Aiming to evaluate the effect of withdrawing ixekizumab (IXE) in patients with psoriatic arthritis (PsA) who had achieved minimal disease activity (MDA) after open-label ixekizumab treatment, a study found continued IXE treatment is superior in maintaining low disease activity. The results comparing continued use vs withdrawl were published in Arthritis & Rheumatology.
The study (SPIRIT-P3) was a multicenter, randomized, double-blind withdrawal trial of biologic-naive adult patients with PsA to open-label IXE (160 mg at week 0, 80 mg every 2 weeks [IXE Q2W]) for 36 weeks. Patients who sustained MDA for more than 3 consecutive months were randomized 1:1 to blinded IXE Q2W withdrawal (placebo) or continued IXE Q2W treatment up to week 104. The primary efficacy endpoint was defined as time to relapse for randomized patients. Relapse was retreated with IXE Q2W until week 104.
Over the trial period, 394 patients received open-label IXE Q2W and of those, 158 patients achieved sustained MDA and were randomized to placebo (N=79) or continued IXE Q2W treatment (N=79). The treatment withdrawal arm experienced relapse (n=67 [85%]) in a median 22.3 weeks (95% CI, 16.1-28.3), whereas continued IXE did not have an estimable median (P<.0001) with only 30 (38%) experiencing relapse. Median time to re-achieving MDA on retreatment was 4.1 weeks (95% CI, 4.1-4.3), with 64 (96%) patients who relapsed with treatment withdrawal re-achieving MDA. The authors added that safety was consistent with the known safety profile for IXE.
According to the study results, continued IXE therapy is superior to withdrawal, particularly by maintaining low disease activity in biologic-naive patients with PsA. Following relapse, retreatment with IXE may restore disease control in case of treatment interruption. —Jessica Garlewicz
Coates LC, Pillai SG, Tahir H, et al; SPIRIT-P3 Study Group. Withdrawing ixekizumab in patients with psoriatic arthritis who achieved minimal disease activity: results from a randomized, double-blind withdrawal study. Arthritis Rheumatol. Published online March 7, 2021. doi:10.1002/art.41716