Spinal Radiographic Progression in Secukinumab-Treated Ankylosing Spondylitis

Secukinumab-treated patients with ankylosing spondylitis were found to have a numerically higher proportion of radiographic non-progressors compared with nonsteroidal anti-inflammatory drug (NSAID) treated patients, according to research published in Arthritis Research & Therapy.

To examine the differences in structural damage progression in patients with ankylosing spondylitis, researchers compared data from 2 clinical trials: the Effects of NSAIDs on Radiographic Damage in Ankylosing Spondylitis (ENRADAS; NCT00715091) and the 16 Week Efficacy and 2 Year Long Safety and Efficacy of Secukinumab in Patients With Active Ankylosing Spondylitis (MEASURE 1; NCT01358175).

Patients in the MEASURE 1 cohort were treated with subcutaneous secukinumab 75 mg or 150 mg; patients in the ENRADAS cohort were biologic-naïve and were treated either continuously or on demand with 150 mg diclofenac for a total time of 2 years.

This retrospective study compared historical radiographic data from both patient cohorts. Lateral cervical and lumbar spine radiographs were combined and independently reevaluated using the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). The primary endpoint of the study was the proportion of patients with no radiographic progression, defined as mSASSS change from baseline to year 2 of ≤ 0.

Demographic characteristics, including mean age, sex, and mSASSS scores were comparable in both cohorts. In total, 84% of patients from the MEASURE 1 and 57% of patients from the ENRADAS cohorts qualified for the Primary Analysis Set; 87% and 64%, respectively, qualified for Sensitivity Analysis Set 1.

Primary analysis found that the proportion of patients with no radiographic progression was 60.7% vs 52.2% in the MEASURE 1 and ENRADAS cohorts (P = .243). Secondary analyses found that the proportion of patients with no radiographic progression was higher in the MEASURE 1 cohort across all cutoff points (change in mSASSS from baseline to year 2 of ≤ 0, ≤ 0.5, ≤ 1, and ≤ 2). The difference was not statistically significant, however. Over the course of 2 years, least-squares mean changes in mSASSS were 0.55 ± 0.139 and 0.89 ± 0.216 for the MEASURE 1 and ENRADAS Primary Analysis Sets, respectively.

“[W]e found a numerically higher proportion of radiographic nonprogressors among secukinumab-treated patients compared with controls… over 2 years,” the researchers of the study wrote; “[h]owever, differences between these groups were not statistically significant…. In this analysis, around 82-85% of patients in MEASURE 1 exhibited inhibition of radiographic progression using an mSASSS cutoff of ≤ 2 at year 2 across all sets analyzed compared with around 71-76% for ENRADAS.”

Study limitations included the retrospective nature of the study and the lack of randomization and stratification of patients leading to heterogeneity between cohorts. In addition, the difference in time between the administration of the 2 studies may have confounded some results.

“The key findings of this analysis showed that over 2 years, secukinumab-treated patients demonstrated a numerically higher proportion of radiographic non-progressors and a numerically, but statistically nonsignificant, lower change in mSASSS compared with biologic-naïve NSAID-treated patients,” the researchers of the study concluded.

Future research, including the SURPASS randomized controlled trial (NCT03259074), will assess the effect of interleukin-17A inhibition with secukinumab on spinal disease progression in AS.

Disclosures: Multiple researchers reported relationships with the pharmaceutical industry. For a complete list of disclosures, please see the full text of the study online.

Reference

Braun J, Haibel H, de Hooge M, et al. Spinal radiographic progression over 2 years in ankylosing spondylitis patients treated with secukinumab: a historical cohort comparison. Arthritis Res Ther. 2019;21(1):142.