Atezolizumab and Chemotherapy Treatment as T-cell Activators in Metastatic Triple Negative Breast Cancer Patients

This study is testing atezolizumab (an immunotherapy drug) combined with chemotherapy as a treatment for people with metastatic triple-negative breast cancer (TNBC) — a type of breast cancer that lacks three common hormone receptors and tends to be harder to treat. Specifically, this is for patients whose tumours express a marker called PD-L1 and who have already received immunotherapy in an earlier treatment setting. **You may be eligible if...** - You have confirmed metastatic triple-negative breast cancer (TNBC) that tests PD-L1 positive - You previously received an anti-PD-1/PD-L1 immunotherapy in an earlier treatment stage (neoadjuvant or adjuvant) - You have not yet received chemotherapy for your metastatic disease - You are not a candidate for surgery **You may NOT be eligible if...** - Your cancer is not TNBC or does not express PD-L1 - You have already received chemotherapy for metastatic breast cancer - You have serious autoimmune conditions or organ problems - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.