A Phase III, Randomized, Double-Blind, Placebo-Controlled Clinical Trial to Evaluate the Efficacy and Safety of Adjuvant Atezolizumab or Placebo and Trastuzumab Emtansine for HER2-Positive Breast Cancer at High Risk of Recurrence Following Preoperative Therapy
Objective
This is a Phase III, two-arm, randomized, double-blind placebo-controlled study in participants with HER2-positive primary breast cancer who have received preoperative chemotherapy and HER2-directed therapy, including trastuzumab followed by surgery, with a finding of residual invasive disease in the breast and/or axillary lymph nodes.
Study Arms
- Active Comparator: Arm A: Placebo + Trastuzumab Emtansine
- Experimental: Arm B: Atezolizumab + Trastuzumab Emtansine
Eligibility
- Histologically confirmed invasive breast carcinoma
- Centrally-confirmed human epidermal growth factor receptor 2 (HER2)-positive invasive breast cancer
- Centrally confirmed PD-L1 and hormone receptor status
- Clinical stage at disease presentation: cT4/anyN/M0, any cT/N2-3/M0, or cT1-3/N0-1/M0 (participants with cT1mi/T1a/T1b/N0 are not eligible)
- Completion of preoperative systemic chemotherapy including at least 9 weeks of taxane and 9 weeks of trastuzumab (anthracycline and/or additional HER2-targeted agents are permitted)
- <=12 weeks between primary surgery and randomization
- Eastern Cooperative Oncology Group (ECOG) Performance Status 0 or 1
- Screening left ventricular ejection fraction (LVEF) >= 50% and no decrease in LVEF by >15% from the pre-chemotherapy LVEF. If no pre-chemotherapy LVEF, screening LVEF >= 55%
- Life expectancy >= 6 months
- Adequate hematologic and end-organ function
