Excellent outcome of allogeneic hematopoietic stem cell transplantation using a conditioning regimen with medium-dose VP-16, cyclophosphamide and total-body irradiation for adult patients with acute lymphoblastic leukemia

Effect of Conditioning Regimens and Graft-versus-Host Disease Prophylaxis on the Outcomes of Umbilical Cord Blood Transplantation Performed with Cyclophosphamide/Total Body Irradiation-Based Regimens

Umbilical cord blood (UCB) is a valuable alternative donor source for allogeneic hematopoietic stem cell transplantation. Various conditioning regimens and graft-versus-host disease (GVHD) prophylaxis regimens aimed at improving the outcomes of umbilical cord blood transplantation (UCBT) have been explored; however, the differences in their effects remain unclear. This study was conducted to elucidate the differences in the effects of conditioning and GVHD prophylaxis regimens on UCBT outcomes by disease type in a nationwide, retrospective study. We retrospectively analyzed the effects of conditioning and GVHD prophylaxis regimens on the outcomes of UCBT performed with cyclophosphamide (Cy)/total body irradiation (TBI)-based regimens in patients with acute myeloid leukemia (AML; n = 1126), acute lymphoblastic leukemia (ALL; n = 620), myelodysplastic syndrome (MDS; n = 170), and lymphoma (n = 128). Multivariate analysis for overall survival (OS) demonstrated the benefit of adding high-dose cytarabine to the Cy/TBI regimen for the AML group (relative risk [RR], .76; P = .003) and lymphoma group (RR, .54; P = .02), but not for the ALL and MDS groups. In the ALL group, adding etoposide to the Cy/TBI regimen was associated with a lower OS (RR, 1.45; P = .03). For GVHD prophylaxis, a tacrolimus/methotrexate regimen was associated with a lower OS compared with a cyclosporine/methotrexate regimen in the AML group (RR, 1.26; P = .01); this difference was not observed in the other groups. These differences in OS according to the conditioning and GVHD prophylaxis regimen were attributable mainly to differences in relapse risk. Our data show that the effects of conditioning regimens and GVHD prophylaxis on UCBT outcomes differed according to disease type. UCBT outcomes could be improved by selecting optimal conditioning regimens and GVHD prophylaxis for each disease type.

Medium-dose etoposide, cyclophosphamide and total body irradiation conditioning potentiates anti-leukemia immunity in adults with acute lymphoblastic leukemia without aggravating graft-versus-host disease

Medium-dose etoposide (ETP), cyclophosphamide (CY) and total body irradiation (TBI) is a beneficial conditioning regimen for allogeneic hematopoietic cell transplantation (allo-HCT) in adults with acute lymphoblastic leukemia (ALL), especially with high-risk ALL, as compared with CY and TBI conditioning. ETP may enhance immunogenicity of leukemia-associated antigens through increased expression of major histocompatibility antigen complex class I, leading to cross-priming of T cells by dendritic cells and generating leukemia-specific cytotoxic T cells. Furthermore, ETP can eliminate activated effector T cells, sparing naïve and memory T cells, accompanied with depletion of regulatory T cells. These mechanisms are supposed to lead to inhibit immune escape of leukemia cells and enhance anti-leukemia immunity in addition to direct cytotoxicity of ETP, followed by an efficient eradication of leukemia cells. According to the findings of pharmacokinetics studies, spreading the administration of low-dose ETP may be more efficacious than non-spreading administration, to induce a potent anti-leukemia immunity without aggravating graft-versus-host disease and transplant-related toxicity. In the present review, I discuss the immunological aspects elicited by the addition of medium-dose ETP to the CY/TBI conditioning and the possible positioning of allo-HCT with this conditioning in adults with ALL, considering recent progress in non-HCT treatment including bispecific antibody-based therapy.

Intensified conditioning regimens improved disease-free survival and engraftment after unrelated single-unit cord blood transplantation but not after matched sibling or matched unrelated donor allogeneic hematopoietic cell transplantation

The impact of conditioning intensity on different donor groups has been unclear in allogeneic transplantation. The objective of this study was to clarify the effect of conditioning intensity on disease-free survival (DFS), relapse, non-relapse mortality (NRM), neutrophil engraftment, and graft-versus-host disease for each donor type. We retrospectively evaluated the effect of conditioning intensity on transplant outcomes for patients with acute leukemia or myelodysplastic syndrome aged between 16 and 60 years in Japan using the transplant conditioning intensity (TCI) scoring system. A total of 8526 patients who received first allogeneic transplantation from 6/6 antigen-matched sibling donor (MSD, n = 2768), 8/8 allele-matched unrelated donor (MUD, n = 2357), and unrelated single-cord blood (UCB, n = 3401) were eligible for the analyses. Compared to conditioning with TCI score 4.0, which was corresponds to conventional myeloablative conditioning, including cyclophosphamide with total body irradiation 12 Gy or busulfan 12.8 mg, and was considered as the reference group in the multivariate analyses, intensified conditioning with TCI score ≥4.5 improved DFS (hazard ratio [HR],0.81, P < 0.001) and relapse rate (HR, 0.70, P < 0.001) but only after UCB transplants and not MSD and MUD transplants. In contrast, NRM was higher after intensified conditioning with TCI score ≥4.5 for MSD (HR, 1.39, P = 0.008) and MUD (HR, 1.47, P = 0.002) transplants but not UCB transplants (HR, 1.12, P = 0.240). Neutrophil engraftment was also significantly higher after intensified conditioning with TCI score ≥4.5 but only for UCB transplants (HR, 1.24, P < 0.001), whereas it was significantly lower after reduced-intensity conditioning with TCI score ≤3.5 for MSD transplants only (HR, 0.82, P < 0.001). These data demonstrated that an intensified conditioning regimen improved survival and engraftment rate only after a UCB transplants. Therefore, TCI scoring system could enable the optimization of conditioning intensity according to donor type, particularly in terms of survival and engraftment.

Adult patients with Ph+ ALL benefit from conditioning regimen of medium-dose VP16 plus CY/TBI

The medium-dose etoposide (VP16) added on cyclophosphamide (CY)/total body irradiation (TBI) is one of the intensified myeloablative conditioning regimens used in allogenic hematopoietic stem cell transplantation (allo-HSCT) for acute lymphoblastic leukemia (ALL). However, the patient subgroups who can actually benefit from VP16/CY/TBI compared to CY/TBI have not been precisely defined. Therefore, we conducted a multi-center retrospective study using the Japanese nationwide registry database to elucidate the efficacy of VP16/CY/TBI on post-transplant prognosis. Biological and clinical distinct subtypes (i.e., Philadelphia chromosome-positive (Ph+) and -negative (Ph-) ALL) were evaluated separately, which included 820 Ph+ and 1463 patients with Ph- ALL, respectively. Compared with the CY/TBI group, the VP16/CY/TBI group showed superior progression-free survival (PFS) in patients with Ph+ ALL (65% vs. 57% at 3 years after HSCT; adjusted hazard ratio (HR), 0.73; 95% confidence interval (CI), 0.55-0.98; p = 0.03), along with significantly reduced incidence of relapse (adjusted HR, 0.58; 95% CI, 0.37-0.90; p = 0.02) without the increase of non-relapse mortality (NRM). By contrast, in patients with Ph- ALL, VP16/CY/TBI did not improve PFS nor incidence of relapse; addition of VP16 reduced relapse (HR, 0.65; p = 0.06) in patients with Ph- ALL transplanted at CR1, while improved PFS was not observed (HR, 0.90; p = 0.52) due to increased NRM. This study demonstrated that VP16/CY/TBI is a more effective and well-tolerated regimen in comparison with CY/TBI in patients with myeloablative allo-HSCT for adult Ph+ ALL. Our findings can provide a novel algorithm for conditioning regimen selection in patients with adult ALL.

