A Study to Evaluate the Efficacy and Safety of Trastuzumab Emtansine in Combination With Atezolizumab or Atezolizumab-Placebo in Participants With Human Epidermal Growth Factor-2 (HER2) Positive Locally Advanced or Metastatic Breast Cancer (BC) Who Received Prior Trastuzumab and Taxane Based Therapy
Conditions
Interventions
- DRUG: Atezolizumab
- DRUG: Trastuzumab emtansine
- OTHER: Placebo
Sponsor
Hoffmann-La Roche