Improved outcome in young adults with de novo acute myeloid leukemia in first remission, undergoing an allogeneic bone marrow transplant

Prognostic prediction of novel risk scores (AML-DRG and AML-HCT-CR) in acute myeloid leukemia patients with allogeneic hematopoietic stem cell transplantation

We aimed to validate and prove the novel risk score models of acute myeloid leukemia (AML)-specific disease risk group (AML-DRG) and AML-Hematopoietic Cell Transplant-composite risk (AML-HCT-CR) in patients with acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (AHCT). Among the 172 AML patients analysed, 48.3% (n = 83) were females. Median age was 31.5 years (range 14 to 62 years), two patients was more than 60 years old (1.2%). Median follow-up was 44 months (range 1 to 94 months). According to the AML-DRG model, 109, 49 and 14 patients were in low-, intermediate- and high-risk group, respectively. According to the AML-HCT-CR model, 108, 30, 20 and 14 patients were in low-, intermediate-, high- and very high-risk group, respectively. Our results showed that the AML-DRG and AML-HCT-CR models significantly predicted cumulative incidence of relapse (p < 0.001; p < 0.001). But AML-DRG model was not associated with NRM (p = 0.072). Univariate analysis showed that the AML-DRG model could better stratify AML patients into different risk groups compared to the AML-HCT-CR model. Multivariate analysis confirmed that prognostic impact of AML-DRG and AML-HCT-CR models on post-transplant OS was independent to age, sex, conditioning type, transplant modality, and stem cell source (p < 0.001; p < 0.001). AML-DRG and AML-HCT-CR models can be used to effectively predict post-transplant survival in patients with AML receiving AHCT. Compared to AML-HCT-CR score, the AML-DRG score allows better stratification and improved survival prediction of AML patients post-transplant.

We do still transplant CML, don't we?

The remarkable clinical activity of tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML) has transformed patient outcome. Consequently, allogeneic stem cell transplantation (allo-SCT) is no longer the only treatment modality with the ability to deliver long-term survival. In contrast to the central position it held in the treatment algorithm 20 years ago, allografting is now largely reserved for patients with either chronic-phase disease resistant to TKI therapy or advanced-phase disease. Over the same period, progress in transplant technology, principally the introduction of reduced intensity conditioning regimens coupled with increased donor availability, has extended transplant options in patients with CML whose outcome can be predicted to be poor if they are treated with TKIs alone. Consequently, transplantation is still a vitally important, potentially curative therapeutic modality in selected patients with either chronic- or advanced-phase CML. The major causes of transplant failure in patients allografted for CML are transplant toxicity and disease relapse. A greater understanding of the distinct contributions made by various factors such as patient fitness, patient-donor HLA disparity, conditioning regimen intensity, and transplant toxicity increasingly permits personalized transplant decision making. At the same time, advances in the design of conditioning regimens coupled with the use of adjunctive posttransplant cellular and pharmacologic therapies provide opportunities for reducing the risk of disease relapse. The role of SCT in the management of CML will grow in the future because of an increase in disease prevalence and because of continued improvements in transplant outcome.

Patients with acute myeloid leukemia undergoing allogeneic hematopoietic cell transplantation: trends in survival during the past two decades

It remains unclear how specific innovations in allogeneic hematopoietic cell transplantation (HCT) attained over the past decades have contributed to improvement in transplantation outcomes. To address this question, we conducted a registry-based study of adults with acute myeloid leukemia in first or second complete remission who underwent allogeneic HCT between 1994 and 2013 from a sibling (N = 1600) or unrelated (N = 2113) donor matched at the antigen level for HLA-A, -B, and -DR. Preliminary analysis led us to focus on comparisons between the 1994-2006 and 2007-2013 periods. Significant improvement in survival was observed in the later cohort compared to the earlier cohort for unrelated HCT (P = 0.004), but not for related HCT (P = 0.767). The improvement in unrelated HCT was solely due to diminished non-relapse mortality (P = 0.001), while incidence of relapse did not change over time (P = 0.934). The percentage of patients receiving transplants from 8/8-matched unrelated donors was significantly higher in the later cohort (P < 0.001), and their survival was significantly better than that of those undergoing mismatched unrelated HCT (P = 0.022). These findings suggest that advances in HLA-typing technology have been vital for improvement in transplantation outcomes.

Reduced-intensity conditioning allogeneic hematopoietic-cell transplantation for older patients with acute myeloid leukemia

Elderly patients (>60 years) with acute myeloid leukemia have a poor prognosis with a chemotherapy-alone approach. Allogeneic hematopoietic-cell transplantation (HCT) can improve overall survival (OS). However, myeloablative regimens can have unacceptably high transplant-related mortality (TRM) in an unselected group of older patients. Reduced-intensity conditioning (RIC) or nonmyeloablative (NMA) conditioning regimens preserve the graft-versus-leukemia effects but reduce TRM. NMA regimens result in minimal cytopenia and may not require stem cell support for restoring hematopoiesis. RIC regimens, intermediate in intensity between NMA and myeloablative regimens, can cause prolonged myelosuppresion and usually require stem cell support. A few retrospective and prospective studies suggest a possibility of lower risk of relapse with myeloablative HCT in fit older patients with lower HCT comorbidity index; however, RIC and NMA HCTs have an important role in less-fit patients and those with significant comorbidities because of lower TRM. Whether early tapering of immunosuppression, monitoring of minimal residual disease, and post-transplant maintenance therapy can improve the outcomes of RIC and NMA HCT in elderly patients will require prospective trials.