Hypothesis: can transfer of primary neoplasm-derived extracellular vesicles and mitochondria contribute to the development of donor cell-derived hematologic neoplasms after allogeneic hematopoietic cell transplantation?

Allogeneic hematopoietic cell transplantation (allo-HCT) is an essential treatment option for various neoplastic and non-neoplastic hematologic diseases. Although its efficacy is modest, a significant proportion of patients experience relapse, graft-versus-host disease, infection or impaired hematopoiesis. Among these, the most frequent cause of post-transplant mortality is relapse, whereas the development of de novo hematologic neoplasms from donor cells after allo-HCT occurs on some occasion as a rare complication. The mechanisms involved in the pathogenesis of the de novo hematologic neoplasms from donor cells are complex, and a multifactorial process contributes to the development of this complication. Recently, extracellular vesicles, particularly exosomes, and mitochondria have been shown to play crucial roles in intercellular communication through the transfer of specific constituents, such as deoxyribonucleic acids, ribonucleic acids, lipids, metabolites and cytosolic and cell-surface proteins. Here, I discuss the potential causative roles of these subcellular components in the development of de novo hematologic neoplasms from donor cells after allo-HCT, in addition to other etiologies.

Outcomes of allogeneic haematopoietic stem cell transplantation with intensity-modulated total body irradiation by helical tomotherapy: a 2-year prospective follow-up study

BACKGROUND AND OBJECTIVES

Intensity-modulated radiation therapy (IMRT) helps achieve good radiation dose conformity and precise dose evaluation. We conducted a single-centre prospective study to assess the safety and feasibility of total body irradiation with IMRT (IMRT-TBI) using helical tomotherapy in allogeneic haematopoietic stem cell transplantation (allo-HSCT).

PATIENTS AND METHODS

Thirty-nine adult patients with haematological malignancy (acute lymphoblastic leukaemia [n = 21], chronic myeloid leukaemia [n = 6], mixed phenotype acute leukaemia [n = 5], acute myeloid leukaemia [n = 4], and malignant lymphoma [n = 3]) who received 12 Gy IMRT-TBI were enrolled with a median follow-up of 934.5 (range, 617-1254) d. At the time of transplantation, 33 patients (85%) achieved complete remission. The conditioning regimen used IMRT-TBI (12 Gy in 6 fractions twice daily, for 3 d) and cyclophosphamide (60 mg/kg/d, for 2 d), seven patients were combined with cytarabine, and five with etoposide. We set dose constraints for the lungs, kidneys and lens as the organs at risk.

RESULTS

The mean doses for the lungs and kidneys were 7.50 and 9.11 Gy, respectively. The mean maximum dose for the lens (right/left) was 5.75/5.87 Gy. The 2-year overall survival (OS), disease-free survival (DFS), cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) were 69, 64, 18 and 18%, respectively. Thirty-six patients developed early adverse events (AEs) (including four patients with Grade 3/4 toxicities), most of which were reversible oral mucositis and may partially have been related to IMRT-TBI. However, the incidence of toxicity was comparable to conventional TBI-based conditioning transplantation. None of the patients developed primary graft failure, or Grade III-IV acute graft-versus-host disease (GVHD). In late complications, chronic kidney disease was observed in six patients, a lower incidence compared to conventional TBI-based conditioning transplantation. No radiation pneumonitis or cataracts were observed in any of the patients.

CONCLUSIONS

IMRT-TBI is safe and feasible for haematological malignancies with acceptable clinical outcomes.KEY MESSAGESIMRT-TBI-helical tomotherapy aids in accurate dose calculation and conformity.It could be used without any considerable increase in the rate of TBI-related AEs.Allo-HSCT with IMRT-TBI may be an alternative to conventional TBI for clinical use.

Acute undifferentiated leukemia limited to neck lymph nodes and a large mediastinal mass

In the 2016 update of the World Health Organization (WHO) classification of myeloid neoplasms, acute undifferentiated leukemia (AUL) was defined by a lack of lineage-specific markers. AUL has very poor prognosis and no established therapies due to its rarity. We report a case of a 31-year-old man with AUL who showed complete molecular response to an acute lymphoblastic leukemia (ALL)-based regimen and received allogeneic hematopoietic stem cell transplantation. The patient's blast cells were CD7-positive and localized to lymph nodes in the neck and to a large mediastinal mass; there was also rearrangement of the T-cell receptor delta locus. Although the tumor showed characteristics of T-cell lymphoblastic lymphoma, it was categorized as AUL based on WHO classification. This case suggests that a high-intensity conditioning regimen could be effective for rare cases of AUL that present only in the extramedullary mass, and chemotherapy for AUL should be selected based on the characteristics of the blasts.

Measurable residual disease affects allogeneic hematopoietic cell transplantation in Ph+ ALL during both CR1 and CR2

Although measurable residual disease (MRD) at the time of allogeneic hematopoietic cell transplantation (allo-HCT) has been reported to be an important prognostic factor for Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL) during first complete remission (CR1), the prognostic impact of MRD is unclear during second CR (CR2). To clarify the impact of MRD for both CR1 and CR2, we analyzed data from a registry database including 1625 adult patients with Ph+ ALL who underwent first allo-HCT during either CR1 or CR2 between 2002 and 2017. Adjusted overall and leukemia-free survival rates at 4 years were 71% and 64%, respectively, for patients undergoing allo-HCT during CR1 with MRD-, 55% and 43% during CR1 with MRD+, 51% and 49% during CR2 with MRD-, and 38% and 29% during CR2 with MRD+. Although survival rates were significantly better among patients with CR1 MRD- than among patients with CR2 MRD-, no significant difference was observed in survival rate between patients with CR1 MRD+ and CR2 MRD-. Relapse rates after 4 years were 16% in patients with CR1 MRD-, 29% in CR1 MRD+, 21% in patients with CR2 MRD-, and 46% in patients with CR2 MRD+. No significant difference was identified in relapse rate between patients with CR1 MRD- and CR2 MRD-. CR2 MRD- was not a significant risk factor for relapse in multivariate analysis (hazard ratio, 1.26; 95% confidence interval, 0.69-2.29; P = .45 vs CR1 MRD-). MRD at time of allo-HCT was an important risk factor in patients with Ph+ ALL during both CR1 and CR2.

