Ruxolitinib for Patients With Low or Intermediate-1 Risk Myelodysplastic Syndrome (MDS)

Inclusion Criteria:

1. Patients with previously treated low or intermediate-1 risk MDS by the IPSS classification (this is defined in table 1)
2. Patients must have one of the following: elevated b2-microglobulin levels (defined as 2 times compared to normal), carry a JAK2 mutation, or presence of phosphorylated p65 NF-kB component in at least 5% of bone marrow cells.
3. Signed informed consent indicating that patients are aware of the investigational nature of this study in keeping with the policies of UTMDACC.
4. Age \>/= 18 years old
5. Prior therapy with growth factor support, lenalidomide, 5-azacytidine, decitabine or other investigational agents are allowed. A four week wash out period will be required before receiving study medication.
6. Patients must have the following non-hematologic values Aspartate aminotransferase (AST/SGOT) and alanine aminotransferase (ALT/SGPT) \</= 2.5 x Upper Limit of Normal (ULN) or \</= 5.0 x ULN if hepatic involvement is present; Serum bilirubin \</= 2 x ULN; Serum creatinine \</= 2 x ULN or 24-hour creatinine clearance \>/= 60 ml/min
7. Patients with Childbearing potential must agree to use appropriate forms of birth control

Exclusion Criteria:

1. Previously untreated low or intermediate-1 risk MDS patients because there are approved therapies for these patients.
2. Uncontrolled undercurrent illness that in the opinion of the treating physician would contraindicate the use of the drug.
3. Patients with active infections including uncontrolled HIV infection, active hepatitis B, C, or any other symptomatic systemic infection requiring active therapy will be excluded from study
4. Patients receiving potent CYP3A4 (such as but not limited to boceprevir, clarithromycin, conivaptan, grapefruit juice, indinavir, itraconazole, ketoconazole, lopinavir/ritonavir, mibefradil, nefazodone, nelfinavir, posaconazole, ritonavir, saquinavir, telaprevir, telithromycin, voriconazole) inhibitors will be excluded from the study.
5. Women who are pregnant or lactating.
6. Patients with a white blood cell count of more than 30x10\^3 K/uL will not be eligible for this study.
7. Patients that have received prior allogeneic stem cell transplantation are excluded from this study.