Breast Cancer A011801

COMPASSHER2 Residual Disease (RD), A Double-Blinded, Phase III Randomized Trial of T-DM1 Compared with T-DM1 and Tucatinib

This phase III trial studies how well trastuzumab emtansine (T-DM1) and tucatinib work in preventing breast cancer from coming back (relapsing) in patients with high risk, HER2 positive breast cancer. T-DM1 is a monoclonal antibody, called trastuzumab, linked to a chemotherapy drug, called DM1. Trastuzumab is a form of targeted therapy because it attaches to specific molecules (receptors) on the surface of cancer cells, known as HER2 receptors, and delivers DM1 to kill them. Tucatinib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving T-DM1 and tucatinib may work better in preventing breast cancer from relapsing in patients with HER2 positive breast cancer compared to T-DM1 alone.

Eligibility Criteria:

  • HER2 positive breast cancer based on pretreatment biopsy and defined as ICH score 3+ and/or positive by in situ ISH according to current  ASCO/CAP guidelines
  • Patients must have either ER- HER2+ residual disease in the breast and/or lymph nodes OR ER+ HER2+, lymph node-positive residual disease (per surgical pathology report)
  • Patients with clinical stage T1-4, N0-3 disease at presentation and residual invasive disease postoperatively are eligible. (Note: Patients with T1a/bN0 tumors at initial breast cancer diagnosis are not eligible)
  • Completion of ≥ 6 cycles of chemo and HER2 directed-therapy, total duration ≥ 12 weeks, including at least 9 weeks of preoperative taxane and trastuzumab (or FDA approved biosimilar) with or without pertuzumab.
  • All systemic chemo should have been completed preoperatively unless participating in the CompassHER pCR..

This study is for patients age 18 and older.

Available at: Hartford Hospital, Hospital of Central Connecticut, Midstate Medical Center, William Backus Hospital, Windham Hospital, Charlotte Hungerford Hospital, St. Vincent's Medical Center.