AB0198 EFFICACY AND SAFETY AFTER TRANSITION FROM REFERENCE ADALIMUMAB TO CT-P17 (ADALIMUMAB BIOSIMILAR: 100 MG/ML) IN COMPARISON WITH THE MAINTAINED TREATMENT (CT-P17 OR REFERENCE ADALIMUMAB) IN PATIENTS WITH MODERATE-TO-SEVERE ACTIVE RHEUMATOID ARTHRITIS: 1-YEAR RESULT

Background: Therapeutic equivalence of CT-P17 to reference adalimumab (ref-adalimumab) has been shown in patients with moderate-to-severe active rheumatoid arthritis (RA) through primary 24-week results [1]. Here, efficacy, pharmacokinetics (PK), safety and immunogenicity up 52-week, including transition data from ref-adalimumab are presented. Objectives: To evaluate PK, when switched compared maintaining or ref-adalimumab. Methods: In this study, 648 RA despite methotrexate treatment were randomized (1:1) either treated doses 40 mg every 2 weeks Week 24. Prior dosing at 26, 608 again their treatments being CT-P17. Efficacy, safety, assessed 52. Results: After the second randomization, 303 continued CT-P17, 153 151 treatments, 48. Demographics baseline characteristics similar among 3 groups. Sustained comparable efficacy terms ACR20/50/70 response rates was achieved not only maintenance groups (CT-P17 ref-adalimumab) but also group 52 (Figure 1). Figure 1. ACR 20/50/70 Response Rates 1 YearAbbreviation: ref-adalimumab, adalimumab.Note. There who could visit study site due COVID-19 pandemic counted as nonresponder for mean trough serum concentration (Ctrough) maintained after 24 all The observed Ctrough within reported therapeutic ranges levels (5-8 μg/mL). profile (Table most common treatment-emergent adverse events (TEAEs) neutropenia. Similar proportions experienced least TEAE: injection reactions, hypersensitivity/allergic reactions infections. One malignancy (basal cell carcinoma; unrelated) group. Safety accumulated over year showed Anti-drug antibody (ADA) neutralizing (NAb) At 52, had ADA/NAbs 28.4%/24.8% maintenance, 27.0%/24.3% 28.3%/26.3% Conclusion: Single efficacious safe without increase immunogenicity. Also, profiles between References: [1]J Kay et al, 2020. Poster Presented Convergence Table Overview TEAEs Weeks 26 (Safety Population – random subset) Patients, n (% ) Second Randomization Maintenance (N=303 Ref-ada (N=152 Switched ≥1 TEAE 121 (39.9) 69 (45.4) 73 (48.0) TESAE 6 (2.0) 5 (3.3) leading drug discontinuation (1.0) (1.3) classified (0.7) 0 (0) (0.3) 4 (2.6) infection 54 (17.8) 41 (27.0) 28 (18.4) Abbreviations: Ref-ada, adalimumab; TEAE, event; TESAE, serious event. Disclosure Interests: Daniel Furst Speakers bureau: CME, Consultant of: Amgen, Corbus, Galapagos, Horizon, Kadmon, Pfizer, Talaris, Grant/research support from: CSL Behring, Gilead, GSK, Novartis, Roche/Genetech, Edward Keystone AbbVie, F. Hoffmann-La Roche Inc., Janssen Merck, Pfizer Pharmaceuticals, Sanofi Genzyme, Bristol-Myers Squibb Company, Celltrion Myriad Autoimmune, Inc, Lilly Sandoz, Sanofi-Genzyme, Samsung Bioepis, PuraPharm, Jonathan Boehringer Ingelheim GmbH, Healthcare Co. Ltd., Jubilant Radiopharma, Merck & Co., Sandoz Scipher Medicine, UCB, Paid University Massachusetts Medical School: Gilead Sciences Novartis Pharmaceuticals Corp., Janusz Jaworski: None declared, Rafal Wojciechowski: Piotr Wiland Eli Lilly, Aventis, Anna Dudek: Marek Krogulec: Sławomir Jeka Roche, Teva, MSD, Abbvie, Egis, Medac, Agnieszka Zielinska: Jakub Trefler: Katarzyna Bartnicka-Masłowska: Magdalena Krajewska-Wlodarczyk Klimiuk: Sang Joon Lee Employee Celltrion, Sung Hyun Kim YunJu Bae GoEun Yang JaeKyoung Yoo TaeKyung Inc.