Trastuzumab Emtansine

This phase III trial evaluates the effect of adding locoregional therapy (surgery and radiation) and metastasis-directed stereotactic body radiation therapy (SBRT) to standard systemic therapy following standard HER2-targeted systemic therapy, compared to standard systemic therapy alone, in treating patients with HER2-positive stage IV breast cancer that has spread from where it first started (primary site) to other places in the body (metastatic) or to a limited number of sites (oligometastatic). The usual approach for patients with (oligo)metastatic HER2-positive breast cancer is systemic drug treatment, which means medicines that travel through the whole body to treat both the breast and any areas where the cancer has spread. There are a number of approved HER2-targeted systemic therapy regimens available to patients. These typically include immunotherapy and/or chemotherapy. Immunotherapy drugs may induce changes in body's immune system and may interfere with the ability of tumor cells to grow and spread. Chemotherapy drugs work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Unlike systemic therapy, locoregional therapies like surgery and radiation are focused treatments at the site of disease, delivered with the intent of sparing healthy tissues. Breast surgeries such as breast conserving therapy or total mastectomy are procedures in which the cancerous breast tissue (and healthy breast tissue in the case of total mastectomy) are surgically removed from the body. Radiation therapy uses high energy x-rays, particles, or radioactive seeds to kill cancer cells and shrink tumors. SBRT is a type of external radiation therapy that uses special equipment to position a patient and precisely deliver radiation to tumors in the body (except the brain). The total dose of radiation is divided into smaller doses given over several days. This type of radiation therapy helps spare normal tissue. Adding locoregional therapy, as well as metastasis-directed SBRT, to standard systemic therapy may help patients with (oligo)metastatic, HER2-positive stage IV breast cancer live longer overall or before their cancer progresses, and may help more patients achieve no evidence of disease, when compared to standard systemic therapy alone.

This phase II trial compares the effect of usual treatment of docetaxel chemotherapy plus trastuzumab, to ado-emtansine (T-DM1) in patients with HER2-postive 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 traztuzumab, 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.