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Our previous research indicated that a reduced-intensity conditioning regimen (fludarabine and melphalan at 100 mg/m2) was useful in allogeneic hematopoietic cell transplantation (HCT) for patients with lymphoma. This retrospective study evaluated the reduced-intensity conditioning regimen in allogeneic HCT for adult patients with hemophagocytic lymphohistiocytosis (HLH). Sixteen patients with HLH were evaluated, including 6 patients who were enrolled in a prospective clinical trial (NCT00772811) and 10 patients who received the same conditioning regimen (fludarabine at 30 mg/m2/day on days –6 to –2 and melphalan at 100 mg/m2 on day –2). The median age was 42 years (range, 18 to 64), and 12 patients had Epstein-Barr virus (EBV)-associated HLH. Donors were an HLA matched sibling for 10 patients, an unrelated matched volunteer for 4 patients, and a mismatched family member for 2 patients. After excluding 3 patients who died soon after HCT, 12 patients achieved an engraftment (neutrophil median, day 12; platelet median, day 16). Five patients experienced acute graft-versus-host disease (GVHD), including 1 case of grade II and 4 cases of grades III to IV. Chronic GVHD occurred in 3 patients (moderate, 1 case; severe, 2 cases). After a median follow-up of 33.8 months 1 patient progressed, 3 patients relapsed, and 9 patients died. Five deaths were unrelated to relapse or progression and were caused by infection (n = 3), bleeding (n = 1), and GVHD (n = 1). No deaths or relapses were observed at >124 days post-transplant. The overall survival rate was 48.6%, and significant differences were observed according to pretransplant ferritin level (P = .007) and cytopenia lineage (P = .021). Before allogeneic HCT 10 of 12 patients still tested positive for EBV DNA: 6 patients tested negative for EBV DNA after HCT, 2 patients had persistent EBV DNA, and 2 patients were unassessable because of early death. Conditioning therapy using a lower dose of melphalan combined with fludarabine appears to be promising in allogeneic HCT for adults with HLH. However, strategies are needed to reduce the risk of early death.

To investigate the role of antithymocyte globulin (ATG)-containing reduced-intensity conditioning (RIC) in hematopoietic cell transplantation (HCT) from unrelated (UD) or haploidentical family donors (HFD), we conducted a phase 2 trial of 237 patients (age range, 16 to 69 years) with acute myeloid leukemia (AML) in remission. Patients undergoing UD-HCT (n = 93) or HFD-HCT (n = 59) received RIC comprising busulfan, fludarabine, and ATG, 9 mg/kg, whereas those undergoing HCT from matched sibling donors (MSD, n = 85) received myeloablative busulfan and cyclophosphamide conditioning or aforementioned RIC with ATG, 4.5 mg/kg. For graft-versus-host disease (GVHD) prophylaxis, cyclosporine and methotrexate were administered. The median follow-up period was 44.7 months after HCT for 161 survivors. For UD-HCT versus HFD-HCT, there were no significant differences in leukemia recurrence, nonrelapse mortality, relapse-free survival, grades 2 to 4 acute GVHD, and moderate-to-severe chronic GVHD. Furthermore, when the outcomes of UD-HCT and HFD-HCT were combined and compared with those of MSD-HCT, there were no significant differences in leukemia recurrence (3-year cumulative incidence, 30% versus 29%), nonrelapse mortality (3-year cumulative incidence, 7% versus 8%), relapse-free survival (3-year estimate, 63% versus 63%), and grades 2 to 4 acute GVHD (120-day cumulative incidence, 16% versus 13%). Moderate-to-severe chronic GVHD, however, occurred less frequently in UD/HFD-HCT (2-year cumulative incidence, 22% versus 40%; P = .006). The addition of ATG to conditioning regimen was a significant predictor for less chronic GVHD (subdistribution hazard ratio, .59). In AML in remission, UD/HFD-HCT after ATG-containing RIC achieved leukemia control equivalent to that of MSD-HCT. Despite HLA disparity in UD/HFD-HCT, chronic GVHD occurred less frequently after ATG-containing RIC, suggesting a strong GVHD-modulating effect of ATG.

