Background/Purpose: The objective of this analysis was to investigate differences in baseline demographic and clinical characteristics of patients with psoriatic arthritis (PsA) who responded to biologics vs those who were non-responders using the US-based Corrona Psoriatic Arthritis/Spondyloarthritis (PsA/SpA) registry.

Methods: This analysis included all patients with PsA aged ≥ 18 years enrolled in the Corrona PsA/SpA registry between March 2013 and March 2016 who were receiving biologics at the time of enrollment (baseline) and had ≥ 2 follow-up visits (at 6-month intervals). Responders were defined as those patients who remained on their index biologic and achieved minimal disease activity (MDA) at the second follow-up visit (mean [SD] follow-up, 15.7 [3.7] months) from baseline.¹ Information on demographics, clinical characteristics, patient-reported outcomes and past/current treatments were collected for all patients at baseline enrollment. Statistical comparisons between responders and non-responders were examined by t-tests for continuous variables and chi-square tests (or Fisher’s exact tests) of independence for categorical variables.

Results: There were 148 patients with PsA in the Corrona PsA/SpA registry that met the inclusion criteria. At the second follow-up visit 34 patients (23.0%) were classified as responders and 114 patients (77.0%) were considered non-responders. The majority of patients were receiving anti–tumor necrosis factor agents at registry enrollment (96.6%). At baseline, responders and non-responders were similar with regards to age, sex, race, disease duration, prevalence of comorbidities (cardiovascular disease, any cancer, diabetes and serious infection), multiple disease measures (e.g., enthesitis and dactylitis counts, Clinical Disease Activity Index and acute phase reactants) and prior/current treatments. Compared with non-responders, responders to biologics had significantly milder disease at the time of registry enrollment as measured by mean tender joint count (3.4 vs 7.2), patient-reported pain (35.7 vs 51.2), patient-reported fatigue (42.4 vs 54.1), Health Assessment Questionnaire score (0.6 vs 1.0), Bath Ankylosing Spondylitis Disease Activity Index score (3.4 vs 5.0) and Bath Ankylosing Spondylitis Functional Index score (2.0 vs 4.0) (Table).

Conclusion: This study from the Corrona PsA/SpA registry found that only 23.0% of patients achieved MDA with their index biologic at the time of the second follow-up visit (mean [SD] follow-up, 15.7 [3.7] months) and were considered responders. Both cohorts were similar with regards to several baseline demographic and clinical characteristics; however, responders generally had less severe disease at enrollment compared with non-responders.

References:

1.    Coates LC, et al. Ann Rheum Dis. 2010;69(1):48-53.