Minimizing Disease Activity in Psoriatic Arthritis

In the SPIRIT-P3 study, the authors conducted a multi-center, randomized, double-blind withdrawal study of biologic treatment-naive adult patients with psoriatic arthritis who were treated with open-label ixekizumab for 36 weeks. Patients who achieved MDA for longer than three months were randomized to blinded withdrawal of ixekizumab or to continue ixekizumab every two weeks until week 104, and patients who experienced relapse were then re-treated with ixekizumab every two weeks until week 104.

Out of an initial 394 patients, 158 (40%) achieved MDA and were randomized to either receive placebo or continue ixekizumab. In the placebo group, 85% of patients experienced relapse compared with 38% of patients in the continued treatment group. In the 67 patients who experienced relapse with treatment withdrawal, 64 patients (96%) achieved MDA again with re-treatment, with a median time of 4.1 weeks to achieve this outcome.5

This study illustrates a few important concepts, including that withdrawal of effective treatment in patients with psoriatic arthritis may precipitate disease relapse at higher rates than continuing treatment, but the recapture rate—that is, the ability to achieve MDA once again with re-treatment—may be quite high depending on the medication in question. More studies have been, and will be, conducted on this topic and, hopefully, will provide useful clinical data for a number of different medications.

Looking Forward

Dr. Husni notes that, in her opinion, the most exciting recent innovations are the extensive efforts now focused on measures specific to psoriatic arthritis rather than using or comparing measures from other forms of inflammatory arthritis, such as rheumatoid arthritis. Dr. Husni’s talk in 2019 and her updates in the present day provide fantastic insight into the state of psoriatic arthritis care.

---

Jason Liebowitz, MD, completed his fellowship in rheumatology at Johns Hopkins University, Baltimore, where he also earned his medical degree. He is currently in practice with Skylands Medical Group, N.J.

References

1. Coates LC, Moverley AR, McParland L, et al. Effect of tight control of inflammation in early psoriatic arthritis (TICOPA): A UK multicentre, open-label, randomised controlled trial. Lancet. 2015 Dec 19;386(10012):2489–2498.
2. Coates LC, Fransen J, Helliwell PS. Defining minimal disease activity in psoriatic arthritis: A proposed objective target for treatment. Ann Rheum Dis. 2010 Jan;69(1):48–53.
3. Gossec L, McGonagle D, Korotaeva T, et al. Minimal disease activity as a treatment target in psoriatic arthritis: A review of the literature. J Rheumatol. 2018 Jan;45(1):6–13.
4. Ng BCK, Jadon DR. Unmet needs in psoriatic arthritis. Best Pract Res Clin Rheumatol. 2021 Jun;35(2):101693.
5. Coates LC, Pillai SG, Tahir H, et al. Withdrawing ixekizumab in patients with psoriatic arthritis who achieved minimal disease activity: Results from a randomized, double-blind withdrawal study. Arthritis Rheumatol. 2021 Sep;73(9):1663–1672.