Long-term outcome of omalizumab-assisted desensitisation to cow's milk and eggs in patients refractory to conventional oral immunotherapy: real-life study.

Background: Oral immunotherapy (OIT) is a promising approach to cow's milk and egg allergies, but reactions are frequent and some patients cannot be desensitized.
Objective: To evaluate long-term OIT outcomes with omalizumab (OMZ) in paediatric patients with severe egg and/or milk allergies.
Methods: This retrospective real-life study analysed findings in children with Immunoglobulin E-mediated allergy to cow's milk and/or hen eggs refractory to conventional OIT, who underwent OIT with OMZ in our department between 1 January 2010 and 31 December 2015.
Results: In all, 41 patients were included (median age: 7 years; interquartile range [IQR]: 5.5-9.5); 26/41 (63.4%) underwent OIT for milk, 8/41 (19.5%) for egg and 7/41 (17.1%) for both. The median time between initiation of OMZ and OIT was 27 weeks (IQR: 22-33). Forty (97.56%) patients reached the maintenance phase (200 mL of cow's milk and 30 mL of raw egg or 1 cooked egg) in a median time of 27 weeks (IQR: 18-37). The median total time with OMZ was 117 weeks (IQR: 88-144). During the OMZ period, 2.44% (1/41) of patients presented anaphylaxis. After discontinuation of OMZ, 29.3% (12/41) presented anaphylaxis, 50% of them had a poor adherence to daily ingestion. One patient (2.44%) was diagnosed with eosinophilic esophagitis after 2 years of discontinuation of OMZ. Currently, after a median time of 9 years (IQR: 7-10) since the initiation of OMZ, 75.6% (31/41) are desensitized (27/31 without OMZ).
Conclusions: Omalizumab allows desensitisation of children with severe allergies to cow's milk and/or egg without developing severe reactions while receiving this treatment. However, discontinuation of OMZ leads to severe allergic reactions, and hence must be monitored carefully.