Achieving minimal disease activity in psoriatic arthritis predicts meaningful improvements in patients' health-related quality of life and productivity

Abstract

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.

Keywords: Ixekizumab; Minimal disease activity; Psoriatic arthritis.

Conflict of interest statement

The study was performed in accordance with the principles of the Declaration of Helsinki. All investigation sites received approval from ethics committees or institutional review boards. For the SPIRIT-P1 study, the institutional review board for the primary investigator was the Western Institutional Review Board (#1–838,258-1), and for the SPIRIT-P2 study, the institutional review board for the primary investigator was the Bellberry Human Research Ethics Committee (#2015–01-049-AA). Patients provided written informed consent before any study-related procedures were undertaken.Not applicable.LCC has served on advisory boards for, and received research funding and speakers’ fees from Abbvie, Pfizer, MSD, UCB, and Celgene. PSH has served on advisory boards for and received speakers’ fees from Amgen, Abbvie, BMS, Janssen, Pfizer, MSD, UCB, and Celgene, and has received research funding from Abbvie and Pfizer. AO has served as a consultant for Eli Lilly, Janssen, Novartis, Pfizer and UCB, and has received research funding from Celgene, Eli Lilly, Horizon, Janssen, and Novartis (to Johns Hopkins University). OB, LK, DHA, CLS, and JB were employees and minor shareholders of Eli Lilly and Company or its subsidiaries.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1

SF-36 domain scores at baseline and Week 24 and change from baseline and difference by MDA responder status. Data for the SF-36 domain scores showing (a) Values at Baseline (red) and Week 24 (blue) by MDA responder status and (b) Change from baseline to Week 24 by MDA responder status. Data labels in panel b show the difference and p-value for difference between MDA responder and non-responder groups. Note that baseline values for all SF-36 domain scores were significantly lower for MDA non-responders versus MDA responders (data shown in Additional file 1: Table S1). MDA = minimal disease activity; SF-36 = 36-Item Short Form Health Survey