Guideline for treating relapsed or refractory myeloid leukemia in children with Down syndrome

Treatment of relapsed and refractory myeloid leukemia in Down syndrome (r/r ML-DS) poses significant challenges, as prognosis is dire and there is no established standard treatment. This guideline provides treatment recommendations based on a literature review and collection of expert opinions, aiming to improve overall and event-free survival of patients. Treatment options include fludarabine and cytarabine (FLA) ± gemtuzumab ozogamicin (GO), azacytidine (AZA) ± panobinostat, and hematopoietic stem cell transplantation (HSCT). Preferred approaches are AZA ± panobinostat for cases with low blast count or FLA ± GO for cases with high blast count, followed by HSCT after remission. Further research is crucial for the investigation of targeted therapies (e.g., BH3 mimetics, LSD1, JAK inhibitors).

Impact of extramedullary disease in AML patients undergoing sequential RIC for HLA-matched transplantation: occurrence, risk factors, relapse patterns, and outcome

We sought to evaluate the role of extramedullary disease (EMD) in sequential RIC retrospectively analyzing data of 144 high-risk AML patients undergoing HLA-matched transplantation. Median long-term follow-up was 11.6 years. Eighteen percent of patients (n = 26/144) presented with extramedullary AML (EM AML) or a history of EMD at time of transplantation. Overall relapse rate was 25% (n = 36/144) with 15% (n = 21/144) of all patients developing isolated BM relapse and 10% (n = 15/144) developing EM AML relapse with or without concomitant BM relapse (EM ± BM). Manifestation of EM relapse after transplantation occurred frequently at multiple sites and presented mostly as solid tumor mass. Only 3/15 patients with EM ± BM relapse showed a prior EMD manifestation. EMD prior to allogeneic transplantation had no impact on post-transplant OS when compared to non-EMD (median post-transplant OS 3.8 years versus 4.8 years; ns). Risk factors (p =  < 0.1) for EM ± BM relapse included younger age and a higher number of prior intensive chemotherapies, whereas the presence of chronic GVHD was a protective factor. Median post-transplant OS (15.5 months vs. 15.5 months), RFS (9.6 months vs 7.3 months), and post-relapse OS (6.7 months vs. 6.3 months) were not significantly different between patients with isolated BM vs. EM ± BM relapse. Taken together, occurrence of EMD prior to as well as of EM ± BM AML relapse after transplantation was moderate, presenting mostly as solid tumor mass after transplantation. However, diagnosis of those does not seem to influence outcomes after sequential RIC. A higher number of chemotherapy cycles prior to transplantation was identified as recent risk factor for EM ± BM relapse.

Lower dose of ATG combined with post-transplant cyclophosphamide for HLA matched RIC alloHCT is associated with effective control of GVHD and less viral infections

This study compares the outcomes before and after reducing the ATG dose from 4.5 to 2 mg/kg, in a combination of PTCy and CsA for GVHD prevention, in 250 patients treated with HLA matched RIC PB-alloHCT (70% received 4.5 mg/kg and 30% received 2 mg/kg). The incidences of grade II-IV and III-IV aGVHD at day +100, and moderate/severe cGVHD at 1-year were 12.6% vs. 20% (p = 0.431), 3.6% vs. 4.5% (p = 0.935), and 10.9% vs. 26.1% (p = 0.480), respectively. PTLD (9.1% vs. 1.3%, p = 0.026) and viral infections (30.3% vs. 12%; p = 0.001) were lower for those treated with 2 mg/kg of ATG. The reduction of the ATG dose resulted in a comparable OS (2-year: 64.7% vs. 64.7%), GRFS (2-year: 48.0% vs. 44.5%), RFS (2-year: 57.0% vs. 62.0%), and NRM (2-year: 17.8 vs. 14.9). The use of (2 mg/kg) ATG-PTCy-CsA for HLA matched RIC alloHCT results in lower viral infections, and incomparable GVHD preventive effect and survival rates.

