Difficult to Treat and Refractory to Treatment in Psoriatic Arthritis

The concept of difficult-to-treat disease in rheumatology: where next?

New pathogenesis-based therapeutics and evidence-based consensus treatment recommendations, often with predefined treatment goals, have remarkably improved outcomes across many chronic diseases. However, a clinically significant subgroup of patients responds poorly to interventions and show a progressive decline in the disease trajectory, which poses an increasing health-care challenge. Difficult-to-treat approaches exist in several areas of medicine and the need for similar definitions has recently also emerged in rheumatology. The term difficult-to-treat refers not only to patients with pathology-driven, treatment-refractory disease, but also implicates multiple other factors that can contribute to patients being in this state, including having few treatment options, misdiagnosis, and coincident psychosocial factors. Therefore, the difficult-to-treat state requires a comprehensive, holistic, multidisciplinary approach that considers the specific characteristics of each disease and the personalised needs of the patient. In this Personal View, we provide an overview of the different aspects of the concept of difficult-to-treat disease, highlight its advantages, and propose the importance of incorporating this concept more widely in the design of rheumatological treatment strategies.

Delineating inflammatory from non-inflammatory mechanisms for therapy optimization in psoriatic arthritis

Psoriatic arthritis (PsA) is anatomically much more heterogeneous than rheumatoid arthritis, as, beyond synovitis, it often also involves enthesitis, peritendinitis, tenosynovitis, osteitis and periostitis. This heterogeneity currently precludes a gold standard for objectively defining resolution of inflammation following treatment, with enthesitis posing a particular challenge. Despite these difficulties, we apply lessons learned from rheumatoid arthritis to describe how patients with PsA and an inadequate response to therapy can be designated within two patient subgroups, characterized by persistent inflammatory PsA (PIPsA) and non-inflammatory PsA (NIPsA), respectively. The NIPsA phenotype is defined by the lack of ongoing joint inflammation, as confirmed through clinical assessment and imaging, along with normalized inflammatory marker levels. NIPsA might be associated with obesity, biomechanical-related pain, osteoarthritis, fibromyalgia, secondary post-inflammatory damage and central pain mechanisms. In this article, we frame PsA composite outcomes measures in relationship to the PIPsA and NIPsA phenotypes and propose that this approach might help to minimize unnecessary or ineffective cycling of PsA therapy in patients who acquire dominant non-inflammatory mechanisms and might also inform future trial design.

Psychological Health in the Management of Patients with Psoriatic Arthritis: An Intricate Relationship

Psoriatic arthritis (PsA) is a chronic inflammatory disease that profoundly impacts both physical and psychosocial well-being. The disease can lead to a range of emotional difficulties, including anxiety, depression, and diminished self-esteem. The visible skin manifestations of psoriasis, coupled with the persistent pain and functional limitations of arthritis, can significantly affect body image and self-worth. Furthermore, the physical limitations and fatigue associated with PsA can affect social interaction, leading to isolation and exacerbating emotional distress. PsA can also disrupt work productivity as a result of pain, fatigue, and impaired physical function. Recognizing and addressing the psychosocial impact of PsA is paramount for comprehensive patient care. A multidisciplinary approach involving rheumatologists, psychologists, and other healthcare professionals is essential. Cognitive behavioral therapy, mindfulness-based stress reduction, and other psychological interventions can help patients with coping strategies for stress, anxiety, and depression. Support groups and peer-to-peer networks can provide invaluable emotional and practical assistance. Comprehensive disease management programs that address both physical and psychosocial needs could also be crucial for improving patient outcomes and overall quality of life. By acknowledging and addressing these concerns in conjunction with the physical symptoms, rheumatologist can facilitate improved patient outcomes and a better quality of life. This narrative review explores the intricate relationship between psychological health and PsA, highlighting the impact of psychological factors on disease outcomes and the potential benefits of integrating psychological interventions into routine clinical practice.

Burden and determinants of multi-b/tsDMARD failure in psoriatic arthritis

OBJECTIVES

Despite significant therapeutic advances in psoriatic arthritis (PsA), many patients do not achieve remission and cycle through multiple biologic (b)- or targeted synthetic (ts)- DMARDs. Identifying the underlying reasons for repetitive therapeutic failure remains a knowledge gap. Here we describe prescribing patterns and characteristics of PsA patients with multi-b/tsDMARD failure at the NYU Psoriatic Arthritis Center.

