switching and first available DAS28-ESR approximately 12 months after switching was used. In addition, the reason for discontinuation with infliximab or the restart with the reference product was recorded. <h3>Results</h3> In total 45 patients switched from the reference product to the biosimilar, 2 patients disagreed upon the switch and continued the reference product. The median treatment duration within fliximab in patients with RA and PsA was 17 (SD=11) years (table 1). During the follow-up period, 3 patients (7%) restarted the reference product due to subjective reasons, increase in disease activity was not objectified by the rheumatologist. The biosimilar was continued by 42 patients (93%). Furthermore, 1 patient switched to another biological due to lack of effect and in 2 biological therapy was stopped because of malignancy. The DAS28-ESR remained comparable before and after the switch, with a mean (SD) of respectively 2.34(±1.02) and 2.31 (±1.11). <h3>Conclusions</h3> In our population, a high amount of patients (n= 42, 93 %) continued the biosimliar during the follow up period of two years. A very low number of the patients (n=3) restarted the reference product, due to subjective reasons, whilst retaining stable DAS28-ESR. <h3>Reference</h3> [1] Jørgensen KK, Olsen IC, Goll GL, Lorentzen M, Bolstad N, Haavardsholm EA, et al. Switching from originator infliximab tobiosimilar CT-P13 compared with maintained treatment with originator infliximab(NOR-SWITCH): A 52-week, randomised, double-blind, non-inferiority trial. <i>Lancet</i>2017;389:2304–16. <h3>Disclosure of Interest</h3> Z. Layegh: None declared, J. Ruwaard: None declared, R. Hebing : None declared, M. L`Ami:None declared, W. van der Weele: None declared, M. Nurmohamed Grant/research support from: Abbvie, Roche, BMS, MSD, UCB, Janssen, Eli Lilly, Celgene &amp;Sanofi., Speakers bureau: Abbvie, Roche, BMS, MSD, UCB, Janssen, Eli Lilly, Celgene &amp; Sanofi., G. Wolbink Grant/research support from: Pfizer, Speakers bureau: Abbvie, UCB, BMS, Pfizer, C. Krieckaert: None declared