ImPassion 031

A Phase III Randomized Study to Investigate the Efficacy and Safety of Atezolizumab (Anti-PD-L1 Antibody) in Combination with Neoadjuvant Anthracycline/Taxane-Based Chemotherapy Compared with Placebo and Chemotherapy in Patients with Primary Invasive Triple-Negative Breast Cancer


This study will evaluate the efficacy and safety of neoadjuvant treatment with atezolizumab (anti-programmed death-ligand 1 [anti-PD-L1] antibody) and nab-paclitaxel followed by doxorubicin and cyclophosphamide (nab-pac-AC), or placebo and nab-pac−AC, in participants eligible for surgery with initial clinically assessed triple-negative breast cancer (TNBC).

Study Arms

  • Experimental: Atezolizumab and Chemotherapy
  • Placebo Comparator: Placebo and Chemotherapy


  • Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
  • Histologically documented TNBC (negative human epidermal growth factor receptor 2 [HER2], estrogen receptor [ER], and progesterone receptor [PgR] status)
  • Confirmed tumor programmed death−ligand 1 (PD-L1) evaluation as documented through central testing of a representative tumor tissue specimen
  • Primary breast tumor size of greater than (>) 2 centimeters (cm) by at least one radiographic or clinical measurement
  • Stage at presentation: cT2-cT4, cN0-cN3, cM0
  • Participant agreement to undergo appropriate surgical management including axillary lymph node surgery and partial or total mastectomy after completion of neoadjuvant treatment
  • Baseline left ventricular ejection fraction (LVEF) greater than or equal to (>=) 53 percent (%) measured by echocardiogram (ECHO) or multiple-gated acquisition (MUGA) scans
  • Adequate hematologic and end-organ function
  • Representative formalin-fixed, paraffin-embedded (FFPE) tumor specimen in paraffin blocks (preferred) or at least 20 unstained slides, with an associated pathology report documenting ER, PgR, and HER2 negativity