The investigators' proposed phase 2 clinical trial will be an open-label, non-randomized study among 80 women with metastatic breast cancer. The study treatment period will be up to twelve months and enrollment will be open at 10-15 clinical sites in the United States. In this Phase 2 trial, 40 participants with hormone receptor positive tumors and 40 with hormone receptor negative tumors will be enrolled and treated with BZL101 20 grams/day (10 grams BID). Hormone receptor positive will be defined as estrogen receptor (ER)+ and progesterone receptor (PR)+, ER+ and PR-, or ER- and PR+. Hormone receptor negative will be defined as ER- and PR-.