The Graft-Versus-Leukemia Effect in AML

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is the most established and commonly used cellular immunotherapy in cancer care. It is the most potent anti-leukemic therapy in patients with acute myeloid leukemia (AML) and is routinely used with curative intent in patients with intermediate and poor risk disease. Donor T cells, and possibly other immune cells, eliminate residual leukemia cells after prior (radio)chemotherapy. This immune-mediated response is known as graft-versus-leukemia (GvL). Donor alloimmune responses can also be directed against healthy tissues, which is known as graft-versus-host disease (GvHD). GvHD and GvL often co-occur and, therefore, a major barrier to exploiting the full immunotherapeutic benefit of donor immune cells against patient leukemia is the immunosuppression required to treat GvHD. However, curative responses to allo-SCT and GvHD do not always occur together, suggesting that these two immune responses could be de-coupled in some patients. To make further progress in successfully promoting GvL without GvHD, we must transform our limited understanding of the cellular and molecular basis of GvL and GvHD. Specifically, in most patients we do not understand the antigenic basis of immune responses in GvL and GvHD. Identification of antigens important for GvL but not GvHD, and vice versa, could impact on donor selection, allow us to track GvL immune responses and begin to specifically harness and strengthen anti-leukemic immune responses against patient AML cells, whilst minimizing the toxicity of GvHD.

Reduced intensity allogeneic stem cell transplant with anti-thymocyte globulin and post-transplant cyclophosphamide in acute myeloid leukemia

OBJECTIVES

We aimed to study the efficacy of reduced intensity conditioning (RIC) allo-HSCT combined with anti-thymocyte globulin (ATG) and post-transplant cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis in AML.

METHODS

One hundred forty-seven patients were included. All patients underwent unmanipulated peripheral blood stem cell RIC allo-HSCT. Median follow-up was 12.8 months (range 0.5-39).

RESULTS

Median age was 58 years. Twenty-nine (20%) recipients received 10/10 MRD grafts, 69 (47%) 10/10 MUD grafts, 20 (13.6%) 9/10 MMUD, and 29 (20%) haploidentical grafts. The cumulative incidence of grade II-IV and III-IV acute GVHD at day +100, and moderate/severe chronic GVHD at 1-year were as follow: 14.3%, 1.4%, and 8.3%. There were no significant differences according to donor type (P = .46) and cumulative incidence of GVHD. One-year overall survival (OS), relapse-free survival (RFS), non-relapse mortality, and GVHD-free/Relapse-free survival were as follows: 66.9% (95% CI 58.4-74), 59.9%, and 18.7% and 53.7%. KPS ≤ 80 was predictive of worst OS (P = .04). Those recipients who received MUD transplants had better RFS (P = .01).

CONCLUSIONS

RIC allo-HSCT combined with ATG and PTCy is safe and a potentially curative strategy and it is associated with impressive GRFS in AML.

Reduced intensity vs. myeloablative conditioning with fludarabine and PK-guided busulfan in allogeneic stem cell transplantation for patients with AML/MDS

Conditioning regimens contribute significantly to outcomes following allogeneic stem cell transplantation (allo-SCT). Reduced-intensity conditioning (RIC) regimens provide lower toxicity at the cost of reduced efficacy compared with myeloablative conditioning (MAC) regimens. However, because pre-transplant prognostic variables often determine the conditioning regimen, studies of RIC vs. MAC have been inconclusive. We present a retrospective analysis of 242 acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) patients, 112 of whom were in 56 pairs matched using propensity scores, to account for variation that may confound clinical outcomes. The uniform conditioning regimens consisted of fludarabine with pharmacokinetic (PK)-guided intravenous busulfan (Bu). The RIC and MAC regimens were dosed at the average daily area under the concentration-vs-time curve (AUC) of 4000 µMol min and 5000-6000 µMol min, or total course AUC of 16,000 µMol min and 20,000-24,000 µMol min, respectively; PK-guided dosing removes overlap in systemic Bu exposure. When patients' data were propensity-matched, there was a trend toward significantly increased full donor chimerism and decreased chronic graft vs. host disease in RIC, and no significant differences in progression free survival and overall survival between RIC and MAC. Our results also elucidate the efficacy of PK-guided-dosing in the setting of allo-SCT for AML and MDS.

Chemosensory changes and quality of life in patients undergoing hematopoietic stem cell transplantation

PURPOSE

To assess magnitude and characteristics of changes in chemosensory function and quality of life (QOL) for patients receiving hematopoietic stem cell transplantation (HSCT).

METHODS

Patients (aged 18 years and above) scheduled to undergo HSCT at the Seattle Cancer Care Alliance were tested for chemosensory function at three time points: pre-transplant (baseline), 30 ± 5 days (day 30), and 80 ± 5 days (day 80) post-HSCT. Gustatory function was assessed following procedures developed at the Monell-Jefferson Taste and Smell Clinic. Olfactory testing was conducted using the National Institute of Health Toolbox Odor Identification test. QOL was also assessed.

