A Study of the Efficacy and Safety of Atezolizumab Plus Chemotherapy for Patients With Early Relapsing Recurrent Triple-Negative Breast Cancer

Inclusion Criteria

• Histologically confirmed triple negative breast cancer (TNBC) that is either locally recurrent, inoperable and cannot be treated with curative intent or is metastatic
• Documented disease progression occurring within 12 months from the last treatment with curative intent
• Prior treatment (of early breast cancer) with an anthracycline and taxane
• Have not received prior chemotherapy or targeted systemic therapy for their locally advanced inoperable or metastatic recurrence. Prior radiation therapy for recurrent disease is permitted
• Measurable or non-measurable disease, as defined by RECIST 1.1
• Availability of a representative formalin-fixed, paraffin-embedded (FFPE) tumour block (preferred) or at least 17 unstained slides obtained from relapsed metastatic or locally advanced diseases may be submitted, if clinically feasible, with an associated pathology report, if available. If a fresh tumour sample is not clinically feasible, either the diagnosis sample, the primary surgical resection sample, or the most recent FFPE tumour biopsy sample should be used.
• Eastern Cooperative Oncology Group performance status 0-1
• Life expectancy ≥ 12 weeks
• Adequate haematologic and end-organ function
• Negative human immunodeficiency virus (HIV) test ---Negative hepatitis B surface antigen (HBsAg) test at screening
• Negative total hepatitis B core antibody (HBcAb) test at screening, or positive HBcAb test followed by a negative hepatitis B virus (HBV) DNA test at screening
• The HBV DNA test will be performed only for patients who have a negative HBsAg and a positive HBcAb test.
• Negative hepatitis C virus (HCV) antibody test at screening, or positive HCV antibody test followed by a negative HCV RNA test at screening.
• Women of childbearing potential must agree to remain abstinent (refrain from heterosexual intercourse) or use a contraceptive method with a failure rate of ≤1% per year during the treatment period and for at least 5 months after the last dose of atezolizumab or 6 months after the last dose of capecitabine, whichever is later. In addition, women must refrain from donating eggs during the same time period.
• Men must agree to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures, and agree to refrain from donating sperm

Inclusion criteria for patients enrolled after the recruitment of all-comers is complete:

-PD-L1-positive tumour status (assessed centrally prior to randomisation), defined as PD-L1 expression on tumour-infiltrating immune cells (IC) of 1% or greater.

Exclusion Criteria

• Spinal cord compression not definitively treated with surgery and/or radiation, or previously diagnosed and treated spinal cord compression without evidence that disease has been clinically stable for > 2 weeks prior to randomisation
• Symptomatic, untreated, or actively progressing central nervous system (CNS) metastases.
• Symptomatic or rapid visceral progression
• No prior treatment with an anthracycline and taxane
• History of leptomeningeal disease
• Uncontrolled pleural effusion, pericardial effusion, or ascites requiring recurrent drainage procedures (once monthly or more frequently) (patients with indwelling catheters such as PleurX® are allowed)
• Uncontrolled tumour-related pain
• Uncontrolled or symptomatic hypercalcemia
• Malignancies other than TNBC within 5 years prior to randomisation)
• Significant cardiovascular disease, within 3 months prior to randomisation, unstable arrhythmias, or unstable angina
• Presence of an abnormal ECG
• Severe infection requiring oral or IV antibiotics within 4 weeks prior to randomisation, including but not limited to hospitalization for complications of infection, bacteraemia, or severe pneumonia.
• Current treatment with anti-viral therapy for HBV.
• Major surgical procedure within 4 weeks prior to randomisation or anticipation of the need for a major surgical procedure during the course of the study other than for diagnosis

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