Studying Genetic Effects on Side Effects of Antibody-Drug Treatments in Advanced or Metastatic Breast Cancer

What this Trial Is About

Researchers are studying how genetic differences affect the way certain antibody-drug conjugates ADCs used in treating locally advanced or metastatic breast cancer are processed in the body. Specifically, they are focusing on the UGT1A1 gene, which influences how the active drug components are eliminated and how toxic side effects may develop. Variants in this gene can increase the risk of severe side effects such as neutropenia and diarrhea, especially with drugs like sacituzumab-govitecan, trastuzumab-deruxtecan, and datopotamab-deruxtecan. The study monitors patients receiving standard clinical doses of these three ADCs as part of their breast cancer treatment. Each drug is given according to routine clinical practice and product guidelines. The research evaluates the presence of UGT1A1 genetic variants and their association with the severity of drug-related toxicities over time. Participants will be followed for up to two years, during which researchers will track severe side effects related to the drugs. Genetic testing will be done at the start to identify UGT1A1 variants. The study aims to develop a predictive model linking these genetic markers to toxicity risk. Patients will receive their usual cancer care while contributing information through genetic analysis and monitoring of treatment outcomes.

Impact of Genetic Variants on the Toxicity of Antibody-Drug Conjugates in Locally Advanced or Metastatic Breast Cancer: The Role of the UGT1A1 Gene as a Predictive Biomarker of Therapeutic Response