PRIMARY OBJECTIVES:~I. To describe the toxicities and assess the tolerability of recombinant EphB4-HSA fusion protein (sEphB4-HSA) in combination with an approved hypomethylating agent (HMA) among patients with myelodysplastic syndrome (MDS) who are refractory to or have lost their response to one or more HMAs and among patients with relapsed/refractory acute myeloid leukemia (AML) previously treated with a HMA.~SECONDARY OBJECTIVES:~I. To measure the expression of EphB4 among marrow and peripheral blood blasts in patients with MDS & AML at baseline and over the course of treatment.~II. To measure the expression of immune check-point activating ligands (such as PD-L1, PD-L2) on marrow and peripheral blood blasts in patients treated with HMA and sEphB4-HSA in combination.~III. To profile immune subsets (activated and exhausted T cells, natural killer [NK] cells, T regulatory cells, and myeloid derived suppressor cells) in the peripheral blood and marrow in patients treated with HMA and sEphB4-HSA in combination.~IV. To assess efficacy of sEphB4-HSA in combination with an HMA as manifest by International Working Group (IWG) response criteria, as well as time to development of acute myeloid leukemia (AML) in patients with MDS and time to progression.~OUTLINE:~Patients receive recombinant EphB4-HSA fusion protein intravenously (IV) over 60 minutes on days 1 and 15. Patients also receive azacitidine IV or subcutaneously (SC) on days 1-7 or days 1-5 and 8-9, or decitabine IV on days 1-5. Administration of recombinant EphB4-HSA fusion protein occurs before or after the HMA (not concurrently). Treatment repeats every 28 days for up to 12 courses in the absence of disease progression or unacceptable toxicity.~After completion of study treatment, patients are followed up every 6 months.
This trial studies the side effects of recombinant EphB4-HSA fusion protein when given together with azacitidine or decitabine in treating patients with myelodysplastic syndrome, chronic myelomonocytic leukemia, or acute myeloid leukemia that has come back or has not responded to previous treatment with a hypomethylating agent. Recombinant EphB4-HSA fusion protein may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Hypomethylating agents, such as azacitidine and decitabine, slow down genes that promote cell growth and can kill cells that are dividing rapidly. Giving recombinant EphB4-HSA fusion protein together with azacitidine or decitabine may work better in treating patients with myelodysplastic syndrome, chronic myelomonocytic leukemia, or acute myeloid leukemia.