Meta-analysis of autologous bone marrow transplantation versus chemotherapy in adult patients with acute myeloid leukemia in first remission

Auto-hematopoietic stem cell transplantation or chemotherapy? Meta-analysis of clinical choice for AML

For patients with acute myeloid leukemia (AML) who are not candidates for allogeneic stem cell transplantation (SCT) or do not have a human leukocyte antigen (HLA)-matched donor, it is unclear whether autologous SCT (ASCT) has a better prognosis after the first complete response (CR1) compared to further chemotherapy treatment. A meta-analysis evaluating ASCT compared to further chemotherapy for AML patients in CR1 was performed. The Medline, Embase, Cochrane Controlled Trials Registry, Cochrane Library, Web of Science, and National Knowledge Infrastructure of China databases were searched for relevant literature as of May 26, 2023. Eligible studies included prospectively enrolled adults with AML and randomized first-time respondent patients who did not have a matched sibling donor. Fourteen randomized controlled trials were identified and included 4281 participants, of which 1499 patients received ASCT and 2782 underwent chemotherapy and continued follow-up. In patients with AML in CR1, a lower relapse rate was associated with ASCT compared to chemotherapy [odds ratio (OR) = 0.49, 95% confidence interval (CI) = 0.41-0.57]. Significant disease-free survival (DFS; OR = 1.37, 95% CI = 1.02-1.84) and relapse-free survival (RFS; OR = 2.78, 95% CI = 1.28-6.02) ASCT benefits were documented, and there was no difference in the overall survival (OS) when the studies were pooled (OR = 1.12, 95% CI = 0.85-1.48). The study results indicated that after the first remission, AML patients receiving autologous stem cell transplantation had higher DFS and RFS, similar OS, and lower relapse compared to patients undergoing chemotherapy treatment. This indicated that autologous stem cell transplantation may have a better prognosis.

Pediatric Autologous Hematopoietic Stem Cell Transplantation: Safety, Efficacy, and Patient Outcomes. Literature Review

Autologous stem cell transplantation (auto-HSCT) is a part of the therapeutic strategy for various oncohematological diseases. The auto-HSCT procedure enables hematological recovery after high-dose chemotherapy, otherwise not tolerable, by the infusion of autologous hematopoietic stem cells. Unlike allogeneic transplant (allo-HSCT), auto-HSCT has the advantage of lacking acute-graft-versus-host disease (GVHD) and prolonged immunosuppression, however, these advantages are counterbalanced by the absence of graft-versus-leukemia. Moreover, in hematological malignancies, the autologous hematopoietic stem cell source may be contaminated by neoplastic cells, leading to disease reappearance. In recent years, allogeneic transplant-related mortality (TRM) has progressively decreased, almost approaching auto-TRM, and many alternative donor sources are available for the majority of patients eligible for transplant procedures. In adults, the role of auto-HSCT compared to conventional chemotherapy (CT) in hematological malignancies has been well defined in many extended randomized trials; however, such trials are lacking in pediatric cohorts. Therefore, the role of auto-HSCT in pediatric oncohematology is limited, in both first- and second-line therapies and still remains to be defined. Nowadays, the accurate stratification in risk groups, according to the biological characteristics of the tumors and therapy response, and the introduction of new biological therapies, have to be taken into account in order to assign auto-HSCT a precise role in the therapeutic strategies, also considering that in the developmental age, auto-HSCT has a clear advantage over allo-HSCT, in terms of late sequelae, such as organ damage and second neoplasms. The purpose of this review is to report the results obtained with auto-HSCT in the different pediatric oncohematological diseases, focusing on the most significant literature data in the context of the various diseases and discussing this data in the light of the current therapeutic landscape.

Hematopoietic Stem Cell Transplantation for Acute Myeloid Leukemia: An Overview of Systematic Reviews

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) has become the main treatment for acute myeloid leukemia (AML) and has been studied in many systematic reviews (SRs), but strong conclusions have not been drawn yet.

OBJECTIVE

This study aimed to summarize and critically evaluate the methodological and evidence quality of SRs and meta-analysis on this topic.

METHODS

PubMed, Embase, the Cochrane Library, and Web of Science were searched for SRs/meta-analyses regarding HSCT for AML. Two reviewers assessed the quality of SRs/meta-analyses in line with AMSTAR-2 and evaluated the strength of evidence quality with the grading of the evaluation system (GRADE) for concerned outcomes independently.

RESULTS

12 SR/Meta articles were included, and the AMSTAR-2 scale showed that the quality grade of all articles was low or very low. GRADE results showed 29 outcomes, 2 of which were high, 12 were moderate, and 15 were low. Limitations and inconsistency were the most important factors leading to degradation, followed by imprecision and publication bias. Allo-SCT had better OS and DFS benefits than auto-SCT and significantly reduced the relapse in intermediate-risk AML/CR1 patients. Auto-SCT was associated with lower TRM than allo-SCT but generally had higher relapse. The results should be confirmed further for the low or moderate evidence quality.

CONCLUSION

Current SRs show that allo-SCT in the treatment of AML might improve the OS, RFS, and DFS. Auto-SCT has significantly lower TRM but higher RR. Whether bone marrow transplantation is superior to nonmyeloablative chemotherapy remains to be evaluated. Meanwhile, the quality of methodology needs to be further improved. The intensity of evidence was uneven, and the high-quality evidence of outcomes was lacking. Considering the limitations of our overview, more rigorous and scientific studies are needed to fully explore the efficacy of different interventions of HSCT in AML, and clinicians should be more cautious in the treatment.