RESULTS

Twenty-nine patients were enrolled in the study between August 2014 and March 2015. Twenty-three patients were included in the analysis, with 16 tested at all three time points (baseline, day 30, and day 80). The primary finding is decreased taste sensitivity for 0.32 M NaCl, 0.0056 M citric acid, and 0.018 M citric acid on day 30 following HSCT. Increased taste sensitivity for 0.32 M sucrose at day 30 was also observed. Taste sensitivity largely recovered by day 80. Olfactory identification scores were unchanged from baseline to day 30. QOL was reduced at day 30 but was restored to an acceptable level of functioning and symptoms by day 80. However, some areas remain impaired.

CONCLUSIONS

Alterations in taste perception were confirmed in the early post-transplant period. This was largely resolved within 2.5 months. No obvious impairments were observed in olfactory function. QOL improved by day 80, though some oral symptoms lingered.

Higher busulfan dose intensity appears to improve leukemia-free and overall survival in AML allografted in CR2: An analysis from the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Allogeneic hematopoietic cell transplantation is a potentially curative treatment in patients with acute myeloid leukemia. Recent advances in the field of hematopoietic cell allografting have resulted in a practice shift, favoring less intense preparative regimens. We present results of a retrospective comparative analysis of two preparative regimens, namely FB2 (IV fludarabine plus IV busulfan 6.4mg/kg±10%) and FB4 (IV fludarabine plus IV busulfan 12.8mg/kg ±10%), in patients with acute myeloid leukemia undergoing hematopoietic cell allografting in second complete remission at EBMT participating centers. Between 2003 and 2010, 128 AML patients in second complete remission were allografted following a preparative regimen of FB2 (n=88) or FB4 (n=40). The median time-to-neutrophil engraftment was similar whether patients received FB2 (16 (5-38) days) or FB4 (16 (9-29) days), p=0.45. A multivariate analysis showed that use of FB4 resulted in improved 2-year leukemia-free (HR=0.44 (95%CI=0.21, 0.94), p=0.03) and overall survival (HR=0.38 (95%CI=0.16, 0.86), p=0.02). Cumulative incidence of non-relapse mortality (2-year) for all patients was 21% (95%CI=14-28%). Our analysis suggests that FB4 improves 2-year leukemia-free and overall survival in AML allografted in second complete remission. A confirmatory randomized controlled trial that compares these two preparative regimens (FB2 vs. FB4) in AML in CR2 is definitely warranted.

JC polyomavirus reactivation is common following allogeneic stem cell transplantation and its preemptive detection may prevent lethal complications

Extended application of allogeneic stem cell transplantation (alloSCT) is expected to increase the frequency of JC polyomavirus (JCPyV)-related progressive multifocal leukoencephalopathy (PML). The aim of this study was to assess frequency, risk factors and course of JCPyV reactivation in allografted hematology patients. This retrospective study included consecutive adult patients, treated with alloSCT between January 2008 and December 2011. Quantitative JCPyV-PCR analysis was performed on whole blood DNA samples, originally drawn for cytomegalovirus detection since transplant date. The study included 164 patients diagnosed with hematological malignancies. Patients received reduced-intensity conditioning (n=74) or myeloablative conditioning (n=90), followed by alloSCT. Twenty patients developed transient and 20 had persistent JCPyV reactivation. Two of the patients with persistent reactivation showed a gradual increase in JCPyV levels, preceding PML development by 96 and 127 days. Cessation of immunosuppression resulted in complete resolution of neurological symptoms in one patient, while the other died of PML. Seventy percent of the 'persistently reactivating' patients died. Multivariate analysis confirmed age to be the only significant predictive factor for JCPyV reactivation. In conclusion, JCPyV reactivation occurs in a quarter of allografted patients. Preemptive detection of JCPyV reactivation in high-risk subjects and early discontinuation of immunosuppressive therapy may prevent development of lethal PML.