Safety of total body irradiation using intensity-modulated radiation therapy by helical tomotherapy in allogeneic hematopoietic stem cell transplantation: a prospective pilot study

Total body irradiation using intensity-modulated radiation therapy total body irradiation (IMRT-TBI) by helical tomotherapy in allogeneic hematopoietic stem cell transplantation (allo-HSCT) allows for precise evaluation and adjustment of radiation dosage. We conducted a single-center pilot study to evaluate the safety of IMRT-TBI for allo-HSCT recipients. Patients with hematological malignancies in remission who were scheduled for allo-HSCT with TBI-based myeloablative conditioning were eligible. The primary endpoint was the incidence of adverse events (AEs). Secondary endpoints were engraftment rate, overall survival, relapse rate, non-relapse mortality, and the incidence of acute and chronic graft-versus-host disease (aGVHD and cGVHD, respectively). Between July 2018 and November 2018, ten patients were recruited with a median observation duration of 571 days after allo-HSCT (range, 496-614). D80% for planning target volume (PTV) in all patients was 12.01 Gy. Average D80% values for lungs, kidneys and lenses (right/left) were 7.50, 9.03 and 4.41/4.03 Gy, respectively. Any early AEs (within 100 days of allo-HSCT) were reported in all patients. Eight patients experienced oral mucositis and gastrointestinal symptoms. One patient experienced Bearman criteria grade 3 regimen-related toxicity (kidney and liver). All cases achieved neutrophil engraftment. There was no grade III-IV aGVHD or late AE. One patient died of sinusoidal obstruction syndrome 67 days after allo-HSCT. The remaining nine patients were alive and disease-free at final follow-up. Thus, IMRT-TBI was well tolerated in terms of early AEs in adult patients who underwent allo-HSCT; this warrants further study with longer observation times to monitor late AEs and efficacy.

Comparing the outcomes between TMLI and non-TMLI conditioning regimens for adult high-risk acute lymphoblastic leukemia patients undergoing allogeneic hematopoietic stem cell transplantation: a single-center experience

This study aimed to retrospectively evaluate the outcomes of adult patients with high-risk acute lymphoblastic leukemia (ALL) who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) with either total marrow and lymphoid irradiation (TMLI)-containing or non-TMLI conditioning regimen. Seventy adult patients with high-risk ALL who received allo-HSCT were enrolled in this study and divided into two groups based on the conditioning regimen type (TMLI group: n = 29 and non-TMLI group: n = 41). We noted significant statistical differences in the 1-year estimated cumulative incidence of relapse (25% vs. 46.5%, p = 0.018), the 1-year estimated overall survival (73.1% vs. 52.6%, p = 0.033) and disease-free survival (65.2% vs. 48.2%, p = 0.026) but found no considerable difference in transplant-related mortality (12% vs. 13.4%, p = 0.619) between patients in the TMLI and non-TMLI groups. The TMLI-containing regimen is safe and alternative for patients with high-risk ALL undergoing allo-HSCT.

Transplantation in Children and Adolescents with Acute Lymphoblastic Leukemia from a Matched Donor versus an HLA-Identical Sibling: Is the Outcome Comparable? Results from the International BFM ALL SCT 2007 Study

Eligibility criteria for hematopoietic stem cell transplantation (HSCT) in acute lymphoblastic leukemia (ALL) vary according to disease characteristics, response to treatment, and type of available donor. As the risk profile of the patient worsens, a wider degree of HLA mismatching is considered acceptable. A total of 138 children and adolescents who underwent HSCT from HLA-identical sibling donors (MSDs) and 210 who underwent HSCT from matched donors (MDs) (median age, 9 years; 68% male) in 10 countries were enrolled in the International-BFM ALL SCT 2007 prospective study to assess the impact of donor type in HSCT for pediatric ALL. The 4-year event-free survival (65 ± 5% vs 61 ± 4%; P = .287), overall survival (72 ± 4% versus 68 ± 4%; P = .235), cumulative incidence of relapse (24 ± 4% versus 25 ± 3%; P = .658) and nonrelapse mortality (10 ± 3% versus 14 ± 3%; P = .212) were not significantly different between MSD and MD graft recipients. The risk of extensive chronic (cGVHD) was lower in MD graft recipients than in MSD graft recipients (hazard ratio [HR], .38; P = .002), and the risks of severe acute GVHD (aGVHD) and cGVHD were higher in peripheral blood stem cell graft recipients than in bone marrow graft recipients (HR, 2.06; P = .026). Compared with the absence of aGVHD, grade I-II aGVHD was associated with a lower risk of graft failure (HR, .63; P = .042) and grade III-IV aGVHD was associated with a higher risk of graft failure (HR, 1.85; P = .020) and nonleukemic death (HR, 8.76; P < .0001), despite a lower risk of relapse (HR, .32; P = .021). Compared with the absence of cGVHD, extensive cGVHD was associated with a higher risk of nonleukemic death (HR, 8.12; P < .0001). Because the outcomes of transplantation from a matched donor were not inferior to those of transplantation from an HLA-identical sibling, eligibility criteria for transplantation might be reviewed in pediatric ALL and possibly in other malignancies as well. Bone marrow should be the preferred stem cell source, and the addition of MTX should be considered in MSD graft recipients.

Perspectives on the Use of a Medium-Dose Etoposide, Cyclophosphamide, and Total Body Irradiation Conditioning Regimen in Allogeneic Hematopoietic Stem Cell Transplantation: The Japanese Experience from 1993 to Present

The outcome for adults with acute lymphoblastic leukemia (ALL) treated with chemotherapy or autologous hematopoietic stem cell transplantation (HSCT) is poor. Therefore, allogeneic HSCT (allo HSCT) for adults aged less than 50 years with ALL is performed with myeloablative conditioning (MAC) regimens. Among the several MAC regimens, a conditioning regimen of 120 mg/kg (60mg/kg for two days) cyclophosphamide (CY) and 12 gray fractionated (12 gray in six fractions for three days) total body irradiation (TBI) is commonly used, resulting in a long term survival rate of approximately 50% when transplanted at the first complete remission. The addition of 30 mg/kg (15 mg/kg for two days) etoposide (ETP) to the CY/TBI regimen revealed an excellent outcome (a long-term survival rate of approximately 80%) in adults with ALL, showing lower relapse and non-relapse mortality rates. It is preferable to perform allo HSCT with a medium-dose ETP/CY/TBI conditioning regimen at the first complete remission in high-risk ALL patients and at the second complete remission (in addition to the first complete remission) in standard-risk ALL patients. The ETP dose and administration schedule are important factors for reducing the relapse and non-relapse mortality rates, preserving a better outcome. The pharmacological study suggests that the prolonged administration of ETP at a reduced dose is a promising treatment.

Toxicity associated with intensive postinduction therapy incorporating clofarabine in the very high-risk stratum of patients with newly diagnosed high-risk B-lymphoblastic leukemia: A report from the Children's Oncology Group study AALL1131

BACKGROUND

Children, adolescents, and young adults with very high-risk (VHR) B acute lymphoblastic leukemia (B-ALL) have poor outcomes, and novel therapies are needed for this subgroup. The AALL1131 study evaluated postinduction therapy using cyclophosphamide (CPM), etoposide (ETOP), and clofarabine (CLOF) for patients with VHR B-ALL.

