Frequency of allogeneic hematopoietic cell transplantation among patients with high- or intermediate-risk acute myeloid leukemia in first complete remission

Prospective analysis to determine barriers to allogeneic hematopoietic cell transplantation in patients with acute leukemia

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative treatment for patients with acute leukemia. Despite this, studies have shown that only a minority of patients ultimately proceed to allo-HCT. The primary objective of this prospective, observational study was to identify the rate of allo-HCT in patients for whom it was recommended, and reasons why patients deemed appropriate and eligible for HCT did not subsequently undergo transplant. Between April 2016 and April 2021, adult patients with newly diagnosed or relapsed/refractory acute leukemia were enrolled at the time of induction/reinduction therapy. Initial transplantation workup and allo-HCT recommendations were made during the early phase of induction/reinduction. Of the 307 enrolled patients, allo-HCT was recommended to 85% (n = 259), of whom 66% (n = 170) underwent transplant. Donor sources comprised 54% human leukocyte antigen (HLA)-matched unrelated donors, 20% HLA-matched sibling donors and HLA-mismatched graft sources with 15% umbilical cord blood units, 8% HLA-mismatched unrelated donors, and 4% HLA-haploidentical donors. The most common reason for transplant disqualification in the 89 patients in whom it was initially recommended was persistent/relapsed disease (70%), followed by early patient death (10%). In this prospective study, we report a high allo-HCT rate, which may be due to early transplant referral and workup. The main allo-HCT barrier was disease control, followed by early patient death. With the increasing availability of HLA-mismatched graft sources, the lack of donor availability was not a transplant barrier. Further development of novel transplant strategies for patients not achieving remission and improvements in induction regimens could result in increased allo-HCT utilization.

Phase 2 study of PD-1 blockade following autologous transplantation for patients with AML ineligible for allogeneic transplant

Allogeneic transplant remains the best postremission therapy for patients with nonfavorable risk acute myeloid leukemia (AML). However, some patients are ineligible because of psychosocial barriers, such as lack of appropriate caregiver support. We hypothesized that immune checkpoint inhibition after autologous transplant might represent effective postremission therapy in such patients. We conducted a phase 2 study of autologous transplantation followed by administration of pembrolizumab (8 cycles starting day +1). Twenty patients with nonfavorable AML in complete remission were treated (median age, 64 years; CR1, 80%); 55% were non-White and adverse-risk AML was present in 40%. Treatment was well tolerated, with only 1 nonrelapse death. Immune-related adverse events occurred in 9 patients. After a median follow-up of 80 months, 14 patients remain alive, with 10 patients in continuous remission. The estimated 2-year LFS was 48.4%, which met the primary end point of 2-year LFS >25%; the 2-year overall survival (OS), nonrelapse mortality, and cumulative incidences of relapse were 68%, 5%, and 46%, respectively. In comparison with a propensity score-matched cohort group of patients with AML receiving allogeneic transplant, the 3-year OS was similar (73% vs 76%). Patients in the study had inferior LFS (51% vs 75%) but superior postrelapse survival (45% vs 14%). In conclusion, programmed cell death protein-1 blockade after autologous transplant is a safe and effective alternative postremission strategy in patients with nonfavorable risk AML who are ineligible for allogeneic transplant, a context in which there is significant unmet need. This trial was registered at www.clinicaltrials.gov as #NCT02771197.

Allogeneic transplantation in acute myelogenous leukemia: a comprehensive single institution's experience

Debates on the role and timing of allogeneic hemtopoietic stem cell transplantation (HSCT) in acute myelogenous leukemia (AML) have persisted for decades. Time to transplant introduces an immortal time and current treatment algorithm mainly relies on the European LeukemiaNet disease risk classification. Previous studies are also limited to age groups, remission status and other ill-defined parameters. We studied all patients at diagnosis irrespective of age and comorbidities to estimate the cumulative incidence and potential benefit or disadvantage of HSCT in a single center. As a time-dependent covariate, HSCT improved overall survival in intermediate- and poor-risk patients (hazard ratio =0.51; P=0.004). In goodrisk patients only eight were transplanted in first complete remission. Overall, the 4-year cumulative incidence of HSCT was only 21.9% but was higher (52.1%) for patients in the first age quartile (16-57 years old) and 26.4% in older patients (57-70 years old) (P<0.001). It was negligible in patients older than 70 years reflecting our own transplant policy but also barriers to transplantation (comorbidities and remission status). However, HSCT patients need to survive, be considered eligible both by the referring and the HSCT physicians and have a suitable donor to get transplantation. We, thus, comprehensively analyzed the complete decision-making and outcome of all our AML patients from diagnosis to last followup to decipher how patient allocation and therapy inform the value of HSCT. The role of HSCT in AML is shifting with broad access to different donors including haploidentical ones. Thus, it may (or may not) lead to increased numbers of allogeneic HSCT in AML in adults.