Our previous study showed that a less toxic regimen comprising reduced cyclophosphamide (Cy), fludarabine and anti-thymocyte globulin (ATG) (Cy-Flu-ATG), was less toxic for allogeneic hematopoietic cell transplantation (alloHCT) compared with standard Cy-ATG in patients with adult severe aplastic anemia (AA). We postulated that replacing Cy with Flu (Flu-ATG) would be more beneficial. Therefore, we performed a randomized phase III study to compare the regimen-related toxicities (RRTs) of two different conditioning regimens: Cy-ATG vs. Flu-ATG. Pre-defined RRTs were defined as pulmonary complications, hepatic sinusoidal obstruction syndrome (SOS), hemorrhagic cystitis and death of any causes. We present the final analysis. Patients in the Cy-ATG arm received Cy at 200 mg/kg. Those in the Flu-ATG arm received fludarabine (Flu) at 180 mg/m2. Bone marrow (BM) as allowed when the donor was matched sibling donor and otherwise stem cell source was mobilized peripheral blood (PB). Regimen for graft-versus-host disease (GvHD) was cyclosporine and short-course methotrexate. A total of 63 patients (31 patients in Cy-ATG and 32 patients in Flu-ATG) were enrolled. The basic patients'characteristics were similar between both arms in terms of gender, age, prior immune suppression therapy history, stem cell source, stem cell dose, donor type and HLA-matching. There were 36 unrelated donors in each arm (p=1.000). All predefined RRTs were similar between Cy-ATG and Flu-ATG (33.3% vs. 21.9%; p=0.691). There was no difference between Cy-ATG and Flu-ATG in terms of pulmonary complications (12.9% vs. 3.1%; p=1.000), SOS (0% vs. 3.1%; p=1.000), hemorrhagic cystitis (6.5% vs. 3.1%; p=0.607) and death of any causes (23.3% vs. 15.6%; p=0.443). Primary engraftment failure was not found in Flu-ATG arm but 2 patients in Cy-ATG (p = 0.230), one of which died of treatment-related hepatic toxicity before engraftment. However, there was higher secondary engraftment failure inFlu-ATG arms compared with Cy-ATG (2nd GF; 21.9% vs. 6.9%; p=0.098). Therefore, any engraftment failure was not different between Cy-ATG vs. Flu-ATG (13.3% vs. 21.9%; p=0.379). The incidence of all grades acute GvHD was significantly higher in Cy-ATG arm (35.7% vs. 9.4%; p=0.013). The incidence of chronic GvHD was lower in Cy-ATG arm but was not statistically significant (11.5% vs. 23.1%; p=0.271). Any significant treatment-related toxicities including RRTs were similar between Cy-ATG and Flu-ATG arms (43.3% vs. 43.8%; p=0.974). The 3-year survival rate did not differ between Cy-ATG and Flu-ATG (72.9% vs. 79.3%; p=0.329). In conclusion, Flu-ATG can be comparable with Cy-ATG in terms of RRT and survival.

The doses of donor-derived natural killer (NK) cells that can be given safely after human leukocyte antigen (HLA)-haploidentical hematopoietic cell transplantation (HCT) remain to be defined. Forty-one patients (ages 17 to 75 years) with hematologic malignancy underwent HLA-haploidentical HCT after reduced-intensity conditioning containing busulfan, fludarabine, and antithymocyte globulin. Cell donors (ages 7 to 62 years) underwent growth factor-mobilized leukapheresis for 3 to 4 days. Cells collected on the first 2 to 3 days were used for HCT, whereas those collected on the last day were CD3-depleted and cultured into NK cells using human interleukins-15 and -21. These NK cells were then infused into patients twice at 2 and 3 weeks after HCT at an escalating doses of .2 × 10(8) cells/kg of body weight (3 patients), .5 × 10(8) cells/kg (3 patients), 1.0 × 10(8) cells/kg (8 patients), and ≥ 1.0 × 10(8) cells/kg or available cells (27 patients). At all dose levels, no acute toxicity was observed after NK cell infusion. After HLA-haploidentical HCT and subsequent donor NK cell infusion, when referenced to 31 historical patients who had undergone HLA-haploidentical HCT after the same conditioning regimen but without high-dose NK cell infusion, there was no significant difference in the cumulative incidences of major HCT outcomes, including engraftment (absolute neutrophil count ≥ 500/μL, 85% versus 87%), grade 2 to 4 acute graft-versus-host disease (GVHD, 17% versus 16%), moderate to severe chronic GVHD (15% versus 10%), and transplantation-related mortality (27% versus 19%). There was, however, a significant reduction in leukemia progression (74% to 46%), with post-transplantation NK cell infusion being an independent predictor for less leukemia progression (hazard ratio, .527). Our findings showed that, when given 2 to 3 weeks after HLA-haploidentical HCT, donor-derived NK cells were well tolerated at a median total dose of 2.0 × 10(8) cells/kg. In addition, they may decrease post-transplantation progression of acute leukemia.

