Hematopoietic stem cell transplantation in adults with acute myeloid leukemia

Moving Myeloid Leukemia Drug Discovery Into the Third Dimension

The development of therapies aimed at leukemia has progressed substantially in the past years but childhood acute myeloid leukemia (AML) remains one of the most challenging cancers to treat. Genomic profiling of AML has greatly enhanced our understanding of the genetic and epigenetic landscape of this high-risk leukemia. With it comes the opportunity to develop targeted therapies that are expected to be more effective and less toxic than current treatment regimens. Nevertheless, often overlooked in leukemia drug discovery are the dynamic interactions between leukemic cells and the bone marrow environment. The interplay between leukemic cells, stromal cells and the extracellular matrix plays critical roles in the development, progression and relapse of AML as well as in drug response and the development of resistance. Here we will review pediatric leukemia with a special focus on acute myeloid disease in children, and discuss the tumor microenvironment in the context of drug resistance and leukemia stem cell survival. We will emphasize how three-dimensional (3D) cell-based drug discovery may offer hope for both the identification and advancement of more effective treatment options for patients suffering from this devastating disease.

Matched unrelated donor transplants-State of the art in the 21st century

Hematopoietic stem cell transplantation (HSCT) is the therapy of choice in many hematological malignant and non-malignant diseases by using human leukocyte antigen (HLA)-matched siblings as stem cell source but only one third of the patients will have HLA-matched siblings. Hence, physicians rely on the availability of matched unrelated donors (URD). The possibility of finding a matched URD is now more than 70% due to continuous expansion of URD registries around the world. The use of URD in adult patients is steadily increasing and in the last 8 years has superseded the numbers of matched sibling donor transplants and has become the most commonly used stem cell source. There is also an increasing trend to use peripheral blood (PB) stem cells rather than bone marrow (BM) stem cells. Outcomes following URD transplants depend mainly upon the indication and urgency of transplant, age and comorbidities of recipients, cytomegalovirus (CMV) matching/mismatching between donor and the recipient, and degree of HLA matching. In some studies outcome of unrelated stem cell transplants in terms of treatment-related mortality (TRM), disease-free survival (DFS), and overall survival (OS) is comparable to sibling donors.

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.

Hematologic Recovery after Pretransplant Chemotherapy Does Not Influence Survival after Allogeneic Hematopoietic Cell Transplantation in Acute Myeloid Leukemia Patients

Pretransplant remission status in patients with acute myeloid leukemia (AML) is 1 of the most important factors determining their outcomes after allogeneic hematopoietic cell transplantation (allo-HCT). Most patients are in complete remission with full hematologic recovery (CR) before undergoing allo-HCT. However, some patients achieve CR without recovery of platelet count (CRp) or a morphologic leukemia-free state (MLFS), defined as meeting all CR criteria without recovery of both neutrophil and platelet counts. Currently, there is a paucity of data regarding transplant outcomes in AML patients achieving MLFS after chemotherapy. To address this question, we evaluated transplant outcomes in 270 AML patients who received 6/6 HLA-matched sibling or 10/10 HLA-matched unrelated donor transplantation at a single institution between 2006 and 2013. Of our 270 patients, 206 were in CR, 45 were in CRp, and 19 were in MLFS before allo-HCT. Patients in CR, CRp, or MLFS had similar 3-year overall survival rates (49%, 46%, and 47%, respectively; P = .88) and 3-year event-free survival rates (45%, 36%, and 40%, respectively; P = .53). However, the cumulative incidence of nonrelapse mortality was significantly higher in patients in MLFS compared with those in CR (58% versus 22%, P = .0004), whereas the cumulative incidence of relapse in patients in MLFS was significantly lower compared with those in CR (11% versus 36%, P = .03). Our results suggest that survival outcomes in AML patients are not influenced by degree of hematologic recovery before allo-HCT.

