High-Dose Post-Transplant Cyclophosphamide and Bortezomib (CyBor) for the Prevention of Graft-versus-Host Disease Following Allogeneic Hematopoietic Stem Cell Transplantation (HSCT)

Inclusion Criteria: * Karnofsky score ≥ 70% * No evidence of progressive bacterial, viral, or fungal infection * Creatinine clearance \> 50 mL/min/1.72m2 * Total bilirubin, ALT and AST \< 2 x the upper limit of normal (except for Gilbert's syndrome) * Alkaline phosphatase ≤ 250 IU/L * Left Ventricular Ejection Fraction (LVEF) \> 45% * Adjusted Carbon Monoxide Diffusing Capacity (DLCO) \> 60% * Negative HIV serology * Negative pregnancy test: confirmation per negative serum β-human chorionic gonadotropin (β-hCG) Exclusion Criteria: * Pregnant or nursing females or women of reproductive capability who are unwilling to completely abstain from heterosexual sex or practice 2 effective methods of contraception from the first dose of bortezomib through 90 days after the last dose. A woman of reproductive capability is one who has not undergone a hysterectomy (removal of the womb), has not had both ovaries removed, or has not been post-menopausal (stopped menstrual periods) for more than 24 months in a row. * Male subjects who refuse to practice effective barrier contraception during the entire study treatment period and through a minimum of 90 days after the last dose of study drug, or completely abstain from heterosexual intercourse. This must be done even if they are surgically sterilized (i.e., post-vasectomy). * Inability to provide informed consent. * Patient had myocardial infarction within 6 months prior to enrollment or has New York Heart Association (NYHA) Class III or I…