Ixekizumab demonstrates efficacy in reducing or preventing the progression of radiographic axial spondyloarthritis (r-axSpA) over a 2-year treatment period, according to study results published in The Journal of Rheumatology.
In the current multicenter, phase 3, long-term extension study, researchers evaluated data from the COAST-V and COAST-W trials (ClinicalTrials.gov Identifiers: NCT02696785 and NCT02696798, respectively) to assess the effect of long-term ixekizumab on radiographic changes in the spine of patients with r-axSpA.
The percentage of patients without spinal radiographic progression after 2-year treatment with ixekizumab 80 mg every 2 weeks (Q2W) or every 4 weeks (Q4W), as well as changes between baseline and 2-year modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS), were evaluated in the 108-week study period. Possible predictors of progression were also assessed, using a 2-step logistic regression model.
A total of 230 participants (Q2W, n=115; Q24, n=115; mean age, 43.0±11.5 years; 81.7% men; mean symptom duration, 15.9±9.8 years) receiving ixekizumab were included in the current analysis.
Mean 2-year change in mSASSS was 0.3±1.8 for the entire group, 0.2±1.4 for the Q2W group, and 0.4±2.1 for the Q4W group. During the 2-year study period, 89.6% of participants showed no progression from baseline (defined by 2-year mSASSS change <2; 75.7% if defined by 2-year mSASSS change ≤0).
At year 2, the predictors of structural progression were identified to be age of 40 years and older, male sex, human leucocyte antigen (HLA)-B27 positivity, and syndesmophytes at baseline. Among those with magnetic resonance imaging (MRI) data (n=109), week-52 inflammation in the Spondyloarthritis Research Consortium of Canada spine score was also found to be a predictor of structural progression.
Study limitations included the lack of follow-up after 2 years; treatment benefit among those who continued to be enrolled in the study vs those who discontinued; insufficient power to observe either an association between the treatment group and prior tumor necrosis factor inhibitor (TNFi) experience or the small differences between the Q2W and Q4W treatment groups; potential unknown confounders; lack of comparator or placebo groups; and potential reader bias.
The study researchers concluded that “the majority of patients treated with [ixekizumab] for 2 years did not show radiographic progression, and the overall mean progression was low.” The researchers also “identified age [40 years and older], baseline syndesmophytes, HLA-B27 positivity, and male sex as potential predictors of progression at year 2.”
Disclosure: This clinical trial was supported by Eli Lilly & Co. Please see the original reference for a full list of authors’ disclosures.
van der Heijde D, Østergaard M, Reveille JD, et al. Spinal radiographic progression and predictors of progression in patients with radiographic axial spondyloarthritis receiving ixekizumab over 2 years. J Rheumatol. 2022;49:265-273. doi:10.3899/jrheum.210471