Management of Myelodysplastic Syndrome Relapsing after Allogeneic Hematopoietic Stem Cell Transplantation: A Study by the French Society of Bone Marrow Transplantation and Cell Therapies

To find out prognostic factors and to investigate different therapeutic approaches, we report on 147 consecutive patients who relapsed after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for myelodysplastic syndrome (MDS). Sixty-two patients underwent immunotherapy (IT group, second allo-HSCT or donor lymphocyte infusion), 39 received cytoreductive treatment alone (CRT group) and 46 were managed with palliative/supportive cares (PSC group). Two-year rates of overall survival (OS) were 32%, 6%, and 2% in the IT, CRT, and PSC groups, respectively (P < .001). In multivariate analysis, 4 factors adversely influenced 2-year rates of OS: history of acute graft-versus-host disease (hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.26 to 2.67; P = .002), relapse within 6 months (HR, 2.69; 95% CI, .82 to 3.98; P < .001), progression to acute myeloid leukemia (HR, 2.59; 95% CI, 1.75 to 3.83; P < .001), and platelet count < 50 G/L at relapse (HR, 1.68; 95% CI, 1.15 to 2.44; P = .007). A prognostic score based on those factors discriminated 2 risk groups with median OSs of 13.2 versus 2.4 months, respectively (P < .001). When propensity score, prognostic score, and treatment strategy were included in Cox model, immunotherapy was found to be an independent factor that favorably impacts OS (HR, .40; 95% CI, .26 to .63; P < .001). In conclusion, immunotherapy should be considered when possible for MDS patients relapsing after allo-HSCT.

A practical approach for a wide range of liver iron quantitation using a magnetic resonance imaging technique

The goal of this study is to demonstrate a practical magnetic resonance imaging technique for quantifying a wide range of hepatic iron concentration (HIC) for hematologic oncology patients with transfusion iron overload in a routine clinical setting. To cover a wide range of T₂* values from hematologic patients, we used a dual-acquisition method with two clinically available acquisition protocols on a 1.5T MRI scanner with different ΔTEs to acquire data in two breath-holds. An in-house image postprocessing software tool was developed to generate T₂*, iron maps, and water and fat images, when fat is presented in the liver. The resulting iron maps in DICOM format are transferred to the institutional electronic medical record system for review by radiologists. The measured liver T₂* values for 28 patients ranged from 0.56 ± 0.13 to 25.0 ± 2.1 milliseconds. These T₂* values corresponded to HIC values ranging from 1.2 ± 0.1 mg/g to 45.0 ± 10.0 mg/g (dry weight). A moderate correlation between overall serum ferritin levels and R₂* was found with a correlation coefficient of 0.83. Repeated phantom scans confirmed that the precision of this method is better than 4% for T₂* measurements. The dual- acquisition method also improved the ability to quantify HIC of the patients with hepatic steatosis.

Impact of azacitidine before allogeneic stem-cell transplantation for myelodysplastic syndromes: a study by the Société Française de Greffe de Moelle et de Thérapie-Cellulaire and the Groupe-Francophone des Myélodysplasies

PURPOSE

To investigate the impact of prior-to-transplantation azacitidine (AZA) on patient outcome after allogeneic stem-cell transplantation (alloSCT) for myelodysplastic syndrome (MDS).

PATIENTS AND METHODS

Of the 265 consecutive patients who underwent alloSCT for MDS between October 2005 and December 2009, 163 had received cytoreductive treatment prior to transplantation, including induction chemotherapy (ICT) alone (ICT group; n = 98), AZA alone (AZA group; n = 48), or AZA preceded or followed by ICT (AZA-ICT group; n = 17). At diagnosis, 126 patients (77%) had an excess of marrow blasts, and 95 patients (58%) had intermediate-2 or high-risk MDS according to the International Prognostic Scoring System (IPSS). Progression to more advanced disease before alloSCT was recorded in 67 patients. Donors were sibling (n = 75) or HLA-matched unrelated (10/10; n = 88). They received blood (n = 142) or marrow (n = 21) grafts following either myeloablative (n = 33) or reduced intensity (n = 130) conditioning.

