POS1024 EFFICACY AND SAFETY OF RISANKIZUMAB (RZB) FOR ACTIVE PSORIATIC ARTHRITIS (PsA): 52-WEEK RESULTS FROM KEEPsAKE 1

Background RZB, a humanized immunoglobulin G1 monoclonal antibody that specifically inhibits the p19 subunit of human cytokine IL-23, is being investigated as treatment for PsA. Objectives To compare efficacy and safety RZB vs. placebo (PBO) in patients with PsA who had an inadequate response or intolerance to conventional synthetic disease modifying antirheumatic drug (csDMARD-IR). Methods KEEPsAKE 1 ( NCT03675308 ) ongoing, phase 3 study includes screening period; 24-week double-blinded, placebo-controlled, parallel-group period (period 1); open-label extension 2). Eligible aged ≥18 years active (symptom onset ≥6 months prior screening, meeting Classification Criteria [CASPAR], ≥5 swollen tender joints) ≥1 csDMARD-IR, were randomized 1:1 receive 150 mg at weeks 0, 4, 16. The primary endpoint was proportion achieving ≥20% improvement American College Rheumatology (ACR20) week 24. Period 2 started 24, switched every 12 through 208. Mixed-effect model repeated measures nonresponder imputation methods used assess continuous binary variables, respectively. Efficacy analyzed all received dose 52. Treatment-emergent adverse events (TEAE) summarized using exposure-adjusted event rates (EAERs, events/100 patient-years [PY]). Results At greater RZB-treated (N=483) vs PBO-treated (N=481) achieved ACR20 (55.3% 32.8%, respectively). 52, 70% 63% PBO switch 24 ACR20. In ≥3% body surface area affected baseline, 52.7% (N=273) 9.9% (N=272) ≥90% Psoriasis Area Severity Index (PASI 90) 24; 67.8% 59.9% PASI 90 Similar results observed other measures. well tolerated 52 treatment. EAERs stable between data cut-off (19 April 2021), total EAER any TEAE receiving 143.1/100 PY. Conclusion Continuous provided durable consistent profile csDMARD-IR. Acknowledgements AbbVie, Inc. participated design; research; collection, analysis, interpretation data. AbbVie funded research this study. Medical writing assistance, by Jay Parekh, PharmD, JB Ashtin. Disclosure Interests Lars Erik Kristensen Speakers bureau: Amgen, Biogen, Bristol Myers Squibb, Gilead, Janssen, Lilly, Merck, Novartis, Pfizer, UCB, Consultant of: Grant/research support from: MAURO KEISERMAN Celgene, GlaxoSmithKline, Roche, Kim Papp Arcutis, Astellas, Bausch Health, Boehringer Ingelheim, Dermavant, Dermira, Incyte, LEO Pharma, Sandoz, Sanofi Genzyme, Baxalta, Baxter, Coherus, EMD Serono, Forward Galderma, Genentech, Meiji Seika Mitsubishi Tanabe Regeneron, Stiefel, Sun Takeda, Ortho Dermatologics, Leslie McCasland Douglas White Wenjing Lu Shareholder Inc., Employee Ahmed M. Soliman Ann Eldred Lisa Barcomb Frank Behrens Chugai, Galapagos, Sanofi,