The purpose of this study is to find the highest dose of an investigational drug called AG-221 that can be given safely in patients with acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) that have continued to grow despite or have returned after receiving standard therapy, and which contain a mutated form of a protein called IDH2. Researchers believe that AG-221 may be more effective and have fewer side effects than additional chemotherapy in these patients.
AG-221 blocks a mutated form of the IDH2 protein. Abnormal IDH2 causes too much of a substance called 2-HG to be produced, which may make these cancers grow. Laboratory studies have shown that AG-221 can reduce the amount of leukemia.