Novel approaches to biological therapy for psoriatic arthritis

Relation Between Fatigue and ACR Response in Patients With Psoriatic Arthritis Treated With Tumor Necrosis Factor Inhibitor Therapy: A Population-based Cohort Study

OBJECTIVE

The objective of this population-based cohort study was to investigate the association between fatigue with disease activity and drug survival in patients with psoriatic arthritis (PsA) receiving their first tumor necrosis factor inhibitor (TNFi).

METHODS

Data on patient characteristics, disease activity, and drug survival were obtained from the DANBIO database on all patients with PsA from 2006 through 2015. Information on comorbidities was obtained through linkage with the Danish National Patient Registry.

RESULTS

A total of 880 patients were eligible for analyses. Patients with upper median fatigue scores had statistically significant higher disease activity measures (Disease Activity Score in 28 joints based on C-reactive protein), pain, and Health Assessment Questionnaire (HAQ) scores; tender joint counts; comorbidities (Charlson Comorbidity Index ≥ 2); and current smoking status at baseline compared to patients with lower median fatigue scores (P < 0.05). In the upper median fatigue group, fewer patients achieved American College of Rheumatology (ACR) responses and improvements in visual analog scale (VAS) fatigue compared to patients in the lower median fatigue group. Kaplan-Meier curves showed shorter drug survival in patients in the upper median fatigue group compared with the lower median fatigue group at 6-month follow-up.

CONCLUSION

Fatigue remains a dominating symptom after TNFi treatment, and is associated with higher baseline disease activity, pain, and HAQ scores; more comorbidities; and increased risk of TNFi treatment discontinuation in a cohort of Danish patients with PsA. The agreement between ACR and VAS fatigue responses is weak to moderate, suggesting heterogeneity between experienced fatigue and joint inflammation.

Disease activity and biologic use in patients with psoriatic arthritis or rheumatoid arthritis

To compare disease burden and biologic use among psoriatic arthritis (PsA) or rheumatoid arthritis (RA) patients recruited to the Corrona registry. Retrospective study of patients with PsA or RA enrolled in Corrona between January 2002 and March 2013 and grouped in 2-year intervals. Clinical outcomes and biologic use were assessed. Biologic use increased over time in both cohorts, with 62 and 52% of patients with PsA and RA, respectively, receiving biologics by 2012–2013. However, 25 and 35% of patients with PsA and RA, respectively, continued to experience moderate/high disease activity. Overall, the progressive increase in biologic use accompanied progressive decreases in Clinical Disease Activity Index (from 14.2 to 10.4 for RA, and 12.4 to 8.1 for PsA) and mean Health Assessment Questionnaire score (from 0.36 to 0.34, and 0.3 to 0.24). Mean patient pain, the proportion of patients reporting morning stiffness, and the mean duration of morning stiffness remained similar for both cohorts. PsA and RA treated in the rheumatology setting had a comparable impact on patient quality of life and functional ability. Disease burden improved with increased biologic utilization in both groups; however, moderate/severe disease remains in a significant proportion of PsA and RA patients.

Pharmacogenetics and pharmacogenomics in psoriasis treatment: current challenges and future prospects

INTRODUCTION

Topical, systemic, oral disease modifying, and biologic agents are part of the armamentarium to manage psoriatic disease. The choice of therapy depends upon disease severity, relevant co-morbidities and patient preference. There is great variability in patient response with these agents, and there is still no clear method of selecting the preferred therapeutic agent for efficacy or lack of adverse events.

AREAS COVERED

This article will review the pharmacogenetic and pharmacogenomic targets that are currently known with respect to psoriasis vulgaris, and the most frequent co-morbidity of psoriasis, psoriatic arthritis.

EXPERT OPINION

Presently, no clinically actionable biomarker exists for any therapeutic agent used to treat psoriasis or psoriatic arthritis. The lack of validated outcome measures and conflicting results of open-label studies conducted may be attributed to a multitude of issues that confound discovery. Consequently, studies have been underpowered to identify genes or genetic variants worth translating to clinical practice. In order to achieve a pharmacogenetic/pharmacogenomic signature, improvements in study design of future investigations are required, including carefully designed prospective studies. It is imperative to combine known clinical, serological, and molecular markers with consistent outcomes and an adequate health economic evaluation before they can be adopted widely in clinical practice.