Abstract: COMPACT is a non-interventional study evaluating the effectiveness and safety in patients (pts) with rheumatoid arthritis (RA), axial-spondyloarthritis (axSpA) or psoriatic arthritis (PsA) treated with GP2015 (an etanercept [ETN] biosimilar) in real-world conditions. Objectives We present the effectiveness and safety data from the final analysis of the COMPACT study for all patient groups. Methods Pts aged ≥18 years on treatment with GP2015 were enrolled. Baseline visit corresponded with date of study inclusion and not with date of GP2015 treatment start. Pts were categorised based on prior treatment status: pts on clinical remission or low disease activity under treatment with reference ETN or biosimilar ETN (initial ETN: [iETN] ) and switched to GP2015 (Group A) or pts who received non-ETN targeted therapies and switched to GP2015 (Group B) or biologic-naïve pts who started GP2015 after conventional therapy failure (Group C) or DMARD-naïve pts with recent diagnosis of RA considered suitable for treatment initiation with a biologic and started on treatment with GP2015 (Group D). Effectiveness assessments included Disease Activity Score 28-joint count Erythrocyte Sedimentation Rate (DAS28-ESR) or Ankylosing Spondylitis Disease Activity Score (ASDAS) until Month 12 after enrolment (baseline) in the study. Results Of the 1466 pts enrolled, 572 were switched from iETN (Group A), 171 were switched from other targeted therapies (Group B), 713 were biologic-naïve (Group C), and 10 were RA DMARD-naïve (Group D). Comorbidities were more frequent in pts with RA (68.7%,) followed by pts with PsA (59.4%) and axSpA (52.1%). After 12 months of treatment with GP2015, pts with RA or PsA achieved comparable DAS28-ESR scores irrespective of whether they switched from iETN, or from other targeted therapies or were biologic-naïve. At Month 12, the mean ASDAS scores were comparable between the treatment groups in pts with axSpA (Table 1). Across all pt groups, no major differences were observed in the disease activity scores between baseline and Month 12 that may be explained by the ongoing GP2015 treatment at the time of enrolment for an observed average of 138 days. Overall, the proportion of patients with at least one adverse event (AE) and serious AE (SAE) was 47.6% and 7.7% in pts who were switched from iETN, 56.7% and 9.9% in pts switched from other targeted therapies, 56% and 8.7% in biologic-naïve pts, and 60% and 0% in DMARD-naïve pts. Rate of injection site reaction was low across the groups (Figure 1). Table 1. Effectiveness outcomes in patients treated with GP2015 Effectiveness outcomes Group A Group B Group C Group D Overall (A-D) RA DAS28-ESR, n, mean (SD) N=295 N=88 N=451 N=10 N=844 Baseline n=259 n=70 n=392 n=8 n=729 2.5 (1.1) 3.6 (1.3) 3.3 (1.5) 3.8 (1.2) 3.0 (1.4) Month 12 n=135 n=47 n=238 n=2 n=422 2.5 (1.3) 2.7 (1.0) 2.8 (1.4) 4.3 (2.5) 2.7 (1.3) PsA N=117 N=36 N=135 N=0 N=288 Baseline n=80 n=30 n=116 - n=226 2.1 (1.0) 2.9 (1.6) 2.9 (1.6) 2.6 (1.5) Month 12 n=32 n=13 n=60 - n=105 2.6 (1.9) 2.6 (1.6) 2.3 (1.4) 2.4 (1.5) AxSpA ASDAS, n, mean (SD) N=160 N=47 N=127 N=0 N=334 Baseline n=77 n=18 n=59 - n=154 1.6 (0.6) 1.8 (0.8) 2.3 (0.9) 1.9 (0.8) Month 12 n=39 n=8 n=23 - n=70 1.8 (0.9) 1.9 (0.6) 1.9 (1.0) 1.8 (0.9) N, total number of patients in the treatment group; n, number of patients with available data at each time point, SD, standard deviation Figure 1. Overall safety outcomes in patients treated with GP2015 Figure 1 represents the adverse events reported during GP2015 treatment. N, total number of patients in the treatment; n, number of patients in each treatment group Conclusion The results show comparable disease activity scores between pts who were switched from iETN, pts switched from other targeted therapies and biologic-naïve pts after 12 months of treatment with GP2015. No impact on the effectiveness of ETN was observed in pts with RA, axSpA or PsA who switched to GP2015. No new safety signals were reported. Disclosure of Interests Marc Schmalzing Speakers bureau: Novartis, AbbVie, Chugai/Roche, Janssen-Cilag, Lilly, Consultant of: AstraZeneca, Chugai/Roche, Hexal/Sandoz, Gilead, AbbVie, Janssen-Cilag, Boehringer/Ingelheim, Grant/research support from: Chugai/Roche, Boehringer/Ingelheim, Celgene, Medac, Herbert Kellner: None declared, Ayman Askari: None declared, Javier de Toro Santos: None declared, JULIO CESAR VAZQUEZ PEREZ-COLEMAN Speakers bureau: Sandoz, Abbvie, Sanofi, Fresenius, Rosario Foti Speakers bureau: Abbivie, Gilead, Lilly, Pfizer, UCB, Roche, Novartis, Pfizer, UCB, Sławomir Jeka: None declared, Boulos Haraoui Consultant of: Abbvie, Amgen, Fresenius Kabi, Lilly and Pfizer, Grant/research support from: Abbvie, Amgen, Fresenius Kabi, Lilly and Pfizer, Yannick Allanore Consultant of: Sandoz Hexal, Mylan, Astra-Zeneca, Masiur Rahman Employee of: Sandoz Hexal AG, Fabricio Furlan Employee of: Sandoz Hexal AG, Sohaib HACHAICHI Employee of: Sandoz Hexal AG, Tom Sheeran Speakers bureau: Pfizer, UCB, Roche, Consultant of: Novartis, Pfizer, Grant/research support from: Novartis, UCB, Roche

