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

Background 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). 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). Methods This post hoc analysis included patients randomly assigned to IXE 80 mg every 4 weeks from COAST-V ([NCT02696785][1]), 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. Results 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. Conclusion 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. Trial registration number [NCT02696785][1]. Data are available on reasonable request. Lilly provides access to all individual participant data collected during the trial, after anonymisation, with the exception of pharmacokinetic or genetic data. Data are available to request 6 months after the indication studied has been approved in the USA and EU and after primary publication acceptance, whichever is later. No expiration date of data requests is currently set once data are made available. Access is provided after a proposal has been approved by an independent review committee identified for this purpose and after receipt of a signed data sharing agreement. Data and documents, including the study protocol, statistical analysis plan, clinical study report, blank or annotated case report forms, will be provided in a secure data sharing environment. For details on submitting a request, see the instructions provided at www.vivli.org. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT02696785&atom=%2Frmdopen%2F10%2F3%2Fe004429.atom