TROPION-Breast02: Datopotamab deruxtecan for locally recurrent inoperable or metastatic triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that is hard to treat. Tumors lack receptors for estrogen and progesterone, which means that standard endocrine therapy is ineffective, and it does not express HER2, so HER2 therapies are also not appropriate. However, the majority of TNBC tumors do possess a cell surface protein called TROP2 which provides a way of directing treatment inside tumor cells that is more selective than traditional chemotherapy. Datopotamab deruxtecan (Dato-DXd) is a drug that consists of two parts: datopotamab (an antibody) and DXd (the cancer-cell killing toxic component), which are joined via a stable linker. Datopotamab binds to the TROP2 protein found on TNBC tumors and is taken into the cell. The linker is then broken and releases DXd, which kills the tumor cell. By binding to cancer cells before releasing the payload, treatment is directed to the tumor, minimizing side effects in the rest of the body. The TROPION-Breast02 study aims to discover whether Dato-DXd is more effective than standard-of-care chemotherapy, allowing patients with TNBC to live longer without their breast cancer getting worse. This study is also looking at how Dato-DXd may affect patients' overall functioning and quality of life. TROPION-Breast02 will recruit approximately 600 patients who: Have cancer that has spread from the original site (metastatic), or cancer that returned to the same site (locally recurrent) that cannot be surgically removed Have not received any prior treatment for this stage of cancer Cannot receive an alternative type of anticancer treatment called PD-(L)1 inhibitors Had any length of time between their last treatment with the aim of cure and return of their disease Eligible patients will be randomly assigned to a treatment group in equal numbers to either Dato-DXd or an appropriate chemotherapy (one of five available options, chosen by the treating doctor). Each patient will generally continue to receive their designated treatments if the tumor is controlled by the drug, there are no unacceptable side effects, or the patient chooses to stop treatment. Clinical Trial Registration: NCT05374512 (ClinicalTrials.gov).