A Phase III Study of Trastuzumab Deruxtecan versus Standard Therapy for HER2-Positive Inoperable or Metastatic Breast Cancer after T-DM1 Therapy


Full Title

DS8201-A-U301: A Phase 3, Multicenter, Randomized, Open-Label, Active-Controlled Study of DS-8201a, an Anti-HER2-Antibody Drug Conjugate, Versus Treatment of Investigator’s Choice for HER2-Positive, Unresectable and/or Metastatic Breast Cancer Subjects Pretreated with Prior Standard of Care HER2 Therapies, Including T-DM1 (WIRB)


The purpose of this study is to compare the effectiveness of the drug trastuzumab deruxtecan with standard therapy in patients with HER2-positive inoperable or metastatic breast cancer who previously received ado-trastuzumab emtansine (T-DM1). Trastuzumab deruxtecan is an antibody drug conjugate (ADC). ADCs have two parts: the antibody targets cancer cells and the other part (a chemotherapy drug attached to the antibody) kills cancer cells.

Trastuzumab, the antibody part, binds to HER2 on breast cancer cells. Deruxtecan is the cell-killing part. When trastuzumab sticks to HER2, deruxtecan is released and kills the cancer cell from within. Trastuzumab deruxtecan is given intravenously (by vein).

Patients in this study will be randomly assigned to receive trastuzumab deruxtecan or standard therapy with either trastuzumab/capecitabine or lapatinib/capecitabine. Lapatinib and capecitabine are taken orally (by mouth).


To be eligible for this study, patients must meet several criteria, including but not limited to the following:

  • Patients must have HER2-positive inoperable or metastatic breast cancer and have previously received T-DM1.
  • This study is for patients age 18 and older.

For more information and to inquire about eligibility for this study, please contact Dr. Shanu Modi at 646-888-5243.