Comparable outcomes between autologous and allogeneic transplant for adult acute myeloid leukemia in first CR

Although allogeneic hematopoietic stem cell transplantation from an HLA-matched sibling donor (MSD) is a potentially curative post-remission treatment for adults with acute myeloid leukemia (AML) in their first CR, transplant-related morbidity and mortality remains a major drawback. We retrospectively compared the outcomes of patients who underwent autologous peripheral blood stem cell transplantation (auto-PBSCT; n=375) with those who underwent allogeneic bone marrow transplantation (allo-BMT; n=521) and allo-PBSCT (n=380) from MSDs for adults with AML/CR1, in which propensity score models were used to adjust selection biases among patients, primary physicians and institutions to overcome ambiguity in the patients' background information. Both the multivariate analysis and propensity score models indicated that the leukemia-free survival rate of auto-PBSCT was not significantly different from that of allo-BMT (hazard ratio (HR), 1.23; 95% confidence interval (CI), 0.92 to 1.66; P=0.16) and allo-PBSCT (HR, 1.13; 95% CI, 0.85-1.51; P=0.40). The current results suggest that auto-PBSCT remains a promising alternative treatment for patients with AML/CR1 in the absence of an available MSD.

Efficacy of Allogeneic Hematopoietic Stem Cell Transplantation in Intermediate-Risk Acute Myeloid Leukemia Adult Patients in First Complete Remission: A Meta-Analysis of Prospective Studies

Hematopoietic stem cell transplantation (HSCT) and consolidation chemotherapy have been used to treat intermediate-risk acute myeloid leukemia (AML) patients in first complete remission (CR1). However, it is still unclear which treatments are most effective for these patients. The aim of our study was to analyze the relapse-free survival (RFS) and overall survival (OS) benefit of allogeneic HSCT (alloHSCT) for intermediate-risk AML patients in CR1. A meta-analysis of prospective trials comparing alloHSCT to non-alloHSCT (autologous HSCT [autoHSCT] and/or chemotherapy) was undertaken. We systematically searched PubMed, Embase, and the Cochrane Library though October 2014, using keywords and relative MeSH or Emtree terms, 'allogeneic'; 'acut*' and 'leukem*/aml/leukaem*/leucem*/leucaem*'; and 'nonlympho*' or 'myelo*'. A total of 7053 articles were accessed. The primary outcomes were RFS and OS, while the secondary outcomes were treatment-related mortality (TRM) and relapse rate (RR). Hazard ratios (HR) and 95% confidence intervals (CI) were calculated for each outcome. The primary outcomes were RFS and OS, while the secondary outcomes were TRM and RR. We included 9 prospective controlled studies including 1950 adult patients. Patients with intermediate-risk AML in CR1 who received either alloHSCT or non-alloHSCT were considered eligible. AlloHSCT was found to be associated with significantly better RFS, OS, and RR than non-alloHSCT (HR, 0.684 [95% CI: 0.48, 0.95]; HR, 0.76 [95% CI: 0.61, 0.95]; and HR, 0.58 [95% CI: 0.45, 0.75], respectively). TRM was significantly higher following alloHSCT than non-alloHSCT (HR, 3.09 [95% CI: 1.38, 6.92]). However, subgroup analysis showed no OS benefit for alloHSCT over autoHSCT (HR, 0.99 [95% CI: 0.70, 1.39]). In conclusion, alloHSCT is associated with more favorable RFS, OS, and RR benefits (but not TRM outcomes) than non-alloHSCT generally, but does not have an OS advantage over autoHSCT specifically, in patients with intermediate-risk AML in CR1.

T-cell-replete haploidentical transplantation versus autologous stem cell transplantation in adult acute leukemia: a matched pair analysis

Adult patients with acute leukemia in need of a transplant but without a genoidentical donor are usually considered upfront for transplantation with stem cells from any other allogeneic source, rather than autologous stem cell transplantation. We used data from the European Society for Blood and Marrow Transplantation and performed a matched pair analysis on 188 T-cell-replete haploidentical and 356 autologous transplants done from January 2007 to December 2012, using age, diagnosis, disease status, cytogenetics, and interval from diagnosis to transplant as matching factors. "Haploidentical expert" centers were defined as having reported more than five haploidentical transplants for acute leukemia (median value for the study period). The median follow-up was 28 months. Multivariate analyses, including type of transplant categorized into three classes ("haploidentical regular", "haploidentical expert" and autologous), conditioning intensity (reduced intensity versus myeloablative conditioning) and the random effect taking into account associations related to matching, showed that non-relapse mortality was higher following haploidentical transplants in expert (HR: 4.7; P=0.00004) and regular (HR: 8.98; P<10(-5)) centers. Relapse incidence for haploidentical transplants was lower in expert centers (HR:0.39; P=0.0003) but in regular centers was similar to that for autologous transplants. Leukemia-free survival and overall survival rates were higher following autologous transplantation than haploidentical transplants in regular centers (HR: 1.63; P=0.008 and HR: 2.31; P=0.0002 respectively) but similar to those following haploidentical transplants in expert centers. We conclude that autologous stem cell transplantation should presently be considered as a possible alternative to haploidentical transplantation in regular centers that have not developed a specific expert program.

