This research study is studying a combination of drugs as a possible treatment for
HER2-Postive Metastatic Breast Cancer.
The interventions involved in this study are:
- Tucatinib
- Abemaciclib (VerzenioTM)
- Trastuzumab (Herceptin®)
- Endocrine Therapy: Exemestane (Aromasin®), Letrozole (Femara®), or Anastrozole
(Arimidex®)