Atezolizumab, Cobimetinib, and Eribulin in Treating Patients With Chemotherapy Resistant Metastatic Inflammatory Breast Cancer

PRIMARY OBJECTIVES: I. To determine ORR (overall response rate) of metastatic inflammatory breast cancer (BC) (mIBC) patients treated with this proposed combinatorial atezolizumab, cobimetinib, and eribulin (ACE) therapy via phase II. (ACE, Cohort I) II. To determine ORR (overall response rate) for double combination of atezolizumab and eribulin (AE). (AE, cohort II) SECONDARY OBJECTIVES: I. To further characterize the safety and tolerability of atezolizumab + cobimetinib + eribulin. II. To further characterize the safety and tolerability of atezolizumab + eribulin. III. To determine CBR (clinical benefit rate): (stable disease \[SD\] + complete response \[CR\] + partial response \[PR\] \>= 24 weeks). III. To determine the duration of response (DOR). IV. To determine progression free survival (PFS). V. To determine 2 years overall survival (OS). EXPLORATORY OBJECTIVES: I. To determine the progressive disease (PD) biomarker changes induced by combinatorial therapy using liquid and tissue based assays to investigate microenvironment via multiplex imaging, proportional study of T cells: CD3, CD8 composition and change, macrophage (M1 and M2), PD-L1 expression on circulating tumor cell (CTC). II. To determine the immune pathway related biomarker changes induced by combinatorial therapy via multiplex serum cytokine assays. III. This translational biomarker assays will be done based on collaboration with plasma based ribonucleic acid (RNA) sequencing (RNA-seq) in collaboration with Lambowitz laboratory (lab) (University of Texas at Austin \[UT Austin\]), Oncomine next-generation sequencing (NGS) study on tumor/circulating tumor deoxyribonucleic acid (ctDNA) with Wistuba lab, and bioinformatics with Futreal lab. OUTLINE: COHORT I: Patients receive atezolizumab intravenously (IV) over about 30-60 minutes every 2 weeks, cobimetinib orally (PO) daily for 3 weeks on, 1 week off for 4 weeks of the safety lead-in course. Patients then receive atezolizumab IV over about 30-60 minutes every 2 weeks, cobimetinib PO daily for 3 weeks on, 1 week off, and eribulin IV over 2-5 minutes on days 1 and 8 of cycles 1-4. Cycles 1-4 repeat every 21 days and subsequent cycles with atezolizumab and cobimetinib repeat every 28 days in the absence of disease progression or unacceptable toxicity. COHORT II: Patients receive atezolizumab IV over about 30-60 minutes every 3 weeks for cycles 1-6 and every 4 weeks for subsequent cycles, and eribulin IV over 2-5 minutes on days 1 and 8 of cycles 1-6. Cycles 1-6 repeat every 21 days and subsequent cycles with atezolizumab repeat every 28 days in the absence of disease progression or unacceptable toxicity. After completion of the study treatment, patients are followed for 3 months and then every 6 months for 2 years.