Intravenous busulfan for autologous stem cell transplantation in adult patients with acute myeloid leukemia: a survey of 952 patients on behalf of the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Oral busulfan is the historical backbone of the busulfan+cyclophosphamide regimen for autologous stem cell transplantation. However intravenous busulfan has more predictable pharmacokinetics and less toxicity than oral busulfan; we, therefore, retrospectively analyzed data from 952 patients with acute myeloid leukemia who received intravenous busulfan for autologous stem cell transplantation. Most patients were male (n=531, 56%), and the median age at transplantation was 50.5 years. Two-year overall survival, leukemia-free survival, and relapse incidence were 67±2%, 53±2%, and 40±2%, respectively. The non-relapse mortality rate at 2 years was 7±1%. Five patients died from veno-occlusive disease. Overall leukemia-free survival and relapse incidence at 2 years did not differ significantly between the 815 patients transplanted in first complete remission (52±2% and 40±2%, respectively) and the 137 patients transplanted in second complete remission (58±5% and 35±5%, respectively). Cytogenetic risk classification and age were significant prognostic factors: the 2-year leukemia-free survival was 63±4% in patients with good risk cytogenetics, 52±3% in those with intermediate risk cytogenetics, and 37 ± 10% in those with poor risk cytogenetics (P=0.01); patients ≤50 years old had better overall survival (77±2% versus 56±3%; P<0.001), leukemia-free survival (61±3% versus 45±3%; P<0.001), relapse incidence (35±2% versus 45±3%; P<0.005), and non-relapse mortality (4±1% versus 10±2%; P<0.001) than older patients. The combination of intravenous busulfan and high-dose melphalan was associated with the best overall survival (75±4%). Our results suggest that the use of intravenous busulfan simplifies the autograft procedure and confirm the usefulness of autologous stem cell transplantation in acute myeloid leukemia. As in allogeneic transplantation, veno-occlusive disease is an uncommon complication after an autograft using intravenous busulfan.

Unrelated donor allogeneic transplantation after failure of autologous transplantation for acute myelogenous leukemia: a study from the center for international blood and marrow transplantation research

The survival of patients with relapsed acute myelogenous leukemia (AML) after autologous hematopoietic stem cell transplantation (auto-HCT) is very poor. We studied the outcomes of 302 patients who underwent secondary allogeneic hematopoietic cell transplantation (allo-HCT) from an unrelated donor (URD) using either myeloablative (n = 242) or reduced-intensity conditioning (RIC; n = 60) regimens reported to the Center for International Blood and Marrow Transplantation Research. After a median follow-up of 58 months (range, 2 to 160 months), the probability of treatment-related mortality was 44% (95% confidence interval [CI], 38%-50%) at 1-year. The 5-year incidence of relapse was 32% (95% CI, 27%-38%), and that of overall survival was 22% (95% CI, 18%-27%). Multivariate analysis revealed a significantly better overal survival with RIC regimens (hazard ratio [HR], 0.51; 95% CI, 0.35-0.75; P <.001), with Karnofsky Performance Status score ≥90% (HR, 0.62; 95% CI, 0.47-0.82: P = .001) and in cytomegalovirus-negative recipients (HR, 0.64; 95% CI, 0.44-0.94; P = .022). A longer interval (>18 months) from auto-HCT to URD allo-HCT was associated with significantly lower riak of relapse (HR, 0.19; 95% CI, 0.09-0.38; P <.001) and improved leukemia-free survival (HR, 0.53; 95% CI, 0.34-0.84; P = .006). URD allo-HCT after auto-HCT relapse resulted in 20% long-term leukemia-free survival, with the best results seen in patients with a longer interval to secondary URD transplantation, with a Karnofsky Performance Status score ≥90%, in complete remission, and using an RIC regimen. Further efforts to reduce treatment-related mortaility and relapse are still needed.

High-Dose Cytarabine Consolidation With or Without Additional Amsacrine and Mitoxantrone in Acute Myeloid Leukemia: Results of the Prospective Randomized AML2003 Trial

Purpose

To assess the treatment outcome benefit of multiagent consolidation in young adults with acute myeloid leukemia (AML) in a prospective, randomized, multicenter trial.

Patients and Methods

Between December 2003 and November 2009, 1,179 patients (median age, 48 years; range, 16 to 60 years) with untreated AML were randomly assigned at diagnosis to receive either standard high-dose cytarabine consolidation with three cycles of 18 g/m2 (3× HD-AraC) or multiagent consolidation with two cycles of mitoxantrone (30 mg/m2) plus cytarabine (12 g/m2) and one cycle of amsacrine (500 mg/m2) plus cytarabine (10 g/m2; MAC/MAMAC/MAC). Allogeneic and autologous hematopoietic stem-cell transplantations were performed in a risk-adapted and priority-based manner.

Results

After double induction therapy using a 3 + 7 regimen including standard-dose cytarabine and daunorubicin, complete remission was achieved in 65% of patients. In the primary efficacy population of patients evaluable for consolidation outcomes, consolidation with either 3× HD-AraC or MAC/MAMC/MAC did not result in any significant difference in 3-year overall (69% v 64%; P = .18) or disease-free survival (46% v 48%; P = .99) according to the intention-to-treat analysis. Furthermore, MAC/MAMAC/MAC led to additional GI and hepatic toxicity and a higher rate of infection and bleeding, resulting in significantly shorter 3-year overall survival in the per-protocol analysis compared with 3× HD-AraC (63% v 72%; P = .04).

Conclusion

In younger adults with AML, multiagent consolidation using mitoxantrone and amsacrine in combination with high-dose cytarabine does not improve treatment outcome and confers additional toxicity.

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.

