Theranostics 2017; 7(5):1266-1276. doi:10.7150/thno.18304

Research Paper

Clinical efficacy of omalizumab in chronic spontaneous urticaria is associated with a reduction of FcεRI-positive cells in the skin

Martin Metz1, Petra Staubach2, Andrea Bauer3, Randolf Brehler4, Janine Gericke1*, Michael Kangas5, Joanna Ashton-Chess5, Philip Jarvis5, Panayiotis Georgiou5†, Janice Canvin5, Rainer Hillenbrand5, Veit J. Erpenbeck5, Marcus Maurer1✉

1. Department of Dermatology and Allergy, Charité - Universitätsmedizin, Berlin, Germany;
2. Department of Dermatology, University Medicine Mainz, Germany;
3. Department of Dermatology, University Allergy Center, University Hospital Carl Gustav Carus, Technical University Dresden, Germany;
4. Department of Dermatology, University Hospital Muenster, Germany;
5. Translational Medicine, Novartis Pharma AG, Basel, Switzerland
* Current address: Novartis Pharma AG, Basel, Switzerland
† Current address: Clovis Oncology, Cambridge UK.

Abstract

Background. Treatment with omalizumab, a humanized recombinant monoclonal anti-IgE antibody, results in clinical efficacy in patients with Chronic Spontaneous Urticaria (CSU). The mechanism of action of omalizumab in CSU has not been elucidated in detail.

Objectives. To determine the effects of omalizumab on levels of high affinity IgE receptor-positive (FcεRI+) and IgE-positive (IgE+) dermal cells and blood basophils. Treatment efficacy and safety were also assessed.

Study design. In a double-blind study, CSU patients aged 18‑75 years were randomized to receive 300 mg omalizumab (n=20) or placebo (n=10) subcutaneously every 4 weeks for 12 weeks. Changes in disease activity were assessed by use of the weekly Urticaria Activity Score (UAS7). Circulating IgE levels, basophil numbers and levels of expression of FcεRI+ and IgE+ cells in the skin and in blood basophils were determined.

Results. Patients receiving omalizumab showed a significantly greater decrease in UAS7 compared with patients receiving placebo. At Week 12 the mean difference in UAS7 between treatment groups was -14.82 (p=0.0027), consistent with previous studies.

Total IgE levels in serum were increased after omalizumab treatment and remained elevated up to Week 12. Free IgE levels decreased after omalizumab treatment.

Mean levels of FcεRI+ skin cells in patients treated with omalizumab 300 mg were decreased at Week 12 compared with baseline in the dermis of both non-lesional and lesional skin, reaching levels comparable with those seen in healthy volunteers (HVs). There were no statistically significant changes in mean FcɛRI+ cell levels in the placebo group. Similar results were seen for changes in IgE+ cells, although the changes were not statistically significant.

The level of peripheral blood basophils increased immediately after treatment start and returned to Baseline values after the follow-up period. The levels of FcεRI and IgE expression on peripheral blood basophils were rapidly reduced by omalizumab treatment up to Week 12.

Conclusions. Treatment with omalizumab resulted in rapid clinical benefits in patients with CSU. Treatment with omalizumab was associated with reduction in FcɛRI+ and IgE+ basophils and intradermal cells.

Keywords: Omalizumab, Chronic Spontaneous urticaria, mode of action

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) license (https://creativecommons.org/licenses/by-nc/4.0/). See http://ivyspring.com/terms for full terms and conditions.
How to cite this article:
Metz M, Staubach P, Bauer A, Brehler R, Gericke J, Kangas M, Ashton-Chess J, Jarvis P, Georgiou P, Canvin J, Hillenbrand R, Erpenbeck VJ, Maurer M. Clinical efficacy of omalizumab in chronic spontaneous urticaria is associated with a reduction of FcεRI-positive cells in the skin. Theranostics 2017; 7(5):1266-1276. doi:10.7150/thno.18304. Available from http://www.thno.org/v07p1266.htm