CD33-specific chimeric antigen receptor T cells exhibit potent preclinical activity against human acute myeloid leukemia

Patients with chemo-refractory acute myeloid leukemia (AML) have a dismal prognosis. Chimeric antigen receptor T (CART) cell therapy has produced exciting results in CD19+ malignancies and may overcome many of the limitations of conventional leukemia therapies. We developed CART cells to target CD33 (CART33) using the anti-CD33 single chain variable fragment used in gemtuzumab ozogamicin (clone My96) and tested the activity and toxicity of these cells. CART33 exhibited significant effector functions in vitro and resulted in eradication of leukemia and prolonged survival in AML xenografts. CART33 also resulted in human lineage cytopenias and reduction of myeloid progenitors in xenograft models of hematopoietic toxicity, suggesting that permanently expressed CD33-specific CART cells would have unacceptable toxicity. To enhance the viability of CART33 as an option for AML, we designed a transiently expressed mRNA anti-CD33 CAR. Gene transfer was carried out by electroporation into T cells and resulted in high-level expression with potent but self-limited activity against AML. Thus our preclinical studies show potent activity of CART33 and indicate that transient expression of anti-CD33 CAR by RNA modification could be used in patients to avoid long-term myelosuppression. CART33 therapy could be used alone or as part of a preparative regimen prior to allogeneic transplantation in refractory AML.

Advances in the treatment of acute graft-versus-host disease

Allogeneic hematopoietic stem cell transplantation (HSCT) has been widely used for the treatment of hematologic malignant and non-malignant hematologic diseases and other diseases. However, acute graft-versus-host disease (GVHD) is a life-threatening complication of allogeneic transplantation. Acute GVHD may occur in 30% of transplant recipients, which is a syndrome of erythematous skin eruption, cholestatic liver disease and intestinal dysfunction, resulting from the activation of donor T lymphocytes by host antigen-presenting cells, resulting in an immune-mediated inflammatory response. Recent scientific advances in the understanding of the pathogenesis involved in the development of acute GVHD and clinical investigation have provided more effective therapeutic strategies for acute GVHD. This review focuses on major scientific and clinical advances in the treatment of acute GVHD.

Incidence and Pattern of Graft-versus-Host Disease in Patients Undergoing Allogeneic Transplantation after Nonmyeloablative Conditioning with Total Lymphoid Irradiation and Antithymocyte Globulin

Nonmyeloablative (NMA) conditioning with total lymphoid irradiation and antithymocyte globulin (TLI/ATG) has been shown to protect against acute graft-versus-host disease (GVHD). We report here our institutional experience with allogeneic transplantation following NMA conditioning with TLI/ATG (n = 21). GVHD prophylaxis consisted of a combination of a calcineurin inhibitor and mycophenolate mofetil. Median patient age was 59 years. The median followup of surviving patients is 545 days. One patient experienced primary graft rejection. The median time to neutrophil engraftment was 18 days and platelet engraftment was 9.5 days. The cumulative incidence (CI) of grade II–IV acute GVHD at day +100 was 28.6% and 38.1% at day +180. The CI for grade III-IV acute GVHD was 28.6% at day +180. CI of chronic GVHD was 45.2% at 1 year. The CI of disease relapse was 9.5% at 1 year. The rate of nonrelapse mortality (NRM) was 0% at day +100 and only 9.5% at 1 year. The overall and progression free survival at 1 year was 81% and 80.4%, respectively. Our limited, retrospective data show encouraging relapse and NRM rates with TLI/ATG-based NMA conditioning, but with higher than previously reported rates of acute and chronic GVHD, underscoring the need for novel strategies designed to effectively prevent GVHD.

Allo-HSCT for acute leukemia of ambiguous lineage in adults: the comparison between standard conditioning and intensified conditioning regimens

