New biologics in allergy

For over two decades targeted biological therapies have emerged and are revolutionizing the care of patients with difficult-to-treat atopic diseases, offering improved efficacy and/or fewer side effects compared to conventional antiinflammatory therapies. Various biological therapies are now approved for use in atopic asthma, eosinophilic asthma, atopic dermatitis, chronic rhinosinusitis with nasal polyposis, eosinophilic granulomatosis with polyangiitis, and chronic idiopathic urticaria. Currently available biologics targeting steps along the Th2 pathway of inflammation include monoclonal antibodies against immunoglobulin E, interleukin (IL)-5, IL-5 receptor, and the IL-4 receptor alpha subunit, with additional targets in the developmental pipeline. The allergist is also often responsible for the care of patients with certain non-Th2 conditions, among them hereditary angioedema. Therapies for hereditary angioedema now include a monoclonal antibody against plasma kallikrein. As more biological therapies become available, the promise of disease control has become a reality for increasing numbers of patients with severe atopic conditions. Yet the era of biological therapies has not yet resulted in maximal disease control for all allergic patients. The high costs of targeted biological therapies often restrict their use to a patient population even more narrowly defined than the Food and Drug Administration-approved indications for these drugs. In addition, treatment failures in some patients highlight the heterogeneity of allergic diseases, such as asthma and atopic dermatitis, and underscore the importance of continued development of biological therapies targeting additional mediators along the Th2 inflammatory pathway.