This study is under Molecular and Cellular Characterization of Myelodysplastic Syndromes (MDS) (eProtocol 15369). The purpose of this proposed study is to analyze existing samples taken from participants participating in a clinical trial evaluating the efficacy and safety of investigational agent ON 01910.Na (eProtocol 16214). This study will use existing blood and marrow samples to determine the rate and duration of objective hematologic and marrow responses, and duration of progression-free survival in ON01910.Na-treated MDS patients.

This study will use existing blood and marrow samples to determine the rate and duration of objective hematologic and marrow responses, and duration of progression-free survival in ON01910.Na-treated MDS patients.

Inclusion Criteria:

• Diagnosis of IPSS Intermediate or High risk MDS by bone marrow biopsy, marrow cytogenetics and blood counts, using FAB morphologic criteria
• Eastern Cooperative Oncology (ECOG) performance status of 0-2
• Adequate Liver Function, as evidenced by a serum bilirubin less or equal to 1.5 times the laboratory normal range (except for patients with a confirmed diagnosis of Gilberts Disease) or an ALT and AST 3 times the laboratory normal range
• A serum creatinine concentration less or equal to 2mg/dl
• Subjects must be equal or greater than 18 years of age at the time of obtaining informed consent
• Written informed consent

Exclusion Criteria:

• Prior history of leukemia or aplastic anemia

• Prior history of bone marrow transplantation

• Platelet count <100,000/mm^3

  *Prior malignancy (other than in situ cervical cancer, controlled prostate cancer, or basal cell cancer of the skin) unless treated with curative intent and without evidence of disease for greater or equal to 3 years before randomization

• Active or uncontrolled infections

• Unstable angina, congestive heart failure [NYHA>classII], uncontrolled hypertension [diastolic >100mmHg], uncontrolled cardiac arrhythmia, or recent (within 1 year) myocardial infarction

• Less than 4 weeks since receipt of any investigational product or device

• Pregnant or breast feeding

• Subjects of reproductive potential who are not using adequate contraceptive precautions, in the judgment of the investigator

• Previously enrolled in this study

• Will not be available for follow-up assessments

• Any disorder that compromises the ability of the subject to give written informed consent and/or to comply with study procedures

Diagnosis of IPSS Intermediate or High risk MDS