Prophylactic versus Preemptive Modified Donor Lymphocyte Infusion for High-risk Acute Leukemia after Allogeneic Hematopoietic Stem Cell Transplantation: A Multicenter Retrospective Study

Abstract

Abstract Donor lymphocyte infusion (DLI) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been widely used in preventing post-transplant relapse. We performed an intent-to-treat analysis to compare the clinical outcomes and superiority of prophylactic modified DLI (pro-DLI) and preemptive modified DLI (pre-DLI) in patients with high-risk relapse features acute leukemia. Pro-DLI was performed in 95 patients, whereas the pre-DLI cohort included 219 patients. Thirty-eight patients in the pre-DLI cohort became MRD positive and received pre-DLI. Pro-DLI cohort had lower 3-year cumulative incidence of relapse (CIR, 25.3% versus 38.0%, P = 0.01) and nonsignificant trend toward survival benefit (overall survival (OS), 65.2% versus 58.4%, P = 0.24; progression-free-survival (PFS), 63.4% versus 53.7%, P = 0.05). Multivariable analysis demonstrated a strong protective effect of pro-DLI on OS (hazard ratio (HR) = 0.62, P = 0.03), PFS (HR = 0.54, P = 0.003) and CIR (HR = 0.45, P = 0.001). Subgroup analysis of patients who received allo-HSCT at first complete remission (CR1) indicated that pro-DLI achieved lower 3-year CIR, higher non-relapse mortality (NRM), and no benefit on survival. In patients who received HSCT beyond CR1, pro-DLI significantly decreased CIR without increasing NRM and improved survival. Pro-DLI can be recommended for patients with high-risk features who received allo-HSCT beyond CR1 while pre-DLI could be chosen by those who transplanted in CR1.