ACHIEVEMENT OF VERY LOW DISEASE ACTIVITY AND REMISSION TREATMENT TARGETS IS ASSOCIATED WITH REDUCED RADIOGRAPHIC PROGRESSION IN PATIENTS WITH PSORIATIC ARTHRITIS TREATED WITH CERTOLIZUMAB PEGOL

Background: Several disease activity measures and thresholds have been recommended as psoriatic arthritis (PsA) treatment targets, although consensus on the most appropriate assessment tool is lacking. Reports suggest low disease activity (LDA) and remission may be associated with minimal structural progression in PsA. Objectives: To report the relationship between PsA disease activity and structural progression over 216 weeks’ (wks) treatment with certolizumab pegol (CZP), an Fc-free, PEGylated, tumour necrosis factor inhibitor (TNFi) that has shown long-term efficacy and safety in PsA. Methods: Patients (pts) enrolled in RAPID-PsA (NCT01087788) with active PsA (≥3 tender joints; ≥3 swollen joints; ESR ≥28 mm/hour and/or CRP >upper limit of normal) who had failed treatment with ≥1 csDMARD were randomised 1:1:1 to CZP 200 mg every 2 wks (Q2W), CZP 400 mg every 4 wks (Q4W), or placebo (PBO). All CZP pts received CZP 400 mg at Wks 0/2/4. PBO pts were re-randomised to CZP 200 mg Q2W or 400 mg Q4W at Wk 16 or 24. Pts were heterogenous for structural damage and disease duration at baseline. Disease activity was assessed using minimal disease activity (MDA) criteria (MDA: 5–6/7 criteria; very LDA [VLDA]: 7/7 criteria), Psoriatic Arthritis Disease Activity Score (PASDAS) (LDA: >1.9–≤3.2; remission: ≤1.9), or Disease Activity Index for Psoriatic Arthritis (DAPSA) (LDA: >4–≤14; remission: ≤4). Radiographs were read in four reading campaigns using the van der Heijde modified Total Sharp Score (mTSS) for PsA. A risk of structural progression (RSP) subgroup (baseline mTSS >median for all pts) was also assessed. Mean change from baseline (CFB) in mTSS and associations with disease activity states were estimated using a hierarchical linear mixed effects model (fixed effects: reading campaign/interactions of concurrent disease activity levels with time; random effects: pt/reading campaign nested within pt) which allowed mean mTSS trajectory, and impact of disease activity levels on this, to differ over time. Results: 407/409 randomised pts were assessed for mTSS at least once. At Wk 0, mean (standard deviation) DAPSA=44.5 (22.7), PASDAS=6.0 (1.1). 3/409 (0.7%) pts reported MDA. The proportion of pts achieving remission/VLDA states increased to Wk 216, as did estimated mean mTSS. Estimated mean mTSS CFB remained low overall (0.46 at Wk 216; standard error 0.16; Figure ). Across disease activity measures, remission/VLDA states were associated with mTSS estimated mean CFB ≤0 in both the overall group and RSP subgroup ( Table ). Conclusion: These data indicate that achievement of remission in PsA is important to prevent further structural damage, particularly in pts with pre-existing structural changes. This supports the rationale for strict disease activity targets. REFERENCES: [1]Coates L. Arthritis Rheumatol 2018;70:345–55; 2. Tucker LJ. Curr Rheumatol Rep 2018;20:71; 3. van der Heijde D. RMD Open 2018;4:e000582. Table. Estimated mTSS (mixed effects model) mTSS estimated mean CFB (standard error) All patients (N=407) RSP (n=202) PASDAS Remission -0.20 (0.25) -0.55 (0.49) LDA 0.01 (0.23) -0.07 (0.47) >LDA 1.31 (0.22) 2.54 (0.43) DAPSA Remission -0.34 (0.23) -0.67 (0.46) LDA 0.40 (0.22) 0.81 (0.44) >LDA 1.37 (0.24) 2.46 (0.48) MDA VLDA -0.40 (0.28) -0.84 (0.55) MDA 0.39 (0.24) 0.55 (0.48) >MDA 0.89 (0.20) 1.73 (0.39) mTSS estimated mean CFB: ≤0; ≤0.5; >0.5. Data to Wk 216 pooled for all pts randomised. Acknowledgments: This study was funded by UCB Pharma. Editorial services were provided by Costello Medical. Disclosure of Interests: Laura C Coates: None declared, Joseph F. Merola Consultant of: Merck, AbbVie, Dermavant, Eli Lilly, Novartis, Janssen, UCB Pharma, Celgene, Sanofi, Regeneron, Arena, Sun Pharma, Biogen, Pfizer, EMD Sorono, Avotres and LEO Pharma, Arthur Kavanaugh Grant/research support from: Abbott, Amgen, AstraZeneca, BMS, Celgene Corporation, Centocor-Janssen, Pfizer, Roche, UCB – grant/research support, Philip J Mease Grant/research support from: Abbott, Amgen, Biogen Idec, BMS, Celgene Corporation, Eli Lilly, Novartis, Pfizer, Sun Pharmaceutical, UCB – grant/research support, Consultant of: Abbott, Amgen, Biogen Idec, BMS, Celgene Corporation, Eli Lilly, Novartis, Pfizer, Sun Pharmaceutical, UCB – consultant, Speakers bureau: Abbott, Amgen, Biogen Idec, BMS, Eli Lilly, Genentech, Janssen, Pfizer, UCB – speakers bureau, Owen Davies Employee of: UCB Pharma, Oscar Irvin-Sellers Employee of: UCB Pharma, Tommi Nurminen Employee of: UCB Pharma, Désirée van der Heijde Consultant of: AbbVie, Amgen, Astellas, AstraZeneca, BMS, Boehringer Ingelheim, Celgene, Cyxone, Daiichi, Eisai, Eli-Lilly, Galapagos, Gilead Sciences, Inc., Glaxo-Smith-Kline, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi, Takeda, UCB Pharma; Director of Imaging Rheumatology BV Citation: Ann Rheum Dis, volume 79, supplement 1, year 2020, page 754Session: Psoriatic arthritis (Poster Presentations)