REVIEW ARTICLE Drug Desensitization in the Management of Hypersensitivity Reactions to Monoclonal Antibodies and Chemotherapy Veronica Mezzano • Pedro Giavina-Bianchi • Matthieu Picard • Joana Caiado • Mariana Castells Published online: 30 August 2013 Ó Springer International Publishing Switzerland 2013 Abstract Hypersensitivity reactions to monoclonal anti- bodies and chemotherapy, which may vary in severity from mild to life-threatening, can lead to their discontinuation and replacement by alternative agents that are often less effective, more toxic, and/or more expensive. Drug desensitization has emerged as the best treatment modality capable of allowing re-introduction of the hypersensitivity reaction-inducing medication in highly sensitized patients in need of first line therapies. In recent years, the avail- ability of new anti-neoplastic drugs and therapeutic monoclonal antibodies has increased, as has the potential for hypersensitivity reactions. Development of desensiti- zation protocols for these new medications requires a careful assessment of the potential risks and benefits. The purposes of this review are to provide an overview of the presentation of hypersensitivity reactions amenable to desensitization and to increase awareness of the indications for and outcomes of desensitization protocols. Rapid drug desensitization has proven to be a safe and effective way of administering first line therapy to patients with hypersen- sitivity reactions, providing an extremely powerful treat- ment modality for patients for whom alternative drugs are deemed unacceptable. Rapid drug desensitization protocols should be administered only by highly trained allergists and nurses who have experience in determining which reactions are amenable to desensitization, and can identify high risk patients and provide them with appropriate care. Efforts should be made to increase awareness of the remarkable safety and efficacy of rapid drug desensitiza- tion among non-allergists, especially in the fields of oncology and rheumatology, so as to favor its universal application. Development of desensitization units to pro- vide state-of-the-art care is possible only through coordi- nated teamwork. 1 Introduction Over the last 20 years, major advances have been made in the treatment of cancer, as well as autoimmune and chronic inflammatory diseases, through the development of targeted therapies, such as monoclonal antibodies, and routine use of multiple-drug combination regimens. This therapeutic approach has improved disease outcomes, quality of life, and survival rates [1]. However, hypersensitivity reactions (HSRs) to these molecules, which may vary in their severity from mild to life-threatening, can lead to their discontinu- ation and replacement by alternative agents that are often less effective, more toxic, and/or more expensive. HSRs are increasing in frequency in patients exposed repeatedly to monoclonal antibodies or multiple courses of chemother- apy, presenting a challenge to both physicians and patients, since they occur unexpectedly and their symptoms may be atypical, leading to a delay in diagnosis. Drug desensitiza- tion has emerged as the best treatment modality capable of allowing re-introduction of the HSR-inducing medication in highly sensitized patients in need of first line therapies. The purposes of this review are to provide an overview of the presentation of HSRs amenable to desensitization and to increase awareness of the indications for and out- comes of desensitization protocols for chemotherapy and monoclonal antibodies. V. Mezzano Á P. Giavina-Bianchi Á M. Picard Á J. Caiado Á M. Castells (&) Division of Rheumatology, Immunology and Allergy, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 1 Jimmy Fund Way, Smith Building, Boston, MA 02115, USA e-mail: mcastells@partners.org BioDrugs (2014) 28:133–144 DOI 10.1007/s40259-013-0066-x