POS1540 EARLY SKIN AND EARLY ENTHESITIS RESPONSES IN PSORIATIC ARTHRITIS PATIENTS TREATED WITH GUSELKUMAB ASSOCIATE WITH LONG-TERM RESPONSE: POST HOC ANALYSIS THROUGH 2 YEARS OF A PHASE 3 STUDY

Background Guselkumab (GUS), an IL-23p19 inhibitor, has demonstrated efficacy in psoriatic arthritis (PsA) across key Group for Research and Assessment of Psoriasis (PsO) Psoriatic Arthritis (GRAPPA)-recommended domains [1,2] . Skin disease enthesitis have been identified as manifestations with earlier response times than others [3] Objectives In this analysis we: (a) Determined whether early skin and/or entheseal predicts future other PsA domains; (b) Evaluated the trajectory achieving skin/entheseal responses by 52 weeks (W) patients (pts) without responses. Methods Pts DISCOVER-1 DISCOVER-2 (D1/2) studies were adults active despite standard therapies. D1 pts had ≥3 swollen tender joints (SJC/TJC) C-reactive protein (CRP) ≥0.3 mg/dL; D2 SJC ≥5, TJC CRP ≥0.6 mg/dL. 31% received 1-2 prior TNF inhibitors; biologic-naïve. randomized 1:1:1 to GUS 100 mg every 4 (Q4W); at W0, W4, then 8 (Q8W); or placebo. These post hoc analyses included only pooled Q4W Q8W (N=748). Early was defined PsO Area Severity Index (PASI) score ≤1 W16 visual analogue scale (VAS) ≤15mm W8 among a baseline (BL) PASI >1 VAS >15mm (first assessment time both); Leeds Enthesitis (LEI) W8; categories vs LEI combined & none W8. Potential W24 W52 achievement minimal activity (MDA), Disease Activity (DAPSA) low (LDA) remission, DAPSA50, enthesitis/dactylitis resolution. Associations between W24/W52 assessed crosstabulations logistic regression. Results associated greater odds MDA, DAPSA LDA, but not dactylitis resolution (Figure 1). all outcomes, including dactylitis, exception remission; remission achieved proportion responders, though association significant W52. both BL enthesitis, responders even more likely subsequently demonstrate W52, individual Among who did achieve responses, approximately half so Conclusion predicted long-term clinical response, remission. A synergistic effect observed, which exhibiting later response. results highlight importance these two on pt outcome. References [1] Deodhar et al. Lancet. 2020;395(10230):1115-25 [2] Mease PJ 2020;395(10230):1125-36 Coates LC A893. EULAR 2022, Denmark Acknowledgements: NIL. Disclosure Interests Laura Speakers bureau: AbbVie, Amgen, Biogen, Celgene, Eli Lilly, Galapagos, Gilead, Janssen, Medac, Novartis, Pfizer UCB, Consultant of: Boehringer Ingelheim, Bristol Myers Squibb, Pfizer, Grant/research support from: Julio Ramírez Dennis McGonagle Sibel Aydin Miriam Zimmermann Shareholder Johnson Johnson, Employee Janssen Scientific Affairs, LLC, Francois Nantel May Shawi Pharmaceutical Companies Emmanouil Rampakakis JSS Medical Research, Peter Nash Boehringher-Ingelheim, GSK, MSD, Samsung, Sun Pharma, Philip J Aclaris, GlaxoSmithKline, Inmagene, UCB.