Allogeneic Hematopoietic Cell Transplantation and Cellular Therapy

Patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) generally require allogeneic hematopoietic cell transplantation (allo-HCT) for a cure, except for patients with favorable genetic genotypes such as those with core-binding factor AML. However, the use of intensive chemotherapy followed by prompt HCT does not fully prevent relapse or refractory disease. Despite improvements in transplant techniques and management of complications, further improvement of HCT outcomes is urgently needed. Moreover, careful patient counseling, donor selection, and choice of transplant type are essential to maximize the benefits of early allografting. Maintenance after HCT focusing on selective immunomodulation combined with targeted immunotherapies that control persisting or relapsed hematologic malignancies is currently under active investigation. To improve the balance between GVHD, relapse, and infection, the use of purified blood stem cell grafts in conjunction with ex vivo expanded T-cells from stem cell donors targeting common infectious and leukemic antigens has been explored. T cells against infectious agents might also be generated using partially HLA-matched third-party T cells from cryopreserved cell banks, and a series of studies confirmed the clinical value of donor-derived CMV- and EBV-specific T cells. This approach has also been applied to acute leukemia, and trials using donor-derived cytotoxic T-cells targeting multiple leukemic antigens such as WT1, PRAME, survivin, and NY-ESO, as well as donor-derived CAR19 T-cells after allo-HCT, are currently underway.

Association Between Measurable Residual Disease in Patients With Intermediate-Risk Acute Myeloid Leukemia and First Remission, Treatment, and Outcomes

Importance

Measurable residual disease (MRD) is widely used as a therapy-stratification factor for acute myeloid leukemia (AML), but the association of dynamic MRD with postremission treatment (PRT) in patients with intermediate-risk AML (IR-AML) has not been well investigated.

Objective

To investigate PRT choices based on dynamic MRD in patients with IR-AML.

Design, Setting, and Participants

This cohort study examined 549 younger patients with de novo IR-AML in the South China Hematology Alliance database during the period from January 1, 2012, to June 30, 2016, including 154 who received chemotherapy, 116 who received an autologous stem cell transplant (auto-SCT), and 279 who received an allogeneic SCT (allo-SCT). Subgroup analyses were performed according to dynamic MRD after the first, second, and third courses of chemotherapy. The end point of the last follow-up was August 31, 2020. Statistical analysis was performed from December 1, 2019, to September 30, 2020.

Exposures

Receipt of chemotherapy, auto-SCT, or allo-SCT.

Main Outcomes and Measures

The primary end points were 5-year cumulative incidence of relapse and leukemia-free survival.

Results

Subgroup analyses were performed for 549 participants (314 male participants [57.2%]; median age, 37 years [range, 14-60 years]) according to the dynamics of MRD after 1, 2, or 3 courses of chemotherapy. Comparable cumulative incidences of relapse, leukemia-free survival, and overall survival were observed among participants who had no MRD after 1, 2, or 3 courses of chemotherapy. Participants who underwent chemotherapy and those who underwent auto-SCT had better graft-vs-host disease-free, relapse-free survival (GRFS) than those who underwent allo-SCT (chemotherapy: hazard ratio [HR], 0.35 [95% CI, 0.14-0.90]; P = .03; auto-SCT: HR, 0.07 [95% CI, 0.01-0.58]; P = .01). Among participants with MRD after 1 course of chemotherapy but no MRD after 2 or 3 courses, those who underwent auto-SCT and allo-SCT showed lower cumulative incidence of relapse (auto-SCT: HR, 0.25 [95% CI, 0.08-0.78]; P = .01; allo-SCT: HR, 0.08 [95% CI, 0.02-0.24]; P < .001), better leukemia-free survival (auto-SCT: HR, 0.26 [95% CI, 0.10-0.64]; P = .004; allo-SCT: HR, 0.21 [95% CI, 0.09-0.46]; P < .001), and overall survival (auto-SCT: HR, 0.22 [95% CI, 0.08-0.64]; P = .005; allo-SCT: HR, 0.25 [95% CI, 0.11-0.59]; P = .001) vs chemotherapy. In addition, auto-SCT showed better GRFS than allo-SCT (HR, 0.45 [95% CI, 0.21-0.98]; P = .04) in this group. Among participants with MRD after 1 or 2 courses of chemotherapy but no MRD after 3 courses, allo-SCT had superior cumulative incidence of relapse (HR, 0.10 [95% CI, 0.06-0.94]; P = .04) and leukemia-free survival (HR, 0.18 [95% CI, 0.05-0.68]; P = .01) compared with chemotherapy, but no advantageous cumulative incidence of relapse (HR, 0.15 [95% CI, 0.02-1.42]; P = .10) and leukemia-free survival (HR, 0.23 [95% CI, 0.05-1.08]; P = .06) compared with auto-SCT. Among participants with MRD after 3 courses of chemotherapy, allo-SCT had superior cumulative incidences of relapse, leukemia-free survival, and overall survival compared with chemotherapy (relapse: HR, 0.16 [95% CI, 0.08-0.33]; P < .001; leukemia-free survival: HR, 0.19 [95% CI, 0.10-0.35]; P < .001; overall survival: HR, 0.29 [95% CI, 0.15-0.55]; P < .001) and auto-SCT (relapse: HR, 0.25 [95% CI, 0.12-0.53]; P < .001; leukemia-free survival: HR, 0.35 [95% CI, 0.18-0.73]; P = .004; overall survival: HR, 0.54 [95% CI, 0.26-0.94]; P = .04). Among participants with recurrent MRD, allo-SCT was also associated with advantageous cumulative incidence of relapse, leukemia-free survival, and overall survival compared with chemotherapy (relapse: HR, 0.12 [95% CI, 0.04-0.33]; P < .001; leukemia-free survival: HR, 0.24 [95% CI, 0.10-0.56]; P = .001; overall survival: HR, 0.31 [95% CI, 0.13-0.75]; P = .01) and auto-SCT (relapse: HR, 0.28 [95% CI, 0.09-0.81]; P = .02; leukemia-free survival: HR, 0.30 [95% CI, 0.12-0.76]; P = .01; overall survival: HR, 0.26 [95% CI, 0.10-0.70]; P = .007).

