Spinal radiographic progression over 2 years in ankylosing spondylitis patients treated with secukinumab: a historical cohort comparison.

Objective: The aim of this study was to compare radiographic progression in patients with ankylosing spondylitis (AS) treated for up to 2 years with secukinumab (MEASURE 1) with a historical cohort of biologic-naïve patients treated with NSAIDs (ENRADAS).

Methods: Baseline and 2-year lateral cervical and lumbar spine radiographs were independently evaluated using mSASSS by two readers, who were blinded to the chronology and cohort of the radiographs. The primary endpoint was the proportion of patients with no radiographic progression (mSASSS change ≤ 0 from baseline to year 2). The Primary Analysis Set included patients with baseline (≤ day 30) and post-baseline day 31-743 radiographs. Sensitivity analyses were performed to assess the robustness of the comparison between the two cohorts, as follows: Sensitivity Analysis Set 1 included all patients with baseline (≤ day 30) and year 2 (days 640-819) radiographs; Sensitivity Analysis Set 2 included all patients with baseline and post-baseline (> day 30) radiographs.

Results: A total of 168 patients (84%) from the MEASURE 1 cohort and 69 (57%) from the ENRADAS cohort qualified for the Primary Analysis Set. Over 2 years, the LS (SE) mean change from baseline in mSASSS for the primary analysis was 0.55 (0.139) for MEASURE 1 vs 0.89 (0.216) for ENRADAS (p = 0.1852). Mean changes from baseline in mSASSS were lower in MEASURE 1 vs ENRADAS for the primary and sensitivity analyses. The proportion of patients with no radiographic progression was consistently higher in the MEASURE 1 vs ENRADAS cohort across all cutoffs for no radiographic progression (change in mSASSS from baseline to year 2 of ≤ 0, ≤ 0.5, ≤ 1, and ≤ 2), but the differences were not statistically significant.

Conclusion: Secukinumab-treated patients demonstrated a numerical, but statistically non-significant, higher proportion of non-progressors and lower change in mSASSS over 2 years versus a cohort of biologic-naïve patients treated with NSAIDs.