PRIMARY OBJECTIVES:~I. To determine the efficacy of the combination of RUX (ruxolitinib phosphate) with AZA (azacytidine) in patients with myelofibrosis (MF) (primary myelofibrosis, post polycythemia vera myelofibrosis, or post essential thrombocythemia myelofibrosis [PMF, post- PV MF, or post - ET MF]) in achieving objective improvements in disease status.~II. To determine the efficacy of the combination of RUX + AZA in patients with myelodysplastic syndromes/myeloproliferative neoplasms (MDS/MPN) including chronic myelomonocytic leukemia (CMML), atypical chronic myeloid leukemia (breakpoint cluster region [BCR]-c-abl oncogene 1, non-receptor tyrosine kinase [ABL1] negative: aCML), and myelodysplastic syndromes/myeloproliferative neoplasms, unclassifiable (MDS/MPN-U), in achieving objective improvements in disease status.~SECONDARY OBJECTIVES:~I. To determine the safety of the RUX + AZA combination in patients with MF and MDS/MPN.~TERTIARY OBJECTIVES:~I. To explore time to response (TTR) and duration of response (DOR). II. To explore the effect of the combination on anemia and transfusion dependence in patients with MF and MDS/MPN.~III. To explore the impact of baseline mutational profile on International Working Group (IWG)-Myeloproliferative Neoplasms Research and Treatment (MRT) response and overall survival in patients with MF and MDS/MPN.~IV. To explore the impact of baseline anemia on overall survival in patients with MF and MDS/MPN.~OUTLINE: Patients are assigned to 1 of 2 treatment arms.~ARM I (MF): Patients with MF receive ruxolitinib phosphate orally (PO) twice daily (BID) on days 1-28. Beginning course 4, patients also receive azacytidine subcutaneously (SC) or intravenously (IV) for 5 days. Treatment repeats every 28 days for 15 courses in the absence of disease progression or unacceptable toxicity.~ARM II (MDS/MPN): Patients with MDS/MPN receive ruxolitinib phosphate and azacytidine as in Arm I.~After completion of study treatment, patients are followed up for 30 days and up to 5 years.
This phase II trial studies how well ruxolitinib phosphate and azacytidine work in treating patients with myelofibrosis or myelodysplastic syndrome/myeloproliferative neoplasm. Ruxolitinib phosphate may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Drugs used in chemotherapy, such as azacytidine, work in different ways to stop the growth of cancer cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving ruxolitinib phosphate and azacytidine may be an effective treatment for myelofibrosis or myelodysplastic syndrome/myeloproliferative neoplasm.