Treat-to-target in real-life psoriatic arthritis patients: achieving minimal disease activity with bDMARDs/tsDMARDs and potential barriers

Objective: (1) to describe the frequency of minimal disease activity (MDA) in a real-life psoriatic arthritis (PsA) cohort, (2) to longitudinally explore predictors of MDA; (3) to examine frequency and predictors of low disease activity (LDA) in patients with axial involvement (axPsA). Methods: consecutive PsA patients in stable biological/targeted-synthetic Disease-Modifying Anti-Rheumatic Drugs (bDMARDs/tDMARDs) who attended our center were enrolled. Disease activity indices, including MDA and ankylosing spondylitis disease activity score-LDA (ASDAS-LDA) for axPsA, were evaluated at baseline and every 6 months, up to 36 months or bDMARDs/tsDMARDs discontinuation. Patients’ history, BMI, comorbidities — including osteoarthritis (OA) and fibromyalgia — were collected. Variables were compared between patients who achieved sustained MDA and those who did not. Multivariable generalized estimating equation (GEE) models were built to identify predictors of MDA and ASDAS-LDA over time. Data were expressed as beta coefficient (95%CI). Results: 104 patients were enrolled, 54% males, mean age 55.7 years; 52% had axPsA. Across all evaluations, 52–61% reached MDA, and 17–24% achieved ASDAS-LDA. AxPsA, fibromyalgia, OA and BMI≥35 were less frequently observed in patients with sustained MDA. The GEE model confirmed the following factors were significantly and independently associated with MDA: age (Beta=–0.05), bDMARDs/tsDMARDs duration (Beta=+0.31), axPsA (Beta=–1.07), fibromyalgia (Beta=–3.35), OA (Beta=–1.87), BMI≥35 (Beta=–2.53). Age (Beta=–0.01), fibromyalgia (Beta=–2.03) and OA (Beta=–1.30) were also independently associated with ASDAS-LDA. Conclusions: MDA is an attainable target in real-life. AxPsA represents a difficult-to-treat subset. Sustained MDA depends on disease features (axPsA) as well as patients’ characteristics (e.g. age, bDMARDs/tDMARDs duration, comorbidities).