Continuing versus withdrawing ixekizumab treatment in patients with axial spondyloarthritis who achieved remission: efficacy and safety results from a placebo-controlled, randomised withdrawal study (COAST-Y).

Abstract

OBJECTIVES:

The objective of COAST-Y was to evaluate the effect of continuing versus withdrawing ixekizumab (IXE) in patients with axial spondyloarthritis (axSpA) who had achieved remission.

METHODS:

COAST-Y is an ongoing, phase III, long-term extension study that included a double-blind, placebo (PBO)-controlled, randomised withdrawal-retreatment period (RWRP). Patients who completed the originating 52-week COAST-V, COAST-W or COAST-X studies entered a 24-week lead-in period and continued either 80 mg IXE every 2 (Q2W) or 4 weeks (Q4W). Patients who achieved remission (an Ankylosing Spondylitis Disease Activity Score (ASDAS)<1.3 at least once at week 16 or week 20, and <2.1 at both visits) were randomly assigned equally at week 24 to continue IXE Q4W, IXE Q2W or withdraw to PBO in a blinded fashion. The primary endpoint was the proportion of flare-free patients (flare: ASDAS≥2.1 at two consecutive visits or ASDAS>3.5 at any visit) after the 40-week RWRP, with time-to-flare as a major secondary endpoint.

RESULTS:

Of 773 enrolled patients, 741 completed the 24-week lead-in period and 155 entered the RWRP. Forty weeks after randomised withdrawal, 83.3% of patients in the combined IXE (85/102, p<0.001), IXE Q4W (40/48, p=0.003) and IXE Q2W (45/54, p=0.001) groups remained flare-free versus 54.7% in the PBO group (29/53). Continuing IXE significantly delayed time-to-flare versus PBO, with most patients remaining flare-free for up to 20 weeks after IXE withdrawal.

CONCLUSIONS:

Patients with axSpA who continued treatment with IXE were significantly less likely to flare and had significantly delayed time-to-flare compared with patients who withdrew to PBO.

• Authors: Robert Bm Landewé, Lianne S Gensler, Denis Poddubnyy, Proton Rahman, Maja Hojnik, Xiaoqi Li, Soyi Liu Leage, David Adams, Hilde Carlier, Filip Van den Bosch, COAST-Y study group
• Journal: Annals of the rheumatic diseases (Ann Rheum Dis) Vol. 80 Issue 8 Pg. 1022-1030 (08 2021) ISSN: 1468-2060 [Electronic] England
• PMID: 33958326 (Publication Type: Clinical Trial, Phase III, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: © Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Chemical References

• Antibodies, Monoclonal, Humanized
• ixekizumab

Topics

• Antibodies, Monoclonal, Humanized
• Axial Spondyloarthritis
• Double-Blind Method
• Humans
• Spondylitis, Ankylosing (chemically induced, drug therapy)
• Treatment Outcome