Knowledge concerning the clinical and biological characteristics of acute leukemia of ambiguous lineage (ALAL) is limited so that there has been a lack of uniformity in treatment. In this report, we retrospectively investigated the effect of intensified conditioning on adult ALAL undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). A total of 59 patients with ALAL (male in 37 cases and female in 22 cases) were consecutively enrolled in the data analyses. Twenty-four patients received the standard conditioning (total body irradiation (TBI) + cyclophosphamide (CY) or busulfan + CY protocol) and 35 received the intensified conditioning (TBI + CY + etoposide or fludarabine + cytarabine plus TBI + CY + etoposide protocol). Five-year transplant-related mortality was 17.6 ± 9.6 % and 25.5 ± 8.0 %, the 5-year overall survival (OS) post-transplantation was 23.8 ± 8.9 % and 64.0 ± 8.4 %, disease-free survival was 16.7 ± 7.6 % and 55.8 ± 9.4 %, the 5-year cumulative incidence of relapse was 80.8 ± 8.5 % and 28.8 ± 9.9 %, respectively, in the standard and the intensified group (P = 0.380, P = 0.029, P = 0.005, and P < 0.001). Both univariate and multivariate analysis indicated that the intensified conditioning regimen and acute graft-versus-host disease were favorable factors to reduce the relapse. The younger patients, patients with CR at the time of transplantation, and the intensified conditioning regimen were favorable factors to elevate the survival. In conclusion, intensified conditioning regimens followed by allo-HSCT might improve long-term survival and decrease relapse of leukemia in adult ALAL compared to the standard conditioning regimens.

Gender differences in health-related quality of life, physical function and psychological status among patients in the early phase following allogeneic haematopoietic stem cell transplantation

OBJECTIVE

The aim of this study was to examine gender differences in quality of life (QOL), physical function and psychological status before and in the early phase after allogeneic haematopoietic stem cell transplantation (allo-HSCT).

METHODS

One hundred patients (66 men, 34 women) who underwent allo-HSCT between July 2007 and June 2011 at Hyogo College of Medicine Hospital were included in this study. Patients were evaluated for health-related QOL using the Medical Outcome Study 36-item Short Form Health Survey; exercise capacity was measured with the 6-min walk test, hand grip strength and knee extensor strength. Fatigue and psychological status were measured by the Piper Fatigue Scale and Hospital Anxiety and Depression Scale, respectively.

RESULTS

Women had significantly lower scores for physical function and general health on health-related QOL tests compared with men (p < 0.01). No difference between genders was found in decline of physical function. In women, exercise capacity was strongly associated with QOL (p < 0.01). In men, depression and anxiety were closely related to QOL (p < 0.01).

CONCLUSIONS

Gender-appropriate rehabilitation in allo-HSCT patients is important. Women may need more endurance exercises and training for activities of daily life. Men may need rehabilitation including a psychological approach.

Clofarabine plus cytarabine compared with cytarabine alone in older patients with relapsed or refractory acute myelogenous leukemia: results from the CLASSIC I Trial

PURPOSE

To compare the receipt of clofarabine plus cytarabine (Clo+Ara-C arm) with cytarabine (Ara-C arm) in patients ≥ 55 years old with refractory or relapsed acute myelogenous leukemia (AML).

PATIENTS AND METHODS

Patients were randomly assigned to receive either clofarabine (Clo) 40 mg/m(2) or a placebo followed by Ara-C 1 g/m(2) for five consecutive days. The primary end point was overall survival (OS). Secondary end points included event-free survival (EFS), 4-month EFS, overall remission rate (ORR; complete remission [CR] plus CR with incomplete peripheral blood count recovery), disease-free survival (DFS), duration of remission (DOR), and safety.

RESULTS

Among 320 patients with confirmed AML (median age, 67 years), the median OS was 6.6 months in the Clo+Ara-C arm and 6.3 months in the Ara-C arm (hazard ratio [HR], 1.00; 95% CI, 0.78 to 1.28; P = 1.00). The ORR was 46.9% in the Clo+Ara-C arm (35.2% CR) versus 22.9% in the Ara-C arm (17.8% CR; P < .01). EFS (HR: 0.63; 95% CI, 0.49 to 0.80; P < .01) and 4-month EFS (37.7% v 16.6%; P < .01) favored the Clo+Ara-C arm compared with Ara-C arm, respectively. DFS and DOR were similar in both arms. Overall 30-day mortality was 16% and 5% for CLO+Ara-C and Ara-C arms, respectively. In the Clo+Ara-C and Ara-C arms, the most common grade 3 to 4 toxicities were febrile neutropenia (47% v 35%, respectively), hypokalemia (18% v 11%, respectively), thrombocytopenia (16% v 17%, respectively), pneumonia (14% v 10%, respectively), anemia (13% v 0%, respectively), neutropenia (11% v 9%, respectively), increased AST (11% v 2%, respectively), and increased ALT (10% v 3%, respectively).

