Alemtuzumab Versus Anti-Thymocyte Globulin As Conditioning Method for Allogenic Hematopoietic Stem Cell Transplant; A Meta-Analysis

Objective: Anti-thymocyte Globulin (ATG) and Alemtuzumab (Ale) are common methods for T cell depletion in the setting of allogenic hematopoietic stem cell transplant. They are both used to promote engraftment and prevent graft-versus-host disease (GVHD). Currently, there's no comparative meta-analysis for safety and efficacy of Ale versus ATG. Therefore, we conducted a meta-analysis to compare the risk of acute graft-versus-host disease (aGVHD), chronic graft-versus-host disease (cGVHD), odd of relapse and overall survival (OS) between Ale and ATG.

Method: We performed a comprehensive literature search in MEDLINE (Pubmed), Cochrane library and EMBASE database from inception to April 2020 for studies that compared the use of Ale and ATG. We conducted a random effect meta-analysis of 11 studies involving a total of 4,239 participants (Ale=1,293, ATG=2,946) and reported the pooled odd ratio (OR) for development of aGVHD, cGVHD, relapse and OS.

Result: We found a significant decreased in odd of aGVHD and cGVHD in the Ale group compared to the ATG group (pooled OR 0.44, 95% CI 0.32-0.61, I²=56.1% and 0.58, 95% CI 0.44-0.77, I²=47.5% respectively) but there were no statistically significant increase in the odd of relapse and OS (pooled OR 1.14, 95% CI 0.81-1.59, I²=64.5% and 1.20, 95% CI 0.83-1.72, I²=76.3% respectively).

Conclusion: There is significantly decreased odd of aGVHD and cGVHD with use of Ale compared to ATG, but there is no statistically significant increased odd of relapse or OS. We concluded that Ale could be the superior method of T cell depletion in terms of decreased aGVHD and cGVHD but there's no significant difference in odd of relapse and OS.