Defining the HER2 Positive (+) Breast Cancer Kinome Response to Trastuzumab, Pertuzumab, Combination Trastuzumab +Pertuzumab, or Combination Trastuzumab + Lapatinib

Kinases are a group of proteins that are important in how cancer cells grow. HER2 is a kind of kinase. This study looks at a new approach to identifying kinases, which may help target therapy more precisely. LCCC1214 is a randomized, multiarm, multicenter, open-label window trial designed to explore the kinome response in Stage I-IV HER2 positive (HER2+) breast cancer patients scheduled to undergo definitive surgery (either lumpectomy, mastectomy or surgical resection of oligometastatic disease). Patients will initiate dosing with either a single HER2-directed agent or a combination of two HER2-directed agents, one week prior to surgery. Forty patients will be randomized to one of four study groups: A) single dose trastuzumab; B) single dose pertuzumab; C) combination single dose trastuzumab plus single dose pertuzumab; or D) combination single dose trastuzumab plus lapatinib daily for 7 days. Pre- and post- dosing tissue will be analyzed for kinome response and resistant signatures. The initiation of study drug will be defined by the surgical schedule; there will be no delays in standard treatment for the purposes of this study.