Conclusions and Relevance

This study suggests that clinical decisions based on dynamic MRD might be associated with improved therapy stratification and optimized PRT for patients with IR-AML. Prospective multicenter trials are needed to further validate these findings.

Prognostic Impact of Cytogenetic Evolution on the Outcome of Allogeneic Stem Cell Transplantation in Patients with Acute Myeloid Leukemia in Nonremission: A Single-Institute Analysis of 212 Recipients

Recent progress in genetic analysis technology has helped researchers understand the pathogenesis of acute myeloid leukemia (AML). Considering this progress, AML karyotype is still one of the most significant prognostic factors that provides risk-adapted treatment approaches. Karyotype changes during treatment have been observed at times, but their prognostic impact is sparse, especially on allogeneic stem cell transplantation (allo-SCT). Here, we retrospectively investigated the effect of chromosomal changes between diagnosis and pretransplantation on the prognosis of allo-SCT by analyzing the outcomes of 212 consecutive patients who underwent allo-SCT for the first time at Toranomon Hospital, Tokyo, Japan, between 2008 and 2018. Cytogenetic abnormalities at diagnosis and pretransplantation were categorized based on the 2017 European Leukemia Net risk stratification. Genetic abnormalities such as FLT3-ITD and NPM1 were not considered in this study due to lack of genetic information in most patients. We defined cytogenetic evolution as chromosomal changes classified from lower category to higher category. Seventeen patients (8%) had cytogenetic evolution between diagnosis and pretransplantation, and they showed a significantly worse relapse rate than those who were categorized in the intermediate group based on the karyotype at diagnosis (3-year confidence interval [CI] of relapse, 57.4% versus 24.9%; P < .01). In multivariate analysis, cytogenetic evolution before allo-SCT had a significant impact on the CI of relapse (hazard ratio [HR], 3.89; CI, 1.75 to 8.67; P < .01), as well as the high score of the hematopoietic cell transplantation-specific comorbidity index (HR, 0.54; CI, 0.31 to 0.94; P = .03), but had no significant impact on overall survival or nonrelapse mortality. These results indicate that cytogenetic evolution has a significant impact after allo-SCT and should be considered during AML treatment.

Time-Varying Effects of Graft Type on Outcomes for Patients with Acute Myeloid Leukemia Undergoing Allogeneic Hematopoietic Cell Transplantation

This study aimed to investigate time-varying effects of graft type on outcomes for patients with acute myeloid leukemia undergoing allogeneic hematopoietic cell transplant. For this purpose we analyzed 3952 patients, 720 of whom underwent matched related bone marrow transplantation (BMT), 1004 matched related peripheral blood stem cell transplantation (PBSCT), 856 matched unrelated BMT, and 1372 umbilical cord blood transplantation (UCBT) during complete remission. The 4-year relapse-free survival (RFS) rates were 59.1%, 52.8%, 59.5%, and 50.6%, respectively. Compared with related BMT, related PBSCT, unrelated BMT, and UCBT were associated with higher risk of nonrelapse mortality and unrelated BMT and UCBT with lower risk of relapse. As a result, both RFS and overall survival were comparable between related BMT and unrelated BMT but were worse for related PBSCT and UCBT than for related BMT. Adverse impact of UCBT was observed only during the early phase of transplant, whereas that of related PBSCT continued even after 2 years post-transplant. Our findings raise concerns about the increased risk of late nonrelapse mortality with the use of PBSC grafts and suggest that related BMT is preferable to related PBSCT; matched unrelated BMT is the next choice in the absence of a matched related donor.

Current state of nonengrafting donor leukocyte infusion (focus on microtransplantation for acute myeloid leukemia)

PURPOSE OF REVIEW

Microtransplantation (or micro-stem cell transplantation, MST) is one permutation of alloreactive immunotherapy increasingly studied in clinical trials. It is most commonly applied to patients with myeloid malignancies who are not suitable candidates for allogeneic hematopoietic cell transplantation. This review highlights the past 2 years of work on stem/progenitor cell products in the field of nonengrafting donor leukocyte infusion (NE-DLI), with a focus on applications of MST in acute myeloid leukemia (AML).

