This peri-operative window of opportunity study in patients with brain metastases will provide a single dose of the antibody-drug conjugate (ADC) patritumab deruxtecan (HER3-DXd, formerly U3-1402) prior to craniotomy to investigate pharmacokinetics, pharmacodynamics, intra- and peritumoral immune activation and responses, safety and explore potential biomarkers. This study will measure the level of the released payload DXd (MAAA-1181a) of patritumab deruxtecan, in resected brain metastasis (BrM) tissue.~Patients will receive a single dose of patritumab deruxtecan intravenously before surgery. Patients will also have procedures such as medical history review, blood draws, MRI scans, ECGs, and lumbar punctures. The amount of time patients are expected to be in this study is approximately 40 days.~Some of the risks of patritumab deruxtecan are diarrhea, nausea, vomiting, fatigue, headache, interstitial lung disease, and low blood counts.~All participants who are administered patritumab deruxtecan as part of this peri-operative window of opportunity study will be included in analyses summarizing adverse events.
The purpose of this study is to determine if the study drug, patritumab deruxtecan (HER3-DXd), can be measured in brain tumor tissue after recieving one dose of patritumab deruxtecan before surgery.