Date: Sunday, October 21, 2018
Session Type: ACR Poster Session A
Session Time: 9:00AM-11:00AM
Background/Purpose: PsA is a highly heterogeneous chronic inflammatory disease combining a range of musculoskeletal and extra-articular manifestations. Ixekizumab (IXE) is approved for the treatment of moderate to severe psoriasis and more recently for active PsA. This post-hoc analysis describes the efficacy of IXE at week 24 in different phenotypes of PsA patients.
Methods: Biologic naïve patients (SPIRIT-P1) were randomized to IXE 80 mg (initial dose 160mg) every 4 (Q4W; N=107) or 2 weeks (Q2W; N=103), to adalimumab 40 mg (Q2W; N=101), or to placebo (PBO; N=106). Patients who had an inadequate response or intolerance to TNF inhibitors (SPIRIT-P2) were randomized to IXE Q4W (N=122) or Q2W (N=123), or to PBO (N=118). Patients fulfilled the Classification Criteria for Psoriatic Arthritis (CASPAR) criteria and had active disease with ≥3TSJ and 3≥SJC. Patients were classified according to the following phenotypes of PsA1: polyarthritis (≥5TJC and/or ≥5SJC), oligoarthritis (<5TJC and <5SJC), DIP joint only, enthesitis and dactylitis according to either the investigator’s judgment or a scale-based definition. In each phenotype ACR 20, 50 and 70 response criteria, Minimal Disease Activity Psoriasis Area Severity Index (MDAPASI), and Disease Activity Psoriatic Arthritis (DAPSA) remission and low disease activity (LDA) response criteria were assessed to evaluate IXE effect at week 24 combining both doses. For each phenotype with a sufficient sample size, the IXE- and PBO-treated patients’ baseline characteristics were assessed. Treatment effects of IXE and PBO were compared using Chi-square tests (or Fisher’s exact tests if appropriate) within each phenotype.
Results: The most frequent phenotypes were: polyarthritis (N=662), enthesitis (investigator: N=459; LEI>0: N=403), and dactylitis (investigator: N=220; LDI-B>0: N=155). Too small sample sizes due to inclusion criteria2,3 or low frequency were observed for “DIP joint only”, oligoarthritis and arthritis mutilans phenotypes (N=22, N=17 and N= 15; respectively). Baseline patient characteristics were generally balanced between treatment arms and similar between the 3 most frequent phenotypes, with no difference in disease activity and duration. Efficacy of IXE was consistent across the different phenotypes for various outcomes at week 24: ACR20/50/70, MDAPASI, DAPSA remission and DAPSA-LDA in SPIRIT trials irrespective of previous biologic DMARD use (Tab.1). Response rates were consistent to overall efficacy reported with IXE in SPIRIT trials2-4.
Conclusion: Treatment responses with IXE at week 24 were consistent regardless of the phenotypes.
1Moll JM, Wright V. Semin Arthritis Rheum. 1973;3:55-78
2Mease PJ, et al. Ann Rheum Dis. 2017;76:79-87
3Nash P, et al. Lancet. 2017;389:2317-2327
4Gladman DD, et al. EULAR18-2325 (SAT0321) abstract accepted, Ann Rheum Dis.
To cite this abstract in AMA style:Behrens F, Nash P, Gossec L, Liu Leage S, de la Torre I, Sapin C, Kurzawa M, Burmester GR, Smolen JS. Efficacy of Ixekizumab in Different Phenotypes of Patients with Active Psoriatic Arthritis (PsA): Results from the Spirit Trials [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 10). https://acrabstracts.org/abstract/efficacy-of-ixekizumab-in-different-phenotypes-of-patients-with-active-psoriatic-arthritis-psa-results-from-the-spirit-trials/. Accessed August 21, 2019.
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