213. Effect of Certolizumab Pegol on Inflammation of Spine and Sacroiliac Joints in Patients with Axial Spondyloarthritis: 12-Week Magnetic Resonance Imaging Results of Rapid-Axspa Study

Abstract

Background: Axial spondyloarthritis (axSpA) includes both AS and axSpA with no definitive sacroiliitis on X‐ray (non‐radiographic axSpA, nr‐axSpA). One of the features of axSpA is bone marrow edema of sacroiliac joints (SIJ) and spine. RAPID‐axSpA (NCT01087762) investigated certolizumab pegol (CZP), a PEGylated Fc‐free anti‐TNF, efficacy and safety in patients with axSpA, including AS and nr‐axSpA. The objective was to report the impact of CZP on inflammation of spine and SIJ in axSpA patients using MRI. Methods: The ongoing 158‐week Phase 3 RAPID‐axSpA trial was double‐blind, placebo controlled to Wk24. Recruited patients had adultonset active axSpA according to the ASAS criteria, and included AS patients also meeting the modified New York criteria and nr‐axSpA patients. Patients must have failed >1 NSAID. Patients were randomized 1:1:1 to placebo (PBO) every 2 weeks (Q2W), or 400mg CZP at Wk0, 2 and 4 (loading dose) followed by either 200mg CZP Q2Wor 400mg CZP every 4 weeks (Q4W). MRI scans of the SIJ and spine were evaluated using an analysis of covariance model. MRI endpoints were least square difference to PBO in change from baseline in the Spondyloarthritis Research Consortium of Canada (SPARCC) SIJ score for inflammation and Berlin modification of AS spine MRI score for disease activity in the spine (ASspiMRI‐a). Data are reported for all patients included in imaging sub‐study (the MRI set). Results: 325 patients were randomized, of which 153 were included in the MRI set. Baseline characteristics were similar across the MRI set, and were representative of overall RAPID‐axSpA patient population. Baseline SPARCC MRI SIJ scores were comparable between AS and nr‐axSpA populations, while Berlin ASspiMRI‐a scores were higher in AS patients. Improvements in SPARCC MRI SIJ scores and ASspiMRIa Berlin modification were observed in both CZP dose arms compared with PBO in the overall, and both AS and nr‐axSpA, populations (Table 1). Greater reductions in SIJ inflammation were observed for patient subgroups with <5 year symptom duration, age <45 years and in males. Conclusion: CZP reduced inflammation in the SIJ and spine, as assessed by MRI, in patients with axSpA, and in both AS and nraxSpA populations. (Table Presented).