Absolute and relative PASI over 1 year of treatment with ixekizumab (IXE): Descriptive analysis in patients with moderate-to-severe plaque psoriasis

Treatment comparisons are usually based on relative improvement from baseline on the Psoriasis Area Severity Index (PASI). However, absolute PASI may be more relevant. The purpose of this pooled analysis was to find an absolute PASI level that is a clinically meaningful alternative treatment goal. Data from a randomized, double-blind, placebo-controlled phase 3 clinical trial comparing etanercept (ETN) and IXE in patients with moderate-to-severe plaque psoriasis were used. Patients with PASI≥12 were randomized to 12 weeks of IXE 80 mg (starting dose 160 mg) every 2 (IXEQ2W) or 4 weeks (IXEQ4W), ETN 50 mg twice weekly (ETN50BIW), or placebo. After this 12-week induction dosing period, patients were allowed to switch to open-label IXEQ4W treatment.
Here, we report the results at 52 weeks. Missing values were imputed as nonresponders. In total, 1274 patients participated in the open-label phase (IXEQ2W/IXEQ4W, N=362; IXEQ4W/IXEQ4W, N=360; ETN50BIW/IXEQ4W, N=369; and placebo/IXEQ4W, N=183). For IXEQ2W/IXEQ4W treatment (approved dose), clinical outcomes were: PASI100=57.7%, PASI≤1=71.3%, PASI90=79.6%, PASI≤2=80.1%, PASI≤3=85.6%, PASI≤5=88.1%, and PASI75=89.2%. For all treatment groups combined, clinical outcomes were: PASI100=56.8%, PASI≤1=70.8%, PASI90=79.0%, PASI≤2=79.1%, PASI≤3=84.4%, PASI75=88.0%, and PASI≤5=88.4%. The percentages of patients reaching PASI75/PASI90/PASI100, respectively, were 100%/100%/80.3% (PASI≤1); 100%/97.4%/71.8% (PASI≤2); 100%/93.3%/67.3% (PASI≤3); and 98.6%/89.4%/64.3% (PASI≤5). For this 1-year study with an inclusion cut-off of PASI≥12, similar proportions of responders are seen for PASI75 vs PASI≤5 and PASI90 vs PASI≤2. As PASI90 is considered the new long-term treatment objective, an absolute PASI≤2 may be a clinically relevant treatment goal for patients with moderate-to-severe plaque psoriasis.

Dr. Nicole Burkhardt

Dr. Nicole Burkhardt completed her PhD (in 2009) and her postdoctoral studies at the University of Geneva, Switzerland. She is a Senior Clinical Research Scientist at Eli Lilly Australia Pty Ltd, and she has published more than 5 papers in reputed journals.