Capecitabine, Tucatinib, and Intrathecal Trastuzumab for Breast Cancer Patients With Leptomeningeal Disease

Patient must have signed a written informed consent form prior to any trial specific procedures. When the patient is physically unable to give their written consent, a trusted person of their choice, independent from the investigator or the sponsor, can confirm in writing the patient's consent;

Patients ≥18 years old;

Histologically confirmed metastatic breast cancer;

Histologically confirmed HER2 positive breast cancer, with HER2 positive defined by in situ hybridization (ISH), immunohistochemistry (IHC), or fluorescence in situ hybridization (FISH) methodology; Note: HER2 testing should be performed preferably metastatic site; any estrogen and progesterone (ER/PR) status is allowed;