IL-23 in axial spondyloarthritis and psoriatic arthritis: a good fit for biological treatment?

ABSTRACT

Introduction

Interleukin 23 (IL-23) is a pro-inflammatory cytokine that plays a protective role against bacterial and fungal infections. However, the dysregulation of the IL-23/IL-17 axis provides a solid substrate for the development of various inflammatory diseases, such as psoriatic arthritis (PsA) and ankylosing spondylitis (AS).

Areas covered

In different clinical trials, several drugs against IL-23 have shown efficacy and safety toward PsA, with excellent results on skin and joint scores. However, the same drugs did not show the same efficacy in AS, suggesting that IL-23 may not be a relevant driver of the pathobiology and clinical symptoms of active axial spondyloarthritis (axSpA).

Expert opinion

These drugs have shown an excellent efficacy and a good safety profile toward PsA, while in AS the efficacy of the IL-23 blockade is lacking for reasons not yet known. Several hypotheses have been reported, but further studies will be needed for a greater understanding. This suggests the involvement of pathways or mechanisms for the development of SpA that remain unknown. In order to allow a wide use of IL-23 inhibitors, further clinical trials and long-term prospective studies are necessary.

KEYWORDS:

• interleukin 23
• psoriatic arthritis
• axial spondyloarthritis
• anti-IL-23 drugs

Article highlights

• IL-23 plays a role in the pathogenesis of spondyloarthritis (SpA). However, the missing results of the anti-IL-23 in axial SpA suggest a different role of this cytokine in ankylosing spondylitis and psoriatic arthritis (PsA).

• Clinical trials on PsA have shown efficacy and safety of anti-IL-23 drugs against different disease characteristics.

• Clinical trials on axial SpA have shown a missing efficacy of anti-IL-23 drugs against spine involvement.

• Several hypotheses have been suggested in order to explain the missing results of the anti-IL-23 drugs on axial SpA.

Disclosure statement

F Atzeni declares consulting fees and speaker honoraria from AbbVie, Amgen, Bristol-Myers Squibb, Janssen, Lilly, Novartis and Pfizer. S D’Angelo declares consulting fees and speaker honoraria from AbbVie, Amgen, Bristol-Myers Squibb, Janssen, Lilly, Merck Sharp & Dohme, Novartis, Pfizer, and Union Chimique Belge. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Author contributions

F Atenzi, S D’Angelo, C Siragusano, IF Masala, V Picerno and A Carriero participated in the literature search and the summary of all articles. All of the authors drafted the manuscript, which was critically reviewed by F Atenzi, S D’Angelo and A Carriero. All of the authors read and approved the final manuscript.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.