CONCLUSION

Although the primary end point of OS did not differ between arms, Clo+Ara-C significantly improved response rates and EFS. Study follow-up continues, and the role of clofarabine in the treatment of adult patients with AML continues to be investigated.

Reduced-Intensity Conditioning Allogeneic Hematopoietic Cell Transplantation in Adults with Acute Myeloid Leukemia

Background

Acute myeloid leukemia (AML), whether de novo or arising from antecedent hematologic disorders in elderly patients, is less likely to be curable with standard chemotherapy regimens used for younger patients. Allogeneic hematopoietic cell transplantation (alloHCT) is currently the most efficient anti-leukemia treatment for AML and has shown a survival advantage in younger patients with intermediate- or poor-risk cytogenetics.

Methods

The authors review their experience as well as the published data regarding the role of reduced-intensity conditioning (RIC) alloHCT in adults with AML. MEDLINE/PubMed and EMBASE/Ovid were searched, as well as reference lists of relevant articles, conference proceedings, and ongoing trial databases.

Results

Elderly patients with AML have a poor survival for all cytogenetics subgroups (except for acute promyelocytic leukemia) and higher rates of transplant-related mortality with myeloablative alloHCT. RIC regimens have been shown to decrease procedure-related toxicity and have emerged as an attractive treatment modality in AML patients not suitable for myeloablative conditioning regimens. While prospective data comparing outcomes of AML patients undergoing RIC alloHCT vs conventional chemotherapy alone are not yet available, RIC alloHCT is a reasonable option for high-risk older patients and for younger AML patients with medical comorbidities who achieve a first or subsequent remission. The application of RIC for patients with refractory disease or untreated relapse as well as the use of alternative donors should be considered within the context of clinical trials.

Conclusions

RIC alloHCT is a safe and effective treatment modality in high-risk elderly AML patients and in younger AML patients with medical comorbidities.

Clofarabine and busulfan conditioning facilitates engraftment and provides significant antitumor activity in nonremission hematologic malignancies

Patients with hematologic malignancies not in remission before allogeneic hematopoietic stem cell transplantation (HSCT) have a poor prognosis. To improve the antitumor activity of conditioning, we combined clofarabine with myeloablative doses of busulfan in a phase 1/2 study in nonremission hematologic malignancies. Forty-six patients were enrolled, including 31 patients with nonremission acute myelogenous leukemia (AML). Patients had a median age of 53 years, with a median comorbidity index of 3. Donors were unrelated, HLA mismatched, or both in 59% of patients. Common grade III to IV nonhematologic toxicities included transient transaminitis (50%), mucositis (24%), hand-foot syndrome (13%), transient hypoxia (13%), nausea/vomiting (9%), and diarrhea (9%). All patients engrafted. Complete remission was achieved in 80% of all patients by day +30 and in 100% of AML patients without prior hematopoietic stem cell transplantation. Two-year nonrelapse mortality for all patients was 31%, and overall survival was 28%. In AML, the overall survival was 48% at 1 year and 35% at 2 years. These data suggest that clofarabine combined with myeloablative doses of busulfan is well tolerated, secures engraftment, and possesses significant antitumor activity, particularly in nonremission AML. This study is registered at www.ClinicalTrials.gov under identifier NCT00556452.

