Ixekizumab Withdrawal In Psoriatic Arthritis May Result In Relapse

Patients with psoriatic arthritis (PsA) who achieved minimal disease activity on ixekizumab may relapse if they terminate treatment, according to a study.

SPIRIT-P3, a multicenter, randomized, double-blind withdrawal study, consisted of biologic-naïve patients with PsA who received ixekizumab. They received 160 mg at week zero, followed by 80 mg every two weeks (IXE Q2W) for 36 weeks. Patients who achieved and maintained minimal disease activity for at least three consecutive months were randomly assigned 1:1 to either IXE Q2W withdrawal (placebo) or continued IXE Q2W treatment through week 104. The main outcome was time to relapse, defined as loss of minimal disease activity. If patients did relapse, they were retreated with IXE Q2W through week 104.

The study initially enrolled 394 patients to open-label IXE Q2W. Minimal disease activity was sustained by 158 patients, who were randomized to either placebo (n=79) or continued IXE Q2W treatment (n=79). The medina time to relapse in the placebo group was 22.3 weeks (95% confidence interval [CI], 16.1-28.3); the median was not estimable in the continued IXE Q2W treatment group (P<0.0001). More patients in the placebo group relapsed than in the treatment group (67 vs. 30). After relapse, the median time to re-achieving minimal disease activity on retreatment was 4.1 weeks (95% CI, 4.1-4.3). Most patients in the placebo group who relapsed were able to re-achieve minimal disease activity on re-treatment (n=64). Safety outcomes were consistent with previous data.

The study was published in Arthritis & Rheumatology.

“Continued ixekizumab therapy is superior to ixekizumab withdrawal in maintaining low disease activity in biologic‐naive patients with PsA. Retreatment with ixekizumab following relapse may restore disease control in case of treatment interruption,” the study authors wrote in their conclusion.

In June 2020 ixekizumab received expanded approval from the Food & Drug Administration (FDA) to treat active non-radiographic axial spondyloarthritis (nr-axSpA) in patients with objective signs of inflammation, making ixekizumab is the first IL-17A antagonist to receive the FDA’s approval for nr-axSpA.