Omalizumab Dose‐Related Efficacy in a Cohort of Children With Severe Food Allergy: OSAFA Observational Study

Background: We recently published on the clinical efficacy of a 1-year-long evaluation of 65 asthmatics with severe IgE-mediated food allergy (FA) under Omalizumab: Omalizumab is safe and able to increase reactivity threshold, allows safe food introduction, and improves quality of life (OSAFA-study, ClinicalTrials.gov, NCT06316414). Herein, we assess Omalizumab dose–related efficacy during the first year Omalizumab treatment in achieving food desensitization in patients with severe FA. Methods: Children (6–18 years) with severe asthma and severe allergy to ≥ 1 food allergen were screened. Oral food challenges (OFCs), skin prick test (SPT), complete blood count, chemistry, total and specific IgE were measured at baseline and at 12 months of Omalizumab. Results: Seventy-six patients (previously published cohort plus 11 newly-enrolled patients) were included (OSAFA [Omalizumab in Severe Asthmatics with Food Allergy] study). 69.7% were male; mean age (SD) 12.2 [4.19] years. 77.6% were allergic to 2+ foods. Total IgE median was 644 kU/L. After adjusting for confounders, such as age, sex, and co-existing allergies, a significant association was observed between the achievement of desensitization and the dosage (mg/month) of Omalizumab (OR: 1.151, 95% CI: 1.066–1.258), while no significant effect was observed for total IgE levels at the baseline (OR: 0.999, 95% CI: 0.998–1.001). Conclusions: The findings of this study indicate that the efficacy of Omalizumab is independent, all else being equal, from total IgE levels, suggesting that body weight is the most appropriate parameter for calculating its dosage in the treatment of patients with severe FA.