METHODS

Nine hundred sixty PsA patients were enrolled in an observational, longitudinal registry. Demographics, medical history, medication use, and psoriatic disease phenotype were collected. Multi-b/tsDMARD failure was defined as requiring ≥ 4 b/tsDMARDs.

RESULTS

Seven hundred twenty-five patients (75%) used ≥ 1 b/tsDMARD during their disease course. The initial b/tsDMARDs prescribed were predominately anti-TNF agents. 166 (17%) patients had multi-b/tsDMARD failure. Compared to those requiring 1 b/tsDMARD, female sex (OR 2.3; 95%CI 1.4-3.8), axial disease (OR 2.1; 95% CI 1.2-3.6), depression (OR 2.0; 95%CI 1.1-3.7), and obesity (OR 1.7; 95%CI 1.0-2.8) were risk factors for multi-b/tsDMARD failure disease after adjustment for age, disease duration, sex, depression, smoking, obesity, and skin severity. Patients with multi-b/tsDMARD failure PsA also had increased disease activity at their clinical visit (i.e., swollen joint count, p = 0.005).

CONCLUSION

In this cohort, 17% patients with PsA experienced multi-b/tsDMARD failure. These patients were more likely to be female, obese, and have higher rates of axial involvement and depression, along with higher active disease activity. This highlights the inflammatory and non-inflammatory drivers of multiple therapeutic failures, underscoring the need for precision medicine strategies and potential non-pharmacologic adjuvant therapies for patients with PsA to improve outcomes and quality of life.

Refractory psoriatic arthritis: emerging concepts in whole process management

Psoriatic arthritis (PsA) is a chronic and progressive inflammatory arthritis associated with psoriasis, mainly affecting the axial and peripheral joints, characterized by a wide range of complex phenotypes, significant heterogeneity, and a multifactorial etiology. To effectively address the distinct challenges in managing PsA, a pivotal emphasis is placed on clarifying the concept of refractory PsA. Here, we propose a distinction between refractory PsA, differentiating between difficult-to-treat PsA (D2T PsA) and Pseudo-D2T PsA. The former centers on the lack of efficacy of multiple disease-modifying anti-rheumatic drugs (DMARDs) and signs suggestive of active/progressive disease, while also considering the challenges posed by comorbidities. The latter focuses on misdiagnosis and mismanagement, detailing the difficulties caused by artificial factors, whether by clinicians or patients. Hoping the clarification of these distinctions will enable clinicians to manage patients with refractory PsA more effectively.

Difficult-to-treat psoriatic arthritis: refining the definition using a statistical model in a real-life cohort

Objectives

The study aims to evaluate the applicability of the D2T psoriatic arthritis (PsA) definition, adapted from rheumatoid arthritis, within a single-center observational cohort of PsA patients treated with b/tsDMARDs. In addition, we aimed to establish a numerical index defining D2T-PsA based on the ratio of observed to expected failed b/tsDMARDs and to develop a predictive model identifying features associated with the D2T condition.

Methods

The study included 267 consecutive adult PsA patients receiving b/tsDMARDs, collecting demographic, clinical, and clinimetric data. The prevalence of D2T PsA patients was assessed using a proposed definition. We then developed a predictive model to assess treatment difficulty, utilizing PsA-normalized failed b/tsDMARDs. A generalized linear model was applied to identify clinical and demographic features associated with D2T PsA, employing a bagging procedure for robust variable selection, followed by univariate and multivariable analyses.

Results

Among the 267 patients, only 8 of them (2.9%) met the proposed D2T PsA criteria. In a subset of 177 patients analyzed using the predictive model, 17.2% of them demonstrated higher treatment difficulty. Univariate analysis revealed associations between treatment difficulty and female sex, psoriasis pattern, fibromyalgia, and steroid therapy. Multivariate analysis confirmed significant associations between fibromyalgia, nail and pustular psoriasis, and steroid use.

Conclusion

According to the predictive model, the proposed D2T PsA definition identified a small subset of patients with increased treatment difficulty. These findings highlight the need for refining the criteria to better define D2T PsA patients, providing valuable insights into managing complex treatment challenges in PsA.