RECENT FINDINGS

Assessing the utility of MST is hampered by lack of randomized controlled trials and by variability in donor selection algorithms, treatment timing, and unknown factors. The inherent complexity of the bidirectional alloreactive reactions, implicating many cell types, makes it challenging to move beyond correlative, population-level biology toward mechanistic explanations for MST's actions in any given patient-donor pair. Yet there are indicators that by stimulating a recipient-vs.-tumor effect, MST might substantially improve complete remission rates in AML and that it might find a role in postremission therapy.

SUMMARY

The mechanistic underpinnings of MST are gradually being disentangled and its clinical development remains in early stages.

Epidemiology of acute myeloid leukemia: Recent progress and enduring challenges

Acute myeloid leukemia (AML) is a malignant disorder of the bone marrow which is characterized by the clonal expansion and differentiation arrest of myeloid progenitor cells. The age-adjusted incidence of AML is 4.3 per 100,000 annually in the United States (US). Incidence increases with age with a median age at diagnosis of 68 years in the US. The etiology of AML is heterogeneous. In some patients, prior exposure to therapeutic, occupational or environmental DNA-damaging agents is implicated, but most cases of AML remain without a clear etiology. AML is the most common form of acute leukemia in adults and has the shortest survival (5-year survival = 24%). Curative therapies, including intensive chemotherapy and allogeneic stem cell transplantation, are generally applicable to a minority of patients who are younger and fit, while most older individuals exhibit poor prognosis and survival. Differences in patient outcomes are influenced by disease characteristics, access to care including active therapies and supportive care, and other factors. After many years without therapeutic advances, several new therapies have been approved and are expected to impact patient outcomes, especially for older patients and those with refractory disease.

Myeloablative Haploidentical Transplantation Is Superior to Chemotherapy for Patients with Intermediate-risk Acute Myelogenous Leukemia in First Complete Remission

PURPOSE

Although myeloablative HLA haploidentical hematopoietic stem cell transplantation (haplo-HSCT) following pretransplant anti-thymocyte globulin (ATG) and granulocyte colony-stimulating factor (G-CSF) stimulated grafts (ATG+G-CSF) has been confirmed as an alternative to HSCT from HLA-matched sibling donors (MSD), the effect of haplo-HSCT on postremission treatment of patients with acute myeloid leukemia (AML) with intermediate risk (int-risk AML) who achieved first complete remission (CR1) has not been defined.

PATIENTS AND METHODS

In this prospective trial, among 443 consecutive patients ages 16-60 years with newly diagnosed de novo AML with int-risk cytogenetics, 147 patients with molecular int-risk AML who achieved CR1 within two courses of induction and remained in CR1 at 4 months postremission either received chemotherapy (n = 69) or underwent haplo-HSCT (n = 78).

RESULTS

The 3-year leukemia-free survival (LFS) and overall survival (OS) were significantly higher in the haplo-HSCT group than in the chemotherapy group (74.3% vs. 47.3%; P = 0.0004 and 80.8% vs. 53.5%; P = 0.0001, respectively). In the multivariate analysis with propensity score adjustment, postremission treatment (haplo-HSCT vs. chemotherapy) was an independent risk factor affecting the LFS [HR 0.360; 95% confidence interval (CI), 0.163-0.793; P = 0.011], OS (HR 0.361; 95% CI, 0.156-0.832; P = 0.017), and cumulative incidence of relapse (HR 0.161; 95% CI, 0.057-0.459; P = 0.001) either in entire cohort or stratified by minimal residual disease after the second consolidation.

CONCLUSIONS

Myeloablative haplo-HSCT with ATG+G-CSF is superior to chemotherapy as a postremission treatment in patients with int-risk AML during CR1. Haplo-HSCT might be a first-line postremission therapy for int-risk AML in the absence of HLA-MSDs. Haplo-HSCT might be superior to chemotherapy as a first-line postremission treatment of intermediate-risk AML in CR1.

Acute myeloid leukemia: 2019 update on risk-stratification and management

Outcome in patients with acute myeloid leukemia (AML) ranges from death within a few days of beginning treatment (treatment related mortality, TRM) to likely cure. The major reason patients are not cured is resistance to treatment, often manifested as relapse from remission, rather than, even in older patients, TRM, whose incidence is decreasing. Knowledge of the pre-treatment mutation status of various genes has improved our ability to assign initial treatment and, of particular importance, knowledge of whether patients ostensibly in remission have measurable residual disease should influence subsequent management. Several new drugs have been approved by the FDA and we discuss their role in treatment.