The rise of cellular therapy

In 1938, the field of Transfusion Medicine began as the simpler entity - Blood Banking. It was a discipline that focused on collecting, processing, storing and distributing end stage blood cells, plasma and plasma fractions to patients. Over the years, the field progressed to include clinical patient services such as apheresis technology and with the development of stem cell transplantation as a standard of care, Cell Therapy. Now the discipline is also finding a niche in the area of Regenerative Medicine. The role played by Transfusion Medicine practitioners in Cell Therapy and Regenerative Medicine was predicated on many factors: (1) pre-existing, established protocols for therapeutic leukapheresis, (2) prior experience with mononuclear cell collection and processing, (3) long term familiarity with, and a clear understanding of, cGMP and cGLP guidelines, Federal regulations, and the voluntary standards established by various organizations, (4) close relationships with practitioners in clinical departments of medicine, pediatrics, oncology, surgery, and their subspecialty areas. While the initial Cell Therapy programs related primarily to hematopoietic stem cell transplantation, as Regenerative Medicine programs developed, transfusion specialists found it to be a related field that would also benefit from their input. Cell Therapy and Regenerative Medicine, now provide fertile soil for the seeds of Transfusion Medicine to grow. The once narrowly defined field of Blood Banking now encompasses involvement in major new Cellular Therapy/Regenerative Medicine research protocols related to treatment of patients with cancer as well as renal, hepatic and cardiac illnesses. This in turn provides opportunities for residents and fellows to consider robust careers in the field of Transfusion Medicine. In this manner we will move forward with one eye on the past and another on the promising future.

Clinical evaluation of cellular immunotherapy in acute myeloid leukaemia

Immunotherapy is currently under active investigation as an adjuvant therapy to improve the overall survival of patients with acute myeloid leukaemia (AML) by eliminating residual leukaemic cells following standard therapy. The graft-versus-leukaemia effect observed following allogeneic haematopoietic stem cell transplantation has already demonstrated the significant role of immune cells in controlling AML, paving the way to further exploitation of this effect in optimized immunotherapy protocols. In this review, we discuss the current state of cellular immunotherapy as adjuvant therapy for AML, with a particular focus on new strategies and recently published results of preclinical and clinical studies. Therapeutic vaccines that are being tested in AML include whole tumour cells as an autologous source of multiple leukaemia-associated antigens (LAA) and autologous dendritic cells loaded with LAA as effective antigen-presenting cells. Furthermore, adoptive transfer of cytotoxic T cells or natural killer cells is under active investigation. Results from phase I and II trials are promising and support further investigation into the potential of cellular immunotherapeutic strategies to prevent or fight relapse in AML patients.

Long-term outcome of reduced-intensity allogeneic hematopoietic SCT in patients with AML in CR

A total of 36 consecutive patients with AML in CR underwent reduced-intensity allogeneic hematopoietic SCT (RISCT) with fludarabine and melphalan conditioning. All patients were ineligible for myeloablative transplantation because of age or comorbidity. In total, 30 patients were in first CR and six patients were in second CR. Donors were siblings in 21 (58%) patients and were unrelated in 15 (42%) patients. Hematopoietic cell transplant specific comorbidity scores ≥3 were present in 26 (72%) patients. With a median follow-up of 52 months (range, 34-103 months), OS and PFS rates at 4 years were 71% (s.e., 8%) and 68% (s.e., 8%), respectively. At 4 years, the cumulative incidence of non-relapse mortality was 20% (s.e., 7%) and of relapse mortality was 8% (s.e., 5%). Neither OS nor PFS was affected by older age (>60 years), unrelated donor, melphalan dose, or comorbidity score. At last follow up, of the 24 surviving patients, 21 (88%) had performance status (ECOG) of 0 without any active chronic GVHD requiring steroids. Hence, RISCT with fludarabine and melphalan conditioning produces durable long-term remission in older patients with AML.

Higher busulfan dose intensity does not improve outcomes of patients undergoing allogeneic haematopoietic cell transplantation following fludarabine, busulfan-based reduced toxicity conditioning

