Bendamustine Hydrochloride, Clofarabine, and Etoposide in Treating Younger Patients With Relapsed or Refractory Hematologic Malignancies

Bendamustine will be combined with clofarabine and etoposide in a five-day cycle. Dexamethasone will be given to prevent capillary leak syndrome associated with clofarabine. If the participant does not develop progressive disease or a dose-limiting toxicity (DLT) during the first cycle, a second cycle may be administered as a bridge to transplant. Each cycle lasts 21-28 days (or until count recovery). Concomitant intrathecal therapy can be given at the investigator's discretion, but not on the same days as chemotherapy. Recommendations are triple intrathecal therapy (methotrexate, hydrocortisone, cytarabine) weekly for participants with CNS2 or CNS3 disease, and every two weeks for participants with CNS1 disease. Leucovorin may be given according to institutional guidelines. The intent of this study design is for all participants to receive and complete one course of therapy. Participants who exhibit signs of disease progression or experience an unacceptable toxicity will be discontinued from protocol treatment.