Difficult to Treat Psoriatic Arthritis: The Road So Far

Psoriatic Arthritis (PsA) is a multifaceted, immune-mediated disease marked by chronic musculoskeletal inflammation (peripheral arthritis and axial disease, dactylitis, and enthesitis), extra-musculoskeletal manifestations (psoriasis, nail involvement, Inflammatory Bowel Disease [IBD], and uveitis) and multi-comorbidity (cardiovascular disease, metabolic syndrome, mental health disorders, and fibromyalgia). Immunological and non-immunological factors have led, despite the progress made in the understanding, treatment and management of PsA, to a minority of patients being able to achieve satisfactory outcomes. Following the establishment of the definition for difficult to treat rheumatoid arthritis, efforts are underway for difficult to treat PsA (D2T PsA). Defining D2T PsA and its predictors is crucial for advancing clinical trials, treatment strategies, and patient care. Proposed definitions and criteria for D2T PsA vary, but the few available data indicate that extensive psoriasis, axial involvement, obesity, female gender, and comorbidities like IBD, depression, and fibromyalgia are involved. Concerns are also raised for the lack of a universally accepted index for disease activity measurement and for the inclusion of a time-related criterion in the definition of D2T. Moreover, the potential need for distinction between D2T and refractory-to-treatment PsA has also been suggested. In this narrative review, we summarise the current knowledge on the D2T PsA field, highlighting the gaps and the necessity of the "D2T" concept, providing further considerations on the matter.

Minimally invasive interventional procedures for osteoarthritis and inflammatory arthritis: A systematic review and meta-analysis

OBJECTIVE

to summarize the evidence on the efficacy of minimally invasive interventional procedures such as radiofrequency ablation (RFA) and transcatheter arterial embolization (TAE) in patients with osteoarthritis or inflammatory arthritis.

METHODS

a literature search was conducted in PubMed and Web of Science databases. Both randomized controlled trials (RCTs) and non-randomized studies of interventions (NRSI) were included. The results were organized according to the treated anatomical site: knee, hip, foot and ankle, shoulder, hand and wrist, sacroiliac joints. Data about treatment efficacy were extracted. The main outcome was change in pain intensity using the 0-10 visual analog scale (VAS) from baseline to 1 month. Additional timepoints at 3, 6 and 12 months were assessed. Change in functional status was evaluated. Pooled estimates were calculated as the mean difference (MD) and 95 % confidence interval relative to baseline. The meta-analyses of RCTs and NRSI were conducted separately.

RESULTS

of the 4599 retrieved articles, 164 were included in the review and, considering all the established timepoints, 111 (38 RCTs and 73 NRSI) were selected for the meta-analysis. Only one article described patients with inflammatory arthritis. In the meta-analysis of RCTs, one month after the procedure, MD in VAS was -3.98 (-4.41 to -3.55; k = 21) for knee RFA, and -3.18 (-3.96 to -2.39; k = 8) for sacroiliac joints RFA. In the meta-analysis of NRSI, MD in VAS was -4.12 (-4.63 to -3.61; k = 23) for knee RFA, -3.84 (-4.77 to -2.92; k = 7) for knee TAE, -4.34 (-4.96 to -3.71; k = 2) for hip RFA, -3.83 (-4.52 to -3.15; k = 3) for shoulder RFA and -4.93 (-5.58 to -4.28; k = 14) for sacroiliac joints RFA. Significant decrease in pain intensity was found also at 3, 6 and 12 months. Additionally, functional status improved at all the assessed timepoints.

CONCLUSION

minimally invasive interventional procedures can improve pain and functional status of patients affected by OA or chronic sacroiliac pain of degenerative origin. Further research is warranted in the field of inflammatory rheumatic diseases.

Identification and characteristics of patients with potential difficult-to-treat psoriatic arthritis: exploratory analyses of the Greek PsA registry

OBJECTIVE

To present the characteristics of patients with potential difficult-to-treat (D2T) PsA.

METHODS

We used data from the Greek multicentre registry of PsA patients. D2T PsA was defined as follows: patients with at least 6 months' disease duration, who have failed to at least one conventional synthetic DMARD and at least two biologic DMARDs/targeted synthetic DMARDs with a different mechanism of action and have either at least moderate disease activity (MODA) defined as DAPSA (Disease Activity index in PSoriatic Arthritis) >14, and/or are not at minimal disease activity (MDA). Demographic and clinical characteristics were compared between D2T and non-D2T PsA patients. In two sensitivity analyses, patients classified as D2T solely according to the MODA or MDA criterion were examined separately.

RESULTS

Among 467 patients included, 77 (16.5%) were considered D2T and 390 non-D2T PsA. Compared with non-D2T, patients with D2T PsA presented more commonly with extensive psoriasis (P < 0.0001) and were more likely to have higher BMI (P = 0.023) and a history of IBD (P = 0.026). In the MODA and MDA sensitivity analyses, 7.5% and 12.5% of patients were considered D2T, respectively. In both sensitivity analyses, extensive psoriasis was again identified as an independent variable for D2T PsA (P = 0.001 and P = 0.008, respectively). Moreover, female gender (P = 0.034) in the MODA analysis and axial disease (P = 0.040) in the MDA analysis were independent variables for D2T PsA.