Role of autologous hematopoietic stem cell transplantation according to the NPM1/FLT3-ITD molecular status for cytogenetically normal AML patients: a GOELAMS study

The choice of postremission therapy for acute myeloid leukemia (AML) patients is now based on the blasts' cytogenetic and molecular profile. However, the potential benefit of autologous hematopoietic stem cell transplantation (auto-HSCT) according to the NPM1/FLT3-ITD status has been poorly studied in AML patients with a normal karyotype (NK). Therefore, we evaluated the NPM1/FLT3-ITD molecular status in 135 NK-AML patients treated by allogeneic HSCT (allo-HSCT), auto-HSCT, or chemotherapy as consolidation therapy within the GOELAMS LAM-2001 trial. In univariate analyzes, 4-year leukemia-free survival (LFS) and overall survival (OS) were significantly higher for NPM1+/FLT3-ITD- patients compared with patients presenting another molecular profile (61 vs. 43% and 72 vs. 48%, P = 0.02 and P = 0.01, respectively). In the NPM1+/FLT3-ITD- subgroup, there was no benefit for allo-HSCT or auto-HSCT vs. chemotherapy (4-year LFS: 71, 56, and 60%; 4-year OS: 73, 71, and 60%, respectively; P = NS). For patients with other NPM1/FLT3-ITD molecular profiles, allo-HSCT was found to be the best consolidation therapy, whereas auto-HSCT was associated with a better outcome when compared with chemotherapy (allo-HSCT-, auto-HSCT-, and chemotherapy-related 4-year LFS: 68, 44, and 36%, P = 0.004; 4-year OS: 68, 52, and 29%, respectively, P = 0.02). Our study indicates that allo-HSCT and auto-HSCT provide similar outcomes compared with chemotherapy as consolidation for NPM1+/FLT3-ITD- NK-AML patients. For NK-AML patients with an adverse molecular profile, auto-HSCT could represent an alternative therapeutic approach when no human leukocyte antigen-matched allogeneic donor is available.

Efficacy of allogeneic and autologous hematopoietic SCT in patients with AML after first complete remission

The most effective post-first CR1 treatment for patients with AML, allogenic hematopoietic SCT (allo-HSCT) or autologous hematopoietic SCT (HSCT), remains to be conclusively determined. This study aimed to compare the effectiveness of treatment with allo-HSCT or auto-HSCT in patients with AML after CR1. We retrospectively reviewed medical records of 127 patients with AML who received allo- (n=52) or auto-HSCT (n=75) after achieving CR1 at a single medical center. The disease-free and overall survival rates and complications were analyzed. During a median follow-up of 1215 days, all patients (100%) in allo-HSCT group and 94.7% of patients in the auto-HSCT group had successful outcomes. The disease-free survival rates were 65.3% and 50.6% for allo- and auto-HSCT groups, respectively (P=0.158), while the overall survival rates were 65.3% and 54.9%, respectively (P=0.486). The recurrence rate was higher with auto-HSCT, whereas the GVHD only happened with allo-HSCT. In conclusion, auto-HSCT was as effective as allo-HSCT for the treatment of patients with AML after CR1. This is encouraging given that allo-HSCT is not always feasible in China because of a lack of matching donors.

Cytarabine Dose of 36 g/m2 Compared With 12 g/m2 Within First Consolidation in Acute Myeloid Leukemia: Results of Patients Enrolled Onto the Prospective Randomized AML96 Study

Purpose

To assess the optimal cumulative dose of cytarabine for treatment of young adults with acute myeloid leukemia (AML) within a prospective multicenter treatment trial.

Patients and Methods

Between 1996 and 2003, 933 patients (median age, 47 years; range 15 to 60 years) with untreated AML were randomly assigned at diagnosis to receive cytarabine within the first consolidation therapy at either a intermediate-dose of 12 g/m2 (I-MAC) or a high-dose of 36 g/m2 (H-MAC) combined with mitoxantrone. Autologous hematopoietic stem-cell transplantation or intermediate-dose cytarabine (10 g/m2) were offered as second consolidation. Patients with a matched donor could receive an allogeneic transplantation in a risk-adapted manner.

Results

After double induction therapy including intermediate-dose cytarabine (10 g/m2), mitoxantrone, etoposide, and amsacrine, complete remission was achieved in 66% of patients. In the primary efficacy analysis population, a consolidation with either I-MAC or H-MAC did not result in significant differences in the 5-year overall (30% v 33%; P = .77) or disease-free survival (37% v 38%; P = .86) according to the intention-to-treat analysis. Besides a prolongation of neutropenia and higher transfusion demands in the H-MAC arm, rates of serious adverse events were comparable in the two groups.

Conclusion

In young adults with AML receiving intermediate-dose cytarabine induction, intensification of the cytarabine dose beyond 12 g/m2 within first consolidation did not improve treatment outcome.

Autologous transplantation gives encouraging results for young adults with favorable-risk acute myeloid leukemia, but is not improved with gemtuzumab ozogamicin

We report the results of a prospective, randomized phase 3 trial evaluating the use of gemtuzumab ozogamicin (GO) in an intensive consolidation approach in 657 patients 17-60 years of age. Patients in first complete remission (CR1) after cytarabine and standard- or high-dose daunorubicin induction received 2 cycles of consolidation with high-dose cytarabine followed by peripheral blood progenitor cell collection. The 352 patients who entered consolidation were randomized to receive GO (n = 132) or not (n = 138) and then proceeded to autologous hematopoietic cell transplantation (HCT). GO was given to 67 patients. Median follow-up was 50.9 months. Results of the intention-to-treat analysis demonstrated a 4-year disease-free survival (DFS) of 33.6% versus 35.9% (P = .54) and an overall survival (OS) of 41.3% versus 41.9% (P = .52) for those randomized to receive GO versus no GO, respectively. Patients with favorable- and intermediate-risk acute myeloid leukemia (AML) treated with high-dose daunorubicin and autologous HCT had 4-year DFS rates of 60% and 40% and OS rates of 80% and 49.3%, respectively. For younger AML patients in CR1, autologous HCT should be considered in favorable- and intermediate-cytogenetic risk patients who do not have an allogeneic donor. The addition of a single dose of GO in this setting did not improve outcomes.

