A Study Comparing Atezolizumab (Anti PD-L1 Antibody) In Combination With Adjuvant Anthracycline/Taxane-Based Chemotherapy Versus Chemotherapy Alone In Patients With Operable Triple-Negative Breast Cancer

Inclusion Criteria:

Non-metastatic operable Stage II-III breast cancer
Histologically documented TNBC (Triple Negative Breast Cancer)
Confirmed tumor PD-L1 evaluation as documented through central testing of a representative tumor tissue specimen
Adequately excised: Patients must have undergone either breast-conserving surgery or mastectomy/nipple- or skin-sparing mastectomy
Adequate hematologic and end-organ function
For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures
For men: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures and agreement to refrain from donating sperm.
No more than 8 weeks (56 days) may elapse between definitive breast surgery and randomization.
Representative formalin-fixed, paraffin embedded (FFPE) tumor specimen from surgical resection in paraffin blocks (preferred) or at least 25 unstained slides.

Exclusion Criteria

Prior history of invasive breast cancer
For the currently diagnosed breast cancer, any previous systemic anti-cancer treatment (e.g., neoadjuvant or adjuvant), including, but not limited to, chemotherapy, anti-HER2 therapy.
Previous therapy with anthracyclines or taxanes for any malignancy
Cardiopulmonary dysfunction
Prior malignancies within 5 years prior to randomization, with the exception of those with a negligible risk of metastasis or death and treated with expected curative outcome
Active or history of autoimmune disease or immune deficiency
History of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced pneumonitis, idiopathic pneumonitis, or evidence of active pneumonitis on screening chest computed tomography (CT) scan
Urinary outflow obstruction
Active tuberculosis
Major surgical procedure other than for diagnosis within 4 weeks prior to initiation of study treatment or anticipation of need for a major surgical procedure during study treatment or within 5 months following the last dose of Atezolizumab (for patients randomized to Atezolizumab)
Prior allogeneic stem cell or solid organ transplant
Treatment with systemic immunosuppressive medications within 2 weeks prior to initiation of study treatment or anticipation of need for systemic immunosuppressive medication during the study