Effect of secukinumab versus adalimumab biosimilar on radiographic progression in patients with radiographic axial spondyloarthritis: Results from a head-to-head randomized phase IIIb study.

INTRODUCTION: Spinal radiographic progression is an important outcome in radiographic axial spondyloarthritis (r-axSpA). SURPASS is the first head-to-head phase IIIb study comparing such changes in patients with r-axSpA treated with secukinumab (IL-17A inhibitor) versus adalimumab biosimilar (Sandoz adalimumab [SDZ-ADL]; TNF inhibitor).

METHODS: Biologic-naïve patients with active r-axSpA, at high risk of radiographic progression (high-sensitivity C-reactive protein [hsCRP] ≥5 mg/L and/or ≥1 syndesmophyte[s] on spinal radiographs) were randomized (1:1:1) to secukinumab (150/300 mg) or SDZ-ADL (40 mg). The proportion of patients with no radiographic progression (change from baseline [CFB] in modified Stoke Ankylosing Spondylitis Spinal Score [mSASSS] ≤0.5) on secukinumab versus SDZ-ADL at week 104 (primary endpoint), mean CFB-mSASSS, proportion of patients with ≥1 syndesmophyte(s) at baseline with no new syndesmophytes(s), and safety were evaluated.

RESULTS: Overall, 859 patients (78.5% male, mSASSS 16.6, BASDAI 7.1, hsCRP 20.4 mg/L, and 73.0% with ≥1 syndesmophyte[s]) received secukinumab 150 mg (n=287), 300 mg (n=286), or SDZ-ADL (n=286). At week 104, the proportion of patients with no radiographic progression was 66.1%, 66.9%, and 65.6% (P=not significant, both secukinumab doses) and mean CFB-mSASSS was 0.54, 0.55, and 0.72 in secukinumab 150 mg, 300 mg, and SDZ-ADL arms, respectively. Overall, 56.9%, 53.8%, and 53.3% of patients on secukinumab 150 mg, 300 mg, and SDZ-ADL, respectively, with ≥1 syndesmophyte(s) at baseline did not develop new syndesmophyte(s) by week 104. There were no unexpected safety findings.

CONCLUSIONS: Spinal radiographic progression over 2 years was low with no significant difference between secukinumab and SDZ-ADL arms. The safety of both treatments was consistent with previous reports.