METHODS

Patients who were 1 to 30 years old and had VHR B-ALL received modified Berlin-Frankfurt-Münster therapy after induction and were randomized to 1) CPM, cytarabine, mercaptopurine, vincristine (VCR), and pegaspargase (control arm), 2) CPM, ETOP, VCR, and pegaspargase (experimental arm 1), or 3) CPM, ETOP, CLOF (30 mg/m2 /d × 5), VCR, and pegaspargase (experimental arm 2) during the second half of consolidation and delayed intensification.

RESULTS

The rates of grade 4/5 infections and grade 3/4 pancreatitis were significantly increased in experimental arm 2. The dose of CLOF was, therefore, reduced to 20 mg/m2 /d × 5, and myeloid growth factor was required after CLOF administration. Despite these changes, 4 of 39 patients (10.3%) developed grade 4 infections, with 1 of these patients developing a grade 5 acute kidney injury attributed to CLOF, whereas only 1 of 46 patients (2.2%) in experimental arm 1 developed grade 4 infections, and there were no grade 4/5 infections in the control arm (n = 20). Four patients in experimental arm 2 had prolonged cytopenias for >60 days, whereas none did in the control arm or experimental arm 1. Counts failed to recover for 2 of these patients, one having a grade 5 acute kidney injury and the other removed from protocol therapy; both events occurred 92 days after the start of consolidation part 2.

CONCLUSIONS

In AALL1131, CLOF, administered with CPM and ETOP, was associated with unacceptable toxicity. Cancer 2018;124:1150-9. © 2017 American Cancer Society.

Improved prognosis with additional medium-dose VP16 to CY/TBI in allogeneic transplantation for high risk ALL in adults

Allogeneic hematopoietic stem cell transplantation (HSCT) with the conventional cyclophosphamide and total body irradiation (CY/TBI) regimen is an essential therapeutic strategy for acute lymphoblastic leukemia (ALL) in adults. Medium-dose etoposide (VP16, 30-40 mg/kg) can be added to intensify this CY/TBI regimen and reduce relapse; however, differences in prognosis between the VP16/CY/TBI and CY/TBI regimens have not yet been fully analyzed. We conducted a retrospective cohort study using a Japanese transplant registry database to compare the prognosis between the VP16/CY/TBI (VP16, total 30-40 mg/kg) (N = 376) and CY/TBI (N = 1178) regimens in adult patients with ALL transplanted at complete remission (CR) between January 1, 2000 and December 31, 2014. Our analyses indicated that VP16/CY/TBI significantly reduced relapse compared with CY/TBI (risk ratio, 0.75; 95% confidence interval [CI], 0.56-1.00; P = .05) with a corresponding improvement in leukemia-free survival (hazard ratio [HR], 0.76; 95%CI, 0.62-0.93; P = .01), particularly in patients transplanted at CR1 with advanced-risk (positive minimal residual disease, presence of poor-risk cytogenetics, or an initial elevated leukocyte count) (HR, 0.75; 95%CI, 0.56-1.00; P = .05) or those transplanted beyond CR2 (HR, 0.58; 95%CI, 0.39-0.88; P = .01). The addition of VP16 did not increase post-transplant complications or nonrelapse mortality (HR, 0.88; 95%CI, 0.65-1.18; P = .38). This study is the first to reveal the efficacy of the addition of medium-dose VP16 to CY/TBI in high-risk ALL. To establish new myeloablative conditioning regimens including VP16, a large-scale prospective study is necessary.

Efficacy and safety of autologous peripheral blood stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia: A study protocol for a multicenter exploratory prospective study (Auto-Ph17 study)

INTRODUCTION

The prognosis of Philadelphia chromosome positive acute lymphoblastic leukemia (Ph + ALL) has been dramatically improved since the introduction of tyrosine kinase inhibitors (TKIs). Although allogeneic hematopoietic cell transplantation (allo-HCT) is a major treatment option, the role of autologous peripheral blood stem cell transplantation (auto-PBSCT) has been reconsidered, especially in patients who achieved early molecular remission.

METHODS AND ANALYSIS

This is a multicenter exploratory study for Ph + ALL patients aged between 55 and 70 years who achieved complete molecular remission within 3 cycles of chemotherapy. The target sample size is 5, and the registration period is 2 years. The primary endpoint is Day100- mortality after transplantation, and the secondary endpoints are survival, relapse rate, nonrelapse mortality, and adverse events.This study is divided into 3 phases: peripheral blood stem cell harvest, transplantation, and maintenance. Chemomobilization is performed using a combination of cyclophosphamide (CPM), doxorubicin, vincristine (VCR), and prednisolone (PSL). As a preparative regimen, the LEED regimen is used, which consists of melphalan, CPM, etoposide, and dexamethasone. Twelve cycles of maintenance therapy using a combination of VCR, PSL, and dasatinib are performed.In association with relapse, the minimal residual disease (MRD) of BCR-ABL chimeric gene and T-cell subsets are analyzed both before and after auto-PBSCT.

ETHICS AND DISSEMINATION

The protocol was approved by the institutional review board of Nagoya University Hospital and all the participating hospitals. Written informed consent was obtained from all patients before registration, in accordance with the Declaration of Helsinki. Results of the study will be disseminated via publications in peer-reviewed journals.

TRIAL REGISTRATION

Trial registration number UMIN000026445.

Pharmacokinetics and dose adjustment of etoposide administered in a medium-dose etoposide, cyclophosphamide and total body irradiation regimen before allogeneic hematopoietic stem cell transplantation

BACKGROUND

We investigated the pharmacokinetics of etoposide (ETP) to reduce the inter-individual variations of ETP concentrations in patients with acute leukemia who underwent allogeneic hematopoietic stem cell transplantation. We also carried out an in vivo study using rats to verify the dose adjustment.

METHODS

This study included 20 adult patients. ETP was administered intravenously at a dose of 15 mg/kg once daily for 2 days (total dose: 30 mg/kg) combined with standard conditioning of cyclophosphamide and total body irradiation. In an in vivo study using rats, ETP was administered intravenously at a dose of 15 mg/kg or an adjusted dose. The ETP plasma concentration was determined by using HPLC. The pharmacokinetic parameters were estimated by using a 1-compartment model.

RESULTS

The peak concentration (Cmax) of ETP and the area under the plasma concentration-time curve (AUC) of ETP differed greatly among patients (range of Cmax, 51.8 - 116.5 μg/mL; range of AUC, 870 - 2015 μg · h/mL). A significant relationship was found between Cmax and AUC (R = 0.85, P < 0.05). Distribution volume (Vd) was suggested to be one of the factors of inter-individual variation in plasma concentration of ETP in patients (range of Vd, 0.13 - 0.27 L/kg), and correlated with Alb and body weight (R = 0.56, P < 0.05; R = 0.40, P < 0.05 respectively). We predicted Vd of rats by body weight of rats (with normal albumin levels and renal function), and the dose of ETP was adjusted using predicted Vd. In the dose adjustment group, the target plasma ETP concentration was achieved and the variation of plasma ETP concentration was decreased.

