Primary and Exploratory Endpoint (Clinical Efficacy) Analysis
It was assumed that hives were not self-limiting and any improvement in outcomes during the study were because of interventions. For primary end-point analysis (i.e., UAS7), data from subjects completing the study (n=9) were analyzed; whereas for the CU-QoL total score exploratory end-point, an intent-to-treat (n=12) and complete responder (n=9) analysis was performed. A repeated-measures mixed-model regression analysis using the ‘glimmix ’ procedure was used to fit a generalized-linear-mixed model for comparison of UAS7 and CU-QoL total scores between visits and between responder phenotypes adjusted for their baseline severity of disease. Correlational analysis between UAS7 and CU-QoL total scores were performed to associate clinical improvements with improved QoL.
Secondary Endpoint Analysis
Cell Infiltrates in Lesional and Non-Lesional Skin Biopsies.Quantitative analysis of mononuclear and mast cells observed around postcapillary venules in lesional skin vs. non-lesional skin at visits 2 and 5 were performed to determine the effect of benralizumab on cell infiltration as its possible therapeutic mechanism in CSU.
Peripheral Blood White Cell Counts. Relative white cell counts in peripheral blood (eos%, basophil%) over the entire duration of the study was performed to determine any significant associations of changes in eos% or basophil%, due to treatment with benralizumab, with the corresponding mean ΔUAS7 and differential gene expression in peripheral blood pre- and post-benralizumab.
Comparison Between Responders And Non-Responders To Benralizumab. Analysis of the effect of benralizumab on the differential white cell count in peripheral blood between responders and non-responders was performed to determine effect.
Differential Gene Expression In Blood. For differential gene expression in peripheral blood, the RNA sequence reads were aligned to the reference genome using the TopHat aligner 29, and reads aligning to each known transcript were counted using Bioconductor packages for next-generation sequencing data analysis. 30 DEGs were analyzed in Ingenuity Pathway Analysis (IPA) platform (Qiagen) for determination of pathway enrichment and upstream regulators.
RESULTS
Subject Characteristics. Twelve CSU and 6 non-CSU (control) subjects were enrolled. The mean age of CSU subjects (F:M-9:3, Black:White-2:10) was 47.3 years. The average duration (with 95% CI) of CSU symptoms was 7.0 (0.2-18) years. Most CSU subjects were prescribed diphenhydramine or hydroxyzine as rescue therapy. Nine subjects completed the study. Three (25%) of the 12 subjects dropped out of the study after the first benralizumab dose (one due to personal issues, one lost to follow-up and one due to non-response); among them, two showed a trend to response and one was a non-responder who had previously also not responded to omalizumab.