POS0941 LONG-TERM CLINICAL OUTCOMES OF CERTOLIZUMAB PEGOL TREATMENT IN PATIENTS WITH ACTIVE NON‑RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS STRATIFIED BY BASELINE MRI AND C-REACTIVE PROTEIN STATUS

Background Certolizumab pegol (CZP) has demonstrated clinical efficacy in patients with active non-radiographic axial spondyloarthritis (nr-axSpA) and objective signs of inflammation during the 52-week (wk) placebo (PBO)-controlled period 104 wk open-label (OL) safety follow-up extension (SFE) C-axSpAnd study. 1 There is, however, a paucity data on long-term biologics nr-axSpA according to patients’ baseline MRI C-reactive protein (CRP) status. Objectives This post hoc analysis from aimed evaluate whether CRP status impacted (3-year) responses CZP. Methods ( NCT02552212 ) was 3-year, phase 3, multicentre Adults (N=317) fulfilling Assessment SpondyloArthritis international Society (ASAS) classification criteria (CRP ≥ upper limit normal (10 mg/L) [CRP+] and/or evidence sacroiliitis [MRI+]) 2 were randomised 1:1 PBO or CZP (400 mg at Wks 0, 4, then 200 every wks [Q2W]) for 52 wks. 3 Those enrolled into SFE received OL (200 Q2W) an additional Ankylosing Spondylitis Disease Activity Score (ASDAS) Bath Index (BASDAI) alongside percentage achieving ASDAS major improvement (ASDAS-MI, primary outcome) ASAS 40% response (ASAS40) 156 assessed prespecified subgroups based MRI/CRP (MRI+/CRP+, MRI−/CRP+, MRI+/CRP−). All are reported as observed case. Results 243/317 (76.7%) entered SFE, 120 group initially (36 MRI+/CRP+, 32 MRI−/CRP+ MRI+/CRP−) 123 initial (30 34 59 MRI+/CRP−; 75/123 had switched treatment double-blind phase). 206/243 completed SFE; 102/120 (85.0%) CZP, 104/123 (84.6%) group. Among CZP-randomised patients, mean similar between timepoints (MRI+/CRP+: 1.6 Wk vs 156; MRI−/CRP+: 2.1 2.2; MRI+/CRP−: 1.7 1.6), ASDAS-MI lower compared across all (Figure A ). Patients showed improvements over time 1.8 2.2 1.9; 2.0 1.7) sustained proportion achieved ASDAS-MI. Similar results shown BASDAI, scores B Mean BASDAI decreased (indicative improvements) PBO, which point values aligned those In ASAS40 52. An increased C Conclusion this inflammation, outcomes after year generally years MRI+/CRP− subgroups; numerically highest MRI+/CRP+ subgroup. References [1]van der Heijde D. Arthritis Rheumatol 2021;73 (suppl 10); [2]Lambert RG. Ann Rheum Dis 2016;75(11):1958–63; [3]Deodhar A. 2019;71(7):1101–11. Acknowledgements study funded by UCB Pharma. Editorial services provided Costello Medical Disclosure Interests Philip Robinson Consultant of: Personal fees AbbVie, Atom Biosciences, Eli Lilly, Gilead, Janssen, Novartis, Roche, Pfizer Pharma, Grant/research support from: Grant funding Novartis Pharma; meeting attendance Bristol Myers Squibb, Walter P Maksymowych Honoraria/consulting Boehringer Ingelheim, Celgene, Galapagos, Research grants AbbVie Pfizer; educational Chief Officer CARE Limited., Lianne S. Gensler Speakers bureau: Speaker Consulting Martin Rudwaleit Bengt Hoepken Shareholder Stockholder Employee Lars Bauer Thomas Kumke Mindy Kim Atul Deodhar Pfizer, Amgen, Aurinia, GSK, MoonLake, Pharma