Comparison of reduced-intensity and myeloablative conditioning regimens for allogeneic hematopoietic stem cell transplantation in patients with acute myeloid leukemia and acute lymphoblastic leukemia: a meta-analysis

Currently, the indications to perform reduced-intensity conditioning allogeneic hematopoietic stem cell transplant (RIC-HCT) are based on data derived mainly from large registry and single-centre retrospective studies. Thus, at the present time, there is limited direct evidence supporting the current practice in selecting patients with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) for RIC versus myeloablative conditioning (MAC) transplants. To determine the relationship between dose intensity of conditioning regimen and survival outcomes after allografting in AML/ALL patients, we performed a meta-analysis of 23 clinical trials reported between 1990 and 2013 involving 15,258 adult patients that compare survival outcomes after RIC-HCT versus MAC-HCT. RIC-HCT resulted in comparable <2-year and 2-6 year overall survival (OS) rates post-transplantation even though the RIC-HCT recipients were older and had more active disease than MAC-HCT recipients. The 2-6 year progression-free survival (PFS), nonrelapse mortality, acute graft-versus-host disease (GvHD) and chronic GvHD rates were reduced after RIC-HCT, but relapse rate was increased. Similar outcomes were observed regardless of disease type and status at transplantation. Odds ratio for all outcomes remained comparable with or without performing separate analyses for the year of HCT and for retrospective versus prospective studies. Among RIC-HCT recipients, survival rates were superior if patients were in CR at transplantation. Significant inter-study heterogeneity for aGvHD data and publication bias for PFS data were observed. This meta-analysis showed no OS benefit of MAC-HCT over RIC-HCT across the entire cohort of patients suggesting that RIC-HCT could be an effective therapeutic option for AML/ALL patients who are ineligible for MAC-HCT and CR status is preferred before RIC-HCT.

Comparing i.v. BU dose intensity between two regimens (FB2 vs FB4) for allogeneic HCT for AML in CR1: a report from the Acute Leukemia Working Party of EBMT

This retrospective analysis compared two regimens of fludarabine combined with i.v. BU 6.4 mg/kg (FB2) or BU 12.8 mg/kg (FB4) for allografting of AML in first CR. A total of 437 patients (median age: 50 years) were administered FB2 (n = 225, 51%) or FB4 (n = 212, 49%). Median follow-up time was 28 months. Use of FB2 resulted in a longer time to neutrophil engraftment (17 vs 15 days, P < 0.0001) but no difference in incidence of grade II-IV acute (P = 0.54) or chronic GVHD (P = 0.51). In patients < 50 years of age, FB2 was associated with a higher 2-year cumulative incidence of relapse (33 ± 6% vs 20 ± 4%, P = 0.04), but there was no difference in 2-year leukemia-free survival (LFS) (P = 0.45), OS (P = 0.53) or non-relapse mortality (P = 0.17). In recipients ⩾ 50 years of age, FB2 resulted in better 2-year LFS (63 ± 4% vs 42 ± 7%, P = 0.02) and OS (68 ± 4% vs 45 ± 7%, P = 0.006); a lower 2-year non-relapse mortality, albeit not statistically significant (15 ± 3% vs 29 ± 6%, P = 0.06), was observed with FB2. FB2 is an effective and well-tolerated regimen in patients ⩾ 50 years of age and does not compromise survival when used in patients <50 years undergoing allogeneic transplantation for AML in first CR.

Managing Hodgkin lymphoma relapsing after autologous hematopoietic cell transplantation: a not-so-good cancer after all!

Hodgkin lymphoma (HL) relapsing after an autologous hematopoietic cell transplant (HCT) poses a therapeutic challenge. In this setting, salvage chemotherapy (for example, gemcitabine-based, ifosfamide-containing and others) or immunotherapy (for example, brentuximab vedotin) is essential as a bridging-cytoreduction strategy to an allogeneic HCT. Myeloablative allogeneic hematopoietic cell transplantation in relapsed HL is associated with high rates of non-relapse mortality. In carefully selected patients with chemosensitive disease, allografting following lower-intensity conditioning regimens can provide durable disease control rates of about 25-35%. Promising early results with haploidentical and umbilical cord transplantation are noteworthy and are expanding this procedure to patients for whom HLA-matched related or unrelated donors are not available. Unfortunately, a significant number of HL patients relapsing after an autologous HCT are not candidates for allografting because of the presence of resistant disease, donor unavailability or comorbidities. Brentuximab vedotin is approved for HL relapsing after a prior autograft. Rituximab and bendamustine are also active in this setting, albeit with short durations of remission. Histone deacetylase inhibitors (for example, panobinostat, mocetinostat), mTOR inhibitors (for example, everolimus) and immunomodulatory agents (lenalidomide) have shown activity in phase II trials, but currently are not approved for this indication. Second autologous HCT are rarely performed but this approach should not be considered standard practice at this time. The need for effective agents for post autograft failures of HL largely remains unmet. Continuous efforts to ensure early referral of such patients for allogeneic HCT or investigational therapies are the key to improving outcomes of this not-so-good lymphoma.

