Use of donor-derived expanded NK-cells to decrease post-transplant relapse

A phase II study at MD Anderson Cancer Center (Houston, TX) evaluated administration of ex vivo expanded donor-derived NK cells to decrease relapse in patients receiving haploidentical stem-cell transplantation for myeloid malignancies. After median 24 months of follow-up the two-years relapse rate was 4%, versus 38% in an independent contemporaneously treated case-matched cohort of patients form the CIBMTR database (p=0.014). The disease-free survival was 66% versus 44% (p=0.1). Among patients without donor-specific anti-HLA antibodies (DSA) the two-year relapse and DFS were 0% versus 40% and 72% versus 44%, respectively (DFS-HR 2.64; p=0.029). The authors conclude that administration of donor-derived expanded NK cells was safe and associated with improved relapse and DFS.