RESULTS

With a median follow-up of 38.7 months, 3-year outcomes in the AZA, ICT, and AZA-ICT groups were 55%, 48%, and 32% (P = .07) for overall survival (OS); 42%, 44%, and 29% (P = .14) for event-free survival (EFS); 40%, 37%, and 36% (P = .86) for relapse; and 19%, 20%, and 35% (P = .24) for nonrelapse mortality (NRM), respectively. Multivariate analysis confirmed the absence of statistical differences between the AZA and the ICT groups in terms of OS, EFS, relapse, and NRM.

CONCLUSION

With the goal of downstaging underlying disease before alloSCT, AZA alone led to outcomes similar to those for standard ICT.

Similar outcomes using myeloablative vs reduced-intensity allogeneic transplant preparative regimens for AML or MDS

Although reduced intensity (RIC) and nonmyeloablative (NMA) conditioning regimens have been used for over a decade, their relative efficacy versus myeloablative (MA) approaches to allogeneic hematopoietic cell transplantation (HCT) in patients with acute myelogenous leukemia (AML) and myelodysplasia (MDS) is unknown. We compared disease status, donor, graft and recipient characteristics with outcomes of 3731 MA with 1448 RIC/NMA procedures performed at 217 centers between 1997 and 2004. Five year univariate probabilities and multivariate relative risk (RR) outcomes of relapse, transplant related mortality (TRM), disease free survival (DFS) and overall survival (OS) are reported. Adjusted OS at 5 years was 34%, 33%, and 26% for MA, RIC and NMA transplants, respectively. NMA conditioning resulted in inferior DFS and OS but there was no difference in DFS and OS between RIC and MA regimens. Late TRM negates early decreases in toxicity with RIC and NMA regimens. Our data suggest higher regimen intensity may contribute to optimal survival in patients with AML/MDS, suggesting roles for both regimen intensity and graft vs. leukemia in these diseases. Prospective studies comparing regimens are needed to confirm this finding and determine the optimal approach to patients who are eligible for either MA or RIC/NMA conditioning.

Reduced-intensity conditioning allogeneic stem cell transplantation for older adults: is it the standard of care?

PURPOSE OF REVIEW

We reviewed reduced-intensity hematopoietic cell transplantation for older patients in the context of recently published studies.

RECENT FINDINGS

Most studies describe applicability of reduced-intensity transplantation to older patients with overall survival rates that compare favorably to chemotherapy alone, though relapse and graft-versus-host disease remain complicating factors. Though transplant recipients likely represent a highly selected population, current studies do not demonstrate an upper age for transplantation and suggest that myeloablative regimens may be considered in older patients with limited comorbidities. Avenues being pursued to improve transplant outcomes include natural killer cell immunotherapy and regulatory T-cell modulation.

SUMMARY

Until prospective studies show otherwise, transplant conditioning intensity for the older patient should be based on individual patient and disease characteristics. Enrollment into clinical trials is paramount in efforts to reduce transplant-related mortality and improve outcomes.

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.

Role of HLA in hematopoietic SCT

HLA disparity between hematopoietic stem cell (HSC) donor and recipient triggers T-cell and NK-cell allorecognition, and induces the GVHD, GVL effect and/or may cause an engraftment failure. This review will cover the scope of human genomic variation, the methods of HLA typing and interpretation of high-resolution HLA results. We describe the main subsets of related and unrelated HSC donors and outline the main aspects of HLA disparity and their effect on the outcome of the patients after allogeneic HSC transplantation (HSCT). The HLA match between HSCT donor and recipient is crucial, but for many patients a perfectly matched donor is not available. The HSCT from the alternative mismatched donor with one allele/antigen mismatch (9/10) can be as beneficial as a HSCT from a fully matched donor, especially in younger patients. For the remaining patients, the donors with permissive mismatches may be the option. The permissiveness depends not only on the potential adverse effect of the HLA mismatches, but also on the urgency of the transplantation, the desirable GVL effect and the potential efficacy of the alternative therapy available for the patient.

Overlap between in vitro donor antihost and in vivo posttransplantation TCR Vbeta use: a new paradigm for designer allogeneic blood and marrow transplantation

Following allogeneic blood and marrow transplantation (BMT), mature donor T cells can enhance engraftment, counteract opportunistic infections, and mount graft-versus-tumor (GVT) responses, but at the risk of developing graft-versus-host disease (GVHD). With the aim of separating the beneficial effects of donor T cells from GVHD, one approach would be to selectively deplete subsets of alloreactive T cells in the hematopoietic cell inoculum. In this regard, TCR Vbeta repertoire analysis by CDR3-size spectratyping can be a powerful tool for the characterization of alloreactive T-cell responses. We investigated the potential of this spectratype approach by comparing the donor T-cell alloresponses generated in vitro against patient peripheral blood lymphocytes (PBLs) with those detected in vivo posttransplantation. The results indicated that for most Vbeta families that exhibited alloreactive CDR3-size skewing, there was a robust overlap between the in vitro antipatient and in vivo spectratype histograms. Thus, in vitro spectratype analysis may be useful for determining the alloreactive T-cell response involved in GVHD development and, thereby, could serve to guide select Vbeta family depletion for designer transplants to improve outcomes.