Spinal Radiographic Progression and Predictors of Progression in Patients With Radiographic Axial Spondyloarthritis Receiving Ixekizumab Over 2 Years.

OBJECTIVE To evaluate the long-term effect of ixekizumab on radiographic changes in the spine in patients with radiographic axial spondyloarthritis (r-axSpA) by measuring change from baseline through 2 years in modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) and to identify potential predictors of progression. METHODS This study evaluates patients from COAST-V (NCT02696785, bDMARD-naive) and COAST-W (NCT02696798, TNFi-experienced) who had mSASSS data at baseline in the originating studies and 108 weeks after baseline in the extension study COAST-Y (NCT03129100). We examined the proportion of patients who did not have spinal radiographic progression through 2 years (108 weeks) of treatment with ixekizumab (80 mg every 2 or 4 weeks) and the change from baseline to year 2 in mSASSS. Potential predictors of spinal radiographic progression were also evaluated. RESULTS Among patients with evaluable radiographs who were originally assigned to ixekizumab (N=230), mean (SD) change in mSASSS from baseline at year 2 was 0.3 (1.8). The proportion of non-progressors over 2 years was 89.6% if defined as mSASSS change from baseline 0) were age ≥40, baseline syndesmophytes, HLA-B27 positivity and male gender. Week 52 inflammation in SPARCC spine was also a predictor of radiographic progression at year 2 in patients with MRI-data in COAST-V (N=109). CONCLUSION The majority of patients with r-axSpA receiving ixekizumab had no radiographic progression in the spine through 2 years of treatment. Predictors were generally consistent with previous studies.