|Inclusion Criteria:||1) Male or female patients 18 years of age or older.|
2) A diagnosis of refractory or relapsed acute myeloid leukemia or Ph+ CML in chronic, accelerated, or blast phase or acute lymphoblastic leukemia, or myelodysplastic syndrome. One of the following parameters is required to meet criteria for accelerated phase CML: 1) blasts in peripheral blood or bone marrow >/=15%; 2) Promyelocytes and blasts in peripheral blood or bone marrow >/=30%; 3) PB or BM basophils >/=20%; 4) Thrombocytopenia < 100x10(3)/ml, not resulting from therapy.
3) **continued from above: Blast phase is defined as >/=30% blasts in peripheral blood or bone marrow, or presence of extramedullary disease, except for liver or spleen.
4) Pts with CML must have demonstrated resistance and/or intolerance to therapy with at least 2 tyrosine kinase inhibitors(TKI). AML and Ph+ ALL should have received at least one prior treatment regimen and either failed to achieve response or relapsed on treatment. MDS patients should have failed prior therapy with a hypomethylating agent or, if associated with a 5q- chromosomal abnormality, lenalidomide. Patients with 5q- unable to receive or intolerant to lenalidomide are also eligible.
5) Patients must have clinically adequate hepatic and renal functions as defined by: ALT<2x ULN; Serum creatinine concentration <2x ULN; Serum bilirubin <2x ULN.
6) Patients must sign an informed consent.
7) Women of child bearing age must have a negative serum or urine pregnancy test prior to the initiation of study drug.
8) Barrier contraceptive precautions are to be used throughout the trial by all study participants of child-bearing potential.
9) Patients must be off anti-cancer therapy for at least two weeks prior to study entry, with the exception of hydroxyurea or anagrelide (24 hours), TKI (5 days), and interferon (2 weeks).