Rationale: Multiple food allergen oral immunotherapy (mOIT) with adjunct omalizumab is associated with increased tolerability and faster desensitization, however, the minimum maintenance dose of each food protein in mOIT required to achieve successful clinical outcomes is not yet known.
Methods: In a pilot, randomized controlled multicenter trial, 60 participants, aged 4-20 years, received 3 monthly doses of omalizumab prior to initiating mOIT. Participants were randomized 1:1 to receive individualized mOIT containing 2-5 allergens and escalate to a maintenance dose of either 300 mg (Group A) or 1200 mg (Group B) of total food protein. Immune markers, including sIgG4 and sIgE were tested at baseline and week 18 to evaluate whether a minimum maintenance dose could induce a >25% increase in the IgG4/IgE ratio after rapid desensitization.
Results: Peanut was the most common allergen included in the mOIT (n=36). The median percent change in the peanut sIgG4/sIgE ratio from baseline to week 18 was 91% (range: -76%, 877%) and no difference was detected between groups A and B (p=0.23). An increase by 25% or more in the peanut sIgG4/sIgE ratio was achieved by 65% (11/17) in Group A and 74% (14/19) in Group B (p=0.72).
Conclusions: An increase in peanut sIgG4/sIgE ratio was achieved within 18 weeks of mOIT with adjunct omalizumab with no significant difference between treatment group A (300 mg) and B (1200 mg) suggesting that biomarker changes are induced early and at a lower maintenance dose than previously known. Larger phase 2 trials are needed to confirm these findings.