Refractory Childhood Myelodysplastic Syndrome

This phase I trial tests the safety, side effects, and best dose of imetelstat in combination with fludarabine and cytarabine in treating patients with acute myeloid leukemia (AML), myelodysplastic syndrome (MDS) or juvenile myelomonocytic leukemia (JMML) that has not responded to previous treatment (refractory) or that has come back after a period of improvement (recurrent). Imetelstat may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Chemotherapy drugs, such as fludarabine and cytarabine, work in different ways to stop the growth of cancer cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving imetelstat in combination with fludarabine and cytarabine may work better in treating patients with refractory or recurrent AML, MDS, and JMML.