The standard treatment of a bacterial infection has been to start antibiotics when a new infection is suspected or when an infection is proven (for example, a positive blood test). Patients who agree to be in the study will receive 1 of 2 treatment plans, Arm A or Arm B. In this study, Arm A is standard treatment, and does not include levofloxacin. The use of the antibiotic prophylaxis called levofloxacin is the experimental arm. Those assigned to the experimental arm (Arm B) will receive the antibiotic prophylaxis called levofloxacin. Levofloxacin will be given from Day 3 of the participant's chemotherapy cycle (for those being treated with chemotherapy) or 2 days before the participant gets a stem cell transplant. The levofloxacin will be stopped once the participant's blood counts have recovered (their neutrophil count is higher than 200). The levofloxacin may be stopped and re-started later if the participant's doctor decides that the participant needs antibiotics for treatment of a new suspected or proven infection. Levofloxacin can be taken by mouth in either a tablet or liquid form, or it can be given using a needle or tubing inserted into a vein (IV). If tolerated, the levofloxacin will be given by mouth. Otherwise, it will be given by IV. Participants will have their muscles and joints checked by their doctor before and after treatment (at 2 and 12 months). The muscle and joint tests will be done at times when the participant is seeing their doctor as part of their regular care. This research study includes an optional biologic study. Some bacteria are able to survive treatment with antibiotics (called antibiotic resistance). For the optional biologic studies, the researchers want to look for bacteria that are resistant to antibiotics in the participant's stool. The optional biologic study includes the collection of peri-rectal swab (placing a sterile swab in the rectum for 5 seconds) or collection of a stool sample.
Must be greater than or equal to 6 months to less than or equal to 21 years of age at enrollment
Must fit 1 of the following 2 categories: a) plan to receive at least 2 consecutive cycles (not required to be the first 2 cycles) of intensive chemotherapy for either De Novo, relapsed or secondary AML, or acute leukemia of ambiguous lineage treated with standard AML therapy, or Relapsed ALL; or b) plan to receive at least 1 stem cell transplant
Must have adequate organ function as defined in the protocol
Must not have chronic active arthritis
Must not have an allergy to quinolones
Must not have been previously enrolled on the trial
Must not be pregnant or breast feeding