A Phase I/II GVHD Prevention Trial Combining Pacritinib With Sirolimus-Based Immune Suppression

Inclusion Criteria: * Must have an available 8/8 HLA-A, -B, -C, and -DRB1 matched-related or unrelated donor allogeneic hematopoietic peripheral blood stem cell graft. * Signed informed consent. * Acute myeloid leukemia, myelodysplasia, acute lymphoblastic leukemia, chronic myeloid leukemia, chronic lymphocytic leukemia, myeloproliferative neoplasms, Hodgkin lymphoma, or non-Hodgkin lymphoma requiring a matched allogeneic hematopoietic stem cell transplantation (HSCT). Acute Leukemia (AML or ALL) must be in complete remission defined as: \<5% marrow blasts with no morphologic evidence of leukemia, no peripheral blasts, marrow \>20% cellular, and peripheral absolute neutrophil count \>1000/uL (platelet recovery is not required). Myelodysplasia (MDS) and chronic myeloid leukemia (CML): Must have \<5% marrow blasts. Myeloproliferative neoplasms (MPN): Must have \<5% peripheral / marrow blasts. Note: Prior use of a JAK2 inhibitor is allowed up to 4 weeks before day 0 of alloHCT. Hodgkin and non-Hodgkin lymphoma: Must have chemosensitive disease. * Adequate vital organ function. * Performance status: Karnofsky Performance Status Score ≥ 80%. Donor Eligibility: * Eligible donors will include healthy sibling, relative or unrelated donors that are matched with the patient at HLA-A, B, C, and DRB1 by high resolution typing as defined by the Collaborative Trials Network. Exclusion Criteria: * Active infection not controlled with appropriate antimicrobial therapy. * History of HIV,…