OA34 Post-hoc analysis of spinal MRI SPARCC inflammation scores in patients with radiographic axial spondyloarthritis treated with ixekizumab: results from the COAST-V study at week 16
Authors: Marzo-Ortega Helena , Tsai Wen-Chan , Kameda Hideto , Konomi Ayako , Bradley Andrew J , Ng Khai Jing , Schymura Yves , Liu-Leage Soyi , Maksymowych Walter P , Østergaard Mikkel 
Published: April 2022

Abstract

Background/Aims
Ixekizumab, an interleukin-17A inhibitor, has demonstrated efficacy in radiographic axial spondyloarthritis (r-axSpA) irrespective of baseline local inflammation as measured by spinal magnetic resonance imaging (MRI) Spondyloarthritis Research Consortium of Canada (SPARCC) inflammation scores. This post-hoc analysis assessed the efficacy of ixekizumab in patients with r-axSpA categorized by MRI SPARCC score at baseline and 16-week change from baseline (CFB).

Methods
COAST-V (NCT02696785) was a phase 3, randomized, controlled trial enrolling patients with active r-axSpA naïve to biologic disease-modifying antirheumatic drugs, randomized 1:1:1:1 to 80-mg ixekizumab every 2 weeks, 80-mg ixekizumab every 4 weeks (Q4W), adalimumab, or placebo for the 16-week blinded treatment period. Three categories were defined according to spinal MRI SPARCC inflammation score at baseline and CFB (based on published minimally important change): 1) low baseline (baseline SPARCC score &lt;5.0 points), 2) low responder (baseline SPARCC score ≥5.0 points and CFB &lt;5.0 points), 3) high responder (baseline SPARCC score ≥5.0 points and CFB ≥5.0 points). Proportions of patients achieving Assessment in SpondyloArthritis international Society 40% (ASAS40), Ankylosing Spondylitis Disease Activity Score (ASDAS) &lt;2.1, and BASDAI (Bath Ankylosing Spondylitis Disease Activity Index) 50 were determined. Means at baseline and week-16 least squares means of CFBs were calculated for ASDAS, BASDAI, Spinal Pain, Bath Ankylosing Spondylitis Functional Index (BASFI), and 36-item Short Form Health Survey Physical Component Summary (SF-36 PCS). Non-responder imputation and modified baseline observation carried forward were used for missing week-16 data in discrete and continuous variables, respectively.

Results
Of 78 patients receiving ixekizumab Q4W, 35 (44.9%), 11 (14.1%), and 32 (41.0%), were MRI SPARCC low baseline, low responders, and high responders, respectively. Similar proportions of ixekizumab-treated patients in all categories achieved ASAS40, ASDAS&lt;2.1, and BASDAI50 week-16 responses; week-16 improvements in other efficacy endpoints were broadly similar, with high responders showing greater improvements in ASAS40 and ASDAS CFB (Table). In adalimumab-treated patients, week-16 improvements were less pronounced in the low baseline and low responder categories.

Conclusion
Patients with r-axSpA receiving ixekizumab Q4W showed broadly similar reduction in the signs and symptoms of r-axSpA irrespective of their spinal MRI SPARCC inflammation score category at week 16.

Disclosure
H. Marzo-Ortega: Honoraria; Abbvie, Celgene, Eli Lilly and Company, Janssen, Novartis, Pfizer, Takeda, UCB, Biogen. Grants/research support; Janssen, Novartis. W. Tsai: Consultancies; Abbvie, Pfizer, Roche. H. Kameda: Consultancies; Abbvie, Asahikasei Pharma, Bristol-Myers Squibb, Eisai, Eli Lilly and Company, Janssen, Mitsubishi Tanabe Pharma, Novartis, Chugai, Pfizer. Member of speakers’ bureau; Abbvie, Asahikasei Pharma, Bristol-Myers Squibb, Eisai, Eli Lilly and Company, Janssen, Mitsubishi Tanabe Pharma, Novartis, Chugai, Pfizer. A. Konomi: Shareholder/stock ownership; Eli Lilly and Company. Other; Employment - Eli Lilly and Company. A.J. Bradley: Shareholder/stock ownership; Eli Lilly and Company. Other; Employment - Eli Lilly and Company. K. Ng: Shareholder/stock ownership; Eli Lilly and Company. Other; Employment - Eli Lilly and Company. Y. Schymura: Shareholder/stock ownership; Eli Lilly and Company. Other; Employment - Eli Lilly and Company. S. Liu-Leage: Shareholder/stock ownership; Eli Lilly and Company. Other; Employment - Eli Lilly and Company. W.P. Maksymowych: Corporate appointments; CARE Arthritis Limited. Consultancies; Abbvie, Boehringer Ingelheim, Celgene, Eli Lilly and Company, Galapagos, Janssen, Novartis, Pfizer, UCB. Member of speakers’ bureau; Abbvie, Janssen, Novartis, Pfizer, UCB. Grants/research support; Abbvie, Novartis, Pfizer, UCB. M. Østergaard: Consultancies; Abbvie, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Eli Lilly and Company, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, UCB. Member of speakers’ bureau; Abbvie, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Eli Lilly and Company, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, UCB. Grants/research support; Abbvie, Celgene, Centocor, Merck, Novartis.