Syngeneic donor hematopoietic stem cell transplantation is associated with high rates of engraftment syndrome

Engraftment syndrome (ES), typically characterized by noninfectious fever, rash, and/or noncardiogenic pulmonary edema, is a complication of autologous and allogeneic hematopoietic stem cell transplantation (HSCT). There are no data on ES after syngeneic HSCT. We retrospectively analyzed syngeneic HSCT outcomes and determined ES incidence, risk factors, and prognostic impact. Thirty-two adult patients with a median age of 46 years (range: 22-60) underwent syngeneic HSCT at our institution between July 1986 and April 2009, primarily for hematologic malignancies (65% lymphoid-including 15% plasma cell; 31% myeloid). The median duration of follow-up was 6.1 years (range: 3.7 months to 18.1 years). Five-year progression-free and overall survival (PFS, OS) was 52% and 67%, respectively. Five-year overall cumulative incidence of relapse and nonrelapse mortality (NRM) was 37.6% and 10.2%, respectively; with increased relapse incidence of 76.3% in myeloid disease (P = .002). Fifteen patients (47%) met diagnostic criteria for ES, 10 (67%) of whom received systemic steroids. Five-year PFS was 47% in patients with ES versus 56% in those without (P = .37). Five-year OS was 63% with ES versus 71% without (P = .80). Five-year cumulative incidence of NRM was 21% with ES versus 0% without (P = .06). Five-year cumulative incidence of relapse was 32% with ES and 44% without (P = .68). Older age (P = .05) and possibly total body irradiation-based conditioning (P = .09) were risk factors for developing ES. In multivariable Cox models only diagnosis (myeloid disease) impaired OS and PFS. In summary, we document a high incidence of ES after syngeneic HSCT. The trend of increased NRM after ES requires reevaluation in a larger syngeneic HSCT cohort.

Acute myeloid leukemia: when to transplant in first complete remission

Allogeneic hematopoietic stem cell transplantation (HSCT) is commonly used to treat acute myeloid leukemia (AML) because it is potentially curative when other therapies have a low likelihood of success. Although most patients with newly diagnosed AML will achieve a first complete remission (CR1) with standard induction chemotherapy, obtaining a durable remission necessarily requires either further (postremission) chemotherapy or allogeneic HSCT. The decision of which of these options to choose is complex and depends on both clinical and molecular variables as well as the availability and histocompatibility of donor stem cells. Important clinical factors include the individual patient's age, performance status, and comorbidities. Molecular and cytogenetic factors are increasingly important in stratifying patients into favorable, intermediate, and unfavorable risk categories. Whereas patients with favorable-risk cytogenetics fare better with postremission chemotherapy, allogeneic HSCT provides superior long-term survival for most non-elderly patients with intermediate-risk or unfavorable-risk AML. Because of the expanded use of umbilical cord blood as a source of hematopoietic stem cells and the use of reduced-intensity conditioning regimens, allogeneic HSCT is an option for an increasing number of patients with AML.

Factors affecting neutrophil recovery after autologous bone marrow-derived stem cell transplantation in patients with acute myeloid leukemia

Bone marrow is currently regarded as the most appropriate source of stem cells for patients with acute myeloid leukemia (AML) undergoing autologous transplants. A total of 55 adult patients with AML in first complete remission receiving autologous bone marrow-derived stem cell (BMSC) transplantation (BMSCT) were analyzed to determine factors affecting the rate of neutrophil recovery. All patients were treated with standard induction and three to four courses of consolidation chemotherapy and, after collection of BMSC, conditioned with BuCy2. The median time to neutrophil reconstitution was 30 (10-62) days and was delayed in 24 patients. Neutrophil recovery was faster in patients who had received granulocyte-macrophage progenitors (CFU-GM) dose >23.5 x 10(4)/kg, CD34(+) cells >3.2 x 10(6)/kg, and mononuclear cells (MNCs) >3 x 10(8)/kg. The speed of neutrophil recovery correlated with the number of transplanted CFU-GM progenitors (P = .0077) and MNCs (P = .0015). CFU-GM progenitors dose was the only factor close to significance in univariate analysis of neutrophil engraftment. Probability for neutrophil recovery was higher in patients transplanted with a higher dose of MNCs. These data suggested that the content of CFU-GM progenitors and MNCs within the bone marrow graft was the most important factor for the quality of neutrophil recovery after autologous BMSCT in AML patients.

Current and emerging therapies for acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is a clonal disease characterized by the proliferation and accumulation of myeloid progenitor cells in the bone marrow, which ultimately leads to hematopoietic failure. The incidence of AML increases with age, and older patients typically have worse treatment outcomes than do younger patients.

OBJECTIVE

This review is focused on current and emerging treatment strategies for nonpromyelocytic AML in patients aged <60 years.

METHODS

A literature review was conducted of the PubMed database for articles published in English. Publications from 1990 through March 2009 were scrutinized, and the search was updated on August 26, 2009. The search terms used were: acute myeloid leukemia in conjunction with treatment, chemotherapy, stem cell transplantation, and immunotherapy. Clinical trials including adults with AML aged > or =19 years were selected for analysis. Conference proceedings from the previous 5 years of The American Society of Hematology, The European Hematology Association, and The American Society for Blood and Marrow Transplantation were searched manually. Additional relevant publications were obtained by reviewing the references from the chosen articles.

RESULTS

Cytarabine (AraC) is the cornerstone of induction therapy and consolidation therapy for AML. A standard form of induction therapy consists of AraC (100-200 mg/m(2)), administered by a continuous infusion for 7 days, combined with an anthracycline, administered intravenously for 3 days. Consolidation therapy comprises treatment with additional courses of intensive chemotherapy after the patient has achieved a complete remission (CR), usually with higher doses of the same drugs as were used during the induction period. High-dose AraC (2-3 g/m(2)) is now a standard consolidation therapy for patients aged <60 years. Despite substantial progress in the treatment of newly diagnosed AML, 20% to 40% of patients do not achieve remission with the standard induction chemotherapy, and 50% to 70% of first CR patients are expected to relapse within 3 years. The optimum strategy at the time of relapse, or for patients with the resistant disease, remains uncertain. Allogeneic stem cell transplantation has been established as the most effective form of antileukemic therapy in patients with AML in first or subsequent remission. New drugs are being evaluated in clinical studies, including immunotoxins, monoclonal antibodies, nucleoside analogues, hypomethylating agents, farnesyltransferase inhibitors, alkylating agents, FMS-like tyrosine kinase 3 inhibitors, and multidrug-resistant modulators. However, determining the success of these treatment strategies ultimately requires well-designed clinical trials, based on stratification of the patient risk, knowledge of the individual disease, and the drug's performance status.

