Purpose of review: Omalizumab, a monoclonal anti-IgE antibody, is currently indicated for the treatment of moderate-to-severe allergic asthma. We have reviewed the published studies and case reports of off-label omalizumab use in the prevention of IgE-mediated hypersensitivity reactions of various causes. Additionally, we have reviewed anaphylaxis associated with omalizumab treatment.
Recent findings: Many case reports and smaller studies have reported the efficacy of omalizumab in the prevention of various hypersensitivity and anaphylactic reactions with or without known trigger. One randomized study has showed partial improvement in the tolerance of peanuts in peanut-allergic patients with anti-IgE therapy. Furthermore, several randomized, placebo-controlled studies and case reports have demonstrated that omalizumab in combination with allergen or venom immunotherapy decreases the incidence of systemic hypersensitivity reactions and may improve the clinical outcomes. Finally, review of the data documents low risk of anaphylaxis with omalizumab use, with one study demonstrating successful desensitization to this medication.
Summary: The available studies indicate that omalizumab is effective and well tolerated in decreasing hypersensitivity reactions associated with allergen immunotherapy in patients with allergic rhinitis and mild-to-moderate asthma. Additionally, omalizumab may represent a promising therapy of anaphylaxis with or without known trigger, which should be further investigated with randomized studies. Moreover, additional research is needed to elucidate the mechanism of anaphylaxis with the medication itself.