Analysis Shows Treatment Efficacy for Nonradiographic Axial Spondyloarthritis Across Patient Subgroups

Secukinumab improved signs and symptoms of nonradiographic axial spondyloarthritis (nr-axSpA) across patient subgroups based on C-reactive protein (CRP) levels, magnetic resonance imaging (MRI) scores, human leukocyte antigen-B27 (HLA-B27) status, and sex, according to a post hoc analysis of a phase III trial published in Arthritis Research & Therapy.

“The highest treatment differences between secukinumab and placebo were observed in patients with both elevated CRP and evidence of sacroiliitis on MRI,” researchers wrote.

The phase III PREVENT study included 555 patients with active nr-axSpA randomized to treatment with subcutaneous secukinumab or placebo. For the post hoc analysis, researchers looked at efficacy outcomes at 16 weeks based on patient CRP levels, MRI scores, HLA-B27 status, and sex.

At week 16, treatment differences between secukinumab and placebo were highest in the following subgroups: patients with elevated CRP levels (CRP+), patients with evidence of sacroiliac joint inflammation on MRI (MRI+), and male patients, according to the study.

In the CRP+ and MRI+ patient subgroup, 52.3% achieved Assessment of SpondyloArthritis international Society response of at least 40% improvement (ASAS40) with secukinumab compared with 21.8% who achieved ASAS40 with placebo. Meanwhile, treatment differences were minimal between HLA-B27 positive and negative subgroups.

Grouping patients by sex revealed a higher ASAS40 response rate with secukinumab compared with placebo in men: 51.2% with secukinumab and 30.8% with placebo, the study showed. However, among women ASAS40 response rates were lower: 31.7% with secukinumab and 25.3% with placebo.

“While clinically meaningful efficacy was seen in both male and female patients, higher responses were consistently observed in males across all outcome measures,” researchers wrote. “These results are consistent with the observations from other studies and support the recommendation for an individual assessment of sex-independent risk factors in patients with axSpA.”

Reference:
Braun J, Blanco R, Marzo-Ortega H, et al. Secukinumab in non-radiographic axial spondyloarthritis: subgroup analysis based on key baseline characteristics from a randomized phase III study, PREVENT. Arthritis Res Ther. 2021 Sep 4;23(1):231. doi:10.1186/s13075-021-02613-9