Post-transplant cyclophosphamide versus antithymocyte globulin in allogeneic hematopoietic cell transplantation: a meta-analysis

Graft-versus-host disease (GVHD) prophylaxis based on post-transplant cyclophosphamide (PTCy) or antithymocyte globulin (ATG) is widely used in allogeneic hematopoietic stem cell transplantations (allo-HCT). The differential impacts of PTCy and ATG on transplantation outcomes are not well characterized. Here we report a meta-analysis of PTCy versus ATG in allo-HCT. Ten studies were eligible, and a total of 1871 patients were included. The incidence of II-IV aGVHD, III-IV aGVHD, and NRM were significantly lower in PTCy arm (HR = 0.63, 95% CI 0.45–0.89; HR = 0.35, 95% CI 0.16–0.77; HR = 0.59, 95% CI 0.48–0.73). PTCy was associated with a better OS and PFS (HR = 0.62, 95% CI = 0.53–0.73; HR = 0.76, 95% CI 0.62–0.93). The relapse rate and cGVHD incidence were not significantly different between PTCy and ATG (HR = 0.85, 95% CI 0.68–1.07; HR = 0.65, 95% CI 0.38–1.12). Thus, compared with ATG, PTCy has a better aGVHD control and OS benefit, without increasing relapse risk, which needs further validation in prospective randomized trials.