A Study to Investigate Atezolizumab and Chemotherapy Compared With Placebo and Chemotherapy in the Neoadjuvant Setting in Participants With Early Stage Triple Negative Breast Cancer

Inclusion criteria: * 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 * For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive methods, and agreement to refrain from donating eggs * For men: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures and agreement to refrain…