CONCLUSIONS

Combinations of AraC and anthracyclines are still the mainstay of induction therapy, and use of high-dose AraC is now a standard consolidation therapy in AML patients aged <60 years. Although several new agents have shown promise in treating AML, it is unlikely that these agents will be curative when administered as monotherapy; it is more likely that they will be used in combination with other new agents or with conventional therapy.

Indications for hematopoietic cell transplantation in acute leukemia

Based on available data, all adults with AML under age 60 years with matched siblings should be considered for allogeneic transplantation in first remission, except for those with favorable risk cytogenetics and possibly those whose disease has normal cytogenetics and is FLT3/ITD negative and NPM1 positive. Patients with matched siblings not transplanted in first remission should be followed closely so that transplantation in early first relapse can be considered. Those without matched siblings should receive a MUD transplant in first CR if they have higher risk disease. All others should receive standard chemotherapy and consider a matched unrelated transplant or autologous transplant, should they relapse. RIC allogeneic transplantation using either a matched family member or a MUD can be considered for patients age 60 years or greater with AML in second or subsequent remission, or AML in first remission with intermediate or high risk disease.

Allogeneic stem cell transplantation for acute myeloid leukemia in first complete remission: systematic review and meta-analysis of prospective clinical trials

CONTEXT

The optimal treatment of acute myeloid leukemia (AML) in first complete remission (CR1) is uncertain. Current consensus, based on cytogenetic risk, recommends myeloablative allogeneic stem cell transplantation (SCT) for poor-risk but not for good-risk AML. Allogeneic SCT, autologous transplantation, and consolidation chemotherapy are considered of equivalent benefit for intermediate-risk AML.

OBJECTIVE

To quantify relapse-free survival (RFS) and overall survival benefit of allogeneic SCT for AML in CR1 overall and also for good-, intermediate-, and poor-risk AML.

METHODS

Systematic review and meta-analysis of prospective trials evaluating allogeneic SCT vs nonallogeneic SCT therapies for AML in CR1. The search used the combined search terms allogeneic; acut* and leukem*/leukaem*/leucem*/leucaem*/aml; myelo* or nonlympho* in the PubMed, Embase, and Cochrane Registry of Controlled Trials databases in March 2009. The search identified 1712 articles.

STUDY SELECTION

Prospective trials assigning adult patients with AML in CR1 to undergo allogeneic SCT vs nonallogeneic SCT treatment(s) based on donor availability and trials reporting RFS and/or overall survival outcomes on an intention-to-treat, donor vs no-donor basis were identified.

DATA EXTRACTION

Two reviewers independently extracted study characteristics, interventions, and outcomes. Hazard ratios (HRs) with 95% confidence intervals (CIs) were determined.

DATA SYNTHESIS

Overall, 24 trials and 6007 patients were analyzed (5951 patients in RFS analyses and 5606 patients in overall survival analyses); 3638 patients were analyzed by cytogenetic risk (547, 2499, and 592 with good-, intermediate-, and poor-risk AML, respectively). Interstudy heterogeneity was not significant. Fixed-effects meta-analysis was performed. Compared with nonallogeneic SCT, the HR of relapse or death with allogeneic SCT for AML in CR1 was 0.80 (95% CI, 0.74-0.86). Significant RFS benefit of allogeneic SCT was documented for poor-risk (HR, 0.69; 95% CI, 0.57-0.84) and intermediate-risk AML (HR, 0.76; 95% CI, 0.68-0.85) but not for good-risk AML (HR, 1.06; 95% CI, 0.80-1.42). The HR of death with allogeneic SCT for AML in CR1 was 0.90 (95% CI, 0.82-0.97). Significant overall survival benefit with allogeneic SCT was documented for poor-risk (HR, 0.73; 95% CI, 0.59-0.90) and intermediate-risk AML (HR, 0.83; 95% CI, 0.74-0.93) but not for good-risk AML (HR, 1.07; 95% CI, 0.83-1.38).

CONCLUSION

Compared with nonallogeneic SCT therapies, allogeneic SCT has significant RFS and overall survival benefit for intermediate- and poor-risk AML but not for good-risk AML in first complete remission.

Are there roles for observational database studies and structured quantification of expert opinion to answer therapy controversies in transplants?

Approaches to determine whether one transplant-related therapy is better than another include: (1) using experimental data, such as those from randomized controlled trials (RCTs); (2) using observational data, such as those from observational databases (ODBs) and (3) using conclusions from the structured quantification of expert opinion based on a consideration of evidence from RCTs, ODBs and other sources. Large RCTs are widely and appropriately regarded as the gold standard of clinical investigation. However, data from large RCTs are rarely available for transplant-related therapy questions. We discuss some of the limitations of RCTs in the transplant setting often including small size and short follow-up. These limitations are only partly solved by meta-analyses of RCTs. Data from high-quality ODBs are not only often useful in this setting but also have limitations. Biases may be difficult or impossible to identify and/or adjust for. However, ODBs have large numbers of diverse subjects receiving diverse therapies and analyses that often give answers more useful to clinicians than RCTs. Side-by-side comparisons suggest analyses from high-quality ODBs often give similar conclusions to meta-analyses of high-quality RCTs. Meta-analyses combining data from RCTs and ODBs are sometimes appropriate. Quantitation of expert opinion, when of high quality, is also useful: experts rarely disagree under precisely defined circumstances and their consensus conclusions are often concordant with results of high-quality RCTs and ODBs. We suggest increased use of ODBs and expert opinion as reliable and effective ways to determine relative efficacies of new therapies in transplant settings.