Abstract: Sandoz etanercept (SDZ ETN) is a biosimilar of etanercept (ETN). COMPACT is an ongoing, non-interventional study, evaluating the effectiveness, safety, and quality of life with SDZ ETN treatment in patients (pts) with rheumatoid arthritis (RA), axial-spondyloarthritis (axSpA) or psoriatic arthritis (PsA) in real-world conditions. Objectives: We have reported an interim analysis, with the effectiveness and safety data focusing on pts who were in clinical remission or low disease activity under treatment with reference ETN or biosimilar ETN other than SDZ ETN (initial ETN; iETN) and switched to SDZ ETN. Methods: Pts aged ≥18 years for whom treatment with SDZ ETN were initiated are being enrolled. Pts were categorized under four treatment groups based on prior treatment status: Group A, pts on clinical remission or low disease activity under treatment with iETN and switched to SDZ ETN; Group B, pts who received targeted therapies and switched to SDZ ETN; Group C, biologic naïve considered uncontrolled with conventional therapy; Group D, DMARD naïve with recent diagnosis of RA considered suitable for treatment initiation with a biologic and started on treatment with SDZ ETN. Effectiveness assessments included Disease Activity Score 28-joint count Erythrocyte Sedimentation Rate (DAS28-ESR) or Ankylosing Spondylitis Disease Activity Score (ASDAS) until Week 24 after enrollment (baseline; BL) in the study. Functional disability was measured by the Health Assessment Questionnaire Disability Index (HAQ-DI). The effectiveness and safety results are reported for the pts who switched from iETN (Group A). Results: Of the 1437 pts recruited (analysis cut-off date: 16 Oct, 2020), 567 pts were switched from iETN, 163 were switched from other targeted therapies, 697 were biologic-naïve, and 10 were RA DMARD-naïve. Among pts who switched from iETN, 51.5% had RA, followed by axSpA (28.0%) and PsA (20.5%). Comorbidities were more frequent in pts with RA (70.2%) followed by PsA (58.6%) and axSpA (49.7%); musculoskeletal and connective tissue disorders were reported in 31.8% and 15.7% of pts with RA and axSpA, respectively. At BL, whilst receiving iETN, the mean (SD) DAS28-ESR scores were 2.5 (1.1) and 2.1 (1.1) in pts with RA and PsA, respectively (figure 1). The mean change from BL in DAS28-ESR score at Week 24 after switch to SDZ ETN was -0.1 (1.1) and 0 (1.0) in pts with RA and PsA, respectively. In pts with axSpA, the mean (SD) ASDAS score was 1.5 (0.7) at BL; mean change from BL in ASDAS score at Week 24 was 0.1 (0.5). At BL, the mean (SD) HAQ-DI scores were 0.8 (0.7), 0.5 (0.7) and 0.5 (0.6) in pts with RA, PsA and axSpA, respectively. Overall, the proportion of patients with at least one adverse event (AE) was 37.3%, 33.6% and 25.8% in pts with RA, PsA and axSpA, respectively. Serious AEs were reported in 6.5%, 1.7% and 3.1% of pts with RA, PsA, and axSpA, respectively. Injections site reactions were reported in 2.7%, 0.9% and 1.3% of pts with RA, PsA and axSpA, respectively. Figure 1. Disease activity in patients who switched from iETN to SDZ ETN Conclusion: The interim analysis results shows that switch from iETN to SDZ ETN does not impact the effectiveness of ETN in pts with RA, axSpA or PsA, without any new safety signals. Disclosure of Interests: Marc Schmalzing Speakers bureau: Novartis, AbbVie, Chugai/Roche, Janssen-Cilag, Lilly, Consultant of: AstraZeneca, Chugai/Roche, Hexal/Sandoz, Gilead, AbbVie, Janssen-Cilag, Boehringer/Ingelheim, Grant/research support from: Travel grants: Chugai/Roche, Boehringer/Ingelheim, Celgene, Medac, Ayman Askari: None declared, Tom Sheeran Speakers bureau: Pfizer, UCB, Roche, Consultant of: Novartis, Pfizer, Grant/research support from: Novartis, UCB, Roche, David Walsh: None declared, Javier de Toro Santos: None declared, JULIO CESAR VAZQUEZ PEREZ-COLEMAN Speakers bureau: Sandoz, Abbvie, Sanofi, Fresenius, Charlotte Both Employee of: Sandoz employee Global Medical Affairs, Fabricio Furlan Employee of: Sandoz employee Global Medical Affairs, Sohaib HACHAICHI Employee of: Sandoz employee Global Medical Affairs, Herbert Kellner: None declared