Researchers at Washington University School of Medicine reported Phase I/II multicenter results in Nature Medicine showing that CRISPR-Cas9 deletion of CD33 from donor cells can help reduce relapse risk after allogeneic hematopoietic cell transplantation in AML and MDS patients at high risk. In the trial, 30 adult patients achieved engraftment by day 28, with a maintenance strategy using gemtuzumab ozogamicin following transplant.