CONCLUSION

The results suggested that inter-individual variation of plasma concentration of ETP could be reduced by predicting Vd. Prediction of Vd is effective for reducing individual variation of ETP concentration and might enable a good therapeutic effect to be achieved.

Impact of conditioning with TBI in adult patients with T-cell ALL who receive a myeloablative allogeneic stem cell transplantation: a report from the acute leukemia working party of EBMT

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is a therapeutic option for adult patients with T-cell ALL (T-ALL). Meanwhile, few allo-SCT data specific to adult T-ALL have been described thus far. Specifically, the optimal myeloablative conditioning regimen is unknown. In this retrospective study, 601 patients were included. Patients received allo-SCT in CR1, CR2, CR >2 or in advanced disease in 69%, 15%, 2% and 14% of cases, respectively. With an overall follow-up of 58 months, 523 patients received a TBI-based regimen, whereas 78 patients received a chemotherapy-based regimen including IV busulfan-cyclophosphamide (IV Bu-Cy) (n=46). Unlike patients aged ⩾35 years, patients aged <35 years who received a TBI-based regimen displayed an improved outcome compared with patients who received a chemotherapy-based regimen (5-year leukemia-free survival (LFS) of 50% for TBI versus 18% for chemo-only regimen or IV Bu-Cy regimens, P=10(-5) and 10(-4), respectively). In multivariate analysis, use of TBI was associated with an improved LFS (hazard ratio (HR)=0.55 (0.34-0.86), P=0.01) and overall survival (HR=0.54 (0.34-0.87), P=0.01) in patients aged <35 years. In conclusion, younger adult patients with T-ALL entitled to receive a myeloablative allo-SCT may benefit from TBI-based regimens.

Comparison of chemotherapeutic agents as a myeloablative conditioning with total body irradiation for pediatric acute lymphoblastic leukemia: A study from the pediatric ALL working group of the Japan Society for Hematopoietic Cell Transplantation

BACKGROUND

As a partner of total body irradiation (TBI) in hematopoietic stem cell transplantation (HSCT) for pediatric acute lymphoblastic leukemia (ALL), various cytotoxic agents are used, but the optimal combination is still unclear.

PROCEDURE

We retrospectively analyzed 767 children who received TBI-based myeloablative allogeneic HSCT in complete remission (CR), using nationwide registry data of the Japan Society for Hematopoietic Cell Transplantation. Combinations of chemotherapy were categorized as follows: cyclophosphamide (CY) (n = 74), melphalan (L-PAM) (n = 139), CY + etoposide (VP16) (n = 408), CY + cytarabine (AraC) (n = 73), and others (n = 73).

RESULTS

Event-free survival (EFS) at 5 years after HSCT was 62.2% for CY, 71.4% for L-PAM, 67.6% for CY + VP16, 52.6% for CY + AraC, and 59.1% for others (P = 0.009). Further detailed comparison of LPAM and CY + VP16 demonstrated superior EFS for LPAM (83.2 ± 6.7%), with a marked difference compared with CY + VP16 (66.7 ± 4.9%) when limited to HSCT from a matched related donor (MRD), and this result was reproduced regardless of disease status (CR1 or CR2). However, EFS for CY + VP16 (68.3 ± 2.8%) was comparable to that for LPAM (64.5 ± 5.7%, P = 0.37) in HSCT from alternative donors, because higher non-relapse mortality attenuated the advantage of LPAM.

CONCLUSIONS

For pediatric ALL in remission, LPAM could provide superior EFS for HSCT from MRD; however, compared to LPAM, CY + VP16 has similar EFS for HSCT from an alternative donor.

Comparison of outcomes of idarubicin intensified TBI-CY and traditional TBI-CY conditioning regimen for high-risk acute lymphoblastic leukemia undergoing allogeneic hematopoietic stem cell transplantation: A single center experience

High-risk acute lymphoblastic leukemia (ALL) carries a very poor prognosis, even after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Exploring novel conditioning regimen to more effectively eliminate leukemic clone while not alter transplant-related mortality (TRM) has become focus of attention. We retrospectively evaluated outcomes of 87 high-risk ALL patients undergoing allo-HSCT: 47 patients received idarubicin (IDA) intensified TBI-CY and 40 patients received traditional TBI-CY regimen. In IDA intensified group, patients received TBI (8Gy) on day-8, IDA of 15mg/m2/d from day-6 to -5, followed by CY (60mg/kg/d) on day-3 to -2. The cumulative incidence of relapse was significantly lower in IDA intensified group compared with TBI-CY group (P=0.018). Oropharyngeal mucositis was observed more frequent in IDA intensified group (P=0.013), while not followed by increased TRM. Very high-risk ALL patients benefit from IDA intensified regimen with only two of eight patients in no remission (NR) pre-transplantation and two of twelve ph+ALL patients relapsed after transplantation. After a median follow-up for all survivors of 21 months (range, 12-53 months), 2-year estimated OS and DFS was 66.2% vs 45.3% (P=0.031) and 62.5% vs 43.5% (P=0.044), respectively. In conclusion, IDA intensified TBI-CY regimen may reduce relapse while not increasing TRM, providing better survival for high-risk ALL patients undergoing allo-HSCT.

Allogeneic hematopoietic stem cell transplantation in adult acute lymphoblastic leukemia: potential benefit of medium-dose etoposide conditioning

The outcomes of adult acute lymphoblastic leukemia (ALL) patients with chemotherapy or autologous hematopoietic stem cell transplantation (HSCT) are unsatisfactory. Therefore, allogeneic (allo) HSCT has been applied to those patients in first complete remission (CR1), and has shown a long-term survival rate of approximately 50 %. In terms of myeloablative conditioning (MAC) regimen, higher dose of cyclophosphamide (CY) and total body irradiation (TBI) (the standard CY + TBI) has been generally applied to allo HSCT. Other MAC regimens such as busulfan-based or etoposide-based regimens have also been used. Among those, medium-dose etoposide (ETP) in addition to the standard CY + TBI conditioning regimen appears to be promising for allo HSCT in adult ALL when transplanted in ALL patients aged under 50 years in CR1 and also in CR2, showing an excellent outcome without increasing relapse or transplant-related mortality (TRM) rates. By contrast, reduced-intensity conditioning (RIC) regimens have also been applied to adult ALL patients and favorable outcomes have been obtained; however, relapse and TRM rates remain high. Therefore, an allo HSCT conditioning regimen which deserves further study for adult ALL patients aged under 50 years in CR1 and CR2 appears to be medium-dose ETP + CY + TBI and RIC is suitable for patients aged over 50 years or for younger patients with comorbid conditions. On the contrary, new therapeutic strategies for adult ALL patients are increasingly utilized with better outcomes; namely, various tyrosine kinase inhibitors for Philadelphia chromosome (Ph)-positive ALL, human leukocyte antigen-haploidentical HSCT, and pediatric-inspired regimens for Ph-negative ALL. Therefore, the optimal treatment modality should be selected considering patient’s age, Ph-positivity, donor availability, risk classification, efficacy, and safety.

