Improvement from ixekizumab treatment in patients with psoriatic arthritis who have had an inadequate response to one or two TNF inhibitors

Targeting cytokines in psoriatic arthritis

Psoriatic arthritis (PsA) is part of the psoriatic disease spectrum and is characterized by a chronic inflammatory process that affects entheses, tendons and joints. Cytokines produced by immune and non-immune cells play a central role in the pathogenesis of PsA by orchestrating key aspects of the inflammatory response. Pro-inflammatory cytokines such as TNF, IL-23 and IL-17 have been shown to regulate the initiation and progression of PsA, ultimately leading to the destruction of the architecture of the local tissues such as soft tissue, cartilage and bone. The important role of cytokines in PsA has been underscored by the clinical success of antibodies that neutralize their function. In addition to biologic agents targeting individual pro-inflammatory cytokines, signaling inhibitors that block multiple cytokines simultaneously such as JAK inhibitors have been approved for PsA therapy. In this review, we will focus on our current understanding of the role of cytokines in the disease process of PsA and discuss potential new treatment options based on modulation of cytokine function.

Difficult-to-treat psoriatic arthritis (D2T PsA): a scoping literature review informing a GRAPPA research project

BACKGROUND

Psoriatic arthritis (PsA) is a multifaceted condition with a broad spectrum of manifestations and a range of associated comorbidities. A notable segment of patients with PsA remains resistant to even advanced therapeutic interventions. This resistance stems from myriad causes, including inflammatory and non-inflammatory factors.

OBJECTIVES

To collate and critically assess the various definitions and criteria of difficult-to-treat (D2T PsA present in the literature.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines, we conducted a scoping review in July 2023, searching PubMed, American College of Rheumatology Convergence 2022, European Alliance of Associations for Rheumatology Congress 2023, Google Scholar and cited articles. Selection was made by two independent authors using Rayyan software, and conflicts were adjudicated by a third author. Eligibility criteria for PubMed focused on all article designs that were written in English, with full-text available, from the past decade, excluding only those not defining D2T PsA or targeting other populations.

RESULTS

From the 565 references sourced, 15 studies were analysed, revealing considerable variations in defining both 'active disease' and 'resistant PsA', which was most often termed 'D2T' PsA.

CONCLUSION

The definitions and criteria for D2T PsA and for 'active disease' are notably heterogeneous, with considerable variation across sources. The ongoing Group for Research and Assessment of Psoriasis and Psoriatic Arthritis initiative stands to bridge these definitional gaps and aims to provide guidance for clinicians and illuminate a path for pharmaceuticals and regulatory agencies to follow.