Partially Matched Related Donor Transplantation Can Achieve Outcomes Comparable with Unrelated Donor Transplantation for Patients with Hematologic Malignancies

Purpose: The study aimed to compare the outcomes of patients undergoing hematopoietic stem cell transplantation (HSCT) from partially matched related donors (PMRD) and unrelated donors (URD) for hematologic malignancies without the use of in vitro T cell depletion. Experimental Design: HSCT was done on 297 consecutive patients from URDs (n = 78) and PMRDs (n = 219) during the same time period. Incidences of graft-versus-host disease (GVHD), relapse, nonrelapse mortality, overall survival, and leukemia-free survival between the PMRD and URD groups were compared. Results: All patients achieved full engraftment. The cumct65ulative incidences of grades 11 to IV acute GVHD in the PMRD and URD cohorts were 47% [95% confidence interval (95% CI), 33-62%] versus 31% (Cl, 20-42%; P = 0.033), with a relative risk of 1.72 (95% Cl, 1.01-2.94; P = 0.046).The incidence of chronic GVHD did not differ significantly between the two cohorts (P = 0.17). The 2-year incidences of nonrelapse mortality and relapse were 20% (Cl, 15-26%) versus 18% (Cl, 10-27%), with P = 0.98, and 12% (Cl, 8-16%) versus 18% (Cl, 10-27%), with P = 0.12, for the PMRD versus the URD cohort, respectively. The 4-year overall survival and leukemia-free survival were 74% (Cl, 67-80%) versus 74% (Cl, 62-85%), with P = 0.98, and 67% (Cl, 59-75%) versus 61% (Cl, 47-74%), with P = 0.74, respectively. Conclusions: Our comparisons show that every major end point, including relapse, nonrelapse mortality, overall survival, and leukemia-free survival, was comparable between the PMRD and the URD groups.