New approaches in allogenic transplantation in AML

Acute myeloid leukemia (AML) is a heterogeneous disorder with high morbidity and mortality. Allogeneic stem cell transplantation (allo-SCT) is an effective, and sometimes the only, curative postremission therapy for AML patients. Based on genetic risk classification, the published data have suggested that allo-SCT be recommended for high- and most intermediate-risk AML but not for low-risk AML in first complete remission (CR1). Recently, the role of allo-SCT in low-risk AML in CR1 is being established with the development of a risk-directed, minimal residual disease-based strategy. Though human leukocyte antigen-matched sibling transplantation remains the preferred therapeutic option for AML, modern approaches and developments pre-, peri- and post-transplant have facilitated other transplant modalities, especially haploidentical SCT, as promising valid alternative choices. In this paper, we review recent advances in allo-SCT for AML, weigh the benefits of allo-SCT for high-, intermediate-, and even low-risk AML in CR1, discuss the best choice of allo-SCT donor for the treatment of AML, and summarize new approaches for refractory and relapsed AML pre- or post-allo-SCT.

Socioeconomic and health system factors associated with lower utilization of hematopoietic cell transplantation in older patients with acute myeloid leukemia

Receipt of hematopoietic cell transplantation (HCT) can improve overall survival in older patients with intermediate or high-risk acute myeloid leukemia (AML); however, utilization of HCT is poor. It is important to understand the factors that affect the receipt of HCT in a real-world setting among the older patients. We utilized the National Cancer Database to determine receipt of HCT in older patients (61-75 years) with intermediate or high-risk AML reported between 2003 and 2012. Multivariate logistic regression analysis was used to determine factors associated with receipt of HCT. Only 5.5% of older patients (n = 17,555) underwent HCT. Factors associated with a lower likelihood of receiving HCT included receipt of care in a non-academic hospital, race other than white, older age, Charlson comorbidity score of ≥1, uninsured status, Medicaid or Medicare insurance, and lower educational status. The receipt of HCT in older patients is low and varies based on biological as well as non-biologic factors, such as hospital type, insurance, and educational status. Nationwide efforts to improve access to HCT for appropriate patients are necessary.

Impact of allogeneic hematopoietic cell transplantation on the outcome of older patients with acute myeloid leukemia

For younger patients with intermediate- or high-risk acute myeloid leukemia (AML) in first remission, allogeneic hematopoietic cell transplantation (HCT) offers the best chance of cure and therefore is the treatment of choice. The role of allogeneic HCT in the treatment of older patients is less well defined. In this review, four issues concerning the role of HCT in the treatment of older AML patients will be addressed: the frequency of allogeneic HCT in the older AML population in the US; the impact of age on the outcome of HCT; the comparative outcome of allogeneic HCT versus chemotherapy in older AML patients; and some of the barriers to the effective use of HCT in older AML patients.

Prognostic Significance of Residual Acute Myeloid Leukemia in Bone Marrow Samples Taken Prior to Allogeneic Hematopoietic Cell Transplantation

OBJECTIVES

We sought to identify features in routine evaluation of pre-hematopoietic cell transplantation (HCT) bone marrow samples from patients with acute myeloid leukemia (AML) that influenced patient outcome.

METHODS

Of 140 patients, evidence of residual leukemia (RL) was identified in 38 (27%) of pre-HCT samples, as defined by 5% or more aspirate blasts, increased blood blasts, clustered or necrotic blasts on biopsy specimens, and/or leukemia-associated karyotypic abnormalities.

RESULTS

Morphologic or karyotypic evidence of RL was significantly associated with shorter leukemia-free survival (LFS) compared with cases without identifiable RL (median, 7.1 vs 28.3 months; P  < .0001). Upon multivariable analysis, RL, prior relapse, age, high-risk karyotype, and alternate donor source were each independently associated with shorter LFS. RL in pre-HCT samples was more strongly associated with shorter LFS in patients with intermediate or favorable-risk AML karyotype ( P  = .001) than secondary or adverse karyotype-risk AML ( P  = .04).

CONCLUSIONS

Rigorous morphologic and karyotypic evaluation of pretransplant marrows is practical and important for posttransplant prognosis.

The increase of the global donor inventory is of limited benefit to patients of non-Northwestern European descent

Between 2001 and 2012, the number of unrelated donors registered worldwide increased from 7 to 21 million, and the number of public cord blood units increased to over 500,000. We addressed the question of whether this expansion resulted in higher percentages of patients reaching transplantation. Unrelated donor searches were evaluated for 3,124 eligible patients in the Netherlands in two cohorts (2001-2006, n=995; 2007-2012, n=2129), comparing results for patients of Northwestern European and non-Northwestern European origin. Endpoints were 'donor found' and 'transplantation reached'. The substantial growth of the donor inventory over the period studied did not increase the median number of potential unrelated donors (n=7) for non-Northwestern European patients, but almost doubled the number for Northwestern European patients from 42 to 71. Before and after 2007, an unrelated donor or cord blood was identified for 91% and 95%, respectively, of Northwestern European patients and for 65% and 82% of non-Northwestern European patients (P<0.0001). Non-Northwestern European patients more often needed a cord blood transplant. The degree of HLA matching was significantly lower for non-Northwestern European patients (P<0.0006). The time needed to identify a donor decreased for both populations. The percentage of Northwestern European patients reaching transplantation increased from 77% to 83% and for non-Northwestern European patients from 57% to 72% (P=0.0003). The increase of the global inventory resulted in more transplants for patients lacking a family donor, although the quality and quantity of (potential) haematopoietic cell grafts for patients of a non-Northwestern European descent remained inferior, indicating the need for adaptation of recruitment.

