- Prior therapy may include any number of chemotherapy, immunotherapy, and/or radiation therapy regimens. Major surgery or systemic chemotherapy must have been completed at least 4 weeks prior to enrollment and residual toxicities from that therapy must be Grade 1 or lower at the time of enrollment with the exception of hemoglobin and absolute granulocyte count. Localized radiation therapy must have been completed at least 2 weeks prior to enrollment and residual toxicities must be Grade 1 or lower at the time of enrollment.