Perlmutter Cancer Center

The purpose of the study is to determine if the invasive disease-free survival (iDFS) with T-DM1 and tucatinib is superior to the iDFS in the control arm (T-DM1 + placebo) when administered to high risk patients with HER2-positive breast cancer and residual disease after neoadjuvant HER2-directed therapy. We want to evaluate whether treatment with tucatinib plus T-DM1 compared to treatment with T-DM1 alone (T-DM1 plus placebo) improves the following: overall survival (OS), breast cancer free survival (BCFS), distant recurrence-free survival (DRFS), disease-free survival (DFS), brain metastases-free survival (BMFS). We want to know whether treatment with tucatinib plus T-DM1 compared to treatment with T-DM1 alone (T-DM1 plus placebo) reduces the incidence of brain metastases.