Fedratinib

This phase II trial studies how well decitabine with ruxolitinib, fedratinib, or pacritinib works before hematopoietic stem cell transplant in treating patients with accelerated/blast phase myeloproliferative neoplasms (tumors). Drugs used in chemotherapy, such as decitabine, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Ruxolitinib, fedratinib, and pacritinib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving chemotherapy before a donor hematopoietic stem cell transplant helps stop the growth of cells in the bone marrow, including normal blood-forming cells (stem cells) and cancer cells. When the healthy stem cells from a donor are infused into the patient they may help the patient's bone marrow make stem cells, red blood cells, white blood cells, and platelets. The donated stem cells may also replace the patient's immune cells and help destroy any remaining cancer cells. Decitabine, with ruxolitinib, fedratinib, or pacritinib may work better than multi-agent chemotherapy or no pre-transplant therapy, in treating patients with accelerated/blast phase myeloproliferative neoplasms.