Review of stem-cell transplantation for myelodysplastic syndromes in older patients in the context of the Decision Memo for Allogeneic Hematopoietic Stem Cell Transplantation for Myelodysplastic Syndrome emanating from the Centers for Medicare and Medicaid Services

Fifty years of BMT: risk stratification, donor matching, and stem cell collection for transplantation

In this review, we discuss recipient risk assessment for allo-HCT regarding comorbidities present at baseline to predict non relapse mortality. We further reviewed the incorporation of remission status and cytogenetic risk prior to allograft transplantation to predict relapse rates for hematologic malignancies. HCT-CI and DRI are tools available to physicians to assess the risk-benefit of allo-HCT in patients referred for transplantation. Next, we discuss our algorithm for donor selection and criteria for donor selection in case matched donors are not available. Finally, we discuss our approach for stem cell mobilization, especially in donors failing G-CSF, and our approach for the use of plerixafor and data supporting its use.

An Optimized Search Prognosis Tool to Predict 8/8 HLA Allele-Matched Unrelated Donor Procurement

For patients in need of allogeneic transplantation who lack an HLA-identical sibling, an 8/8 HLA allele-matched unrelated donor (URD) is a standard alternative. However, delays in URD procurement can adversely impact patient care. Recipient genotype and search assessment (MSKv1.0)-based tools can predict search prognosis for many, but both tools have lower performance in non-European ancestry patients. Using the MSKv1.0 tool, we analyzed searches from 1530 potential allograft recipients (including 863 who underwent transplantation) with the aim of creating an optimized MSKv2.0 search prognosis tool that can classify a URD search as either Good or Poor with a high level of accuracy while also limiting an ambiguous Fair search prognosis regardless of patient ancestry. By MSKv2.0, the 8/8 URD search prognosis distribution was 57% Good, 21% Fair, and 22% Poor in Europeans and 15% Good, 21% Fair, and 63% Poor in non-Europeans. Importantly, compared to MSKv1.0, the likelihood of Fair categorization was reduced to <25% with comparable Fair rates (P = .847) in both European and non-European groups. Moreover, all patients with an MSKv2.0 Good prognosis had an 8/8 URD identified, and almost all of those who underwent transplantation had an 8/8 URD (Europeans, 99%; non-Europeans, 98%; P = .504). The MSKv2.0 tool also was highly accurate at classifying Poor searches, with <10% identifying an 8/8 URD, and almost all patients who underwent transplantation (Europeans, 95%; non-Europeans, 96%) receiving an alternative donor. Using preliminary search results, MSKv2.0 accurately classifies patients by likelihood of 8/8 URD procurement, greatly facilitating triage to 8/8 URD (Good prognosis) or alternative donor (Poor prognosis) transplantations.

Health-related quality of life in reduced-intensity hematopoietic cell transplantation based on donor availability in patients aged 50-75 with advanced myelodysplastic syndrome: BMT CTN 1102

For myelodysplastic syndrome (MDS), allogeneic hematopoietic cell transplantation (alloHCT) is the only available curative therapy. The Blood and Marrow Transplant Clinical Trials Network study 1102 (BMT CTN 1102, NCT02016781) was a multicenter, biologic assignment trial based on matched donor availability in adults aged 50-75 with higher risk de novo MDS who were candidates for reduced-intensity conditioning (RIC) alloHCT. The primary analysis showed that those who received alloHCT had a survival benefit, but whether this is at the cost of worse quality of life (QOL) has not been described in detail. English- and Spanish-speaking trial participants completed the Functional Assessment of Cancer Therapy-General (FACT-G), the SF-36, and the EQ-5D, at enrollment, every 6 months until 24 months, and 36 months. We compared patient-reported outcome (PRO) scores between study arms using an inverse probability weighted-independent estimating equation (IPW-IEE) model. Between January 2014 and November 2018, 384 subjects (median age 66.7 years, range: 50.1-75.3) enrolled at 34 centers. PRO completion rates were generally high at 65%-78%. The PRO trajectories for both arms were similar, with most decreasing or stable from baseline to 6 months and improving thereafter. Baseline PRO scores were the most consistent independent predictors of subsequent QOL outcomes and survival, even after controlling for clinical and patient-level factors. For older adults with MDS, the survival advantage associated with donor availability and alloHCT did not come at the cost of worse QOL. These results should reassure older patients and clinicians who prefer a curative approach to treating MDS.

