Ixekizumab Provides Improvements Through 52 Weeks in Physical Function, Quality of Life, and Work Productivity in Biologic Disease-Modifying Antirheumatic Drug-Naive Patients With Active Psoriatic Arthritis

Objectives: To evaluate whether the monoclonal antibody ixekizumab (IXE), a high-affinity interleukin-17A antagonist, improves patient-reported outcomes (PROs) over 52 weeks in biologic disease-modifying antirheumatic drug (bDMARD)-naive patients with active psoriatic arthritis (PsA) in a phase 3 study (SPIRIT-P1). Previously reported results of this study showed that IXE significantly improved (versus placebo), at Week 24, PRO measures of the Health Assessment Questionnaire-Disability Index (HAQ-DI), Short Form-36 Health Survey Physical Component Summary (SF-36 PCS), European Quality of Life 5 Dimensions Visual Analog Scale (EQ-5D VAS), and Work Productivity and Activity Impairment-Specific Health Problem (WPAI-SHP; presenteeism, work productivity, and activity impairment). Methods: 417 bDMARD-naive patients with active PsA were randomly assigned 1:1:1:1 to subcutaneous IXE 80 mg every 4 weeks (Q4W) or 2 weeks (Q2W), each with a 160 mg starting dose; adalimumab 40 mg Q2W (active reference); or placebo in the double-blind treatment period (Weeks 0 to 24). Of these patients, 381 continued into the extension period (EP; Weeks 24 to 52). Placebo- and adalimumab-treated patients were randomly reassigned (1:1) to 80 mg IXEQ4W or IXEQ2W at Week 16 (inadequate responders) or Week 24. Analyses for the EP were conducted on the EP population (patients who received at least 1 dose of study drug during the EP). Missing values were imputed by nonresponder imputation for categorical data and modified baseline observation carried forward for continuous data. Results: Baseline demographics and clinical characteristics were generally similar between treatment groups; population mean baseline (Week 0) scores for HAQ-DI, SF-36 PCS, and EQ-5D VAS indicated impaired physical function and quality of life. Physician-assessed American College of Rheumatology (ACR) 20 response was achieved by 69% of patients treated with IXE for 52 weeks. Patients receiving IXEQ4W or IXEQ2W for 52 weeks reported similar improvements from baseline in HAQ-DI (IXEQ4W: -0.53, IXEQ2W: -0.55), SF-36 PCS (9.5, 9.2) EQ-5D VAS (14.7, 14.4), and WPAI-SHP (presenteeism [-23.6, -25.4], work productivity [-25.3, -24.9], and activity impairment [-26.2, -29.1]) as reported at Week 24. The percentage of patients receiving IXE for 52 weeks with improvement from baseline HAQ-DI score ≥ 0.35 who achieved a minimally clinically important difference for HAQ-DI was sustained at Week 52 (57.1%) compared with Week 24. At Week 52, patients receiving adalimumab/IXE showed similar improvements in ACR20 response and most PRO measures to those observed at Week 24. Conclusion: IXE provided sustained improvement over 52 weeks in physical function, quality of life, and work productivity in bDMARD-naive patients with active PsA