Clinical and MRI remission in axial spondyloarthritis: one-year outcomes and predictors from the TRACE treat-to-target study with secukinumab

Evidence on treat-to-target strategies in axial spondyloarthritis (axSpA) remains limited. We evaluated 1-year clinical and MRI outcomes of a secukinumab-based dose-escalation treat-to-target strategy aiming for clinical remission (ASDAS < 1.3), and investigated predictors of clinical and MRI-remission. TRACE (NCT03639740), was an investigator-initiated, prospective multicentre study including biologic-naïve patients with active axSpA. All patients initiated secukinumab 150mg; those not achieving clinical remission escalated to 300mg; patients still not reaching clinical remission switched to TNF-inhibitors. Sacroiliac joint (SIJ) and spine MRI were performed at baseline and weeks (w) 4, 16, 24, and 56 and centrally scored using SPARCC and CANDEN systems. Predictors of w16 and w56 remission were assessed using multivariable logistic regression. Of 90 included patients, 54 completed w56; 24, 8, and 22 received secukinumab 150mg, 300mg, and TNF-inhibitors, respectively. Overall, 32 patients (59%) achieved w56-clinical-remission. From week 0–56, total MRI-inflammation (SIJ + spine) decreased from mean 39.0 to 6.7, with 43% achieving w56-MRI-remission (SPARCC-SIJ ≤ 1 + CANDEN-spine ≤ 2). Structural lesion remodelling was evident by w4 and sustained through w56 (erosion decreased, fat lesion and backfill increased, new bone formation/ankylosis unchanged). Changes in MRI-inflammation and structural lesions were comparable irrespective of w56-clinical-remission status and treatment at w56. Independent baseline predictors were: Of w16-clinical-remission: ASDAS and BMI; Of w56-clinical-remission: none; Of w16-MRI-remission: female sex, lower MRI-inflammation and higher MRI-erosion score; Of w56-MRI-remission: lower MRI-inflammation and HLA-B27 positivity. A 1-year secukinumab-based treat-to-target strategy in axSpA patients provided rapid and sustained clinical improvement, MRI-inflammation reduction and structural remodelling. BMI, sex, HLA-B27 and clinical/MRI disease activity predicted clinical and MRI-remission.