Ixekizumab in radiographic axial spondyloarthritis with and without elevated C-reactive protein or positive magnetic resonance imaging

Objective. To evaluate response rates at week 16 with ixekizumab in patients with radiographic axial SpA (r-axSpA) and elevated or normal/low baseline inflammation measured by serum CRP or spinal MRI using data from two randomized, double-blind, placebo (PBO)-controlled phase III trials. Methods. Biologic-naive (COAST-V) or TNF inhibitor-experienced (COAST-W) adults with active r-axSpA received 80 mg ixekizumab every 2 weeks (IXEQ2W) or 4 weeks (IXEQ4W) or PBO or active reference [40 mg adalimumab every 2 weeks (ADAQ2W) in COAST-V. At week 16, patients receiving ixekizumab continued as assigned and patients receiving PBO or ADA were rerandomized 1:1 to IXEQ2W or IXEQ4W through week 52. Assessment of SpondyloArthritis international Society 40% (ASAS40) response rates were examined by baseline CRP (<= 5 or >5 mg/ I) and Spondyloarthritis Research Consortium of Canada (SPARCC) MRI spine inflammation score (<2 or >= 2). Results. In the COAST-V/W integrated dataset (N=567), significantly more patients treated with ixekizumab achieved ASAS40 response at week 16 by CRP <= 5 mg/I (27% IXEQ4W, P< 0.05; 35% IXEQ2W, P< 0.01 vs 12% PBO), CRP >5 mg/I (39% IXEQ4W, P<0.001; 43% IXEQ2W, P< 0.001 vs 17% PBO), SPARCC MRI spine score <2 (40% IXEQ4W P<0.01, 52% IXEQ2W P<0.001 vs 16% PBO), and SPARCC MRI spine score >2 (44% IXEQ4W P< 0.001, 47% IXEQ2W P< 0.001 vs 19% PBO). ASAS40 response was observed with CRP <= 5 mg/I and SPARCC MRI spine score <2 with IXEQ4W (29%) and was significant with IXEQ2W (48%; P< 0.05) vs PBO (13%). Conclusion. Ixekizumab demonstrated efficacy in the treatment of AS/r-axSpA in patients with and without elevated CRP or evidence of spinal inflammation on MRI.

Automated summary

This study evaluated the efficacy of ixekizumab in the treatment of patients with radiographic axial SpA, regardless of elevated CRP levels or evidence of spinal inflammation on MRI. Ixekizumab demonstrated significant efficacy in improving symptoms in these patients.