 The purpose of the trial is to study the clinical and biological effects of metformin in combination with standard systemic chemotherapy in a disease relapsed ALL that has a dismal outcome, as well as to do a dose escalation study to find the Maximum Tolerated Dose MTD of metformin in conjunction with ALL therapy. There have also been analysis of patients enrolled on trials who were diabetics on metformin and their outcome was better than patients on the same trial that were not on metformin as their antihyperglycemic. 