Rationale: Adjunct therapy with omalizumab with multiallergen food oral immunotherapy (mOIT) has been shown to be safe and effective, however optimal omalizumab dosing strategies have not been explored in the setting of mOIT.
Methods: In a pilot study, participants received 3 monthly doses of 150 mg of omalizumab prior to initiating mOIT and were randomized 1:1 to receive total protein maintenance mOIT doses of either 300 mg (Group A) or 1200 mg (Group B). Each participant’s 150 mg omalizumab dose was divided by their weight and total IgE in post-hoc analysis. Those receiving less than 0.016 mg/kg/(IU/mL) were categorized as low-dose (LD) and the remainder were categorized as standard-dose (SD). Time to mOIT maintenance (TTM) was compared for groups A and B and within each group for SD versus LD.
Results: Sixty participants aged 4-20 years were randomized to 30 in each treatment arm, with 9 and 21 in each arm receiving the SD and LD omalizumab, respectively. Within Group A, TTM was not different between SD and LD (p=0.66). However, TTM was significantly different between SD and LD (p<0.001) within Group B, where those in SD reached maintenance much faster than those in the LD arm and a higher proportion of participants reached the maintenance dose at week 12 (p=0.01; 42% in LD vs 100% in SD).
Conclusions: Our preliminary data suggest that when pursuing higher dose mOIT, SD omalizumab dosing significantly reduces TTM. Further randomized controlled trials are needed to better define optimal dosing strategies for omalizumab in food allergy.