Testing the Use of Ado-Trastuzumab Emtansine Compared to the Usual Treatment (Chemotherapy With Docetaxel Plus Trastuzumab) or Trastuzumab Deruxtecan for Recurrent, Metastatic, or Unresectable HER2-Expressing Salivary Gland Cancers

This phase II trial compares the effect of usual treatment of docetaxel chemotherapy plus trastuzumab, to ado-emtansine (T-DM1) in patients with HER2-positive salivary gland cancer that has come back (recurrent), that has spread from where it first started (primary site) to other places in the body, or cannot be removed by surgery (unresectable). This trial is also testing how well trastuzumab deruxtecan works in treating patients with HER2-low recurrent or metastatic salivary gland cancer. Trastuzumab is a form of targeted therapy because it works by attaching itself to specific molecules (receptors) on the surface of cancer cells, known as HER2 receptors. When trastuzumab attaches to HER2 receptors, the signals that tell the cells to grow are blocked and the cancer cell may be marked for destruction by body's immune system. Trastuzumab emtansine contains trastuzumab, linked to a chemotherapy drug called emtansine. Trastuzumab attaches to HER2 positive cancer cells in a targeted way and delivers emtansine to kill them. Trastuzumab deruxtecan is a monoclonal antibody called trastuzumab, linked to a chemotherapy drug called deruxtecan. Trastuzumab is a form of targeted therapy because it attaches to specific molecules (receptors) on the surface of cancer cells, known as HER2 receptors and delivers deruxtecan to kill them. Docetaxel is in a class of medications called taxanes. It stops cancer cells from growing and dividing and may kill them. Trastuzumab emtansine may work better compared to usual treatment of chemotherapy with docetaxel and trastuzumab or trastuzumab deruxtecan in treating patients with recurrent, metastatic or unresectable salivary gland cancer.