Clinical Trial of Oral Ciprofloxacin and Etoposide in Subjects With Resistant Acute Myeloid Leukemia (AML)(UF-AML-CE-101)

Inclusion Criteria: * Diagnosis of AML confirmed by review of bone marrow pathology at the University of Florida. * Patients with relapsed and /or refractory AML who: failed to achieve complete remission (CR) or complete remission with incomplete blood count recovery (CRi) after at least one cycle of induction chemotherapy and not suitable for a second cycle of standard intensive chemotherapy; or who have progressed after 1 cycle of hypomethylating agent or intolerant to hypomethylating agent therapy and not suitable for standard induction chemotherapy regimens; or have relapsed after any duration of response. * Per the treating physician, the subject must have a life expectancy of \>= 4 weeks. * Subject performance status must be Eastern Cooperative Oncology Group (ECOG) 0, 1, or 2. * Subject must have a total bilirubin \<= 2 mg/dL and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) \<= 2.5 times the upper limit of normal. * Subject must have serum creatinine \< 2 mg/dL. * Females of child-bearing potential may participate, provided they meet the following conditions: Must agree to use physician-approved contraceptive methods throughout the study and for 6 months following the last dose of ciprofloxacin and/or etoposide; Must have a negative serum pregnancy test within 7 days prior to beginning treatment on this study. * Males with female partners of child-bearing potential must agree to use physician-approved contraceptive methods throughout the study and should avoid conceiving children for 6 months following the last dose of ciprofloxacin and/or etoposide. * Must provide written informed consent and be willing to comply with all study-related procedures. Exclusion Criteria: * History of allergic or significant adverse reaction \[e.g., anaphylaxis, prolonged QTc, or severe tendonitis\] to ciprofloxacin or etoposide. * Acute promyelocytic leukemia (APL) with t(15;17). * Prolonged baseline QTc, defined as QTc interval \> 470 msec in women and \> 450 msec in men, or \> 480 msec in subjects with a bundle branch block. * Uncontrolled, clinically significant infection. Subjects with a fever (temperature \>= 38.3) thought to be related to leukemia are eligible assuming that blood cultures are negative during the 7 days prior to Cycle 1 Day 1 and there is no clinical evidence of active infection (e.g., negative or stable radiographs and negative physical examination). * Ongoing, symptomatic Clostridium difficile infection. Subjects who are asymptomatic with negative stool for C. difficile may participate. * Pregnant and or nursing. * History of Myasthenia Gravis. * Treatment with any anticancer therapy (standard or investigational) within 14 days prior to the first dose of ciprofloxacin or less than full recovery from the clinically significant toxic effects of that treatment. The use of hydroxyurea is allowed only during the first 14 days of Cycle 1.