Omalizumab in asthmatics with IgE levels > 700 IU/ml

Introduction: Omalizumab, a monoclonal antibody against IgE, has been effectively used to control symptoms and reduce steroid requirements in asthmatics with serum IgE levels between 30-700 IU/ml and positive testing for perennial allergens. Its use when IgE levels are > 700 IU/ml is unclear. Aim: To evaluate the response of asthmatics treated with omalizumab with IgE levels > 700 IU/ml. Methods: A retrospective, case-controlled study was performed in an allergy referral clinic. Consecutive asthmatics treated with omalizumab ≥ 6 months with elevated IgE levels were identified, and demographic variables recorded. Systemic corticosteroid requirements, emergency room visits, hospitalizations, FEV1, Asthma Control Test (ACT) scores, medications and allergen responses were recorded for a period of 6 months pre and post treatment. Results: Twenty-six patients with an IgE >700 IU/ml (Group 1) and 26 with an IgE of 30 to 700 IU/ml (Group 2) were identified. The mean IgE level was 2371 IU/ml (786-10979) vs. 221 IU/ml (30-578) respectively (p<0.001). Age, gender, and weight were similar in both groups. Both, Group 1 and Group 2, had an improvement in asthma control based on the mean ACT pre and post treatment (15.6 vs. 18.9 [p=0.016] and 15.4 vs. 19 [p=0.006]) respectively. There was also a significant reduction in the frequency of systemic corticosteroid use during the 6 months pre and post treatment (2.58 vs. 0.96 and 2.62 vs. 1.23/steroid bursts) respectively (p<0.001). Conclusions: Omalizumab was effective in controlling asthma symptoms and reducing the need for systemic corticosteroids in patients with IgE levels > 700 IU/ml and produced clinical improvement similar to patients with IgE levels between 30-700 IU/ml.