Post-transplant Cyclophosphamide Versus Thymoglobulin in HLA-Mismatched Unrelated Donor Transplant for Acute Myelogenous Leukemia and Myelodysplastic Syndrome.

ABSTRACT Limited information is available on the efficacy of post-transplantation cyclophosphamide (PTcy) or thymoglobulin for graft-versus-host disease (GVHD) prophylaxis in mismatched unrelated donor (MMUD) transplants. We retrospectively compared outcomes of 76 adult patients with acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS) who underwent 7/8 HLA-MMUD transplantation and received either PTcy (50 mg/kg on day 3 and 4) or thymoglobulin (total dose 4.5 mg/kg) for GVHD prophylaxis. In addition, tacrolimus and mycophenolate were used in both groups. Propensity score-based multivariable analyses (PSCA) were performed to adjust confounding effects of patient characteristics between both groups. Between January 2006 and June 2019, 25 patients received PTcy, and 51 received thymoglobulin. Median age of the population was 57 years, 78% of patients had AML, most common graft source was peripheral blood (96%), and 46% received myeloablative conditioning regimens. Median time to neutrophil (15 versus 11 days, P