Achieving minimal disease activity in psoriatic arthritis predicts meaningful improvements in patients' health-related quality of life and productivity.
Coates LC., Orbai A-M., Morita A., Benichou O., Kerr L., Adams DH., Shuler CL., Birt J., Helliwell PS.
Background: Although psoriatic arthritis is complex and involves multiple domains, recent advances in treatments have made remission or near-remission of most symptoms a potentially achievable goal for many patients. We sought to evaluate whether achieving minimal disease activity (MDA) criteria represented meaningful improvement from the patient perspective. Methods: Data were combined from two randomized, multinational, 24 week clinical studies of ixekizumab, a high-affinity monoclonal antibody selectively targeting interleukin-17A, in biological drug-naïve or experienced adults. MDA required 5 of 7 of: tender joint count ≤1; swollen joint count ≤1; Psoriasis Area and Severity Index total score ≤ 1 or body surface area ≤ 3%; patient's assessment of pain visual analogue scale (VAS) ≤15; patient's global assessment of disease activity VAS ≤20; Health Assessment Questionnaire Disability Index ≤0.5; and tender entheseal points ≤ 1. MDA responders and non-responders were compared for mean change from baseline on the 36-Item Short Form Health Survey (SF-36), European Quality of Life 5 Dimension 5 Level Health Questionnaire (EQ-5D-5 L); EQ-5D-5 L VAS; and Work Productivity and Activity Impairment-Specific Health Problem (WPAI-SHP) questionnaire. Results: MDA responders had significantly greater improvements versus non-responders in each SF-36 domain and in the SF-36 physical summary score; improvements were also greater in the EQ-5D-5 L and EQ-5D-5 L VAS, and in 3 of the 4 WPAI-SHP domains. MDA responders were more likely to achieve minimal clinically important differences than non-responders. Conclusion: These findings support MDA response as being strongly associated with achieving improved disease status based on measures of patient reported health-related quality of life and productivity. Trial registration: SPIRIT-P1, NCT01695239, First Posted: September 27, 2012; and SPIRIT-P2, NCT02349295, First Posted: January 28, 2015.