Two-year Imaging Outcomes from a Phase 3 Randomized Trial of Secukinumab in Patients with Non-radiographic Axial Spondyloarthritis

Background: Radiographic progression and course of inflammation over 2 years in patients with non-radiographic axial spondyloarthritis (nr-axSpA) from the phase 3, randomized, PREVENT study are reported here.

Methods: In the PREVENT study, adult patients fulfilling the Assessment of SpondyloArthritis International Society classification criteria for nr-axSpA with elevated CRP and/or MRI inflammation received secukinumab 150 mg or placebo. All patients received open-label secukinumab from week 52 onward. Sacroiliac (SI) joint and spinal radiographs were scored using the modified New York (mNY) grading (total sacroiliitis score; range, 0-8) and modified Stoke Ankylosing Spondylitis Spine Score (mSASSS; range, 0-72), respectively. SI joint bone marrow edema (BME) was assessed using the Berlin Active Inflammatory Lesions Scoring (0-24) and spinal MRI using the Berlin modification of the AS spine MRI (ASspiMRI) scoring (0-69).

Results: Overall, 78.9% (438/555) of patients completed week 104 of the study. Over 2 years, minimal changes were observed in total radiographic SI joint scores (mean [SD] change, - 0.04 [0.49] and 0.04 [0.36]) and mSASSS scores (0.04 [0.47] and 0.07 [0.36]) in the secukinumab and placebo-secukinumab groups. Most of the patients showed no structural progression (increase ≤ smallest detectable change) in SI joint score (87.7% and 85.6%) and mSASSS score (97.5% and 97.1%) in the secukinumab and placebo-secukinumab groups. Only 3.3% (n = 7) and 2.9% (n = 3) of patients in the secukinumab and placebo-secukinumab groups, respectively, who were mNY-negative at baseline were scored as mNY-positive at week 104. Overall, 1.7% and 3.4% of patients with no syndesmophytes at baseline in the secukinumab and placebo-secukinumab group, respectively, developed ≥ 1 new syndesmophyte over 2 years. Reduction in SI joint BME observed at week 16 with secukinumab (mean [SD], - 1.23 [2.81] vs - 0.37 [1.90] with placebo) was sustained through week 104 (- 1.73 [3.49]). Spinal inflammation on MRI was low at baseline (mean score, 0.82 and 1.07 in the secukinumab and placebo groups, respectively) and remained low (mean score, 0.56 at week 104).

Conclusion: Structural damage was low at baseline and most patients showed no radiographic progression in SI joints and spine over 2 years in the secukinumab and placebo-secukinumab groups. Secukinumab reduced SI joint inflammation, which was sustained over 2 years.

Trial Registration: ClinicalTrials.gov, NCT02696031.