Time to address the challenge of difficult to treat psoriatic arthritis: Results from an international survey

Psoriatic arthritis (PsA) is a highly heterogeneous disease with involvement of multiple tissues, underpinned by complex pathogenesis. Despite major improvements in the range and availability of efficacious treatment options, including biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs),1 significant clinical unmet needs remain, with overall low rates of achievement of disease remission.2 Furthermore, a divergence of response is often seen between tissues, particularly skin and joints, or poor response in the presence of comorbidities, including mental health and other factors, leading to a growing number of patients having ongoing symptoms and apparent difficult to treat or manage PsA. Similar to rheumatoid arthritis (RA), a proportion of PsA patients exhibit disease which is refractory or resistant to more than one class of b/tsDMARD.3 4 The European Alliance of Associations for Rheumatology has recently proposed a definition for ‘difficult-to-treat (D2T) RA’ now used in clinical practice and research.5 6 In the absence of a similar definition in PsA, which has a more heterogeneous phenotype and b/tsDMARD options beyond those in RA, we launched a survey of rheumatologists globally to gather emerging perceptions on the possible terminology, definition and scope of D2T PsA. The survey, consisting of 19 questions (see online supplemental material), was designed by the authors following expert review and discussion and circulated electronically and via social media between 1 June 2023 and 31 July 2023. Categorical/ordinal survey data variables were analysed using R Studio 2023.06.0+421. In addition, three qualitative, free-text response questions were added to identify the most popular themes/answers to capture the breadth of opinion and consensus on each topic