Rapid and Sustained Effect of Ixekizumab on Patient Global, Spinal Pain, Stiffness, and Fatigue in Chinese Patients with Radiographic Axial Spondyloarthritis.

Introduction: Ixekizumab, an interleukin 17A (IL-17A) inhibitor, has demonstrated rapid and sustained improvement in the signs and symptoms in patients with active radiographic axial spondyloarthritis (r-axSpA) in global and Chinese populations. We studied the effect of ixekizumab on patient-reported outcomes (PROs) (including patient global, spinal pain, stiffness, and fatigue) and overall health-related quality of life (HRQoL) of ixekizumab in the phase 3 study in China.

Methods: In this Chinese phase 3, randomized, double-blind, placebo-controlled study, patients with r-axSpA were randomized (1:1) to receive ixekizumab 80 mg every 4 weeks (IXEQ4W; starting dose 160 mg) or placebo for 16 weeks. At week 16, patients receiving placebo were switched to IXEQ4W, and those receiving IXEQ4W continued, until week 52. Data for patient global, spinal pain, spinal pain at night, stiffness, and fatigue were collected through week 52. Minimally clinical important differences (MCIDs) were determined for spinal pain and spinal pain at night. The subgroup analyses by baseline disease duration since diagnosis and baseline C-reactive protein (CRP) level were conducted post hoc.

Results: Compared with placebo, patients treated with IXEQ4W reported significantly greater improvement with a rapid onset in changes from baseline of PROs (patient global, spinal pain, spinal pain at night, stiffness, and fatigue) through week 16. Improvements were maintained through week 52. A similar trend of improvement was also observed in MCID response in spinal pain and spinal pain at night. The improvement in overall HRQoL was supported by EQ-5D-5L assessment. Subgroup analyses demonstrated that IXEQ4W provided significantly greater efficacy at week 16 compared with placebo, irrespective of baseline disease duration or baseline CRP level.

Conclusion: IXEQ4W provided rapid and sustained improvement in clinically relevant PROs and overall HRQoL through 1-year treatment in Chinese patients with r-axSpA. Regardless of the baseline disease duration or baseline CRP level, consistent efficacy was observed.

Trial Registration: ClinicalTrials.gov identifier NCT04285229.