Multifaceted Burden of Chronic Graft-versus-Host Disease

Haploidentical Cord Blood Transplantation with 8 mg/kg Antithymocyte Globulin as Graft-versus-Host Disease Prophylaxis Compared to Haploidentical Transplantation with 10 mg/kg Antithymocyte Globulin in the Treatment of Acute Leukemia

Clinical outcomes of the transplantation strategy combined with a haploidentical stem cell graft and an unrelated umbilical cord blood unit (haplo-cord HSCT) with low-dose antithymocyte globulin (ATG) as graft-versus-host disease (GVHD) prophylaxis for the treatment of acute leukemia remains unclear. This study aimed to explore the clinical outcomes of haplo-cord HSCT in acute leukemia patients with the GVHD prevention strategy of 8 mg/kg ATG compared with haploidentical transplantation with 10 mg/kg ATG. A total of 130 patients with acute leukemia who underwent allogeneic HSCT between January 2016 and December 2020 were included in this study, including 70 patients who received haploidentical stem cell grafts and unrelated umbilical cord blood units (haplo-cord HSCT) with 8 mg/kg ATG (haplo-cord-ATG8 group) and haploidentical HSCT with 10 mg/kg ATG (haplo-ATG10 group) in 60 patients. Clinical data were collected and analyzed retrospectively. Patients in the haplo-cord-ATG8 group were significantly older compared with the haplo-ATG10 group (P = .000). Haplo-cord HSCT with reduced ATG to 8 mg/kg results in more rapid neutrophil recovery (P = .036). No between-group differences were observed in platelet recovery or the incidences of Epstein-Barr virus viremia, bloodstream infection, or hemorrhagic cystitis. The rate of grade II-IV acute GVHD by day 100 post-transplantation was higher in the haplo-ATG10 group (27.16% versus 11.48%; P = .033), as was the rate of chronic GVHD at 1 year (14.60% versus 3.36%; P = .048). The rate of cytomegalovirus reaction was higher in the haplo-ATG10 group (48.31% versus 26.30%; P = .022). With a median follow-up of 27.4 months for the haplo-cord-ATG8 group and 27.5 months for the haplo-ATG10 group, overall survival (OS) at 2 years was 79.4% versus 62.8% (P = .005), event-free survival (EFS) was 76.3% versus 55.9% (P = .001), the cumulative incidence of relapse was 10.11% versus 25.97% (P = .164), and nonrelapse mortality (NRM) was 14.33% versus 24.43% (P = .0040). Multivariate analysis identified Center for International Blood and Marrow Transplant Research Disease Risk Index was the sole significant predictor of relapse, NRM, OS, and EFS. Haplo-cord HSCT supported by cord blood with 8 mg/kg ATG as GVHD prophylaxis results in better outcomes compared with haplo-HSCT with 10 mg/kg ATG.

Haploidentical vs haplo-cord transplant in adults under 60 years receiving fludarabine and melphalan conditioning

Haplo-identical transplant with posttransplant cyclophosphamide (haplo) and umbilical cord blood transplant supported by third-party CD34 cells (haplo-cord) are competing approaches to alternative donor transplant. We compared, in adults younger than age 60 years, the outcomes of 170 haplo at 1 institution with that of 137 haplo-cord at 2 other institutions. All received reduced intensity conditioning with fludarabine and melphalan ± total body irradiation. GVHD prophylaxis for haplo consisted of cyclophosphamide, tacrolimus, and mycophenolate, whereas haplo-cord received antithymocyte globulin, tacrolimus, and mycophenolate. Haplo transplant used mostly bone marrow, and peripheral blood stem cells were used in haplo-cord transplants. Haplo-cord were older and had more advanced disease. Haplo-cord hastened median time to neutrophil (11 vs 18 days, P = .001) and platelet recovery (22 vs 25 days, P = .03). At 4 years, overall survival (OS) was 50% for haplo-cord vs 49% for haplo. Progression-free survival (PFS) was 40% for haplo-cord vs 45% for haplo. In multivariate analysis, the disease risk index was significant for OS (hazard ratio, 1.8; 95% confidence interval, 1.48-2.17; P = .00) and PFS. Total body irradiation was associated with decreased recurrence and improved PFS, age >40 with increased nonrelapse mortality. The type of transplant had no effect on OS, PFS, relapse, or nonrelapse mortality. Cumulative incidence of grade 2-4 acute graft-versus-host disease (GVHD) by day 100 was 16% after haplo-cord vs 33% after haplo (P < .0001), but grade 3-4 GVHD was similar. Chronic GVHD at 1 year was 4% after haplo-cord vs 16% after haplo (P < .0001). Haplo or haplo-cord results in similar and encouraging outcomes. Haplo-cord is associated with more rapid neutrophil and platelet recovery and lower acute and chronic GVHD. Institutional review board authorization for this retrospective study was obtained at each institution. Some patients participated in trials registered at www.clinicaltrials.gov as #NCT01810588 and NCT01050946.