Myelodysplastic syndrome with isolated del(q) (q-syndrome) Myelodysplastic syndrome (MDS), unclassifiable Patients with a myelodysplastic/myeloproliferative neoplasm Myelodysplastic or myeloproliferative syndrome other than MDS. Myelodysplastic Syndrome (MDS) Myelodysplastic syndrome Any evidence of myelodysplastic syndrome or marrow chromosomal changes suggesting myelodysplasia (-, - etc) Bone marrow examination revealing myelodysplastic syndrome or megakaryocyte underproduction for patients with a platelet count < ,/uL No prior history of myelodysplastic syndrome or other myeloid malignancy Prior treatment of myelodysplastic syndrome or myeloproliferative neoplasm with hypomethylating agent acceptable Patients with a diagnosis of myelodysplastic syndrome/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U) that require therapy Myelodysplastic/myeloproliferative disease\r\n* Juvenile myelomonocytic leukemia (JMML)\r\n* Myelodysplastic syndrome and/or pre-leukemia at any stage Myelodysplastic syndrome Known history of myelodysplastic syndrome/leukemia at any time Criteria Myelodysplastic syndrome Known presence of intermediate- or high-grade myelodysplastic syndrome. Myelodysplastic syndrome (MDS) or myelofibrosis; Myelodysplastic syndrome (MDS): primary or therapy related Diagnosis of myelodysplastic syndrome. History of myelodysplastic syndrome or organ transplantation Patients with a history of myelodysplastic syndrome (MDS) Myelodysplastic syndromes History of another primary invasive cancer, hematologic malignancy, or myelodysplastic syndrome that has not been in remission for at least year For Cohort A: Has myelodysplastic syndrome Presence of known intermediate- or high-grade myelodysplastic syndrome Subject who has any histopathologic finding consistent with myelodysplastic syndrome on bone marrow studies. Myelodysplastic syndrome Known history of myelodysplastic syndrome (MDS). Patients must not have been diagnosed with myelodysplastic syndrome or with any malignancy other than neuroblastoma Myelodysplastic syndrome Patients who have a history of myelodysplastic syndrome Diagnosis of Myelodysplastic Syndrome. Prior treatment of myelodysplastic syndrome or myeloproliferative neoplasm acceptable Myelodysplastic syndrome with fibrosis (MF ) A pathologically confirmed diagnosis of leukemia or myelodysplastic syndrome (MDS) Myelodysplastic syndrome (MDS): primary or therapy related; or Previously untreated for Myelodysplastic Syndrome (MDS) Known presence of myelodysplastic syndrome Known presence of myelodysplastic syndrome Myelodysplastic Syndrome (MDS) at any stage. Known presence of myelodysplastic syndrome Myelodysplastic syndrome\r\n* =< years of age and >= % blasts, not responsive to hypomethylating agents and/or conventional therapy Diagnosis of myelodysplastic syndrome (MDS) or a hematologic malignancy. Patients with low- and Int--risk myelodysplastic syndrome Patients with myelodysplastic syndrome Patients with myelodysplastic syndrome Patients with myelodysplastic syndrome. Myelodysplastic syndrome (MDS) Known myelodysplastic syndrome Known myelodysplastic syndrome. Diagnosis of myelodysplastic syndrome (MDS). Phase I: Hematologic malignancy diagnosis including any subset of myeloma, lymphoma, leukemia, or myelodysplastic syndrome Phase II: Hematologic malignancy diagnosis including any subset of lymphoma, leukemia, or myelodysplastic syndrome Known relapsed acute leukemia or myelodysplastic syndrome Current Myelodysplastic syndrome only subjects Subjects with a history of myelodysplastic syndrome Diagnosed with hematological malignancy or marrow failure syndrome such as but not limited to: aplastic anemia, myelodysplastic syndrome or leukemia Intermediate (Int)- or high risk myelodysplastic syndrome (MDS) Subjects with treatment-related myelodysplastic syndrome. A defined myelodysplastic syndrome(s) (MDS) Myelodysplastic Syndrome Current or prior history of myelodysplastic syndrome, leukemia or clinically significant (as per Investigator judgment) bone marrow failure.