Biologic Assignment Trial of Reduced-Intensity Hematopoietic Cell Transplantation Based on Donor Availability in Patients 50-75 Years of Age With Advanced Myelodysplastic Syndrome

PURPOSE

Allogeneic hematopoietic cell transplantation (HCT) is the only potentially curative therapy for myelodysplastic syndromes (MDS), although it is infrequently offered to older patients. The relative benefits of HCT over non-HCT therapy in older patients with higher-risk MDS have not been defined.

METHODS

We conducted a multicenter biologic assignment trial comparing reduced-intensity HCT to hypomethylating therapy or best supportive care in subjects 50-75 years of age with intermediate-2 or high-risk de novo MDS. The primary outcome was overall survival probability at 3 years. Between January 2014 and November 2018, we enrolled 384 subjects at 34 centers. Subjects were assigned to the Donor or No-Donor arms according to the availability of a matched donor within 90 days of study registration.

RESULTS

The median follow-up time for surviving subjects was 34.2 months (range: 2.3-38 months) in the Donor arm and 26.9 months (range: 2.4-37.2 months) in the No-Donor arm. In an intention-to-treat analysis, the adjusted overall survival rate at 3 years in the Donor arm was 47.9% (95% CI, 41.3 to 54.1) compared with 26.6% (95% CI, 18.4 to 35.6) in the No-Donor arm (P = .0001) with an absolute difference of 21.3% (95% CI, 10.2 to 31.8). Leukemia-free survival at 3 years was greater in the Donor arm (35.8%; 95% CI, 29.8 to 41.8) compared with the No-Donor arm (20.6%; 95% CI, 13.3 to 29.1; P = .003). The survival benefit was seen across all subgroups examined.

CONCLUSION

We observed a significant survival advantage in older subjects with higher-risk MDS who have a matched donor identified and underwent reduced-intensity HCT, when compared with those without a donor. HCT should be included as an integral part of MDS management plans in fit older adults with higher-risk MDS.

Survival Rate and Prognostic Factors Among Patients Undergoing Hematopoietic Stem Cell Transplantation: Using the Joint Model

Background: Hematopoietic stem cell transplantation (HSCT) is the most effective of all hematologic malignancies treatments, resulting in a significant improvement in survival rate. Objectives: This study aimed at determining the survival rate and factors affecting the survival in patients undergoing hematopoietic stem cell transplantation, using the joint model. Methods: This study was a retrospective cohort study, used for collecting data from patients with hematopoietic malignancies who underwent hematopoietic stem cell transplantation in Taleghani Hospital (Shahid Beheshti University of Medical Sciences), Tehran, Iran during the years 2007 and 2015 and were followed up till 2017. A Bayesian joint model of longitudinal and survival was chosen, using Win Bugs software. Results: A total of 395 patients were enrolled. The median overall survival was 6.3 years (95% CI (5.86, 6.76)). Eighty-one patients had died. The obtained results from this study manifested that age (HR: 1.02, 95% CI: (1.002, 1.04)) and pre-transplantation relapse (HR = 1.64, 95% CI: (1.09, 2.4)) have incremental impact on death after transplantation, while malignancy type (NHL (HR: 0.33, 95%CI: (0.152, 0.73)) and AML (HR: 0.62, 95% CI: (0.29, 0.7)) are also effective in reducing death after transplantation. Similarly, the correlation index between longitudinal and survival models proved to be significant (HR: 0.6, 95% CI: (0.0802, 0.37)). Conclusions: This study showed that age, per-transplantation relapse, and malignancy type are the effective factors in the survival rate. Moreover, the link parameter between longitudinal response (WBC) and the survival indicated that an increase in WBC count leads to a decrease in the death risk.

Healthcare resource utilization and costs in patients with myelodysplastic syndromes treated with hypomethylating agents: a SEER-Medicare analysis

AIMS

To describe healthcare resource utilization (HRU) and costs in patients with myelodysplastic syndromes (MDS) treated with hypomethylating agents (HMA) based on HMA-treatment response.

MATERIALS AND METHODS

SEER-Medicare data (January 2006-December 2016) were used to identify adults diagnosed with MDS (SEER: January 2009-December 2015) initiated on HMA (index date). HMA-treatment success (indicators: ≥7 HMA cycles, stem cell transplantation, and transfusion independence) or failure (indicators: acute myeloid leukemia [AML], AML-like treatment, and death) was determined using a claim-based algorithm. HRU and costs were assessed from the index date to 1-year post-index, overall and stratified by HMA-treatment success or failure. Among patients with HMA-treatment failure, HRU and costs were also assessed from failure to 1-year post-failure.

