trastuzumab

This study is being done to find out if tucatinib with other cancer drugs works better than standard of care to treat participants with HER2 positive colorectal cancer. This study will also determine what side effects happen when participants take this combination of drugs. A side effect is anything a drug does to the body besides treating your disease. Participants in this study have colorectal cancer that has spread through the body (metastatic) and/or cannot be removed with surgery (unresectable). Participants will be assigned randomly to the tucatinib group or standard of care group. The tucatinib group will get tucatinib, trastuzumab, and mFOLFOX6. The standard of care group will get either: * mFOLFOX6 alone, * mFOLFOX6 with bevacizumab, or * mFOLFOX6 with cetuximab mFOLFOX6 is a combination of multiple drugs. All of the drugs given in this study are used to treat this type of cancer.

This study is a randomized, open-label, multicenter clinical study for patients with early or locally advanced (T≥2cm, N0-3, M0) HER2-positive breast cancer, aiming to compare the peripheral blood ctDNA clearance of neoadjuvant pyrotinib + trastuzumab + docetaxel and pertuzumab + trastuzumab + docetaxel for one course and to evaluate the therapeutic effectiveness of four courses of neoadjuvant therapy

The goal of this multicentre, randomized, double-blind controlled, phase III clinical trial is to compare the efficacy and safety of disitamab vedotin in combination with pyrotinib versus the standard first-line treatment of paclitaxel in combination with trastuzumab and pertuzumab (THP) for newly diagnosed recurrent/metastatic Human epidermal growth factor receptor 2 (HER2) positive advanced breast cancer, and to explore the impact of biomarkers on clinical efficacy and safety. The main questions it aims to answer are: * Analyse the efficacy and safety of disitamab vedotin in combination with pyrotinib versus the standard first-line treatment of THP. * Explore the impact of biomarkers on clinical efficacy and safety of the combination of disitamab vedotin in combination with pyrotinib treatment. Participants in the experimental group will receive disitamab vedotin in combination with pyrotinib for 6-8 cycles (each cycle lasting 28 days), followed by maintenance treatment with trastuzumab in combination with pyrotinib. Participants in the control group will receive paclitaxel in combination with trastuzumab and pertuzumab for 6-8 cycles (each cycle lasting 21 days), followed by maintenance treatment with trastuzumab and pertuzumab. Researchers will compare disitamab vedotin in combination with pyrotinib versus the standard first-line treatment of paclitaxel in combination with trastuzumab and pertuzumab to see if disitamab vedotin in combination with pyrotinib could be a new option for first-line treatment of HER2-positive metastatic breast cancer.