No major effect of age (< 40 vs. ≥ 40 years) on response to secukinumab in patients with axSpA: a post hoc analysis of six phase 3 trials

BACKGROUND: Secukinumab is an interleukin (IL)-17 inhibitor approved to treat patients with axial spondyloarthritis (axSpA), including radiographic (r)-axSpA and non-radiographic (nr)-axSpA. Treatment recommendations highlight the importance of individualized treatment of patients with axSpA according to symptoms, extra-musculoskeletal manifestations, and comorbidities. The objective of this post hoc analysis was to compare clinical responses to secukinumab treatment through Week 16 between younger and older patients with r-axSpA and nr-axSpA from six placebo-controlled phase 3 clinical studies. METHODS: This post hoc analysis evaluated data pooled from 1427 patients with axSpA from the MEASURE 1-5 trials (NCT01358175, NCT01649375, NCT02008916, NCT02159053, and NCT02896127) and the PREVENT trial (NCT02696031). All patients were randomized to secukinumab 150 mg, 300 mg, or placebo through Week 16. Patient subgroups were defined based on median age at baseline (18 to < 40 years vs. ≥ 40 years). Treatment effect (secukinumab 150/300 mg vs. placebo) within each age subgroup and the difference in treatment effect between younger vs. older age subgroups were assessed. RESULTS: Secukinumab treatment demonstrated clinical efficacy and improvements in patient-reported outcomes vs. placebo at Week 16 in patients with r-axSpA or nr-axSpA irrespective of age. No difference in treatment effect of ASAS20, ASAS40, or ASDAS response was observed between younger vs. older patients with r-axSpA or nr-axSpA (all P>.05). Among patients with r-axSpA, younger patients experienced a larger treatment effect of secukinumab on SF-36 than older patients (difference in least-squares mean [LSM]: 2.2; P < .05). Among patients with nr-axSpA, younger patients experienced a larger treatment effect of secukinumab on the Berlin SIJ total edema score (difference in LSM: - 1.2; P < .05) and Total ASspi-MRI-a score (LSM, - 0.4; P<.05). CONCLUSION: Clinical efficacy of secukinumab vs. placebo at Week 16 was generally similar between older and younger patients with either r-axSpA or nr-axSpA.