Tucatinib, Trastuzumab, and Capecitabine for the Treatment of HER2+ LMD

Inclusion criteria

• ✓. Contrast-enhanced MRI Note: If patient has implants in place that are MRI incompatible, these must be removed prior to enrollment.
• ✓. Placement of an Ommaya reservoir (ventricular access device). Note: This is mandatory for the first 15 patients enrolled onto the protocol (first stage). In the second stage, this is strongly recommended per protocol. If a patient cannot or chooses not to undergo Ommaya placement in the second stage, the patient will be allowed to enroll.
• ✓. Evaluation by medical oncologist at baseline and at every cycle (required)
• ✓. Evaluation by neurologist/neuro-oncologist at baseline and at every cycle (strongly recommended); if this is not possible at a site, a medical oncologist may per perform the protocol specified evaluations at each visit.
• ✓. \>14 days since last dose of any previous endocrine therapy, chemotherapy, trastuzumab or other antibody-based therapy. NOTE: If patients have been previously receiving trastuzumab on a weekly basis (at a dose of 2mg/kg), only a 7 day washout will be required.
• ✓. \>14 days or five half-lives since previous treatment with any experimental agent, whichever is greater
• ✓. Cumulative dose of doxorubicin \>360 mg/m2 or previous treatment with another anthracycline with cumulative dose equivalent to \>360 mg/m2 doxorubicin is not allowed.
• ✓. Patients must not have received any therapy specifically directed at LMD, including prior systemic or intrathecal therapy for LMD.