Pos1521 characteristics of Difficult to Treat Psoriatic Arthritis: A Comparative Analysis

Abstract

BackgroundThe concept of difficult-to-treat rheumatoid arthritis (D2T RA) has recently emerged. It is defined by the persistence of disease activity and the failure of at least 2 b/tsDMARDs of 2 different mechanisms of action (MoA) [1]. In this definition, the period of time during which the treatments have failed is not included. The D2T concept has not yet been applied with consensus in psoriatic arthritis (PsA).ObjectivesTo study the characteristics of patients with D2T PsA to better identify the potential causes of treatment failure. The 2ndobjective was to study a sub-group of D2T PsA patients with a predefined time criteria.MethodsA monocentric retrospective longitudinal study was performed in a tertiary center. PsA diagnosis was based on CASPAR criteria. Patients were followed up from February 2004 to August 2022. Patients starting a b/tsDMARDs with a minimum of 2-year follow-up were included. D2T PsA patients were defined as patients who received more than 2 b/tsDMARDs with different MoA among b/tsDMARD available. These patients were compared to non-D2T PsA patients (nD2T PsA) using statistical tests. Very D2T PsA patients were defined as patients who received at least 2 b/tsDMARDs in less than 2 years during the time of follow-up.Results150 patients were included, 49 were D2T PsA and 101 nD2T PsA. Baseline characteristics are presented in the Table 1. No statistical difference was found between the 2 groups regarding main comorbidities, including fibromyalgia and depression.In the D2T PsA group, 91.7% and 69.1% of patients received an anti-TNF alpha as the 1stand 2ndlines of treatment; anti-IL17 drugs represented 0% and 12.2% of 1stand 2ndlines; anti-IL12-23 represented 8% and 18.4% of prescriptions in 1stand 2ndlines. After 3 lines, 38.8% of patients had received 3 bDMARDs with different MoA, 30.6 % received 2 bDMARDs with different MoA.17 patients were categorized as very D2T PsA. When compared to the rest of the D2T PsA group, no significant difference was observed. Proportion of men was 64.7% (p=0.39). Mean age was 55.0 ± 8.3 yo (p=0.67) and mean BMI was 30.4 ± 6.5 kg/m2(p=0.65).Table 1.Baseline characteristics of patientsParametersND2T PsA n = 49NnD2T PsA n = 101p valueMen4929 (59.2)10152 (51.5)0.37Age (years), mean ± SD4954.2 ± 11.910153.7 ± 14.20.82BMI, mean ± SD4629.6 ± 7.29627.7 ± 5.70.093PsA duration (years), median (IQR)4917.0 (8.0 to 20.0)9911.0 (6.0 to 21.0)0.22Current smoker status4916 (32.7)10133 (32.7)1.00Clinical PsA characteristics at baselineAxial involvement4821 (43.8)10026 (26.0)0.030Peripheral involvement4949 (100)10199 (98)NAMonoarthritic483 (6.3)10111 (10.9)-Oligoarthritic4822 (45.8)10151 (50.5)-Polyarthritic4823 (47.9)10137 (36.6)-Dactylitis4510 (22.2)10132 (31.7)0.24Psoriasis at baseline496 (12.2)10112 (11.9)0.95Structural damage at baseline (axial and peripheral)4232 (76.2)9649 (51.0)0.006IBD490 (0.0)1013 (3.0)NABaseline CRP (mg/L), median (IQR)4013.6 (6.0 to 31.5)868.1 (3.0 to 20.0)0.11BASDAI Baseline, mean ± SD865.1 ± 16.62258.5 ± 11.70.23bDMARD discontinuation due to poor dermatological control4719 (40.4)10119 (18.8)0.005Values are expressed as number (%) unless otherwise stated. BASDAI: Bath Ankylosing Spondylitis Disease Activity Index; bDMARD: biological disease modifying antirheumatic drug; BMI: body mass index; CRP: C-reactive protein; (n)D2T: (non) difficult-to-treat; HLA: human leukocyte antigen IBD: inflammatory bowel disease; IQR: interquartile range; N: number of available observations; NA: not applicable; PsA: psoriatic arthritis; SD: standard deviation.ConclusionSignificant differences were found between the characteristics of patients D2T PsA and nD2T PsA, which were the presence of axial manifestation, structural damage at baseline and discontinuation due to poor dermatological control. Limitations exist about applying the EULAR D2T RA definition to PsA. The inclusion of a time period should also be considered.Reference[1]Nagy G, Roodenrijs NM, Welsing PM, et al. EULAR definition of difficult-to-treat rheumatoid arthritis. Ann Rheum Dis 2021;80:31–5.Acknowledgements:NIL.Disclosure of InterestsNone Declared.