Clinical significance of the administration of cytarabine or thiotepa in addition to total body irradiation and cyclophosphamide for allogeneic hematopoietic cell transplantation in patients with acute leukemia

A multicenter retrospective study was performed to determine the significance of adding cytarabine (CA) or thiotepa (TT) in the context of total body irradiation (TBI) and cyclophosphamide (CY). A total of 322 patients who underwent allogeneic hematopoietic cell transplantation (HCT) were distributed to the following three groups: TBI/CY (n = 75), TBI/CY/CA (n = 77), and TBI/CY/TT (n = 170). In the TBI/CY/TT group, 164 of patients (96 %) received HCT during the previous year (2000-2005). Multivariate analysis revealed that the TBI/CY/TT group demonstrated a trend of poorer survival rate than the TBI/CY group, [hazard ratio (HR) = 1.49, 95 % confidence interval (CI) 0.99-2.24, P = 0.055] with a higher non-relapse mortality (NRM) (HR = 2.34, 95 % CI 1.35-4.06, P = 0.002) rates, while TBI/CY/CA group demonstrated similar outcomes. Even in the subgroup analyses of disease type or disease risk, the outcomes with intensified conditioning regimens were not superior to those with TBI/CY. In conclusion, although the significant bias has to be carefully considered, the clinical benefit of adding CA or TT to the TBI/CY regimen was not demonstrated.

A Safety and Efficacy Study of Medium-Dose Etoposide, Cyclophosphamide and Total Body Irradiation Conditioning Before Allogeneic Stem Cell Transplantation for Acute Lymphoblastic Leukemia

Prognosis for adult patients with acute lymphoblastic leukemia (ALL) has been reported to be approximately 35% to 50%, even after allogeneic stem cell transplantation (allo-SCT). We previously reported retrospective analyses of a conditioning regimen of medium-dose etoposide, cyclophosphamide (CY), and total body irradiation (TBI) before allo-SCT for ALL. To prospectively analyze the efficacy of this conditioning regimen, we conducted a trial prospectively.

Reduced-intensity vs myeloablative conditioning allogeneic hematopoietic SCT for patients aged over 45 years with ALL in remission: a study from the Adult ALL Working Group of the Japan Society for Hematopoietic Cell Transplantation (JSHCT)

In this study, outcomes for 575 adult ALL patients aged ≥45 years who underwent first allo-SCT in CR were analyzed according to the type of conditioning regimen (myeloablative conditioning (MAC) for 369 patients vs reduced-intensity conditioning (RIC) for 206 patients). Patients in the RIC group were older (median age, 58 vs 51 years, P<0.0001). There were no statistically significant differences in 3-year OS, disease-free survival (DFS) and non-relapse mortality (NRM): 51% vs 53%, 47% vs 39% and 38% vs 36%, respectively. Multivariate analysis showed that CR2 and HLA mismatching were associated with poor OS (P=0.002 and P=0.019, respectively). HLA mismatching was associated with lower rate of relapse (P=0.016), but was associated with higher rate of NRM (P=0.001). RIC was associated with good OS and DFS in patients who received HLA-mismatch transplantation and were aged ≥55 years compared with MAC by multivariate analysis for each event with interaction (hazard ratio (HR) and 95% confidence interval 0.35 and 0.15-0.81, P=0.014 for OS and 0.36 and 0.16-0.81, P=0.013 for DFS). Therefore, patients ≥55 years of age with HLA-mismatch transplantation should be candidates for RIC rather than MAC.

High-dose etoposide in allogeneic stem cell transplantation

The anti-leukemic effect of etoposide is well documented. High-dose etoposide 60 mg/kg in combination with fractionated total body irradiation (TBI), usually single fractions of 1.2 Gy up to a total of 13.2 Gy, is used as conditioning therapy for allogeneic stem cell transplantation. Most studies of this conditioning regimen have included patients with acute leukemia receiving bone marrow or mobilized stem cell grafts derived from family or matched unrelated donors, and the treatment is then effective even in patients with high-risk disease. The most common adverse effects are fever with hypotension and rash, nausea and vomiting, sialoadenitis, neuropathy and metabolic acidosis. A small minority of patients develop severe allergic reactions. Etoposide has also been tested in a wide range of combination regimens, but for many of these combinations, relatively few patients are included, and some combinations have only been tested in patients who have undergone autologous transplants. However, the general conclusion is that many of these combinations are effective in patients with high-risk malignancies and the toxicity often seems acceptable. Thus, etoposide-based conditioning therapy should be further evaluated in patients having allogeneic transplants, but randomized trials are needed and the design of future trials should be based on the well-characterized TBI + high-dose etoposide regimen.

Schedule-dependent cytotoxicity of etoposide (VP-16) and cyclophosphamide in leukemia cell line K-562

In allogeneic bone marrow transplantation (allo-BMT) in patients with leukemia, the combination of VP-16 and cyclophosphamide (CY) is commonly used for the conditioning regimen. In the present study, we demonstrated schedule-dependent cytotoxicity of VP-16 and CY in K-562 cells. K-562 cells were pretreated with low concentrations (2.5 and 5 µg/mL) of 4-hydroperoxycyclophosphamide (40487S), which is a preactivated analog of CY. It was confirmed that these concentrations did not influence cell viability. Cells subsequently exposed to 0.5-100 µg/mL of VP-16 showed reduced the viability compared to that of control cells not treated with 40487S. In contrast, there was no change in the viability of K-562 cells pretreated with low concentrations (0.5 and 1 µg/mL) of VP-16. It was confirmed that these concentrations did not influence cell viability. Viability of subsequently exposed to 1-20 µg/mL was not different from that of control cells not treated with VP-16. VP-16 caused cell cycle arrest at G₂/M phase. On the other hand, 40487S arrested the cell cycle at S phase. Thymidine-synchronized cells, VP-16 showed cell cycle specificity for cell killing from early-S to mid-S phase. On the other hand, 40487S showed cell cycle-independent cytotoxicity. Exposure of cells to VP-16 after 40487S induced a greater cytotoxic effect on K-562 cells. The findings may lead to improvements in clinical combination chemotherapy.

