Residual Disease Associated with Suboptimal Treatment Response in Patients with Psoriatic Arthritis: A Systematic Review of Real-World Evidence

Objective This systematic literature review aimed to identify and summarise real-world observational studies reporting the type, prevalence and/or severity of residual symptoms and disease in adults with psoriatic arthritis (PsA) who have received treatment and been assessed against remission or low disease activity targets. Methods Patients had received treatment and been assessed with treat-to-target metrics, including minimal disease activity (MDA), Disease Activity Index in PsA (DAPSA) and others. MEDLINE, Embase (R) and the Cochrane Database of Systematic Reviews (CDSR) were searched using search terms for PsA, treatment targets and observational studies. Screening of search results was completed by two independent reviewers; studies were included if they reported relevant residual disease outcomes in adults with PsA who had received one or more pharmacological treatments for PsA in a real-world setting. Non-observational studies were excluded. Information from included studies was extracted into a prespecified grid by a single reviewer and checked by a second reviewer. Results Database searching yielded 2328 articles, of which 42 publications (27 unique studies) were included in this systematic literature review. Twenty-three studies reported outcomes for MDA-assessed patients, and 14 studies reported outcomes for DAPSA-assessed patients. Physician- and patient-reported residual disease was less frequent and/or severe in patients reaching targets, but often not absent, including when patients achieved very low disease activity (VLDA) or remission. For example, studies reported that 0-8% patients in remission according to DAPSA (or clinical DAPSA) had > 1 tender joint, 25-39% had Psoriasis Area and Severity Index (PASI) score > 1 and 0-10% had patient-reported pain > 15. Residual disease was usually less frequent and/or severe among patients achieving MDA-assessed targets versus DAPSA--assessed targets, especially for skin outcomes. Conclusion The findings demonstrate a need for further optimisation of care for patients with PsA.