Study of Trastuzumab Deruxtecan in Adults With HER2-Low or HER2-Ultralow Unresectable or Metastatic Breast Cancer Including a Registry for Patients Treated With Conventional Chemotherapy in Europe

What this Trial Is About

Researchers are investigating the use of Trastuzumab deruxtecan T-DXd in adults with unresectable or metastatic HER2-low and HER2-ultralow breast cancer. This includes patients who have previously received chemotherapy for metastatic breast cancer or have hormone receptor-positive disease treated with endocrine therapy but are unsuitable for further endocrine treatment. The study aims to understand treatment effectiveness, patient characteristics, and experiences in a real-world setting through a non-interventional approach. Participants will be observed while receiving either T-DXd or conventional chemotherapy as part of their routine care, without any drug administration by the study itself. The study includes two groups one with patients having HER2-low breast cancer treated with T-DXd after prior chemotherapy, and another with hormone receptor-positive, HER2-low or HER2-ultralow breast cancer patients treated with either T-DXd or conventional chemotherapy but not prior chemotherapy for metastatic disease. Data will be collected on treatments, side effects, and management of adverse drug reactions. During the study, participants demographic and clinical data, treatment patterns, tolerability, and quality of life will be monitored over approximately 37 months. Assessments include the time to next treatment, treatment discontinuation, physician-reported safety events, patient-reported tolerability, quality of life questionnaires, and symptom diaries. This long-term observation will help evaluate real-world outcomes and patient experiences with T-DXd and conventional chemotherapy in this population.

DESTINY Breast Respond HER2-(Ultra)Low Europe