Safety and efficacy of total body irradiation, cyclophosphamide, and cytarabine as a conditioning regimen for allogeneic hematopoietic stem cell transplantation in patients with acute lymphoblastic leukemia

Disease relapse still greatly interferes with the success of allogeneic hematopoietic stem cell transplantation (HSCT) for acute lymphoblastic leukemia (ALL). This study retrospectively evaluated the long-term safety and efficacy of a conditioning regimen consisting of total body irradiation (TBI; 12 Gy), cyclophosphamide (CY; 60 mg kg(-1) , two doses), and high-dose cytarabine (Ara-C; 2 g m(-2) ; four doses) for patients with ALL. Fifty-five patients (median age: 31-years old) were evaluated. Stem cells were from human leukocyte antigen-identical siblings in 22 patients and from alternative donors in 33. There were no cases of early death before engraftment, and 100-day transplant-related mortality was 7.3%. With a median follow-up period of 9.6 years, 5-year overall and disease-free survival were 63.2% (95% CI: 46.5-79.9%) and 63.6% (95% CI: 47.1-80.1%) in patients with complete remission, respectively, both of which were significantly higher than the values of 27.3% (95% CI: 8.7-46.0%) and 22.7% (95% CI: 5.3-40.1%) for patients in advanced stages (P < 0.01). These results suggest that TBI and CY (TBI-CY) plus Ara-C could be a feasible and effective conditioning regimen for adult patients with ALL both in remission and in advanced stages, and a future study to compare this combination therapy with TBI-CY is required.

The role of cytotoxic therapy with hematopoietic stem cell transplantation in the treatment of adult acute lymphoblastic leukemia: update of the 2006 evidence-based review

Clinical research published since the first evidence-based review on the role of hematopoietic stem cell transplantation (SCT) in the treatment of acute lymphoblastic leukemia (ALL) in adults is presented and critically evaluated in this update. Treatment recommendations changed or modified based on new evidence include: (1) myeloablative allogeneic SCT is an appropriate treatment for adult (<35 years) ALL in first complete remission for all disease risk groups; and (2) reduced-intensity conditioning may produce similar outcomes to myeloablative regimens. Treatment recommendations unchanged or strengthened by new evidence include: (1) allogeneic SCT is recommended over chemotherapy for ALL in second complete remission or greater; (2) allogeneic is superior to autologous SCT; and (3) there are similar survival outcomes after related and unrelated allogeneic SCT. New treatment recommendations based on new evidence include: (1) in the absence of a suitable allogeneic donor, autologous SCT may be an appropriate therapy, but results in a high relapse rate; (2) it is appropriate to consider cord blood transplantation for patients with no HLA well-matched donor; and (3) imatinib therapy before and/or after SCT (for Ph+ ALL) yields significantly superior survival outcomes. Areas of needed research in the treatment of adult ALL with SCT were identified and presented in the review.

A comparison of oral mucositis in allogeneic hematopoietic stem cell transplantation between conventional and reduced-intensity regimens

Severe oral mucositis developed in allogeneic hematopoietic stem cell transplantation (HSCT) accompanies intolerable pain and risk for systemic bacteremia infection. Conventional stem cell transplantation (CST) and reduced-intensity regimens for allogeneic HSCT (RIST) may differently affect the occurrence and severity of oral mucositis. Here, we comparatively examined oral mucositis in patients undergoing CST and that in RIST patients to search for measures to alleviate oral mucositis. We retrospectively analyzed the data of 130 consecutive patients undergoing HSCT (conventional, 60; RIST, 70). Oral mucositis was evaluated according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. We also investigated the risk factors for severe oral mucositis in each regimen. The incidence of oral mucositis was not significantly different between RIST and CST patients. The use of opioid analgesics to control pain due to oral mucositis was significantly less in patients undergoing RIST compared with those receiving CST. The risk factors for severe oral mucositis, determined by univariate and multivariate analyses, were "younger age (<40)" in CST and "longer duration of neutropenia (≥ 14 days)" in RIST. Although the incidences of oral mucositis were almost the same, the need for opioid analgesics and the risk factors for severe oral mucositis differed between CST and RIST patients.

Idarubicin-intensified BUCY2 regimens may lower relapse rate and improve survival in patients undergoing allo-SCT for high-risk hematological malignancies: a retrospective analysis

We conducted a retrospective study to evaluate the outcome of 94 consecutive patients with high-risk hematological malignancies who received allo-PBSCT, following idarubicin (IDA)-intensified BUCY2 (IDA-BUCY2) myeloablative conditioning regimens (n=53) and BUCY2 conditioning regimens (n=41). IDA 15 mg/m(2) once daily was administered by continuous infusion on days -11 to -9, followed by BU, 3.2 mg/kg in divided doses daily, on days -6 to -4, and i.v. injection of CY, 1.8 g/m(2) once daily on days -3 to -2 in the IDA-BUCY2 group. The relapse rate in patients in the IDA-BUCY2 and BUCY2-conditioning regimens group was 18.9 and 39%, respectively (P=0.030). There was no significant difference in terms of TRM. The cumulative probabilities of OS and disease-free survival at 2 years for patients conditioned with the IDA-BUCY2 and BUCY2 regimens were 65.3% vs 46.8% (P=0.038), and 63.5% vs 43.4% (P=0.025), respectively. Multivariate analysis showed that IDA-BUCY2 regimens and limited chronic GVHD were the only two factors resulting in improved survival and reduced relapse rate. This retrospective study suggests that IDA-intensified BUCY2 may be substituted for BUCY2 as conditioning regimen for patients with high-risk hematological malignancies.

Clinical tolerance in large field radiotherapy--the knowledge gained over the last ten years

Malignant disorders are still far from being successfully managed in spite of the apparent progress achieved by surgical treatment, high energy radiotherapy (RT) and chemotherapy (CHT). They keep being the second most frequent cause of lethal outcomes both in Bulgaria and in most countries of the world. One of the promising approaches to increasing the efficaciousness of treatment is development and use of methods that are in full accord with the modern requirements of a complex therapy. Over the last fifty years, large field radiation techniques, applied as systemic therapy in oncology, have been investigated and established. These techniques show the transition in oncology to using actively various variants of large field radiotherapy (LFR), the "heavy artillery" of oncoradiologic practice, as an alternative or adjunct therapy to chemotherapy (CHT). In the present paper we review the current knowledge in the field and present the clinical experience accumulated over the last ten years with respect to clinical tolerance in the major large-field radiotherapy techniques--total body irradiation, half body irradiation, whole abdominal irradiation, total and partial lymphoid irradiation. Described in detail are the contemporary knowledge about clinical and hematologic tolerance in total body irradiation as part of the myelo- and nonmyeloablative conditioning regimens as well as in half body irradiation as a systemic therapy in oncology. We also present the amassed experience in clinical tolerance in partial body irradiation in the form of whole abdominal and total or partial lymphoid irradiation. Another point worth noting based again on the experience gained over the last ten years is that for LFR we need to develop a radiotherapy technique that is designed carefully to achieve an optimal therapeutic effect that should include the disease control, good clinical tolerance and reduction of post-radiotherapy sequelae.

