Retrospective analysis of the efficacy of omalizumab in chronic refractory urticaria

Abstract

Omalizumab has been shown to be effective in chronic urticaria (CU) patients in numerous reports. However, it remains unknown whether there are specific phenotypes of CU that are more responsive to omalizumab therapy. We sought to identify CU phenotypes responsive to treatment with omalizumab by characterizing patients and their response patterns. A retrospective chart review analysis of refractory CU patients unresponsive to high-dose H1-blockers and immunomodulators and subsequently treated with omalizumab at the University of Wisconsin Allergy Clinic was performed with particular focus on their autoimmune characteristics, response to therapy, and dosing parameters. We analyzed 19 refractory CU patients (16 patients failed or had toxic side effects to immunomodulators) treated with omalizumab with an overall response rate of 89% (17/19). Of these 19 patients, 9 patients (47%) had a complete response, 8 patients (42%) had a partial response, and 2 patients (11%) had no response. In comparing the response patterns to omalizumab, we found no statistically significant differences among "autoimmune positive" versus "autoimmune negative" patients. No statistically significant differences in responses were observed when comparing demographic parameters including age, gender, IgE levels, or dosing regimen. Our study shows that omalizumab has robust efficacy in refractory CU patients regardless of their autoimmune status, age, gender, IgE levels, or dosing protocol.

Figure 1.

Response patterns to omalizumab. The number of patients on y-axis with complete (black bar), partial (gray bar), or no (white bar) response are shown for subgroups separated based on (A) age, (B), gender, (C) IgE level, and (D) dosing protocol. The p values for statistical comparison of response patterns are shown in each panel.

Figure 2.

Response patterns of omalizumab to individual autoimmune markers. The number of patients on y-axis with complete (black bar), partial (gray bar), or no (white bar) response are shown for subgroups separated based on (A) antinuclear antibody (ANA), (B) antithyroglobulin (ATG), (C) antithyroperoxidase (ATPO), and (D) chronic urticaria (CU) index. Positive (+) and negative (−) for ANA, ATPO, ATG, and CU index were based on standards from the respective testing laboratory. The p values for statistical comparison of response patterns are shown in each panel.

Figure 3.

Response patterns of omalizumab to overall autoimmune status. The number of patients on y-axis with complete (black bar), partial (gray bar), or no (white bar) response are shown for subgroups with any positive autoimmune marker (+) and no positive autoimmune marker (−). The p value for statistical comparison of response patterns is shown.