New evidence-based points to consider and consensus definitions for people with psoriatic arthritis

Some people with psoriatic arthritis (PsA) may have disease that is difficult to manage (D2M) or does not respond to treatment. EULAR - The European Alliance of Associations for Rheumatology - has released new evidence-based points to consider and consensus definitions for these groups.

PsA is a progressive inflammatory disease, with both a skin and joint component. Many people with PsA also have cardiometabolic comorbidities, and PsA is also linked to other conditions such as gout, osteoarthritis, and fibromyalgia, which can complicate management. Today, there are many good treatment options for PsA - and EULAR management recommendations about which to use when.¹ Yet despite this, many people with PsA do not get a satisfactory response to disease-modifying antirheumatic drugs (DMARD).

In other diseases, definitions of D2M and treatment-refractory populations have been published, but there is a gap in PsA. EULAR set out to address this by developing new points-to-consider and consensus definitions. These have been developed by a multidisciplinary task force from 15 countries. The group included health professionals across rheumatology and dermatology, as well as patient research partners. The work was completed in line with EULAR standardised operating procedures.

The manuscript - developed by EULAR and published in the October 2025 issue of the Annals of the Rheumatic Diseases - includes four overarching principles and six points to consider. The principles emphasise that a proportion of people with PsA have an unsatisfactory treatment response despite receiving the current standard of care; this has a significant impact, including on well-being and societal functioning. Unsatisfactory treatment response may be multifactorial and establishing the reasons for ongoing signs and symptoms is essential to guide and optimise further management.

The points to consider outline the main factors underpinning the definitions for D2M and treatment-refractory PsA formulated by the task force. These include failure to achieve or maintain low disease activity, presence of extra-musculoskeletal manifestations or other comorbidities, plus evidence of inflammatory activity.

Importantly, the work also includes two new consensus definitions. D2M PsA is a wide concept that includes persistent signs and symptoms of disease that are driven by inflammation, comorbidities, and psychosocial or other factors. As such, D2M is an umbrella term. Within this, treatment-refractory disease is defined by persistent disease activity and objective evidence of active inflammation. People with both D2M and treatment-refractory disease will have failed to achieve or maintain a response to at least two biologic or targeted synthetic DMARDs with at least two different mechanisms of action - and will have signs and/or symptoms that are perceived as problematic by the patient and/or the rheumatologist, alongside evidence of persistent disease. Of note, the paper stresses that the term "difficult" is applied to the disease and not to the individual.

These definitions aim to provide a framework for research in this area. Whereas D2M is an umbrella concept encompassing many factors contributing to ongoing symptoms, which may benefit from non-pharmacological interventions, the key to understand treatment non-response is to identify the biology behind it - essentially whether is there inflammation present or not. Dissecting these phenotypes will allow for research to be focused on improved, personalised treatment options as well as prevention".

Helena Marzo-Ortega - lead author on the paper and Honorary Professor of Clinical Translational Rheumatology, University of Leeds, UK

This new work should help both healthcare professionals and patients to explore the factors behind non-response in people with persistent symptoms and objective signs of inflammation despite trying a number of different treatments. EULAR hopes the new definitions will provide a framework to facilitate research in this area, helping to further characterise these populations and test new treatments - ultimately improving care for people living with PsA.