Long-term clinical outcomes of certolizumab pegol treatment in non-radiographic axial spondyloarthritis stratified by baseline MRI and CRP status.

OBJECTIVE: There is a paucity of data on long-term clinical responses in patients with non-radiographic axial spondyloarthritis (nr-axSpA) based on their baseline objective signs of inflammation such as MRI or C-reactive protein (CRP) levels. This study reports clinical outcomes up to 3 years of the C-axSpAnd trial, including safety follow-up extension (SFE) from Weeks 52 to 156, stratified by patients' baseline MRI and CRP status.

METHODS: C-axSpAnd (NCT02552212) was a phase 3, multicentre study that evaluated certolizumab pegol (CZP) in patients with active nr-axSpA who had active sacroiliitis on MRI and/or elevated CRP. In this post hoc analysis, efficacy outcomes are reported to Week 156 of C-axSpAnd for patients stratified according to their MRI and CRP status at Week 0 (MRI+/CRP-, MRI-/CRP+ and MRI+/CRP+).

RESULTS: Across all outcome measures, including major improvement in Ankylosing Spondylitis Disease Activity Score (ASDAS-MI) and Assessment of SpondyloArthritis international Society criteria ≥40% response (ASAS40), outcomes were generally sustained in SFE patients from Week 52 to Week 156. MRI+/CRP+ patients showed numerically higher or comparable responses relative to MRI-/CRP+ and MRI+/CRP- patients at Weeks 52 and 156; however, all three subgroups demonstrated substantial improvements from Week 0 (in CZP-randomised patients, ASDAS-MI at Week 156 [observed case]: MRI+/CRP+: 73.1%, MRI-/CRP+: 52.2%, MRI+/CRP-: 30.4%; ASAS40: MRI+/CRP+: 76.9%, MRI-/CRP+: 62.5%, MRI+/CRP-: 65.2%).

CONCLUSIONS: In patients with nr-axSpA and objective signs of inflammation, long-term clinical outcomes achieved after 1 year were generally sustained at 3 years across MRI+/CRP+, MRI-/CRP+ and MRI+/CRP- subgroups.