Early clinical response associates with long-term outcomes with ixekizumab in radiographic axial spondyloarthritis

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<jats:title>Background</jats:title>
<jats:p>The Assessment of SpondyloArthritis international Society-European Alliance of Associations for Rheumatology recommendations for axial spondyloarthritis (axSpA) management include patient assessment for biological disease-modifying antirheumatic drug (bDMARD) treatment response after at least 12 weeks of treatment. The current treat-to-target strategy for axSpA is to achieve inactive disease (ID; Axial Spondyloarthritis Disease Activity Score (ASDAS) <1.3) or at least low disease activity (LDA; 1.3≤ASDAS<2.1).</jats:p>
<jats:p>To investigate the association between treatment response at week 12 and/or week 24 and attainment of the ASDAS<2.1 treat-to-target recommendation at week 52 in bDMARD-naïve patients with radiographic (r-)axSpA treated with ixekizumab (IXE).</jats:p>
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<jats:title>Methods</jats:title>
<jats:p>This post hoc analysis included patients randomly assigned to IXE 80 mg every 4 weeks from COAST-V (<jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="clintrialgov" xlink:href="NCT02696785">NCT02696785</jats:ext-link>), a phase 3 trial in bDMARD-naïve patients with r-axSpA. The proportion of patients who achieved ASDAS<2.1 at week 52 was measured among those who attained or not clinically important improvement (CII, ∆ASDAS≥1.1) response, and among those with ID, LDA and high or very high disease activity at week 12 and/or week 24. Non-response was assumed for missing data.</jats:p>
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<jats:title>Results</jats:title>
<jats:p>Amongst 81 patients, 47 (58.0%) achieved ASDAS CII at week 12, with 70.2% (n=33) achieving ASDAS<2.1 at week 52. At week 24, 52 (64.2%) patients achieved ASDAS CII, with 71.2% (n=37) achieving ASDAS<2.1 at week 52. Of the 24 patients who did not achieve ASDAS CII at either week 12 or week 24, 5 (20.8%) achieved ASDAS<2.1 at week 52.</jats:p>
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<jats:title>Conclusion</jats:title>
<jats:p>This analysis reinforces the current recommendation that continuing treatment in those achieving ASDAS CII at week 12 and/or week 24 increases the likelihood of obtaining ID/LDA at week 52.</jats:p>
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<jats:title>Trial registration number</jats:title>
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<jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="clintrialgov" xlink:href="NCT02696785">NCT02696785</jats:ext-link>.</jats:p>
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