Consensus Definitions on Difficult to Treat Psoriatic Arthritis Save

A substantial number of patients with psoriatic arthritis (PsA), have difficult, persistent and hard-to-treat disease. A GRAPPA task force has developed a consensus terminology for two distinct states: 

• Complex-to-manage PsA (C2M-PsA)
• Treatment-refractory PsA (TR-PsA)

C2M-PsA is defined as persistent symptoms despite treatment with at least one biologic or targeted synthetic DMARD (b/tsDMARD) and possibly influenced by factors such as comorbidities, overlapping conditions, psychosocial burden and treatment-related challenges (eg, non-adherence). 

TR-PsA, is a specific subset of C2M-PsA, limited to failure of at least three therapies (each with different mechanisms of action); this should include two or more biologic/targeted synthetic DMARDs), persistent problematic symptoms with objective evidence of ongoing inflammation. 

The goal of this construct is to standardize terminology, support individualized care, and allow for further research that will benefit practice.

It is well know that PsA may be complicated by frequent comorbidities, such as metabolic syndrome, cardiovascular diseases, anxiety, depression and fibromyalgia, all of which contribute to disease activity, patient burden and therapeutic challenges. 

Despite the many advances in therapy in the last two decades, it is unknown which and when to use what.  With the constructs of C2M and TR-PsA we might have a better way of comparing therapies that target tumor necrosis factor (TNF), interleukin-12 (IL-12)–IL-23, IL-17, IL-23, phosphodiesterase-4 (PDE4), cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and Janus kinases (JAKs).

Recent reviews show that < 30% of people with PsA achieve remission and nearly 50% report continued symptoms despite treatment.  It is unknown how many PsA patients can be labeled as C2M or TR-PsA. 

This has been better studied in rheumatoid arthritis, which has benefitted from a consensus EULAR definition of D2T rheumatoid arthritis (D2T-RA); requiring  failure of at least two b/tsDMARDs with active disease.  Using the EULAR D2T-RA criteria on PsA cohorts, the prevalence ois roughly 16–30% in 3 different studies.

The definition of C2M and TR-PsA are practical and serve as a foundation for future observational studies and clinical trials to better manage patients with PsA.