World Allergy Forum - IgE: Bench to Bedside
Anti IgE and Immunotherapy
The management of allergic diseases is based on the general principles of environmental control (allergen avoidance), pharmacologic therapy, allergen immunotherapy, and patient education. Specific immunotherapy (SIT) can be an effective treatment for allergic rhinitis and allergic asthma, if adequate doses of standardized allergens are administered, with the possibility of long-term benefits extending beyond the course of treatment. However, the clinical effect of SIT may be incomplete in the first year of therapy, especially in polysensitized patients.
The monoclonal anti-IgE antibody, omalizumab, lowers levels of serum free IgE in humans and reduces IgE-mediated symptoms, regardless of the allergen specificity (and biological role) of the IgE involved.
We conducted a randomized, double-blind trial to assess the efficacy and safety of subcutaneously administered anti-IgE (omalizumab) or placebo in children and adolescents with seasonal allergic rhinitis in both birch- and grass-pollen seasons (sequential seasons lasting on average 84 days). There were 4 treatment arms. Each subject was started on SIT-birch or SIT-grass, and anti-IgE or placebo was started before and maintained during (total 24 weeks) the anticipated pollen seasons. The primary efficacy variable was symptom load, the sum of daily symptom severity score plus rescue medication use.
221 subjects (intent-to-treat population) aged 6-17 years were analyzed for efficacy. Combination therapy reduced symptom load over the pollen seasons by 48% (P < .001) over SIT alone. When analyzed separately by season, the two groups receiving unrelated SIT were considered as placebo controls. In the grass season, symptom loads were: unrelated (birch)-SIT + placebo: 0.89 (reference value); unrelated (birch)-SIT + anti-IgE: 0.49 (-45%); SIT-grass + placebo: 0.61 (-32%); SIT-grass + anti-IgE: 0.26 (-71%). Anti-IgE therapy conferred a protective effect independent of type of allergen. Additional clinical benefit was demonstrated in both pollen seasons, whether covered by SIT or not.
The combination of specific immunotherapy and anti IgE may be a novel strategy to further reduce symptoms and additional rhinitis medication requirements in patients for whom specific immunotherapy is indicated. The lack of dependence on allergen specificity makes anti-IgE especially suitable for use in polysensitized allergic patients.
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Kuehr J, et al. Efficacy of combination treatment with anit-IgE plus specific immunotherapy in polysensitized children and adolescents with seasonal allergic rhinitis. J Allergy Clin Immunol (in press).