Safety and Efficacy of 72-hour and 120-hour Infusion of Rigosertib in Acute Myeloid Leukemia (AML) and Acute Lymphoid Leukemia (ALL)

Inclusion Criteria:

1. Histologically documented or cytologically confirmed diagnosis of one of the following hematological malignancies:

   * Acute myelocytic leukemia (AML) refractory to standard induction treatment, or relapsed after standard therapy (including transformed myeloproliferative diseases with at least 10% blasts in bone marrow and chronic myeloid leukemia in a blast phase)
   * Transformed myeloproliferative neoplasms (MPNs; i.e., myelofibrosis, essential thrombocythemia (ET), polycythemia vera (PV)) with at least 10% blasts in bone marrow and chronic myeloid leukemia in a blast phase refractory or relapsing after standard therapy
   * Acute lymphocytic leukemia (ALL) refractory to induction treatment, or relapsed after standard therapy
2. Patients should not have received any prior chemotherapy for their leukemia or transformed MPN within 14 days and should have recovered from any toxicity related to prior chemotherapy to at least grade 1. In the presence of rapidly proliferating disease, patients can be included after a washout period of 7 days. Hydroxyurea can be administered as clinically indicated, and no washout is required.
3. Patients may not be candidates for, or must have declined, bone marrow transplantation from an HLA-identical donor in the immediate future (ie, within 4 weeks) or other chemotherapeutic regimens known to produce consistent remissions.
4. Patients with known meningeal infiltration may be enrolled only if radiation has been completed, and a clearing of peripheral blood blasts has been noted. Intrathecal therapy can be continued if judged to be in the best interest of the patient to prevent recurrence, provided there is no toxicity associated with it and there has been clearance of blasts in the cerebrospinal fluid.
5. ECOG Performance Status 0, 1 or 2.
6. Willing to adhere to the prohibitions and restrictions specified in this protocol.
7. Patient must have signed an informed consent document indicating that he/she understands the purpose of and procedures required for the study and is willing to participate in the study.

Exclusion Criteria:

1. Any active malignancy within the past year except basal cell or squamous cell skin cancer or carcinoma in situ of the cervix or breast.
2. Known HIV-1 seropositivity.
3. Uncontrolled intercurrent illness including, but not limited to symptomatic congestive heart failure, unstable angina pectoris or cardiac arrhythmia.
4. Uncontrolled active systemic infection not adequately responding to appropriate therapy.
5. Total bilirubin ≥ 1.5 mg/dL not related to hemolysis or Gilbert's disease.
6. ALT or AST ≥ 2.5 X ULN.
7. Serum creatinine ≥ 2.0 mg/dL.
8. Ascites requiring active medical management including paracentesis, or hyponatremia (defined as serum sodium value of \<130 Meq/L).
9. Female patients who are pregnant or lactating; Male patients with female sexual partners who are unwilling to follow the strict contraception requirements (condom use). Patients of reproductive potential who do not agree to use adequate contraceptive before entry and throughout the study; Female patients with reproductive potential who do not have a negative serum or urine beta-HCG pregnancy test at screening.
10. Major surgery without full recovery or major surgery within 3 weeks of rigosertib treatment start.
11. Uncontrolled hypertension (defined as a systolic pressure equal to or greater than 160 and/or a diastolic pressure equal to or greater than 100).
12. New onset seizures (within 3 months prior to the first dose of rigosertib) or poorly controlled seizures
13. Any concurrent investigational agent or chemotherapy, radiotherapy or immunotherapy.
14. Psychiatric illness/social situations that would limit the patient's ability to tolerate and/or comply with study requirements.