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
Status: COMPLETED
Study type: INTERVENTIONAL
Conditions: Metastatic Breast Cancer
Interventions: DRUG: Atezolizumab|DRUG: Trastuzumab emtansine|OTHER: Placebo
Sponsor: Hoffmann-La Roche