RESULTS

The study included 3,046 patients (mean age: 77.4 years; females: 36.8%). Rates of HMA-treatment success and failure were 44.4% and 76.2%, respectively (20.6% had HMA-treatment success then failure). Overall, patients had 15.2 inpatient admissions per-100-patients-per-month (median follow-up: 5.9 months). Patients with HMA-treatment success had 7.5 inpatient admissions per-100-patients-per-month (median follow-up: 12.0 months), while those with HMA-treatment failure had 20.4 and 35.3 admissions per-100-patients-per-month pre- and post-HMA-treatment failure, respectively (median follow-up: 4.3 and 1.8 months, pre- and post-HMA-treatment failure, respectively). Mean total healthcare costs were $12,494 per-patient-per-month overall, $8,069 per-patient-per-month among patients with HMA-treatment success, and $13,809 and $19,242 per-patient-per-month pre- and post-HMA-treatment failure, respectively. Outpatient costs (68.3%) were the main contributor of total healthcare costs overall, while inpatient costs (80.3%) were the main cost driver post-HMA-treatment failure.

LIMITATIONS

Without available laboratory test results, clinical indicators observed in claims were used to assess HMA-treatment response.

CONCLUSIONS

Over 75% of patients with MDS failed HMA-treatment within 6 months of initiation and were observed with more inpatient admissions than those with HMA-treatment success, translating into substantially higher healthcare costs. HMA-treatment failure results in an important economic burden in MDS patients.

Pretransplant serum beta-2 microglobulin level is a potential novel prognostic marker of overall survival after allogeneic hematopoietic cell transplantation - a retrospective observational study

Although elevated serum beta-2 microglobulin (BMG) has been reported as a poor prognostic marker for various hematological malignancies, no study has assessed its prognostic significance in allogenec hematopoietic cell transplantation (allo-HCT). Therefore, we conducted this retrospective observational study in 227 consecutive patients with available pretransplant serum BMG levels between April 2010 and September 2017 at our institute. We also collected and retrospectively analyzed various pretransplant variables likely related to transplant outcomes. Multivariable analysis, including major prognostic variables, such as the disease risk index and the hematopoietic cell transplant-comorbidity index, showed a significant association between higher serum BMG levels and poorer overall survival (OS) in all three adjusted models [hazard ratio (HR) per its standard deviation (SD) (SD = 1.094): 1.67 (1.35-2.03; P < 0.001), HR per SD: 1.46 (1.14-1.86; P = 0.002), HR per SD: 2.03 (1.62-2.55; P < 0.001)], respectively, due to the significant association between higher serum BMG levels and relapse/progression [HR 1.52 (1.20-1.94; P < 0.001)] instead of nonrelapse mortality [HR 1.06 (0.70-1.60; P = 0.780)]. Moreover, DRI and serum BMG had statistically significantly higher c-statistic estimates for OS compared with DRI alone (c-index 0.74 and 0.68, respectively; P < 0.001). In conclusion, pretransplant serum BMG level may serve as a useful prognostic marker and help clinical decision in allo-HCT.

Serotonin receptor type 1B constitutes a therapeutic target for MDS and CMML

Myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML) are chronic myeloid clonal neoplasms. To date, the only potentially curative therapy for these disorders remains allogeneic hematopoietic progenitor cell transplantation (HCT), although patient eligibility is limited due to high morbimortality associated with this procedure coupled with advanced age of most patients. Dopamine receptors (DRs) and serotonin receptors type 1 (HTR1s) were identified as cancer stem cell therapeutic targets in acute myeloid leukemia. Given their close pathophysiologic relationship, expression of HTR1s and DRs was interrogated in MDS and CMML. Both receptors were differentially expressed in patient samples compared to healthy donors. Treatment with HTR1B antagonists reduced cell viability. HTR1 antagonists showed a synergistic cytotoxic effect with currently approved hypomethylating agents in AML cells. Our results suggest that HTR1B constitutes a novel therapeutic target for MDS and CMML. Due to its druggability, the clinical development of new regimens based on this target is promising.

Treatment Choices: A Quality of Life Comparison in Acute Myeloid Leukemia and High-risk Myelodysplastic Syndrome

BACKGROUND

In the present exploratory, observational study, we compared the effect of intensive versus nonintensive treatment on quality of life for patients aged ≥ 60 years diagnosed with acute myeloid leukemia or high-risk myelodysplastic syndrome at 1 month after treatment.

