Safety of anti-IgE treatment with omalizumab in children with seasonal allergic rhinitis undergoing specific immunotherapy simultaneously.

Introduction: Seasonal allergic rhinitis (SAR) affects at least 10-25% of the Caucasian race and about 40% of patients are children. Standard treatment of SAR is specific immunotherapy (SIT), but anti-allergic drugs can significantly enhance efficacy of SIT. One candidate is the humanized monoclonal anti-IgE antibody omalizumab.
Material and Methods: Randomized, double-blind, placebo-controlled, multi-centre trial in Germany. A total of 221 children were randomly assigned to four different groups and treated with SIT (either grass or birch pollen), starting at least 14 wk before the local birch pollen season. After the 12-wk SIT titration phase, either anti-IgE (omalizumab) or placebo (NaCl 0.9%) therapy was added. This combination therapy with SIT and anti-IgE or placebo lasted 24 wk. To record local reactions and adverse events (AE), the injection site was examined by a clinician 20 min after application of study medication. Further, patients stated any AE and the use of rescue medication by means of a diary 3 days after every injection. Finally, any AE or serious adverse event (SAE) reported by the patients was specified on a standard form by clinicians. Overall tolerance was judged by the doctors according to the patient's diaries. To test differences between the groups, we used either the two-sided Wilcoxon rank-sum test or the two-sided chi-square test.
Results: Tolerability of SIT and omalizumab treatment was good (82% of patients). Only some AE with possible causal relationship to treatment occurred slightly more often in the verum groups, i.e. local reactions (16.8 vs. 12.3%) and gastrointestinal (2.7 vs. 0.9%) and ear symptoms (1.8 vs. 0%). Most AE (93.4% in omalizumab and 87.2% in placebo group) were judged by the patients as mild to moderate. SAE were restricted to four patients with asthma in the placebo group, two subjects with headache in the verum group and three patients with infections (two in verum and one in placebo group). Only the cases of asthma were judged to be possibly related to study medication. Further, redness and swelling at the SIT injection site appeared significantly more often in the placebo group which suggests a positive effect of omalizumab on local reaction induced by SIT.
Conclusion: Omalizumab represents an important clinical advance in the management of allergic diseases and can be considered to be safe in children.
(© 2009 John Wiley & Sons A/S.)