Continuing Ixekizumab Superior to Withdrawal in Stable Psoriatic Arthritis

Sarfaroj Khan 


March 16, 2021


  • In biologic-naive patients with psoriatic arthritis (PsA), continued ixekizumab (IXE) therapy was superior to IXE withdrawal in maintaining minimum disease activity (MDA).

  • A vast majority of patients who lost MDA after IXE withdrawal regained MDA with IXE re-treatment.

Why this matters

  • Findings indicate that continuous IXE treatment is optimal for maintaining MDA; however, patients can regain MDA after re-treatment with IXE in case of treatment interruption.

Study design

  • SPIRIT-P3 was a multicentre, randomised, double-blind withdrawal study of 394 biologic-naive patients with PsA who received open-label IXE (160 mg at week 0, 80 mg every 2 weeks) for 36 weeks.

  • Between weeks 36 and 64, 158 patients who achieved sustained MDA (>3 months) were randomised (1:1) to continue on 80-mg IXE every 2 weeks or placebo until week 104.

  • Primary efficacy outcome: time to relapse (loss of MDA).

  • Funding: Eli Lilly and Company.

Key results

  • Patients relapsed more rapidly with IXE withdrawal (median, 22.3 weeks [95% CI, 16.1-28.3]) vs continued IXE treatment (median was not estimable because <50% of patients had relapsed by the end of study period, P<.0001).

  • The cumulative relapse rate from week 24 to week 104 was significantly higher for the withdrawal group vs continued treatment group (85% vs 38%; P<.0001).

  • The median time to re-achieving MDA on retreatment was 4.1 weeks (95% CI, 4.1-4.3); 64 (95.5%) of 67 patients who relapsed with treatment withdrawal re-achieved MDA on retreatment.

  • Overall, safety data were consistent with previous IXE PsA studies with no unexpected safety signals.


  • Approved dosing regimen for PsA in the US and Europe is IXE every 4 weeks, whereas the dose used in this study was every 2 weeks.


Coates LC, Pillai SG, Tahir H, Valter I, Chandran V, Kameda H, Okada M, Kerr L, Alves D, Park SY, Adams DH, Gallo G, Hufford MM, Hojnik M, Mease PJ, Kavanaugh A. Withdrawing Ixekizumab in Patients with Psoriatic Arthritis who Achieved Minimal Disease Activity: Results from a Randomized, Double-Blind Withdrawal Study. Arthritis Rheumatol. 2021 Mar 7 [Epub ahead of print]. doi: 10.1002/art.41716. PMID: 33682378.  View abstract 

This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.


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