We evaluated the impact of busulfan dose intensity in patients undergoing reduced toxicity/intensity conditioning allogeneic transplantation in a multicenter retrospective study of 112 consecutive patients. Seventy-five patients were conditioned with busulfan (0.8 mg/kg/dose IV × 8 doses), fludarabine (30 mg/m(2) /day, days -7 to -3), and 6 mg/kg of ATG [reduced intensity conditioning (RIC) group], while 37 patients received a more-intense conditioning with busulfan (130 mg/m(2) /day IV, days -6 to -3), fludarabine (40 mg/m(2) /day, days -6 to -3) and 6 mg/kg of ATG [reduced toxicity conditioning (RTC) group]. At baseline both groups were matched for median age, unrelated donor allografts, and human leukocyte antigen-mismatched allografts. More patients in RIC group had high-risk disease, and higher median comorbidity index. There were no graft rejections. Median time to neutrophil (17 days vs. 15 days; p = 0.003) and platelet engraftment (16 days vs. 11 days; p < 0.001) was significantly longer in the RIC group. RTC group had significantly more bacterial (62.2% vs. 32%; p = 0.004) and fungal infections (13.5% vs. 1.3% p = 0.01). For RIC and RTC groups rates of grades II-IV acute GVHD (34% vs. 40%; p-value = 0.54), and chronic GVHD (45% vs. 57%; p-value = 0.30) were not significantly different. In similar order at 1 year the cumulative-incidence of non-relapse mortality (NRM; 12% vs. 21%; p-value = 0.21) and relapse rates (38% vs. 39%; p = 0.96) were not significantly different. Patients in RIC and RTC groups had similar 1-year overall survival (61% vs. 50%, p = 0.11) and progression-free survival (50% vs. 36%, p-value = 0.39). Our data suggest that the merits of higher busulfan dose intensity in the context of fludarabine/busulfan-based RTC may be offset by higher early morbidity.

Shortcomings in the clinical evaluation of new drugs: acute myeloid leukemia as paradigm

Drugs introduced over the past 25 years have benefitted many patients with acute myeloid leukemia (AML) and provided cure for some. Still, AML remains difficult to treat, and most patients will eventually die from their disease. Therefore, novel drugs and drug combinations are under intense investigation, and promising results eagerly awaited and embraced. However, drug development is lengthy and costs are staggering. While the phase 1-phase 2-phase 3 sequence of clinical drug testing has remained inviolate for decades, it appears intrinsically inefficient, and scientific flaws have been noted by many authors. Of major concern is the high frequency of false-positive results obtained in phase 2 studies. Here, we review features of phase 2 trials in AML that may contribute to this problem, particularly lack of control groups, patient heterogeneity, selection bias, and choice of end points. Recognizing these problems and challenges should provide us with opportunities to make drug development more efficient and less costly. We also suggest strategies for trial design improvement. Although our focus is on the treatment of AML, the principles that we highlight should be broadly applicable to the evaluation of new treatments for a variety of diseases.

Autologous hematopoietic stem cell transplantation as an intensive consolidation therapy for adult patients in remission from acute myelogenous leukemia

Autologous peripheral blood stem/progenitor cell transplantation (APBSCT) has been investigated as a potential therapeutic option to improve outcome in patients with acute myelogenous leukemia (AML). However, its optimal role in treatment for adults in remission has not been clearly established. We performed a retrospective analysis on 45 patients aged 21 to 73 years (median 51 years) with de novo AML who underwent APBSCT stratified by age, complete remission status, and cytogenetic risk. The 5-year disease-free survival (DFS) for all patients was 33.9% (95% confidence interval [CI], 20.1%-53.7%) and overall survival (OS) was 43.6% (CI, 29.2%-62.8%). For patients under the age of 60 years, the 5-year DFS for intermediate and high cytogenetic risk was 53.3% (CI, 23.5%-85.6%) and 50.0% (CI, 16.1%-100.0%); the 5-year OS for patients under the age of 60 years with low, intermediate, and high cytogenetic risk was 80.0% (CI, 40.0%-100.0%), 60.0% (CI, 31.2%-90.7%), and 75.0% (CI, 39.0%-100.0%), respectively. For patients over the age of 60 years, the 5-year DFS and OS for intermediate cytogenetic risk was 21.4% (CI, 7.9%-58.4%) and 21.4% (CI, 7.9%-58.4%). The DFS and OS of these patients are comparable to the historic survival of those who underwent allogeneic stem cell transplantation when adjusted by age. In addition, there was no treatment-related mortality (TRM). We conclude that APBSCT is a reasonable and safe intensive consolidation for patients with AML who do not have a suitable HLA-matched donor.