Allogeneic stem cell transplantation (ASCT) has improved the outcome of acute myelogenous leukemia (AML). To further improve the treatment outcome of ASCT in AML, finding a modifiable prognostic factor is mandatory. We evaluated the effect of CD34(+) cell dose on survival in allogeneic bone marrow transplantation (BMT) from HLA-matched sibling donors for AML patients in first complete remission (CR1). The 99 patients included in our analysis were classified into high CD34(+) cell dose group (CD34(+) cells > or = 2.5 x 10(6)/kg) and low CD34(+) cell dose group (CD34(+) cells < 2.5 x 10(6)/kg). The high CD34(+) cell dose patients had better overall survival (5-year overall survival rate, 75% +/- 6% vs 52% +/- 9%; P = .01) and leukemia-free survival (5-year leukemia-free survival rate, 70% +/- 6% vs 44% +/- 9%; P = .04). CD34(+) cell dose was the only independent prognostic factor in overall survival and leukemia-free survival. The high CD34(+) cell dose group had a lower relapse incidence with a borderline statistical significance (5-year relapse rate, 27% +/- 6% vs 50% +/- 10%; P = .09). There were no differences in the engraftment of neutrophil and platelet, grade II-IV acute graft-versus-host disease (GVHD), extensive-stage chronic GVHD, and transplant-related mortality between the high and low CD34(+) cell dose groups. We confirmed that high CD34(+) cell dose favorably affects the outcomes in allogeneic BMT for AML. The effort to attain a high CD34(+) cell dose should be pursued during bone marrow harvest in allogeneic BMT for AML in CR1.

Sixty patients were randomized to receive intravenous busulfan (iBU) either as 0.8 mg/kg, over 2 hours 4 times a day (BU4 arm) or 3.2 mg/kg, over 3 hours once a day (BU1 arm) in conditioning therapy for hematopoietic cell transplantation. The complete pharmacokinetic parameters for the first busulfan dose were obtained from all patients and were comparable between the 2 arms: for the BU4 and BU1 groups, elimination half-life (mean ± SD) was 2.75 ± 0.22 versus 2.83 ± 0.21 hours, estimated daily AUC was 6058.0 ± 1091.9 versus 6475.5 ± 1099.4 μM·min per day, and clearance was 2.05 ± 0.36 versus 1.91 ± 0.31 mL/min/kg, respectively. Times to engraftment after transplantation were similar between the 2 arms. No significant differences were evident in the occurrence of acute graft-versus-host disease (aGVHD) and hepatic veno-occlusion disease (VOD). Moreover, other toxicities observed within 100 days after transplantation were not significantly different between the 2 arms. The cumulative incidence of nonrelapse mortality was 20.8% in BU4 arm and 13.3% in BU1 arm. In conclusion, our randomized study demonstrates that the pharmacokinetic profiles and posttransplant complications are similar for once-daily iBU and traditional 4-times-daily iBU.

We retrospectively compared the outcomes of 225 patients with adult acquired aplastic anemia (AA) who underwent allogeneic hematopoietic stem cell transplantation (alloHSCT) from matched related donors (MRDs), and those treated by alloHSCT from alternative donors (ADs). Univariate and multivariate analyses of factors associated with survival were performed. Multivariate analysis showed that age at alloHSCT of ≤ 31 years, MRD, successful engraftment, absence of acute graft-versus-host disease (aGVHD), and platelet engraftment at ≤ 21 days, were independent predictors of longer survival. In addition, time to aGVHD and cumulative nonrelapse mortality (NRM) were better in MRD than in AD recipients. Using propensity score matching (PSM), we performed a case-control study comparing 25 patients in each group who underwent alloHSCT from MRDs and ADs. Pretransplantation clinical factors were well balanced in either group. Median survival time was similar, and no statistically significant difference in transplantation outcomes was apparent when MRD and AD recipients were compared. In conclusion, our results suggest that alloHSCT from an AD should be considered earlier in adult patients with AA who do not have an MRD.

Intravenous (i.v.) busulfan can produce a more consistent pharmacokinetic profile than oral formulations can, but nonetheless, significant interpatient variability is evident. We investigated the influence of polymorphisms of 3 GST isozyme genes (GSTA1, GSTM1, and GSTT1) on i.v. busulfan clearance. Fifty-eight adult patients who received 3.2 mg/kg/day of busulfan as conditioning for hematopoietic cell transplantation were included in this study. Stepwise multiple linear regression demonstrated that GSTA1 variant GSTA1∗B (P = .004), GSTM1/GSTT1 double-null genotype (P = .039), and actual body weight (P = .001) were significantly associated with lower clearance of i.v. busulfan. A trend test analyzing the overall effect of GST genotype on busulfan pharmacokinetics, combining GSTA1 gene polymorphism and the number of GSTM1- and GSTT-null genotypes, showed a significant correlation between GST genotype and busulfan clearance (P = .001). The clearance of i.v. busulfan was similar between patients with GSTA1∗A/∗A and GSTM1/GSTT1 double-null genotypes and those with GSTA1∗A/∗B and GSTM1/GSTT1 double-positive genotypes. In conclusion, a pharmacogenetic approach using GST gene polymorphisms may be valuable in optimizing the i.v. busulfan dosage scheme. Our results also highlight the importance of including polygenic analyses and addressing interactions among isozyme genes in pharmacogenetic studies.