4CPS-136 Analysis of the use of omalizumab in oral tolerance induction for high-risk food allergies in children

Background Omalizumab-assisted oral-induced tolerance (oaOTI) has been proved to reduce the number of adverse events and shorten the time needed to reach tolerance compared to conventional OTI in patients with high-risk food allergy (hrFA). However, there are no established recommendations for omalizumab use for this indication. Purpose The objective of this study was to describe the experience of oaOTI in patients with hrFA and its economic impact. Material and methods This was an observational retrospective study including all paediatric patients with hrFA who underwent oaOTI in a tertiary care hospital. Patients initiated oaOTI in the case of previous OTI failure and/or anaphylaxis after allergen intake and/or specific IgE >100 UI/mL. Demographic data, dosage, duration of treatment and clinical outcomes were obtained from the prescription and clinical data software. Results Sixteen patients (50% girls) with a median age of 13.5 (range 8–18) years’ old were included: 12 were allergic to milk and four to eggs. Median basal IgE was 1142 (255–3,960) KUI/mL and 69% of patients had a specific IgE >100 UI/mL. Omalizumab was started at least 16 weeks before OTI initiation. Mean ±standard deviation initial dose was 556±366 mg/month (75–1,200 mg). Dosage recommendations for omalizumab in allergic asthma included in the Summary of Product Characteristics were followed in eight patients: six patients received lower doses and one patient received higher doses than recommended (there were no recommendations for one patient with IgE >1,500 UI/mL). All patients successfully completed OTI and omalizumab was then tapered to the minimum tolerated dose. Two patients were able to stop omalizumab after 44.7 and 61 months, 14 patients are still on omalizumab maintenance and the dose was reduced in 12 (75%) patients. Anaphylaxis occurred in three patients during OTI. Omalizumab injection was well tolerated: only one case of headache and one case of rash were reported. Median monthly cost was €1100 (€738–€2,952)/patient, including the initial dose. Conclusion oaOTI allowed patients with hrFA to acquire tolerance rapidly and safely, however, it had a great economic impact. Further research is needed to define how to reduce or interrupt omalizumab treatment in patients receiving the drug as an adjuvant to OTI. Reference and/or acknowledgements Labrosse R, et al . The use of omalizumab in food oral immunotherapy. Archiv Immunolog Ther Experi 2016;65:189–99. No conflict of interest.