Comparative outcome of reduced intensity and myeloablative conditioning regimen in HLA identical sibling allogeneic hematopoietic stem cell transplantation for acute leukemia patients: a single center experience

Due to the high transplant related morbidity and mortality (TRM), relatively younger acute leukemia patients that have a good performance status and no comorbidity are eligible for myeloablative conditioning (MAC) followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT). The outcomes of 84 consecutive adult patients with ALL (n=38) or AML (n=46) who underwent allo-HSCT from their HLA-identical siblings were evaluated retrospectively. The median age at transplantation was 34 (17-58 years) for the whole patient population. Of these, 24 patients received a MAC and 60 patients received a fludarabine-based reduced intensity conditioning regimen (RIC). After a median follow-up of 32 months (range, 1-119), for the entire group, the 3-year estimated overall survival (OS) was 57.5% and the disease-free survival (DFS) was 51.5%. The OS for ALL and AML patients were 53.9% vs 62.1%: and DFS were 50.5% and 53.4%, respectively. The 3-year estimated OS for RIC and MAC patients were 63.2% and 41.7%; and DFS were 57.1% and 34.7%, respectively. In ALL patients, conditioning regimens (RIC vs MAC) led to similar OS and DFS; however, in AML patients both OS (70.1% vs 21.4%) and DFS (59.3% vs 42.9%) were found to be higher in RIC patients compared to MAC recipients. Overall, the TRM at day 100 was 1.7% and has increased up to 5.1% at 1st year. In multivariate analysis, the diagnosis (p=0.03) and RIC regimen (p=0.027) were the prognostic variables for prolonged OS in all patients; and RIC regimen (p=0.031) was the only prognostic factor for prolonged OS in AML patients. The first complete remission (CR1) was correlated with a prolonged DFS as an independent variable for all patients (p=0.09). Eleven of the RIC patients (18.3%) and 6 of the MAC patients (25%) developed acute graft-versus-host disease (GvHD). Seventeen of the RIC patients (33.3%) and 4 of the MAC patients (16.7%) developed chronic GvHD. In conclusion, RIC conditioning regimens may provide a longer OS and DFS, especially in patients with AML who are in first CR, not eligible for MAC conditioning.

Acute myeloid leukaemia in adults

The outlook for patients with acute myeloid leukaemia has improved in the past 30 years. Unlike other cancers, much of this progress is attributable to refinement of supportive treatment, rather than the introduction of new drugs. New antibacterial and antifungal agents, antiemetics, and improved transfusion support have decreased the rate of early death, and morbidity and mortality from allogeneic stem cell transplantation has been substantially reduced. However, more than half of young adult patients and about 90% of older patients still die from their disease. Refractoriness to initial induction treatment and, more frequently, relapse after complete remission, are still the main obstacles to cure. Accordingly, new treatment approaches with mechanisms of action different from those of conventional chemotherapy are needed. Our knowledge of the various chromosomal and molecular abnormalities implicated in the pathogenesis of the many subtypes of the disease has greatly expanded; as a result, clinical research is moving towards the investigation of new non-cytotoxic agents in combination with chemotherapy. The goal is to target the molecular abnormalities identified at diagnosis; however, several aberrations can coexist in subclones of acute myeloid leukaemia, making the disease less likely to be inhibited by a single agent.

Prognostic impact of allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia patients with internal tandem duplication of FLT3

The FLT3 gene with internal tandem duplication (ITD) is a poor prognostic factor in patients with acute myeloid leukemia (AML), and the efficacy of allogeneic hematopoietic stem cell transplantation (HSCT) for AML patients with FLT3-ITD is controversial. We examined 122 AML patients; 34 patients had FLT3-ITD and 39 patients received allogeneic HSCT. The median overall survival (OS) of patients with wtFLT3/nonHSCT, wtFLT3/HSCT, FLT3-ITD/nonHSCT and FLT3-ITD/HSCT was 40.7 months, 53.4 months, 9.8 months and not reached, respectively (p=0.006). Compared to the wtFLT3/nonHSCT patients, the hazard ratio (95% CI) of OS for wtFLT3/HSCT, FLT3-ITD/nonHSCT and FLT3-ITD/HSCT was 1.39 (0.61-3.18), 3.57 (1.58-8.10) and 0.40 (0.11-1.59), respectively, after adjustment of age, sex, WBC, LDH, karyotype, NPM, and FAB classification. This result indicated that patients with FLT3-ITD/nonHSCT had a significantly worse outcome, but allogeneic HSCT improved the prognosis for patients with FLT3-ITD.