CONCLUSION

Despite the availability of therapies, D2T PsA is common in real-life cohorts of patients with PsA and extensive psoriasis. High BMI, female gender, axial disease and history of IBD were also associated with D2T PsA.

Deciphering difficult-to-treat psoriatic arthritis (D2T-PsA): a GRAPPA perspective from an international survey of healthcare professionals

Objectives

This study contributes to the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA)'s effort to define 'difficult-to-treat' PsA (D2T-PsA), leveraging insights of healthcare professionals who are GRAPPA members. The primary objective is to inform GRAPPA's D2T PsA project, ensuring the consensus definition reflects clinical experience and expertise.

Methods

An online survey was conducted among GRAPPA's healthcare professionals managing PsA patients. The survey covered demographic details, structured questions, and open-ended queries to gather comprehensive insights into the experts' viewpoints.

Results

About 223 physicians completed the survey, comprising 179 (80.2%) rheumatologists and 40 (17.9%) dermatologists. The majority, 184 (82.5%), favoured establishing distinct definitions for D2T-PsA and complex-to-manage PsA (C2M-PsA). Furthermore, 202 (90.5%) supported a definition that includes objective inflammation signs (clinical, laboratory, imaging, among others). However, opinions varied on the criteria for prior treatment failures, with most (93, 41.7%) favouring a definition that includes at least one conventional synthetic disease-modifying anti-rheumatic drug and two or more biological- or targeted-synthetic-DMARDs with different mechanisms of action.

Conclusion

The survey reveals a majority opinion among GRAPPA experts favouring the differentiation between D2T-PsA and C2M-PsA, and the inclusion of objective inflammatory markers in these definitions. However, there is less than 50% agreement on the specific treatment failure criteria, particularly regarding the number of therapies needed to classify PsA as D2T. These findings suggest a need for continued discussion to reach a more unified approach in defining D2T-PsA, reflecting the complexity of the condition.

Clinical Characteristics of "Severe" Peripheral Psoriatic Arthritis: A Retrospective Analysis of a Longitudinal Cohort

INTRODUCTION

The concept of severity in a multidomain disease such as psoriatic arthritis (PsA) is still not well defined. The aim of this study was to identify the clinical characteristics of patients with severe peripheral PsA.

METHODS

Retrospective analysis of a longitudinal cohort. Demographic and clinical characteristics of patients with PsA were collected at baseline and at last follow-up. We defined the severe population using the modified Composite Psoriatic Disease Activity Index (mCPDAI); which excludes ankylosing spondylitis quality of life scale). Hence, patients with a score of 3 in at least one domain were defined as having severe PsA. Clinical characteristics of patients fulfilling the definition of severe PsA were compared to those non-severe.

RESULTS

We evaluated 177 patients with peripheral PsA (M/F: 98/76). Of these, 64 (36.1%) were identified as severe according to the mCPDAI criteria, at baseline. Eighteen patients (10.1%) at last follow-up still met the definition of severe PsA. At last follow-up visit, severe patients with PsA were only males (18/18, P < 0.01) and have worse outcomes in terms of disease activity, pain, function, and impact of disease. Male sex and the severity of skin involvement at baseline were factors associated with the presence of severe PsA. The agreement between the presence of severe PsA and the absence of minimal disease activity was slight [Cohen's k: 0.174 (0.084-0.264)].

CONCLUSIONS

Our study showed that severe patients with PsA had more disease activity, pain, and impact of disease than non-severe patients. Furthermore, we demonstrated that severity and disease activity are not interchangeable concepts.

Unmet needs in psoriatic arthritis, a narrative review

Psoriatic arthritis is a chronic rheumatic disease that poses challenges in its diagnosis, evaluation, and management. The heterogeneity in the manifestations and the absence of definitive diagnosis biomarkers often complicates the process of accurate diagnosis. Furthermore, the involvement of multiple disease domains poses difficulties in assessing disease activity and defining the concept of remission. Despite therapeutic advancements, a subset of patients remains refractory to treatment, leading to the emergence of the concept of "difficult-to-treat" patients and the necessity for novel therapeutic approaches (e.g., drugs with novel mechanisms of action; combinations of treatments). This review addresses key unmet needs in psoriatic arthritis, in terms of diagnosis, classification, evaluation, comorbidities and treatment.

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.