Safety profile of Trastuzumab deruxtecan in patients with advanced HER2+ breast cancer: an active pharmacovigilance study

Abstract

Objective: To analyze the safety profile of the drug Trastuzumab deruxtecan and describe the clinical and epidemiological characteristics of patients diagnosed with advanced breast cancer as HER2 positive. Methods: This is a retrospective observational study, approved by the Research Ethics Committee, in which patients with HER2 positive breast cancer undergoing chemotherapy based on Trastuzumab deruxtecan were evaluated through the hospital management system, from March/2022 to March/2024, finding the adverse events presented, clinical and epidemiological data, as well as information regarding the treatment. The events presented in previous treatments were considered in order to avoid brightness bias. Causality was assessed by the Naranjo Algorithm and severity by the Common Terminology Criteria for Adverse Events methodology. Results: 45 patients were selected, 3 of which were excluded due to loss of follow-up. Of the group of patients analyzed, 33% did not report any complications or complaints arising from Trastuzumab deruxtecan and previous protocols. Some patients presented more than one adverse event, all of which were considered. Among the observations, the following stand out: nausea and vomiting (78.6%), followed by asthenia (46.4%), alopecia (32.1%), constipation (21.4%), mucositis (14.3%) and loss of appetite (10.7%). Regarding the causality profile, it was found that 31.5% were defined as definite and 68.5% as probable, with the majority defined as grade 1 (67.1%). Conclusion: The results reflect agreement with the literature regarding the profile, severity and causality of the events. It is suggested that real-life studies be conducted with a larger population and for a longer period to evaluate the long-term safety profile.