Itacitinib, Tacrolimus, and Sirolimus for the Prevention of GVHD in Patients with Acute leukemia, Myelodysplastic Syndrome, or Myelofibrosis Undergoing Reduced Intensity Conditioning Donor Stem Cell Transplantation

Inclusion Criteria

• Documented informed consent of the participant and/or legally authorized representative * Assent, when appropriate, will be obtained per institutional guidelines
• Age: 18 to 75 years if meets transplant criteria per institutional guidelines per SOP.
• Performance status: Karnofsky >= 70%
• Patients with neoplastic hematologic disorders with indication of allogeneic transplant according to the standard guidelines as follows: * Acute leukemia (AL) in first complete response (CR1) or subsequent complete response (CR) or active disease with bone marrow (BM) blast of < 5% * Myelodysplastic syndrome (MDS) with intermediate-2 or high risk per International Prognostic Scoring System (IPSS) or * Myelofibrosis; primary or secondary if intermediate-2 or high risk per Dynamic International Prognostic Scoring System (DIPPS) * Myelodysplastic syndrome / myeloproliferative neoplasm (MDS/MPN) and chronic myelomonocytic leukemia (CMML) if high risk per IPSS-R or lower risk IPSS-R with poor-risk genetic features, profound cytopenia, and high transfusion burden * Chronic phase chronic myelogenous leukemia (CML)
• All candidates for this study must have a matched related donor (MRD) who is willing to donate BM or peripheral blood stem cells or an 8/8 allele matched unrelated donor (MUD)
• Total bilirubin =< 1.5 X upper limit of normal (ULN) (unless has Gilbert’s disease) (performed within 28 days prior to day 1 of protocol therapy unless otherwise stated. In case of active disease, evaluation should be done within 15 days)
• Aspartate aminotransferase (AST) =< 2.5 x ULN (performed within 28 days prior to day 1 of protocol therapy unless otherwise stated. In case of active disease, evaluation should be done within 15 days)
• Alanine aminotransferase (ALT) =< 2.5 x ULN (performed within 28 days prior to day 1 of protocol therapy unless otherwise stated. In case of active disease, evaluation should be done within 15 days)
• Creatinine clearance of >= 60 mL/min per 24 hour urine test or the Cockcroft-Gault formula (performed within 28 days prior to day 1 of protocol therapy unless otherwise stated. In case of active disease, evaluation should be done within 15 days)
• Left ventricular ejection fraction (LVEF) >= 50% * Note: To be performed within 28 days prior to day 1 of protocol therapy
• If able to perform pulmonary function tests: forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and diffusion capacity of the lung for carbon monoxide (DLCO) (diffusion capacity) >= 50% of predicted (corrected for hemoglobin). If unable to perform pulmonary function tests: oxygen (O2) saturation > 92% on room air. * Note To be performed within 28 days prior to day 1 of protocol therapy
• Seronegative for human immunodeficiency virus (HIV) antigen (Ag)/antibody (Ab) combination (combo), hepatitis C virus (HCV), active hepatitis B virus (HBV) (surface antigen negative), and syphilis (rapid plasma reagin measurement [RPR]) * If HCV positive, hepatitis C ribonucleic acid (RNA) quantitation must be performed
• Meets other institutional and federal requirements for infectious disease titer requirements * Note Infectious disease testing to be performed within 28 days prior to day 1 of protocol therapy
• Women of childbearing potential (WOCBP): negative urine or serum pregnancy test. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required
• Agreement by females and males of childbearing potential to use an effective method of birth control or abstain from heterosexual activity for the course of the study through at least 6 months after the last dose of protocol therapy * Childbearing potential defined as not being surgically sterilized (men and women) or have not been free from menses for > 1 year (women only)

Exclusion Criteria

• Prior allogeneic transplantation
• Chemotherapy, radiation therapy, biological therapy, and/or immunotherapy within 21 days prior to day 1 of protocol therapy * Note: Conditioning regimen within 21 days prior to day 1 of protocol therapy is not considered as an exclusion criterion * Note: Patients on maintenance chemotherapy with agents listed are not excluded
• History of allergic reactions attributed to compounds of similar chemical or biologic composition to study agent
• Psychological issues, no appropriate caregivers identified, or non-compliant to medication
• Uncontrolled medical or psychiatric disorders which may preclude patients to undergo clinical studies (Discretion of the attending physician)
• Active diarrhea due to inflammatory bowel disease or malabsorption syndrome
• Clinically significant uncontrolled illness
• Active, uncontrolled systemic infection (bacterial, viral, or fungal) requiring antibiotics
• Known history of immunodeficiency virus (HIV) or hepatitis B or hepatitis C infection
• Other active malignancy
• Females only: Pregnant or breastfeeding
• Any other condition that would, in the investigator’s judgment, contraindicate the patient’s participation in the clinical study due to safety concerns with clinical study procedures
• Prospective participants who, in the opinion of the investigator, may not be able to comply with all study procedures (including compliance issues related to feasibility/logistics)