Older Patients With Acute Myeloid Leukemia: Treatment Challenges and Future Directions

BACKGROUND

Even though acute myeloid leukemia (AML) occurs most commonly in adults ≥60 years, the treatment of AML in older patients remains a significant challenge.

METHODS

We reviewed the current literature regarding patient assessment tools, treatment options, and current therapies in clinical trial for patients with AML who are ≥60 years.

RESULTS

Our approach to the older patient with AML is evolving with better understanding of the unique disease epidemiology in this population and the development of tools to assess individual patient functional status, including grading systems for comorbidities, geriatric assessment tools, and measurements of frailty. Almost all older patients will benefit from therapy, whether intensive curative therapy, such as allogeneic stem cell transplant that should be considered whenever possible, or low-intensity therapy that should be offered with concurrent palliative care at diagnosis to improve patient survival and quality of life. To achieve the improved survival demonstrated in younger adults, older patients should also be considered for clinical trial enrollment as more studies are being designed to specifically target this unique patient population.

CONCLUSION

Older patients with AML are candidates for and benefit from the entire spectrum of AML therapy, including intense chemotherapy, allogeneic stem cell transplant, and clinical trial participation after thorough patient assessment. Older patients with AML would benefit from increased clinical trial enrollment and early inclusion of palliative medicine.

The long-term outcome of reduced-intensity allogeneic stem cell transplantation from a matched related or unrelated donor, or haploidentical family donor in patients with leukemia: a retrospective analysis of data from the China RIC Cooperative Group

This study compared 6-year follow-up data from patients undergoing reduced-intensity conditioning (RIC) transplantation with an HLA-matched related donor (MRD), an HLA-matched unrelated donor (MUD), or an HLA-haploidentical donor (HID) for leukemia. Four hundred and twenty-seven patients from the China RIC Cooperative Group were enrolled, including 301 in the MRD, 79 in the HID, and 47 in the MUD groups. The conditioning regimen involved fludarabine combined with anti-lymphocyte globulin and cyclophosphamide. Graft-versus-host disease (GVHD) prophylaxis was administered using cyclosporin A (CsA) and mycophenolate mofetil (MMF). Four hundred and nineteen patients achieved stable donor chimerism. The incidence of stage II-IV acute GVHD in the HID group was 44.3 %, significantly higher than that in the MRD (23.6 %) and MUD (19.1 %) groups. The 1-year transplantation-related mortality (TRM) rates were 44.3, 17.6, and 21.3, respectively. Event-free survival (EFS) at 6 years in the HID group was 36.7 %, significantly lower than that of the MRD and MUD groups (59.1 and 66.0 %, P < 0.001 and P = 0.001, respectively). For advanced leukemia, the relapse rate of the HID group was 18.5 %, lower than that of the MRD group (37.5 %, P = 0.05), but the EFS at 6 years was 31.7 and 30.4 % (P > 0.05), respectively. RIC transplantation with MRD and MUD had similar outcome in leukemia which is better than that with HID. RIC transplantation with HID had lower relapsed with higher TRM and GVHD rate, particularly in advanced leukemias. RIC transplantation with MRD and MUD had similar outcomes in leukemia and they were better than those with HID. RIC transplantation with HID had a lower relapse rate but higher TRM and GVHD rates, particularly in cases of advanced leukemia.

Acute myeloid leukemia: 2016 Update on risk-stratification and management

Evidence suggest that even patients aged 70 or above benefit from specific AML therapy. The fundamental decision in AML then becomes whether to recommend standard or investigational treatment. This decision must rest on the likely outcome of standard treatment. Hence we review factors that predict treatment related mortality and resistance to therapy, the latter the principal cause of failure even in patients aged 70 or above. We emphasize the limitations of prediction of resistance based only on pre- treatment factors and stress the need to incorporate post-treatment factors, for example indicators of minimal residual disease. We review various newer therapeutic options and considerations that underlie the decision to recommend allogeneic hematopoietic cell transplant. Am. J. Hematol. 91:825-846, 2016. © 2016 Wiley Periodicals, Inc.

Are we curing more older adults with acute myeloid leukemia with allogeneic transplantation in CR1?

PURPOSE OF REVIEW

Despite the fact that acute myeloid leukemia (AML) is most common in older adults aged at least 60 years, curative therapy remains elusive in this population. Here we examine the data for predicting which patients are candidates for 'curative therapy', available therapeutic options, and the utilization of reduced intensity allogeneic stem cell transplantation in first remission.

RECENT FINDINGS

Incorporation of geriatric assessment tools to assess patient frailty, in addition to evaluation of comorbid conditions, improves patient selection for intense therapy. The majority of patients eligible for and treated with induction chemotherapy achieve complete remission, and overall survival in the older AML population is superior after allogeneic stem cell transplant. However, population-based studies continue to demonstrate the undertreatment or lack of treatment of older AML patients.

