AB0204 THE PROPER STUDY: INTERIM ANALYSIS OF A PAN-EU REAL-WORLD STUDY OF SB5 BIOSIMILAR FOLLOWING TRANSITION FROM REFERENCE ADALIMUMAB IN PATIENTS WITH RHEUMATOID ARTHRITIS, AXIAL SPONDYLOARTHRITIS, OR PSORIATIC ARTHRITIS
Authors: U. Müller-Ladner, K. Gaffney, D. Jadon, U. Freudensprung, J. Addison
Journal: Annals of the Rheumatic Diseases (2021)

Background: SB5, a biosimilar to reference adalimumab (ADL), received EU marketing authorisation in August 2017, based on the totality of evidence from pre-clinical and clinical Phase I and III studies that demonstrated bioequivalence, similar efficacy, and comparable safety and immunogenicity to the reference. This real-world study provides data on outcomes of the transition from reference to biosimilar ADL outside the controlled, randomised, clinical trial setting. Objectives: To evaluate candidate predictors of persistence on SB5 in EU patients (pts) across multiple indications. Methods: This ongoing observational study enrolled 1000 pts with rheumatoid arthritis (RA), axial spondyloarthritis (axSpA), psoriatic arthritis (PsA), ulcerative colitis, or Crohn’s disease who initiated SB5 as part of routine clinical practice following a minimum of 16 weeks’ treatment with reference ADL, at clinics in Belgium, Germany, Ireland, Italy, Spain, and the UK. Data are captured from clinic records retrospectively for the 24 weeks prior to transition, and prospectively and/or retrospectively for 48 weeks following transition. Primary outcome measures include baseline clinical characteristics, disease activity scores and clinical management over time; data on COVID-19 infection has recently been captured. This interim analysis (IA) provides an overview of baseline characteristics, disease scores and dose regimen up to 48 weeks post-initiation of SB5, and COVID-19 infection reported to date, in subjects with RA, axSpA, or PsA enrolled at 35 specialist sites and followed up to the data extract date of 18 th December 2020. Results: Of the 504 pts included in this IA, 201 have RA, 169 have PsA, and 134 axSpA. At time of data extract, 216 pts had completed 48 weeks on SB5, 73 pts had discontinued SB5, and 8 had discontinued the study. RA (N=201 ) axSpA (N=134 ) PsA (N=169 ) Mean (SD ) Q1, Q3 Mean (SD ) Q1, Q3 Mean (SD ) Q1, Q3 Age at SB5 initiation (years ) 60.2 (11.7) 53, 68 50.5 (13.6) 38, 61 53.0 (12.2) 43, 62 Duration of disease (years ) 13.5 (11.7) 4.5, 20 18.7 (13.2) 9, 25 12.7 (9.9) 4, 20 n % n % n % Women 144 71.6 41 30.6 77 45.6 SB5 Dosing regimen: Baseline 40 mg Q2W 149 74.1 120 89.6 156 92.3 Week 48 40mg Q2W 69 77.5 67 85.9 98 92.5 Baseline Other* 52 25.9 14 10.4 13 7.7 Week 48 Other* 20 22.4 11 14.1 8 7.5 Disease Score (paired patients ) DAS28 FFbH BASDAI Tender Joint Count Swollen Joint Count Baseline, n, mean (95% CI ) 69 2.5 (2.3–2.7) 22 73.9 (65.6–82.1) 42 2.8 (2.3–3.4) 49 1.8 (0.1–3.0) 49 0.6 (0.2–0.9) Week 48, n, mean (95% CI ) 69 2.6 (2.3–2.8) 22 72.1 (64.0–80.2) 42 3.0 (2.4–3.7) 49 1.9 (0.5–3.3) 49 0.6 (0.1–1.1) Patient diagnosed with COVID-19 at any time on-study, n (% ) No 142 95.3 96 88.1 140 98.6 Yes 3 2.0 1 0.9 1 0.7 Unknown 4 2.7 12 11.0 1 0.7 Imraldi regimen stopped or changed due to COVID-19, regardless of diagnosis, n (% ) No 130 98.5 106 97.2 134 100 Yes 2 1.5 3 2.8 0 0 SD standard deviation; Q1 1st quartile, Q3 3rd quartile; CI Confidence Interval *Other includes all other reported doses and/or dosing intervals: 40mg QW, 80mg Q2W, and unspecified frequency DAS28 Disease Activity Score 28; FFbH Hanover Functional Ability Questionnaire; BASDAI Bath Ankylosing Spondylitis Disease Activity Index Conclusion: This IA provides a first insight into clinical management of pts over 48 weeks, in a contemporary cohort of EU pts with established RA, axSpA and PsA, switched from reference to biosimilar ADL SB5 in clinical practice. The majority of pts showed no meaningful difference in disease score or dose regimen of SB5 by Week 48 post-transition. As of data extract date, the proportion of pts with a known positive COVID-19 test was low (1.3%) and a small minority (1.3%) had SB5 treatment changed or interrupted as a result of the COVID-19 pandemic. With follow-up of pts ongoing to Q4 2021, the study will continue to provide pertinent information about clinical outcomes of transition from reference to biosimilar ADL in real-world practice and in indications not investigated in controlled studies. Acknowledgements: Statistical services gave been provided by FGK Clinical Research GmbH, Munich, Germany. Data management services were provided by Worldwide Clinical trial, Research Triangle Park, NC, USA; funding was provided by Biogen International GmbH. Disclosure of Interests: Ulf Müller-Ladner Consultant of: Biogen, Grant/research support from: Biogen, Karl Gaffney Consultant of: AbbVie, Celgene, Gilead, Lilly, MSD, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Celgene, Gilead, Lilly, MSD, Novartis, Pfizer, and UCB, Deepak Jadon Consultant of: AbbVie, Celgene, Eli Lilly, Gilead, Janssen, MSD, Novartis, Oxford University Press, Pfizer, Roche, Sandoz, UCB, Grant/research support from: AbbVie, Celgene, Eli Lilly, Gilead, Janssen, MSD, Novartis, Oxford University Press, Pfizer, Roche, Sandoz, UCB, Ulrich Freudensprung Shareholder of: Biogen, Employee of: Biogen, Janet Addison Shareholder of: Biogen, Employee of: Biogen