Daiichi Sankyo
This study will evaluate the safety and efficacy of trastuzumab deruxtecan (T-DXd) in participants with human epidermal growth factor receptor 2 (HER2)-low or HER2 immunohistochemistry (IHC) 0 (who are both hormone receptor \[HR\]-negative and HR-positive) unresectable and/or metastatic breast cancer.
The primary endpoint of interest in this study is time to next treatment (TTNT), a measure that will determine how long T-DXd allows patients to derive clinical benefit from the study drug.
Inclusion Criteria: * Sign and date the main informed consent form * Must agree to provide a newly obtained or archival baseline biopsy from primary and/or metastatic lesion. * Pathologically documented Breast Cancer (BC) tumor * Is unresectable and/or metastatic. * Is hormone receptor-negative or hormone receptor-positive. * Must include percentage of positively stained cells to characterize if hormone receptor-positive or -negative. * Has confirmed HER2 IHC 1+ or IHC 2+/ISH- (HER2-low) status or HER2 IHC 0 status as determined according to ASCO CAP 2018 guidelines1 based on samp…
Intravenous administration, 5.4 mg/kg on Day 1 of each 21-day cycle until radiographic disease progression as assessed by the investigator, unacceptable toxicity, other discontinuation criteria are met, or 2 years after first dose of study drug