Do different conditioning regimens really make a difference?

Over the past 15 years, the use of reduced-intensity/nonmyeloablative conditioning regimens before allogeneic hematopoietic stem cell transplantation has been increasing. Despite major disparities in the level of myeloablation, intensity of immunosuppression (including great diversity of in vivo T-cell depletion), and postgraft immunomodulation, the different approaches have contributed jointly to a modification of the stage of allogeneic stem cell transplantation: transplantation-related procedure mortality has been decreased dramatically, allowing allogeneic immunotherapy to be used in previously excluded populations, including elderly patients, young but clinically unsuitable patients, patients with lymphoid malignancies or solid tumors, and patients without an HLA-identical related or unrelated donor. Together, these diverse regimens have provided one of the biggest breakthroughs since the birth of allogeneic BM transplantation. However, consensus on how to reach the optimal goal of minimal transplantation-related mortality with maximum graft-versus-tumor effect is far from being reached, and further studies are needed to define optimal conditioning and immunomodulatory regimens that can be integrated to reach this goal. These developments, which will most likely vary according to different clinical situations, have to be compared continuously with advances achieved in traditional allogeneic transplantation and nontransplantation treatments. However, the lack of prospective comparative trials is and will continue to make this task challenging.

Dose intensification of busulfan in the preparative regimen is associated with improved survival: a phase I/II controlled, randomized study

Dose intensity is important for disease control in patients undergoing allogeneic stem cell transplantation. We conducted a phase I/II controlled, adoptive, randomized study to determine the optimal dosing schedule of i.v. busulfan. Patients aged ≤75 years with advanced hematologic malignancies with human leukocyte antigen-compatible donor were eligible. All patients received fludarabine at 30 mg/m(2)/d for 4 days, and busulfan was administered in different doses in oral or i.v. formulations. As determined by the phase I trial, i.v. busulfan at a dose of 11.2 mg/kg/d was used for the phase II expansion cohort. Altogether, 80 patients with a median age of 56 years were enrolled. Forty percent had active disease at the time of transplantation. Engraftment occurred in 91%, and a complete response was achieved in 79% of patients posttransplantation. At a median follow-up of 91 months in the surviving patients, the outcomes for i.v. busulfan dose of 11.2 mg/kg/d versus other doses were as follows: nonrelapse mortality, 34% versus 23% (P = .4); cumulative incidence of relapse, 43% versus 68% (P = .02); relapse-free survival, 25% versus 9% (P = .017); and overall survival, 27% versus 9% (P = .02). We conclude that optimizing i.v. busulfan dose intensity in the preparative regimen may overcome disease-associated poor prognostic factors.

Comparison of conditioning regimens of various intensities for allogeneic hematopoietic SCT using HLA-identical sibling donors in AML and MDS with <10% BM blasts: a report from EBMT

In this multicenter retrospective study, the long-term outcomes of 878 adults with AML and refractory anemia with excess blasts (RAEB) with BM blasts <10% who underwent transplantation with an HLA-identical sibling donor between 1998 and 2004 were analyzed according to four regimens of conditioning intensity: reduced-intensity conditioning (RIC) (either intermediate RIC (IntermRIC) or non-myeloablative (NMA) RIC), and myeloablative conditioning (MC) in 718 patients (either conventional MC or hyperintense MC. In multivariate cox analysis, patients undergoing NMA transplantation had lower non-relapse mortality risk in the first 100 days after transplantation (P<0.01), but a higher risk beyond day +100 (P=0.02), as well as higher relapse incidence in the first 12 months (P<0.01), but the risk was similar in all groups beyond 12 months. The probabilities of PFS and OS up to 7 years were significantly lower only in the NMA subgroup (P0.01 for both). The 7-year OS was 53%, 29%, 56% and 51%, respectively. Our data suggest that prospective studies comparing RIC regimens (especially IntermRIC) with MC are appropriate in patients with AML and RAEB who are in a non-advanced disease status.