Graft-versus-host Disease-free, Relapse-free Survival After HLA-identical Sibling Peripheral Blood Stem Cell Transplantation With Tacrolimus-based Graft-versus-host Disease Prophylaxis in Japanese Patients

The ideal post-allogeneic hematopoietic cell transplantation recovery is not just the cure of hematologic malignancies but also freedom from ongoing morbidity. Recent studies have revealed that HLA-identical sibling peripheral blood stem cell transplantation (PBSCT) had been providing impaired graft-versus-host disease (GVHD)-free relapse-free survival (GRFS) due to a higher risk of GVHD. Study on GVHD prophylaxis bears clinical reliance when focused on Japanese population because risk of GVHD differs among races. We identified 15 consecutive Japanese patients who received tacrolimus-based GVHD prophylaxis after myeloablative HLA-identical sibling PBSCT. No episode of grade ≥ II acute GVHD and only one episode of grade III toxicity were documented, with the control of mean weekly blood tacrolimus concentrations during the first 4 weeks at 13 to 17 ng/mL. An estimated 46.7% (95% CI: 21.4% to 71.9%) of the patients enjoyed their GRFS at 3 years after transplantation, and failure in the treatment of chronic GVHD was not reported during the median follow-up period of 1059 days (range, 784 to 1778 days) after the development of chronic GVHD. The results suggest that the application of tacrolimus with the optimization of its blood concentrations may effectively prevent ongoing morbidities after HLA-identical sibling PBSCT.