Bleakley M, Sehgal A, Seropian S, et al. Naive T-Cell Depletion to Prevent Chronic Graft-Versus-Host-Disease. Journal of Clinical Oncology. 2022; (doi: 10.1200/JCO.21.01755).
Depletion of naive T cells (TN), which are known to trigger severe graft-versus-host disease (GVHD) in mouse models, might help prevent the complication from developing after allogeneic hematopoietic cell transplantation. Researchers drew that conclusion after analyzing evidence from three Phase II investigations populated by a collective 138 patients with acute leukemia. After receiving TN-depleted peripheral blood stem-cell (PBSC) allografts, participants were followed for a median period of four years. Cases of chronic GVHD occurred infrequently, with a three-year cumulative incidence of 7%, and were generally mild in nature. Also observed was that severe cases of grade III and IV acute GVHD were uncommon, occurring at rates of 4% and 0%, respectively. The cumulative incidence of grade II acute GVHD was 71%, largely presenting as stage 1 upper gastrointestinal GVHD. The rate of overall survival at three years was 77%, while the rates of relapse-free survival, relapse, and nonrelapse mortality were 68%, 23%, and 8%, respectively. Unlike other graft engineering strategies for allo-HCT, TN appears to achieve favorable outcomes without unacceptable risk of relapse or non-relapse mortality.