- Any number of prior endocrine, biologic or chemotherapy regimens is permitted. All previous chemotherapy and biologic therapy must have been discontinued at least 3 weeks prior to beginning study drug. Endocrine therapy may not be used concurrently with protocol treatment. All acute toxic effects (excluding alopecia or neuropathy) of any prior therapy must have resolved to NCI CTC (version 4.0) Grade ≤ 1 or to baseline