Cabozantinib for Metastatic Triple Negative BrCa

OBJECTIVES: Primary \* To evaluate the activity of cabozantinib, as defined by objective response rate in patients with triple-negative metastatic breast cancer Secondary * To evaluate progression free survival * To evaluate c-Met and phospho c-Met expression in archival tumor tissue * To evaluate the incidence of c-Met amplified circulating tumor cells at baseline * To evaluate potential plasma biomarkers of cabozantinib DESIGN: This study uses a two-stage design enrolling 35 patients to evaluate efficacy of cabozantinib based on overall response defined as complete or partial response per RECIST1.1 criteria. The null and alternative overall response rates were 5% and 20%. If one or more patients enrolled in the stage one cohort (n=13 patients) achieve PR or better then accrual proceeds to stage two (n=22 patients).