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

National Taiwan Uni Hospital; General Surgery, Taipei

Chang Gung Memorial Hospital - Linkou, Taoyuan District

China Medical University Hospital; Surgery, Taichung

Changhua Christian Hospital; Dept of Surgery, Changhua

Chi-Mei Medical Center, Tainan City

Kaohsiung Medical Uni Chung-Ho Hospital; Dept of Surgery, Kaohsiung City

St George Hospital; Cancer Care Centre, Kogarah

Calvary Mater Newcastle, Waratah

Peter MacCallum Cancer Center, East Melbourne

Sunshine Hospital, St Albans

Peninsula and South Eastern Haematology and Oncology Group, Frankston

Princess Alexandra Hospital Woolloongabba; Clinical Hematology and Medical Oncology, Woolloongabba

St John of God Hospital; Bendat Cancer Centre, Subiaco

Laura and ISAAC Perlmutter Cancer Center at NYU Langone., New York

National Cancer Center, Goyang-si

Koo Foundation Sun Yat-Sen Cancer Center; Hemato-Oncology, Taipei

HELIOS Klinikum Berlin-Buch; Klinik für Gynäkologie und Geburtshilfe, Berlin

Hospital Universitario Reina Sofia; Servicio de Oncologia, Córdoba

Studienzentrum Berlin City, Berlin

Complejo Hospitalario Universitario A Coruña (CHUAC, Materno Infantil), Oncología, A Coruña

Magee Womens Hospital, Pittsburgh

Cancer Care Associates of York, York

MedStar Georgetown University Hospital (Lombardi Comprehensive Cancer Center), Washington D.C.

Johns Hopkins Univ Med Center, Baltimore

Hospital Ramon y Cajal; Servicio de Oncologia, Madrid

Northside Hospital, Atlanta

Centro Di Riferimento Oncologico; SOC Oncologia Medica C, Aviano

Florida Cancer Specialists; Saint Petersburg, St. Petersburg

SCRI Florida Cancer Specialists South, Fort Myers

Tennessee Oncology; Sarah Cannon Research Institute, Nashville

SCRI Tennessee Oncology Chattanooga, Chattanooga

A.O.U Policlinico S. Orsola Malpighi di Bologna U.O di Medicina Interna Borghi - Pad.2, Bologna

Ospedale Regionale Di Parma; Divisione Di Oncologia Medica, Parma

Ohio State Uni Medical Center, Columbus

Klinikum Essen-Mitte Ev. Huyssens-Stiftung / Knappschafts GmbH; Klinik für Senologie / Brustzentrum, Essen

Hospital Clinico Universitario de Valencia; Servicio de Onco-hematologia, Valencia

Hospital Arnau de Vilanova (Valencia) Servicio de Oncologia, Valencia

Institut für Versorgungsforschung in der Onkologie GbR Koblenz, Koblenz

Ospedale Santo Stefano, Azienda USL Centro Prato, Prato

Nationales Centrum für Tumorerkrankungen (NCT) ; Gyn. Onk. Frauenklinik; Uniklinikum Heidelberg, Heidelberg

Praxis für Interdisziplinäre Onkologie und Hämatologie GbR, Freiburg im Breisgau

University of Colorado, Aurora

IRCCS Istituto Nazionale Tumori Fondazione Pascale; Oncologia Medica A, Napoli

San Juan Oncology Associates, Farmington

Breastlink Med Group Inc, Orange

Centro Catanese Di Oncologia; Oncologia Medica, Catania

University of Washington, Seattle

Lakeridge Health Oshawa; Oncology, Oshawa

The Ottawa Hospital Cancer Centre; Oncology, Ottawa

Sunnybrook Odette Cancer Centre, Toronto

McGill University; Sir Mortimer B Davis Jewish General Hospital; Oncology, Montreal

McGill University; Glen Site; Oncology, Montreal

Hopital du Saint Sacrement, Québec

Samsung Medical Center, Seoul

Seoul National University Hospital, Seoul

Severance Hospital, Yonsei University Health System, Seoul

Asan Medical Center, Seoul

Hospital Univ Vall d'Hebron; Servicio de Oncologia, Barcelona

VETERANS GENERAL HOSPITAL; Department of General Surgery, Taipei

Royal United Hospital; Oncology Department, Bath

Beatson West of Scotland Cancer Centre, Glasgow

Royal Free Hospital; Dept of Oncology, London

Royal Marsden Hosp NHS Fnd; Breast Unit, London

Christie Hospital; Breast Cancer Research Office, Manchester

Nottingham City Hospital, Nottingham

Weston Park Hospital; Cancer Clinical Trials Centre, Sheffield

Royal Marsden Hosp NHS Fnd; Medicine - Breast Unit, Sutton

Singleton Hospital; Pharmacy, Swansea