This phase II trial studies how well eltrombopag olamine works in increasing platelet counts in patients undergoing transplant. Eltrombopag olamine may help platelet counts and the immune system recover from blood or bone marrow transplant.

PRIMARY OBJECTIVES:

I. To estimate the rate of platelet engraftment by day 60 in patients undergoing cord blood transplant (CBT) or haploidentical donor stem cell transplantation treated with eltrombopag (eltrombopag olamine).

SECONDARY OBJECTIVES:

I. To assess safety of eltrombopag in this population. II. To assess neutrophil engraftment with eltrombopag in this population. III. To characterize immune reconstitution. IV. To assess overall survival (OS). V. To assess progression free survival (PFS). VI. To assess incidence of acute graft-versus-host disease (GVHD).

OUTLINE: Patients are assigned to 1 of 2 arms.

ARM I (CORD BLOOD TRANSPLANT): Patients receive eltrombopag olamine orally (PO) once daily (QD) for 60 days beginning on day -1.

ARM II (HAPLOIDENTICAL DONOR STEM CELL TRANSPLANT): Patients receive eltrombopag olamine PO QD for 60 days beginning on day 5.

After completion of study treatment, patients are followed up at 1, 2, 3, 6, and 12 months.

Inclusion Criteria:

• Patients undergoing a cord blood or haploidentical transplantation on any protocol or standard of care treatment plan.
• Age >/= 18.
• Females of child bearing potential defined as not post-menopausal for 12 months or no previous surgical sterilization or breast-feeding must be willing to use an effective contraceptive measure until 30 days after the last dose of eltrombopag. Males who have had sexual contact with female of child-bearing potential must be willing to use contraceptive techniques until 30 days after the last dose of eltrombopag.
• Patient or patient's legal representative(s) is/are able to provide written informed consent to participate.

Exclusion Criteria:

• ALT and AST >/= 2.5 ULN.
• Serum direct bilirubin >/= 1 mg/dl (except Gilbert's syndrome or hemolysis).
• Patients of east Asian ancestry (Chinese, Japanese, or Korean Origin).
• Calculated creatinine clearance < 30ml./min. Creatinine clearance will be calculated using the MDRD method.
• Arterial or venous thrombosis in the last year except for line-related venous thrombosis more than 3 months ago.
• Positive beta HCG within 7 days prior to consent in female of child-bearing potential defined as not post-menopausal for 12 months or no previous surgical sterilization or breast-feeding.