Researchers are looking for other ways to treat breast cancer (BC) that is hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2-) and either unresectable locally advanced or metastatic. * HR positive (HR+) means the cancer cells have proteins that attach to estrogen or progesterone (hormones) which help the cancer to grow and spread * HER2 negative (HER2-) means the cancer cells have a low amount of a protein called HER2 * Unresectable locally advanced means the cancer cannot be completely removed by surgery and has spread into nearby tissue or muscles * Metastatic means the cancer has spread to other parts of the body Treatment for this type of breast cancer usually includes endocrine therapy (ET) and sometimes a second treatment. The main goal of this study is to learn if people who receive patritumab deruxtecan (also known as HER3-DXd and MK-1022) live longer overall or without the cancer growing/spreading, compared to people who receive chemotherapy or a different drug called trastuzumab deruxtecan.
Phase 3 trials are pivotal studies with large patient populations (hundreds to thousands) designed to prove efficacy and safety for FDA submission. A successful Phase 3 readout is typically the last major hurdle before a New Drug Application (NDA) or BLA filing.
Currently recruiting: the trial is enrolling patients. A data readout is not expected until after enrollment closes and the follow-up period is complete.
Merck & Co (MRK) is the sponsoring company for this trial. BiotechSign currently grades this company F (35/100) based on composite catalyst signals across its full pipeline. This trial is one data point in that overall catalyst picture.