The Combination of Allergen Immunotherapy and Biologics for Inhalant Allergies: Exploring the Synergy.

The development of monoclonal antibodies that selectively target IgE and type 2 immunity has opened new possibilities in the treatment of allergies. Although they have been used mainly as single therapies that have shown efficacy in the management of asthma and other T2-mediated diseases, there is a growing interest in using these monoclonal antibodies in combination with allergen immunotherapy (AIT). AIT has transformed the treatment of allergic diseases by aiming to modify the underlying immune response to allergens rather than just providing temporary symptom relief. Despite the proven efficacy and safety of AIT, unmet needs call for further research and innovation. Combination strategies involving biologics and AIT exhibit potential in improving short-term efficacy, reducing adverse events, and increasing immunological tolerance. Anti-IgE emerges as the most promising therapeutic strategy, not only enhancing AIT's safety and tolerability but also providing additional evidence of efficacy compared to AIT alone. Anti-IL-4 receptor offers a reduction in side effects and an improved immunological profile when combined with AIT, however its impact on short-term efficacy appears limited. The combination of cat dander subcutaneous immunotherapy with anti-TSLP was synergistic with enhanced efficacy and altered immune responses that persisted for one year after discontinuation compared to AIT alone. Long-term studies are needed to evaluate the sustained benefits and safety profiles of combination strategies.