Neratinib

Patient will be treated with neratinib, an aromatase inhibitor and trastuzumab for 24 weeks prior to surgery, following an initial 3 weeks of neratinib alone, aromatase inhibitor alone or the combination of neratinib and an aromatase inhibitor. A breast biopsy will be performed prior to Day 1 of week 4 of treatment. Following surgery, patients will receive standard of care HER2-directed and endocrine therapy at the treating physician's discretion.

This is a Phase 2 study for patients with resected Stage I-III HER2+ breast cancer with detected molecular residual disease (MRD+) following standard neoadjuvant and locoregional therapy delivered with curative intent. In this study Patients will be treated with neratinib in addition to their standard T-DM1 adjuvant therapy. Neratinib will be administered orally at a dose of 160 mg daily for up to 12 months, or until the time of clinical recurrence, discontinuation due to toxicity, or withdrawal of consent. This study will have two stages, stage 1 would enroll up to 8 participants to clear the Minimal Residual Disease (MRD) and Stage 2 will enroll up to 5 participants. The purpose of this study is to determine if this study population would have a better outcome from adding neratinib to their standard T-DM1 adjuvant therapy.

The purpose of this study is to learn if certain drug combinations are effective treatments for patients with advanced ER+/HER2- who have previously been treated with palbociclib, ribociclib, or abemaciclib.

The purpose of this study is to further advance the ability to practice personalized medicine by learning which new drug agents are most effective with which types of breast cancer tumors and by learning more about which early indicators of response (tumor analysis prior to surgery via magnetic resonance imaging (MRI) images along with tissue and blood samples) are predictors of treatment success.