Clinical management of primary non-acute promyelocytic leukemia acute myeloid leukemia: Practice Guidelines by the Italian Society of Hematology, the Italian Society of Experimental Hematology, and the Italian Group for Bone Marrow Transplantation

As many options are now available to treat patients with de novo acute myeloid leukemia, the Italian Society of Hematology and two affiliated societies (SIES and GITMO) commissioned project to an Expert Panel aimed at developing clinical practice guidelines for acute myeloid leukemia treatment. After systematic comprehensive literature review, the Expert Panel formulated recommendations for the management of primary acute myeloid leukemia (with the exception of acute promyelocytic leukemia) and graded them according to the supporting evidence. When evidence was lacking, consensus-based statements have been added. First-line therapy for all newly diagnosed patients eligible for intensive treatment should include one cycle of induction with standard dose cytarabine and an anthracycline. After achieving complete remission, patients aged less than 60 years should receive consolidation therapy including high-dose cytarabine. Myeloablative allogeneic stem cell transplantation from an HLA-compatible sibling should be performed in first complete remission: 1) in children with intermediate-high risk cytogenetics or who achieved first complete remission after the second course of therapy; 2) in adults less than 40 years with an intermediate-risk; in those aged less than 55 years with either high-risk cytogenetics or who achieved first complete remission after the second course of therapy. Stem cell transplantation from an unrelated donor is recommended to be performed in first complete remission in adults 30 years old or younger, and in children with very high-risk disease lacking a sibling donor. Alternative donor stem cell transplantation is an option in high-risk patients without a matched donor who urgently need transplantation. Patients aged less than 60 years, who either are not candidate for allogeneic stem cell transplantation or lack a donor, are candidates for autologous stem cell transplantation. We describe the results of a systematic literature review and an explicit approach to consensus techniques, which resulted in recommendations for the management of primary non-APL acute myeloid leukemia.

Hematopoietic stem cell transplantation in adults with acute myeloid leukemia

Hematopoietic stem cell transplantation (HSCT) is an integral part of the treatment of many patients with acute myeloid leukemia (AML). Despite extensive study, the appropriate role and timing of allogeneic and autologous transplantation in AML are poorly defined. This review critically analyzes the extensive literature, focusing on the recent advances, and provides practical recommendations for the use of HSCT in AML.

The role of cytotoxic therapy with hematopoietic stem cell transplantation in the therapy of acute myelogenous leukemia in adults: an evidence-based review

Clinical research examining the role of hematopoietic stem cell transplantation (HSCT) in the therapy of acute myelogenous leukemia (AML) in adults is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are presented in Table 3, entitled Summary of Treatment Recommendations Made by the Expert Panel for Adult Acute Myelogenous Leukemia, and were reached unanimously by a panel of AML experts. The identified priority areas of needed future research in adult AML include: (1) What is the role of HSCT in treating patients with specific molecular markers (eg, FLT3, NPM1, CEBPA, BAALC, MLL, NRAS, etc.) especially in patients with normal cytogenetics? (2) What is the benefit of using HSCT to treat different cytogenetic subgroups? (3) What is the impact on survival outcomes of reduced intensity or nonmyeloablative versus conventional conditioning in older (>60 years) and intermediate (40-60 years) aged adults? (4) What is the impact on survival outcomes of unrelated donor HSCT vesus chemotherapy in younger (<40 years) adults with high risk disease?

Consolidation therapy for adult acute myeloid leukemia: a systematic analysis according to evidence based medicine

Post-remission therapy in acute myeloid leukemia (AML) remains problematic. It has been demonstrated that younger patients can maintain longer complete remissions (CR) with aggressive post-remission therapies after induction treatment: allogeneic (allo), autologous (auto) stem cell transplantation (SCT), or intensive chemotherapy (ICC). The purpose of our study was to identify the most important randomized and controlled studies comparing these three therapeutic options, in order to draw conclusions and possible suggestions for post-remission therapy of AML, according to the evidence based medicine (EBM) rules. We performed an exhaustive analysis of the literature, searching either in electronic databases or among the references of the identified articles (hand searching). We searched the MEDLINE computer database for reports from 1985 through January 2005 and selected for analysis the clinical trials conducted over adults affected by newly diagnosed AML aged less than 65 years. The study design had to satisfy strict methodological criteria and must consider global mortality and/or disease free survival as primary outcomes. Overall we found 7750 papers; by using the limits "clinical trial" as publication type, "all adults 19+ years", we were able to select 344 papers. Among these, a further selection was made, based on two main clinical queries: 1) is auto-SCT superior to ICC/no other therapy in improving DFS and/or OS in adult AML patients in first CR? 2) is allo-SCT superior to auto-SCT/other therapeutic options in improving DFS and/or OS in adult AML patients in first CR? Concerning the first query, a possible advantage of auto-SCT over ICC was not clearly supported by data from clinical trials; there is no evidence that auto-SCT is superior in terms of OS to chemotherapy. Nevertheless, the reported TRM has been significantly reduced within the past years. Thus, the percentage of patients suitable for auto-SCT in CR has increased. Moreover, the scarce data concerning the comparison between auto-SCT and chemotherapy in different subsets of patients are unable to suggest a differentiated approach in patients with high-risk, standard-risk or low-risk AML. Data from the literature show that patients with unfavorable risk disease are more often addressed to allo-SCT and patients with low-risk disease receive more often intensive consolidation chemotherapy. Concerning the second query, interpretation of data from the main prospective studies about the role of allo-SCT in previously untreated AML is not easy. The first problem is the lack of real randomized clinical trials; in fact, according to the reported studies, AML patients generally receive allo-SCT on the basis of donor availability (the so called "genetic randomization"). The second problem is the frequent absence of intention to treat analysis. Despite methodological limitations, it was possible to compare allo-SCT with auto-SCT on a donor versus no-donor analysis and within risk groups. No overall benefit of allo-grafting on survival was demonstrated by any trial. In conclusion, the EBM approach highlighted the limitations observed in the published studies concerning consolidation therapy in AML; some suggestions, emerging from non-randomized, as well as randomized studies, are adequate, but not conclusive. This point, coupled with the intrinsic complexity to study AML biological heterogeneity, is probably a major obstacle to draw conclusive evidences for consolidation therapy in AML. These observations should plan to address new randomized studies on AML therapy; however, due to the emergence of genetic subgroups and new drugs targeting specific abnormalities, these trials should probably be designed directly focusing on the single entities. In this way, the cure of AML could eventually become the cure of each specific AML subset with its peculiar biological, molecular and prognostic features.

