Hypersensitivity reactions to chemotherapy and biologics: Outcomes and safety of 927 desensitization in Mexico.

IntroductionChemotherapy and monoclonal antibodies are increasingly associated with hypersensitivity reactions (HSRs), including anaphylaxis. Desensitization modulates allergic responses to drugs, facilitating temporary tolerance to full therapeutic doses.MethodsObservational, descriptive, ambispective study from August 2020 to August 2024, including cancer patients who came for treatment administration and developed a hypersensitivity reaction, and underwent 3-bag 12-step desensitization in 5.67 h. Demographic variables, atopic and oncological history, hypersensitivity reactions, breakthrough reactions (BTR) during desensitization, and safety of the protocols were reported.Results927 desensitization in 219 patients, 20.7% with personal atopy and 84% female. The most common oncological diagnoses were: breast cancer (23.3%), ovarian (22.1%), and cervical (15.9%). The drugs of the most hypersensitivity reactions were Paclitaxel 372 (40.2%), Carboplatin 172 (18.7%), Oxaliplatin 66 (7.1%), Docetaxel 59 (6.4%), Rituximab 40 (4.3%) and Trastuzumab 40 (4.3%). The most frequent hypersensitivity reactions were cutaneous 172 (18.6%), respiratory 173 (18.7%) and cardiovascular 165 (17.8%) with a severity scale of Brown I 12.1%, Brown II 43.3% and Brown III 44.6%. During desensitization 80/927 cases (8.6%) had breakthrough reactions: cutaneous 56 (6%), respiratory 18 (1.9%) and cardiovascular 17 (1.8%), of which the majority were mild reactions. All patients completed their desensitization with no deaths reported.ConclusionsOur study reports that patients undergoing desensitization protocols had a lower percentage of breakthrough reactions compared to the previous hypersensitivity reactions, showing that this procedure is safe and effective to continue first-line oncological treatment.