Increased risk of bacterial infection after engraftment in patients treated with allogeneic bone marrow transplantation following reduced-intensity conditioning regimen

Although bacterial infection is a major cause of death even after reduced-intensity conditioning (RIC) for allogeneic stem cell transplantation (SCT), little is known about the epidemiology and risk factors. The incidence of bacterial infection in 43 patients who received allogeneic bone marrow transplantation (BMT) using a RIC regimen was compared with that in 68 patients who received BMT using a myeloablative conditioning regimen, and risk factors for bacterial infection were identified. Before engraftment, incidences of febrile neutropenia (FN) and documented infections (DI) were significantly decreased in RIC patients (FN: 59.5% vs. 89.6%, P<0.01, DI: 4.8% vs. 17.9%, P<0.01). However, incidence of bacterial infection was significantly increased in RIC patients in the post-engraftment phase (53.8% vs. 11.1%, log-rank, P<0.01). Blood stream was the most frequent focus of infection in both groups. In multivariate analysis, RIC and acute graft-versus-host disease were revealed to be significant risk factors for bacterial infection in this phase. In summary, risk of bacterial infection after engraftment was significantly higher in RIC patients, although infection was decreased before engraftment, and we need to develop a RIC-specific strategy against bacterial infection after RIC SCT.

Successful treatment of acute myelogenous leukemia with favorable cytogenetics by reduced-intensity stem cell transplantation

Acute myelogenous leukemia (AML) with favorable cytogenetics responds well to chemotherapy. If the leukemia relapses, allogenic hematopoietic stem transplantation (allo-HSCT) is considered as a treatment option. Since the efficacy of reduced-intensity stem cell transplantation (RIST) for AML with favorable cytogenetics has not been established, we retrospectively analyzed the outcomes of allo-HSCT in AML patients according to cytogenetic risks. The outcome of allo-HSCT for AML patients with favorable cytogenetics seemed to be superior to that for AML patients with intermediate cytogenetics. In AML patients with favorable cytogenetics, the 3-year overall survival (OS) and relapse-free survival (RFS) rates were 88 and 76%, respectively, in the RIST group. Both the 3-year OS and RFS rates were 81% in the conventional stem cell transplantation (CST) group. The outcome of RIST for AML patients with favorable cytogenetics was comparable to that for patients who received CST despite the more advanced age and greater organ dysfunction in RIST group than in CST group. None of the patients died within 90 days after RIST. Moreover, there was no relapse in patients with favorable cytogenetics who were in hematological remission prior to RIST. Thus, RIST for AML patients with favorable cytogenetics in remission is safe and effective.

Graft-versus-leukemia effect of nonmyeloablative stem cell transplantation

Nonmyeloablative stem cell transplantation (NST) is increasingly used with beneficial effects because it can be applied to older patients with hematological malignancies and those with various complications who are not suitable for conventional myeloablative stem cell transplantation (CST). Various conditioning regimens differ in their myeloablative and immunosuppressive intensity. Regardless of the type of conditioning regimen, graft-versus- host disease (GVHD) in NST occurs almost equally in CST, although a slightly delayed development of acute GVHD is observed in NST. Although graft-versus-hematological malignancy effects (i.e., graft-versus-leukemia effect, graft-versus-lymphoma effect, and graft-versus-myeloma effect) also occur in NST, completely eradicating residual malignant cells through allogeneic immune responses is insufficient in cases with rapidly growing disease or uncontrolled progressive disease. Donor lymphocyte infusion (DLI) is sometimes combined to support engraftment and to augment the graft-versus-hematological malignancy effect, such as the graft-versus-leukemia effect. DLI is especially effective for controlling relapse in the chronic phase of chronic myelogenous leukemia, but not so effective against other diseases. Indeed, NST is a beneficial procedure for expanding the opportunity of allogeneic hematopoietic stem cell transplantation to many patients with hematological malignancies. However, a more sophisticated improvement in separating graft-versus-hematological malignancy effects from GVHD is required in the future.

Regimen-related mucosal injury of the gut increased the incidence of CMV disease after allogeneic bone marrow transplantation

Cytomegalovirus (CMV) infection is 1 of the major causes of morbidity in patients undergoing allogeneic stem cell transplantation (allo-SCT). The incidences of CMV antigenemia and CMV disease in 43 patients who received allogeneic bone marrow transplantation (BMT) using a reduced-intensity conditioning (RIC) regimen, which mainly consisted of fludarabine (Flu), busulfan (Bu), and total body irradiation (TBI), were compared with those in 68 patients who received a myeloablative conditioning (MAC) regimen, and risk factors for CMV antigenemia and CMV disease were identified. Before engraftment, grade 3-4 mucosal injury because of the conditioning regimen was significantly decreased in RIC patients (stomatitis: P = .02; diarrhea: P < .01). Rate of engraftment, incidences of acute graft-versus-host disease (aGVHD), and rate of corticosteroid administration were not different in RIC patients and MAC patients. Although the incidences of CMV antigenemia were not significantly different in RIC patients and MAC patients (64.1% versus 57.8%, log rank, P = .59), the incidence of CMV disease was significantly decreased in RIC patients (5.4% versus 20.3%, log rank, P = .04). CMV seropositivity in the patients (P < .01) and corticosteroid administration (P < .01) were revealed by multivariate analysis to be significant risk factors for CMV antigenemia. Grade II-IV aGVHD (P = .02) and grade 3-4 diarrhea before engraftment (P = .04) were revealed to be risk factors for CMV disease. The present study is the first study to show that severe diarrhea before engraftment is a significant risk factor for CMV disease. In summary, risk of CMV disease was significantly decreased in patients without severe mucosal injury of the gut because of the conditioning regimen before engraftment.

Prognostic factors of survival time after hematopoietic stem cell transplant in acute lymphoblastic leukemia patients: Cox proportional hazard versus accelerated failure time models

Background

The aim of this study is to evaluate the prognostic factors of overall survival (OS) after haematopoietic stem cell transplant (HSCT) in acute lymphoblastic leukaemia (ALL) patients using accelerated failure time (AFT), Cox proportional hazard (PH), and Cox time-varying coefficient models.

Methods

206 patients were enrolled after HSCH in Shariati Hospital between 1993 and 2007. There was evidence of marked departures from the proportional hazards assumption with two prognostic factors, relapse and chronic graft-versus-host disease (cGVHD) (P < .001). Performance among AFT and Cox's models was assessed using explained variation and goodness of fit methods. Discrimination among the exponential, Weibull, generalized gamma (GG), log-logistic, and lognormal distributions was done using maximum likelihood and Akaike information criteria.

Results

The 5-year OS was 52% (95%CI: 47.3–56.7). Peak mortality hazard occurred at months 6–7 after HSCT followed by a decreasing trend. In univariate analysis, the data was better fitted by GG distribution than by other distributions. Univariate analysis using GG distribution showed a positive association between OS with acute graft-versus-host disease (aGVHD) (P = .021), no relapse (P < .001), cGVHD (P < .001), neutrophil recovery (P < .001) and platelet recovery (P < .001). Based on Cox PH models; however cGVHD and relapse were the predictive factors of OS (P < .001). Multivariate analysis indicated that, OS is related to relapse (P < .001) and platelet recovery (P = .037), where predictive power of Weibull AFT models was superior to Cox PH model and Cox with time-varying coefficient (R² = 0.46 for AFT, R² = .21 for Cox PH and R² = .34 for Cox time-varying coefficient). Cox-Snell residual shows Weibull AFT fitted to data better than other distributions in multivariate analysis.

Conclusion

We concluded that AFT distributions can be a useful tool for recognizing prognostic factors of OS in acute lymphoblastic leukemia patients.