Is there a plateau in the survival curve after autologous transplantation in patients with intermediate and high-risk acute myeloid leukemia? A 20-year single institution experience

In an attempt to examine whether autologous SCT provides long-term disease control in patients with intermediate and high-risk AML where a suitable donor is not available, we analyzed the outcomes of autologous SCT in patients with intermediate and high-risk AML from 1986 to 2005. No relapses occurred after 2.2 years. The overall survival curve appears to have developed a plateau after 2.2 years. In conclusion, autologous SCT in patients with AML in whom an allogeneic transplantation is not feasible appears to be a safe alternative and a plateau in the survival curve indicates cure in a small proportion of patients.

Alternative donor transplantation in acute myeloid leukemia: which source and when?

PURPOSE OF REVIEW

Acute myeloid leukemia is a heterogeneous disease with a prognosis determined mostly by the leukemic karyotype. Allogeneic transplant in first remission is offered to patients with intermediate- and poor-risk cytogenetics. Only the minority of patients, however, have a matched sibling donor.

RECENT FINDINGS

Matched unrelated, genetically haploidentical and umbilical cord blood have been increasingly used. Pros and cons of each procedure are discussed, and whenever available, comparisons are made.

SUMMARY

With the progress made in supportive care and prophylaxis of graft-versus-host disease, significant improvement in results of transplant from alternative donors has enabled its increasing use in specific disease stages. The recommended transplant for a given patient and the timing of transplant are discussed.

Current therapeutic strategies for acute myeloid leukaemia

Improvements in survival in adult acute myeloid leukaemia (AML) have yet to be gleaned from either refinements in the understanding of the pathophysiology of the disease or from the expanding pool of targeted therapies. Outcomes have remained particularly dismal in older patients. Ongoing and planned trials will assess the effects of drugs targeting biological pathways whose clinical importance may vary as a function of the unique genotype and phenotype of each case of AML. The success of these ventures will ultimately require well-designed clinical trials in subsets of patients with risk being dependent not only on age and cytogenetics, but on additional, increasingly quantifiable biological variables. Inhibitors of fms-like tyrosine kinase-3, farnesyl transferase, apoptotic and angiogenic pathways are being studied alone and in combination with chemotherapy. Biological therapies, including monoclonal antibodies, peptide vaccines and interleukin-2, are undergoing evaluation. The role of autologous as well as allogeneic myeloablative and reduced-intensity transplantation continues to be defined. Several potentially useful new cytotoxic agents are being introduced. Critically important to advancing the field in light of such an increasing number of choices is a reassessment of traditional phase II trial designs so that more efficient evaluation of new therapies may take place, even as well-designed phase III trials continue to be performed.

Autologous stem cell transplantation in the treatment of adults with acute myeloid leukaemia

Most adult patients under 60 years with acute myeloid leukaemia (AML) who achieve a complete remission after induction chemotherapy will relapse if they do not receive further therapy. Consolidation treatment with autologous stem cell transplantation (SCT) is one option that has been studied extensively. High-dose cytotoxic therapy followed by autologous SCT or intensive cycles of chemotherapy furnish overall approximately similar probabilities of survival when applied in first remission. Here, we present a concise update regarding the place of autologous SCT in the treatment of AML. Particular issues discussed are the value of autologous SCT in different prognostic subsets of AML and the value of autologous mobilised peripheral blood stem cell transplants, which offer a much faster haematopoietic recovery.

A Long-term Follow-up Analysis in Adult Acute Myeloid Leukemia Patients after Hematopoietic Stem Cell Transplantation

Aims and Background

Over the last 17 years, 119 adult acute myeloid leukemia patients have undergone hematopoietic stem cell transplantation at our Center.

Study Design

Seventy patients in first complete remission received hematopoietic stem cell transplantation (28 allogeneic and 42 autologous HSCT) as late intensification after conventional chemotherapy; 38 patients received allogeneic hematopoietic stem cell transplantation in a more advanced phase. A reference group was built up by collecting 40 acute myeloid leukemia patients who received high-dose cytosine arabinoside as late intensification and whose complete remission lasted more than 10 months.

Results

Results of the study led to conclude that an earlier timing of allogeneic hematopoietic stem cell transplantation can be recommended in order to treat patients who would otherwise suffer an early relapse.

Conclusions

The outcome of autologous hematopoietic stem cell transplantation in patients not in first complete remission supports the possibility of achieving good quality second complete remissions and suggests that autografting may be a life-saving strategy in selected acute myeloid leukemia patients with advanced disease.