Ruxolitinib Phosphate, Tacrolimus and Sirolimus in Preventing Acute Graft-versus-Host Disease During Reduced Intensity Donor Hematopoietic Cell Transplant in Patients With Myelofibrosis

Inclusion Criteria: * Primary or secondary myelofibrosis intermediate or high risk by Dynamic International Prognostic Scoring System 26 (DIPSS26) in chronic or accelerated phase * Transformed acute myeloid leukemia (AML) with marrow fibrosis is allowed, if AML is in complete remission after induction therapy * Patients with a performance status of \>= 70% on the Karnofsky scale * Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control or abstinence) prior to study entry and for 1 year following transplant as per City of Hope standard operating procedure, (SOP) for allogeneic transplantation; should a woman become pregnant or suspect that she is pregnant while participating on the trial, she should inform her treating physician immediately * Bone marrow and peripheral blood studies must be available for confirmation of diagnosis; cytogenetics, flow cytometry, and molecular studies (such as JAK-2, myeloproliferative leukemia \[MPL\] and calreticulin \[CALR\] mutational status) will be obtained as per standard practice * Bone marrow aspirates/biopsies should be performed within 23 ± 7 days from registration to confirm disease remission status * All candidates for this study must have a human leukocyte antigen (HLA) (A, B, C, DR) identical siblings who is willing to donate bone marrow or primed blood stem cells or an 8/8 allele-matched unrelated donor * All ABO blood group combinations of the donor/recipient…