Published on May 18, 2026
GVHD Prophylaxis After Cord Blood Transplantation in Patients With High-risk AML: A Nationwide Japanese Cohort Study
by Alex Kadhim
In a nationwide, retrospective cohort study, researchers from St. Mary’s Hospital, Kurume, and a nationwide consortium of Japanese transplant centers have shown that mycophenolate mofetil (MMF) accelerates neutrophil engraftment compared to methotrexate (MTX) in cord blood transplantation (CBT). Unfortunately, this was accompanied by significantly higher rates of graft-versus-host disease (GVHD) and viral complications. Published in Blood Advances, the study highlights that both prophylaxis approaches remain clinically viable, although regimen selection should be individualized according to patient comorbidities, infection risk, disease status, and transplant characteristics.
High-risk acute myeloid leukemia (AML), including therapy-related AML (t-AML) and AML with myelodysplasia-related changes, often requires allogeneic hematopoietic cell transplantation. As CBT remains an important option for patients without suitable matched donors, MMF- and MTX-based GVHD prophylaxis regimens are widely used. To date, direct comparative evidence in this setting has been limited. Therefore, the authors utilized the Transplant Registry Unified Management Program, which captures physician-certified data from more than 300 Japanese transplant centers to compare treatment regimens. Adults undergoing first CBT between January 2010 and December 2023 received cyclosporine or tacrolimus combined with either MMF or MTX, and outcomes were evaluated separately in t-AML and non-t-AML.
The study included 3,222 patients, comprising 423 with t-AML and 2,799 with non-t-AML. MMF was associated with faster neutrophil engraftment, with median recovery occurring at 19–20 days versus 20–21 days with MTX, and higher cumulative day-35 engraftment rates of 85–86% versus 78–82%. Notably, MMF recipients experienced substantially higher rates of grade 2–4 acute GVHD at 100 days (47–52% versus 29–32%). This was also accompanied by higher chronic GVHD, transplant-related mortality, and markedly increased HHV-6 encephalitis, which occurred in 10–12% of MMF recipients compared with 2–3% of MTX recipients. Relapse rates were broadly similar, while two-year overall and disease-free survival favored MTX. Together, these real-world data provide important benchmarks for GVHD prophylaxis selection in CBT for high-risk AML and support future prospective trials incorporating emerging strategies such as posttransplant cyclophosphamide and JAK inhibitors.
Reference:
Yamasaki S, Yanada M, Mizuno S, et al. GVHD prophylaxis after cord blood transplantation in patients with high-risk AML: a nationwide Japanese cohort study. Blood Adv. 2026;10(8):2648-2660. http:doi.org/10.1182/bloodadvances.2025018626
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