Inclusion Criteria:

          -  Patients with any of the following diagnoses are eligible: 1) high-risk MDS (i.e.
             refractory anemia with excess blasts [RAEB-1 or RAEB-2] by World Health Organization
             [WHO] classification, or any WHO subset with International Prognostic Scoring System
             [IPSS] intermediate-2 or high, or any patients that have failed prior therapy with
             hypomethylating agents); 2) chronic myelomonocytic leukemia (CMML); 3) acute myeloid
             leukemia (AML) by WHO classification; 4) chronic myeloid leukemia in blast phase
             (CML-BP); 5) myelofibrosis with high-risk features (e.g., accelerated phase disease
             -10-19% blasts in peripheral blood or bone marrow-, or with Dynamic International
             Prognostic Scoring System [DIPSS]-plus high risk score)

          -  Patients must have relapsed/refractory disease and have failed, or are not candidates
             for, or have declined all available therapies of proven efficacy; they should also not
             be eligible for at the time of enrollment or have declined hematopoietic stem cell
             transplantation

          -  Eastern Cooperative Oncology Group (ECOG) performance status of 0-2

          -  The effects of Hu8F4 on a fetus or nursing child are unknown; women of child-bearing
             potential (i.e., women who are pre-menopausal or not surgically sterile) must use
             acceptable contraceptive methods (abstinence, intrauterine device [IUD], oral
             contraceptive or double barrier device), and must have a negative urine pregnancy test
             within 2 weeks prior to beginning treatment on this trial; nursing patients are
             excluded; sexually active men must also use acceptable contraceptive methods for the
             duration of time on study

          -  Patients must have human leukocyte antigen (HLA)-A2 phenotype

          -  Must be able and willing to give written informed consent

          -  Patients must be at least 2 weeks from prior chemotherapy, radiation therapy, or major
             surgery, and at least 4 weeks or 5 half lives from other investigational anticancer
             therapy, and have recovered from prior toxicities at least to grade 1; the exception
             is hydroxyurea that requires no washout prior to the start of study drug

          -  Clinically significant toxicities from prior chemotherapy must not be greater than
             grade 1

          -  Clearance creatinine or glomerular filtration rate (GFR) >= 40 mL/min

          -  Total bilirubin =< 1.5 x the upper limit of normal unless considered due to Gilbert's
             syndrome or leukemic involvement

          -  Alanine aminotransferase (ALT) =< 3 x the upper limit of normal unless considered due
             to leukemic involvement

        Exclusion Criteria:

          -  Uncontrolled intercurrent illness including, but not limited to uncontrolled infection
             (patients must have no temperature >= 38.3 degrees Celsius [C] due to infection for at
             least 48 hrs to consider an infection controlled), psychiatric illness that would
             limit compliance with study requirements, or active heart disease including confirmed
             myocardial infarction within previous 3 months, symptomatic coronary artery disease,
             clinically significant arrhythmias not controlled by medication, or uncontrolled
             congestive heart failure New York (NY) Heart Association class III or IV

          -  Patients with current active malignancies or any remission for < 18 months, except
             patients with carcinoma in situ or with non-melanoma skin cancer who may have active
             disease or be in remission for less than 6 months

          -  Patients receiving any other standard or investigational treatment for their
             hematologic malignancy other than supportive care

          -  Patients who have had any major surgical procedure within 14 days of day 1

          -  Patients with known central nervous system infiltration with leukemia

          -  Patients who received an allogeneic stem cell transplant =< 90 days from the start of
             therapy

          -  Patients with active >= grade 3 graft versus host disease (GVHD), or receiving
             systemic steroids (> 10 mg/day of prednisone or equivalent) for GVHD

          -  Patients with known active central nervous system (CNS) disease; patients with history
             of active CNS disease should have at least two negative spinal fluid evaluations
             before being considered eligible