SUMMARY

New patient assessment tools, ability to offer more successful outcomes after induction chemotherapy, and improved survival after allogeneic transplantation has not yet translated to increased 'curative' treatment on a population level of older AML patients. It is critical that the tools and therapies available be put into practice while older patient enrollment in well designed therapeutic clinical trials which include the option of allogeneic transplantation is increased.

Unrelated bone marrow transplantation or immediate umbilical cord blood transplantation for patients with acute myeloid leukemia in first complete remission

BACKGROUND

While unrelated bone marrow transplantation (UBMT) has been widely used as alternative donor transplantation, the use of umbilical cord blood transplantation (UCBT) is increasing recently.

METHODS

We conducted a decision analysis to address which transplantation procedure should be prioritized for younger patients with acute myeloid leukemia (AML) harboring high- or intermediate-risk cytogenetics in first complete remission (CR1), when they lack a matched related donor but have immediate access to a suitable umbilical cord blood unit. Main sources for our analysis comprised the data from three phase III trials for a chemotherapy cohort (n = 907) and the registry data for a transplantation cohort (n = 752).

RESULTS

The baseline analysis showed that when the 8/8 match was considered for UBMT, the expected 5-year survival rate was higher for UBMT than for UCBT (58.1% vs. 51.8%). This ranking did not change even when the 7/8 match was considered for UBMT. Sensitivity analysis showed consistent superiority of UBMT over UCBT when the time elapsed between CR1 and UBMT was varied within a plausible range of 3-9 months.

CONCLUSIONS

These results suggest that 8/8 or 7/8 UBMT is a better transplantation option than UCBT even after allowing time required for donor coordination.

New approaches to transplantation in acute myelogenous leukemia

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative therapeutic option for acute myelogenous leukemia (AML). This is due to the combined effect of chemo/radiation therapy and the immunologic graft-versus-leukemia effect. The field of HSCT has benefited from advances in a variety of “fronts,” including our increasing ability to break the human leukocyte antigen barrier, which has led to greater access to transplantation. Furthermore, progress in the biologic, genetic, and pharmacologic arenas is creating a scenario where traditional borders between transplant and non-transplant therapies are less clear. This overlap is exemplified by new approaches to pharmacologic maintenance of remission strategies after HSCT. In addition, cellular adoptive immunotherapy has the potential to exploit narrowly targeted anti-tumor effects within or outside the allogeneic HSCT “frame,” holding the promise of avoiding off target side effects, such as graft-versus-host disease. Here we discuss these and other lines of active investigation designed to improve outcomes of HSCT for AML.

Novel therapies in AML: reason for hope or just hype?

We have entered the genomic sequencing era in the treatment of acute myeloid leukemia (AML); our patients increasingly and justifiably demand personalized treatment based on aberrations of their own leukemia. Except in rare cases we are not yet able to provide truly personalized therapy, so the question of "hope or hype?" posed by the American Society for Clinical Oncology (ASCO) for this educational topic is quite timely. The answer based solely on advances in genomic sequencing is "both". There is an element of expectation among the public that we are "almost there" in solving the genetic cancer puzzle, an expectation indeed based on hype. However, there is no question that ultimate success lies in understanding the genetic underpinnings of disease. When decades of research in molecular biology and immunology are combined with transformative advances in cancer genetics, the answer is undeniably that our patients finally have reason for hope. Here, we review selected novel therapies for AML in areas such as immunotherapeutics, epigenetics, kinase inhibition/pathway inhibition, and the marrow microenvironment.

Allogeneic Transplantation for Unfavorable-Risk Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a complex, heterogeneous disorder that can have devastating effects. Although control of AML can be attained with various induction regimens, long-term cure is much more difficult to maintain. This is understated in patients with unfavorable-risk AML, who are usually older and have prior myeloid and/or therapy-related disease and more challenges in curing this disease.

Generation of lentivirus-induced dendritic cells under GMP-compliant conditions for adaptive immune reconstitution against cytomegalovirus after stem cell transplantation

Background

Reactivation of latent viruses such as human cytomegalovirus (HCMV) after allogeneic hematopoietic stem cell transplantation (HSCT) results in high morbidity and mortality. Effective immunization against HCMV shortly after allo-HSCT is an unmet clinical need due to delayed adaptive T cell development. Donor-derived dendritic cells (DCs) have a critical participation in stimulation of naïve T cells and immune reconstitution, and therefore adoptive DC therapy could be used to protect patients after HSCT. However, previous methods for ex vivo generation of adoptive donor-derived DCs were complex and inconsistent, particularly regarding cell viability and potency after thawing. We have previously demonstrated in humanized mouse models of HSCT the proof-of-concept of a novel modality of lentivirus-induced DCs (“SmyleDCpp65”) that accelerated antigen-specific T cell development.

