PO:03:037 | The Impact of Peripheral Joint Involvement, Pain, and Inflammatory Bowel Diseases on Drug Persistence in Axial Psoriatic Arthritis

Giuseppe Lopalco¹, Sergio Del Vescovo¹, Maria Sole Chimenti², Giuliana Guggino³, Serena Guiducci⁴, Eleonora Celletti⁵, Alberto Cauli⁶, Luca Cantarini⁷, Valentino Paci⁸, Eneida Cela², Lidia La Barbera³, Gemma Lepri⁴, Myriam Di Penta⁵, Alberto Floris⁶, Alice Agostinelli⁸, Vincenzo Venerito¹, Michele Maria Luchetti⁸, Florenzo Iannone¹ | ¹Rheumatology Unit, Department of Precision and Regenerative Medicine and Ionian Area, Bari, Italy; ²Reumatology, Allergology and Clinical Immunology University of Rome Tor Vergata, Roma, Italy; ³Department of Health Promotion Sciences, Maternal and Infant Care, Internal Medicine and Medical Specialties, Palermo, Italy; ⁴Divisions of Internal Medicine and Rheumatology AOUC, Department of Experimental and Clinical Medicine, Firenze, Italy; ⁵Rheumatology Unit, SS. Annunziata Hospital of Chieti, G. D'Annunzio, Chieti, Italy; ⁶Department of Medical Science and Public Health, Cagliari, Italy; ⁷Policlinico Le Scotte, Siena, Italy; ⁸Clinical Medicine, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche, Ancona, Italy

Objectives. Axial psoriatic arthritis (PsA) may present with varying patterns of peripheral joint involvement. Previous studies have suggested that axial PsA patients with a polyarticular subset exhibit a more aggressive disease course and shorter drug survival compared to those with axial involvement and oligoarticular subset or isolated axial disease. The primary objective of this study was to compare the retention rates of first-line ts-/bDMARDs among the three axial PsA subgroups.

Materials and Methods. We performed a retrospective analysis of patients with axial PsA from a real-world cohort who fulfilled the CASPAR criteria for PsA and had axial involvement confirmed by clinical diagnosis and imaging findings. Patients were stratified into three groups: isolated axial disease (axPsA), axial disease with oligoarticular involvement (axPsA+oligo), and axial disease with polyarticular involvement (axPsA+poly). Baseline assessments included demographic, clinical data, and disease activity measures. Differences across groups were evaluated using chi-square tests for categorical variables and Student's t-tests for continuous variables. Kaplan-Meier survival analysis was performed to assess drug persistence. Multivariate Cox regression analysis was used to identify independent predictors of treatment discontinuation.

Results. A total of 560 axial PsA patients were analyzed, including 175 axPsA (31.2%), 189 axPsA+oligo (33.8%), and 196 axPsA+poly (35.0%) (Table 1). The axPsA group had the highest prevalence of concomitant psoriasis (82.3% vs 75.5% vs 66.5%, p<0.01) (Table 2). In contrast, the axPsA+poly group exhibited a greater disease burden, with significantly higher BMI (27.6±5.3 vs 26.2±4.8 vs 26.3±5.5, p=0.02), higher rates of multimorbidity (57.7% vs 36.8% vs 48.1%, p<0.001), and elevated disease activity scores (ASDAS-CRP: 3.10±0.80 vs 2.54±0.98 vs 2.84±2.11, p<0.01) (Table 2). HLA-B27 positivity was higher in the axPsA group (18.9% vs 10.3% vs 10.1%, p=0.05). Imaging findings revealed that sacroiliitis was more frequent in both the axPsA and axPsA+oligo groups (86.2% vs 86.2% vs 70.1%, p<0.001), while spondylitis was more prevalent in the axPsA group (21.8% vs 16.9% vs 15.0%, p<0.01). Analysis of drug persistence demonstrated significant differences among the groups (p=0.016), with mean survival times of 65.57 months (±5.80) for axPsA, 75.14 months (±8.05) for axPsA+oligo, and 67.07 months (±7.09) for axPsA+poly (Figure 1). Multivariate Cox regression analysis identified a higher baseline VAS pain (HR=1.013, 95% CI: 1.007–1.020, p<0.0001) and the presence of inflammatory bowel disease (IBD) (HR=1.89, 95% CI: 1.03–3.4, p=0.04) as independent predictors of treatment discontinuation.

Conclusions. This real-world study suggests that axial PsA phenotypes exhibit distinct clinical profiles, with the polyarticular subset showing a higher disease burden and activity scores. Baseline pain severity emerged as the strongest independent predictor of treatment discontinuation, along with the presence of IBD, underscoring the impact of this comorbidity in PsA patients.