Anti-IgE therapy versus allergen-specific immunotherapy for food allergy: weighing the pros and cons

Abstract

With the recent FDA approval of the anti-IgE biologic, omalizumab, in 2024 for the treatment of food allergy, it is critical to consider the advantages and disadvantages of anti-IgE and allergen-specific immunotherapies (AITs) to help determine optimal patient care. Several AITs have been studied for food allergy, including oral (OIT), sublingual (SLIT), and epicutaneous immunotherapy (EPIT) with varying degrees of safety and efficacy. There are obvious advantages of treating food allergies with omalizumab, including less frequent administration (every 2 or 4 weeks) compared to the daily dosing of AITs, treating multiple food allergies with one medication, and the potential benefit for comorbid asthma and environmental allergies. However, disadvantages of omalizumab include the requirement for lifelong treatment of a costly biologic that will not induce immunologic tolerance. On the other hand, AITs have been shown to effectively induce desensitization in most individuals and can lead to long-term tolerance or remission in a subset of patients. In this review, we will discuss the pros and cons of omalizumab and AITs and the potential benefit of combining both approaches in young children to achieve immediate increases in reaction threshold while also inducing tolerogenic immunologic responses.

Keywords: IgE; allergy immunotherapy; desensitization; epicutaneous immunotherapy; omalizumab; oral immunotherapy; sublingual immunotherapy.

Figure 1

Mechanisms of action for omalizumab and allergen-specific immunotherapy (AIT). In peanut allergic individuals, IgE coats mast cells, which upon peanut exposure, degranulate releasing allergic mediators that cause allergic symptoms (top panel). Omalizumab binds free IgE resulting in absence of peanut-specific IgE on mast cells, which do not degranulate during peanut exposure (left panel). AIT reduces Th2-type cells and cytokines with an increase in Tregs, ultimately leading to decreased peanut-specific IgE and increased peanut-specific IgG4. Upon peanut exposure, mast cells do not degranulate owing to peanut-specific IgG present on mast cells and the neutralization of peanut by IgG4 (right panel). Created in Biorender.

Figure 2

Comparing the pros and cons of omalizumab and allergen-specific immunotherapy (AIT). There are many factors to consider when comparing the two types of therapies, including administration routes and frequency, long-term immune modulation, side effects, and comorbid allergic conditions. The left panel shows potential advantages of AIT (green) compared to omalizumab (red). The right panel shows advantages of omalizumab (green) compared to AIT (red). Created in Biorender.