Methods

Here we demonstrate the feasibility of good manufacturing practices (GMP) for production of donor-derived DCs consisting of monocytes from peripheral blood transduced with an integrase-defective lentiviral vector (IDLV, co-expressing GM-CSF, IFN-α and the cytomegalovirus antigen pp65) that were cryopreserved and thawed.

Results

Upscaling and standardized production of one lot of IDLV and three lots of SmyleDCpp65 under GMP-compliant conditions were feasible. Analytical parameters for quality control of SmyleDCpp65 identity after thawing and potency after culture were defined. Cell recovery, uniformity, efficacy of gene transfer, purity and viability were high and consistent. SmyleDCpp65 showed only residual and polyclonal IDLV integration, unbiased to proto-oncogenic hot-spots. Stimulation of autologous T cells by GMP-grade SmyleDCpp65 was validated.

Conclusion

These results underscore further developments of this individualized donor-derived cell vaccine to accelerate immune reconstitution against HCMV after HSCT in clinical trials.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0599-5) contains supplementary material, which is available to authorized users.

Acute myeloid leukemia: 2014 update on risk-stratification and management

OVERVIEW

Evidence suggests that even patients aged 70 or above benefit from specific AML therapy. The fundamental decision in AML then becomes whether to recommend standard or investigational treatment. This decision must rest on the likely outcome of standard treatment. Hence we review factors that predict treatment related mortality and resistance to therapy, the latter the principal cause of failure even in patients aged 70 or above. We emphasize the limitations of prediction of resistance based only on pre-treatment factors and stress the need to incorporate post-treatment factors, for example indicators of minimal residual disease. We review various newer therapeutic options and considerations that underlie the decision to recommend allogeneic hematopoietic cell transplant.

[Current indications of allogeneic stem cell transplant in adults with acute myeloid leukemia]

Allogeneic stem cell transplantation (SCT) is an increasingly important therapeutic option for the treatment of adult patients with acute myeloid leukemia. Here we review the current indications of SCT in this disease. While patients with favorable cytogenetics should receive consolidation chemotherapy, patients with unfavorable karyotype are prime candidates for SCT or new approaches to SCT (which should be done in first complete remission). Patients with intermediate prognoses should also receive SCT in first complete remission. In the absence of a suitable matched related donor, most patients will be able to find an alternative donor to proceed to a potentially curative allogeneic transplantation. The use of reduced-intensity conditioning regimens before SCT has allowed patients in the sixth or seventh decades of life to be routinely transplanted. Despite major differences among transplant centers in the intensity and composition of the conditioning regimen and immunosuppression, choice of graft source, postgraft immune-modulation, and supportive care, there has been a dramatic improvement in terms of tolerance. Although it is presumed to be a curative strategy, major complications of SCT remain graft-versus-host disease, delayed immune recovery, multiple comorbidities, and relapse after transplant.

Allogeneic hematopoietic cell transplantation for acute myeloid leukemia during first complete remission: a clinical perspective

Allogeneic hematopoietic cell transplantation (HCT) is the most potent therapy for preventing relapse of acute myeloid leukemia (AML). Although its efficacy is compromised by a high risk of treatment-related morbidity and mortality, an accumulating body of evidence has led to the general recommendation favoring allogeneic HCT from a matched sibling donor during first complete remission (CR1) for younger patients with cytogenetically intermediate- or high-risk AML. Over the past few decades, this field has seen a great many advancements. The indications for allogeneic HCT have been refined by taking into account the molecular profiles of leukemic cells and the degree of comorbidities. The introduction of high-resolution human leukocyte antigen-typing technology and advances in immunosuppressive therapy and supportive care measures have improved outcomes in alternative donor transplantation, while the parallel growth of unrelated donor registries and greater use of umbilical cord blood and haploidentical donors have considerably improved the chance of finding an alternative donor. The development of reduced-intensity and non-myeloablative conditioning has made it possible to receive allogeneic HCT for patients who might once have been considered ineligible due to advanced age or comorbidities. Thanks to these advances, the role of allogeneic HCT during CR1 has become progressively more important in the treatment of AML.

Allogeneic hematopoietic cell transplantation for myelodysplastic syndromes: lingering uncertainties and emerging possibilities

The landscape of transplantation in myelodysplastic syndrome (MDS) has evolved rapidly in the last decade, driven mostly by advances in patient selection through better risk stratification, increasing age of allogeneic recipients, introduction of reduced-intensity conditioning regimens, increased availability of unrelated donors, new donor sources, and improvements in transplant technology and supportive care. Despite these advances, several issues, mostly centering on approaches to improve post-transplant survival while minimizing transplant-related mortality, continue to present significant challenges. Advances in understanding the molecular pathogenesis of MDS have made it feasible to construct clinically useful risk models that integrate prognostic genes with conventional risk parameters for better selection of patients likely to benefit from hematopoietic cell transplantation. Simultaneous research efforts in several areas, including comorbidity assessment, novel preparative regimens, optimal pretransplant cytoreductive strategy, and post-transplantation therapies, are expected to improve long-term disease-free survival and quality of life.