Efficacy of Ixekizumab in Chinese Patients with Moderate-to-Severe Psoriasis and Special Body Area Involvement: Sub-analysis of a Randomized, Double-Blind, Multicenter Phase 3 Study.

Introduction: Special body area involvement is common in psoriasis and can be challenging to treat. We investigated the efficacy of ixekizumab (IXE) in Chinese patients with moderate-to-severe psoriasis and fingernail, scalp, or palmoplantar involvement.

Methods: A post-hoc sub-analysis of a phase 3 trial, in which patients were randomized to receive placebo, IXE 80 mg every 2 (IXE Q2W) or 4 (IXE Q4W) weeks. At Week 12, patients classified as IXE responders [static Physician's Global Assessment (sPGA) score of 0 or 1 [0,1)] were re-randomized (2:1) to IXE Q4W or placebo until Week 60. Efficacy was assessed by body-region specific parameters including Nail Psoriasis Severity Index (NAPSI), Psoriasis Scalp Severity Index (PSSI), and Palmoplantar Psoriasis Area Severity Index (PPASI).

Results: Of 438 patients, 99.1% (434) had ≥ 1 special area involvement [fingernail (76.5%, 335), scalp (97.3%, 426), palmoplantar (27.9%, 122)]. Significantly greater improvements from baseline in NAPSI score were observed with IXE Q4W and Q2W at Week 12 versus placebo (p < 0.001 for both). These improvements were further increased and sustained over 60 weeks in IXE Q4W and Q2W responders who were re-randomized to IXE Q4W, who achieved a 77.9% and 89.7% improvement from baseline, respectively, at Week 60. Significantly higher proportions of patients receiving IXE Q4W and Q2W achieved NAPSI 50 at Week 12 versus placebo (44.4%, 36.6% vs. 14.1%; p < 0.001 and < 0.01, respectively). Similarly, significantly higher proportions of patients receiving IXE Q4W and Q2W achieved PSSI 100 and PPASI 100 at Week 12 versus placebo (60.6% and 65.1% vs. 1.2%, and 67.4%, 84.3% vs. 21.4%, respectively; p < 0.001 for all comparisons). Improvements across all outcomes were sustained in patients re-randomized to IXE Q4W until Week 60.

Conclusion: IXE led to a rapid onset of action and sustained efficacy over 60 weeks in Chinese patients with moderate-to-severe psoriasis and special body area involvement.

Clinicaltrials: gov identifier, NCT03364309.