<qa>  What is the purpose of the study?The purpose of this study is to assess the safety, establish the maximum tolerated dose MTD and generate pharmacokinetic profiles of BSI-201 after IV administration in adult subjects with histologically documented advanced solid tumors that are refractory to standard therapy or for which no standard therapy is available. Additionally, the safety and tolerability and clinical response of BSI-201 irinotecan will be investigated in patients with metastatic breast cancer in the phase 1b portion of the study. 