Omalizumab is a humanized, monoclonal anti-IgE antibody that binds specifically to circulating IgE molecules, thus interrupting the allergic cascade.
Omalizumab has been shown to be highly effective in treating children and adults with moderate to severe allergic asthma. Beyond this indication, the mode of action itself suggests that omalizumab is not only an antiasthmatic drug but also a promising therapeutic option for various allergic conditions, including allergic rhinitis, food allergy, urticaria, allergic bronchopulmonary aspergillosis, insect hypersensitivity, and atopic dermatitis. However, data from double-blind, placebo-controlled clinical trials are only available for allergic rhinitis and moderate to severe bronchial asthma.
The aim of this review is to discuss the current clinical data as well as possible further indications of omalizumab treatment.

Airway diseases such as allergic asthma and rhinitis are characterized by a T-helper type 2 (Th2) response.
Treatment of allergic airway diseases is currently limited to drugs that relieve disease symptoms and inflammation. In the search for new therapeutics, efforts have been made to treat allergic airway disease with gene therapy, and many preclinical studies have demonstrated its impressive potential. Most strategies focus on blocking the expression of proinflammatory proteins or transcription factors involved in the disease pathogenesis using antisense oligonucleotides, DNAzymes, small interfering RNA, or blocking of microRNAs using antagomirs. Changing the Th1/Th2 balance by overexpressing Th1-stimulating factors is another treatment option. Although the proof of concept is convincing in animal models, progress in humans remains limited.
In this review, we focus on preclinical models to describe the recent developments and major breakthroughs for treating allergic airway diseases with gene therapy.