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.

Treatment of acute myeloid leukemia with hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation provides the most powerful antileukemic effect in the treatment of acute myeloid leukemia. Due to its significant morbidity and mortality, it should be used in first remission patients whose relapse risk is substantial. Reduced intensity transplantation is safer and extends the application of early transplantation to older patients and those with comorbidities. In patients with advanced disease, allotransplantation provides a lower chance for cure, but is often the only curative treatment available. Advances in histocompatibility typing and supportive care have improved results of allogeneic transplantation in acute myeloid leukemia.

The EBMT activity survey 2007 with focus on allogeneic HSCT for AML and novel cellular therapies

The 2007 report describes the current status of HSCT activity in Europe, highlights the increasing role of allogeneic HSCT in treatment of AML and gives the first quantitative information on novel cellular therapies. In 2007, there were 25 563 first HSCTs, 10 072 allogeneic (39%), 15 491 autologous (61%) and 3606 additional transplants reported from 613 centers in 42 countries. The main indications were leukemias (8061 (32%; 89% allogeneic)); lymphomas (14 627 (57%; 89% autologous)), solid tumors (1488 (6%; 96% autologous)) and nonmalignant disorders (1302 (5%; 91% allogeneic)). Peripheral blood was the main source of stem cells for autologous HSCT (98%) and the predominant source for allogeneic HSCT (71%). Among allogeneic HSCTs, the number of unrelated donor grafts equaled the number of HLA-identical sibling donor grafts for the first time (47% each). AML was the most frequent indication for allogeneic HSCT (32% of all allogeneic HSCTs), with an increase of 247 (8%). Information on novel cellular therapies was collected for the first time; there were 212 mesenchymal SCTs and 212 HSCTs for nonhematopoietic use. The indications for the latter were cardiovascular disorders (97; 46%), neurological disorders (94; 44%) and tissue repair (21; 10%). These data illustrate the expanding role of cellular therapies.

The efficient generation of immunocompetent dendritic cells from leukemic blasts in acute myeloid leukemia: a local experience

Dendritic cells (DCs) are the most important antigen presenting cells with potentially useful applications in cancer immunotherapy. Leukemic cells of patients with acute myeloid leukemia (AML) could be differentiated to DC-like cells possessing the ability of stimulating anti-leukemic immune response. Despite obvious progress in DC-based immunotherapy, some discrepancies were reported in differentiation potential of AML blasts from all patients toward DC like cells. The present study, as a local experience, was set up to generate DCs from AML blasts of various subtypes. Leukemic Blasts from 16 Iranian AML patients were differentiated into functional DCs by culturing in the presence of rhGM-CSF, rhIL-4 and TNF-alpha for 8 days. The morphology, expression of key surface molecules and allostimulatory activity of resultant DCs were compared with primary blasts and cultured but cytokine untreated control groups. The pattern of angiotensin-converting enzyme (ACE) expression was used to approve the leukemic origin of generated DCs. Neo-expression or upregulation of DC-associated markers were occurred during culturing period in cytokine treated cells compared with primary blasts and cultured but cytokine untreated control groups: CD1a (63.22% vs. 3.22% and 11.79%), CD83 (41.27% vs. 0.11% and 0.70%), CD40 (15.17% vs. 0.00% and 0.04%), CD80 (49.96 vs. 0.02% and 0.32%), CD86 (56.49% vs. 0.50% and 5.71%) and HLA-DR (52.52% vs. 14.32% and 2.49%) respectively. The potency of generated DCs to induce allogeneic T cell proliferation increased significantly compared to pre and post culture control groups (27,533.4 +/- 2,548.3, 8,820.4 +/- 1,639.4 and 3,200.35 +/- 976 respectively). The expression pattern of ACE in AML-DCs, blast cells and DCs derived from normal monocytes (7.93%, 1.28% and 74.97% respectively) confirmed the leukemic origin of DCs. Our data confirmed the generation of sufficient AML-derived cells with the properties of DCs in all cases. This potency of AML blasts, offers a useful route for active immunotherapy of AML patients.