PATIENTS AND METHODS

A total of 73 patients with acute myeloid leukemia or high-risk myelodysplastic syndrome who had been treated at the inpatient and outpatient malignant hematology at Moffitt Cancer Center, a National Cancer Institute-designated comprehensive cancer center, were included. Two paired measurements of self-reported quality of life were used, 1 before treatment and 1 at 1 month after treatment to compare intensive versus nonintensive treatment. Patients completed the Functional Assessment of Cancer Therapy-Leukemia version for the quality-of-life measurement. Repeated measures analysis of variance was used to compare the effect of treatment and time and the interaction of treatment and time. The main research variables were intensive versus nonintensive treatment as the independent variable and quality of life measured using the Functional Assessment of Cancer Therapy-Leukemia version as the dependent variable.

RESULTS

Physical function and leukemia symptoms improved for patients treated with intensive chemotherapy. A trend was found for improved quality of life for the intensive treatment compared with nonintensive treatment, for which the quality of life was stable at 1 month.

CONCLUSION

The study participants treated with inpatient, induction chemotherapy experienced statistically significant improvement in their quality of life at 1 month. The outpatient, nonintensive study participants had stable quality of life at 1 month.

Validation of an Algorithm to Predict the Likelihood of an 8/8 HLA-Matched Unrelated Donor at Search Initiation

A strategy to rapidly determine if a matched unrelated donor (URD) can be secured for allograft recipients is needed. We sought to validate the accuracy of (1) HapLogic match predictions and (2) a resultant novel Search Prognosis (SP) patient categorization that could predict 8/8 HLA-matched URD(s) likelihood at search initiation. Patient prognosis categories at search initiation were correlated with URD confirmatory typing results. HapLogic-based SP categorizations accurately predicted the likelihood of an 8/8 HLA-match in 830 patients (1530 donors tested). Sixty percent of patients had 8/8 URD(s) identified. Patient SP categories (217 very good, 104 good, 178 fair, 33 poor, 153 very poor, 145 futile) were associated with a marked progressive decrease in 8/8 URD identification and transplantation. Very good to good categories were highly predictive of identifying and receiving an 8/8 URD regardless of ancestry. Europeans in fair/poor categories were more likely to identify and receive an 8/8 URD compared with non-Europeans. In all ancestries very poor and futile categories predicted no 8/8 URDs. HapLogic permits URD search results to be predicted once patient HLA typing and ancestry is obtained, dramatically improving search efficiency. Poor, very poor, andfutile searches can be immediately recognized, thereby facilitating prompt pursuit of alternative donors.

Allogeneic Hematopoietic Stem Cell Transplantation Is Underutilized in Older Patients with Myelodysplastic Syndromes

Allogeneic hematopoietic stem cell transplantation (HCT) is the only curative treatment for myelodysplastic syndrome (MDS). The proportion of MDS patients referred for transplantation evaluation, those undergoing transplantation, and the reasons for not undergoing transplantation are unknown. In this retrospective analysis, predefined HCT eligibility and indications criteria were applied to 362 unselected patients with newly diagnosed MDS seen by leukemia faculty between 2008 and 2015 at Memorial Sloan Kettering Cancer Center. Two hundred ninety-four patients (81%) were deemed eligible for transplantation and among these, transplantation was considered indicated in 244 (83%). Of these, 158 of 244 (65%) were referred for transplantation evaluation at a median of 3.9 months from diagnosis. Overall 120 of 362 (33%) underwent transplantation at a median of 7.7 months from diagnosis. Metastatic solid-organ malignancy was the major reason for transplantation ineligibility (54%), and death due to MDS, which occurred in 41% of candidates who did not undergo transplantation, was the major reason for not undergoing transplantation. Factors associated with a lower likelihood of referral for transplantation evaluation included age ≥65 (P < .001), ≥2 comorbidities (P = .008), intermediate-1/low risk MDS (P < .001), <5% blasts at diagnosis (overall P < .001), having Medicare/Medicaid health insurance (P < .001), not being married (P = .017), and diagnosis between 2008 and 2011 (P = .035). On multivariate analysis adjusting for all of the previous factors, diagnosis between 2008 and 2011 (P < .001), age ≥65 (P = .001), and <5% blasts at diagnosis (overall P = .031) were associated with a lower likelihood of referral for transplantation evaluation. Factors associated with a lower likelihood of undergoing transplantation included age ≥65 (P < .001), ≥2 comorbidities (P = .003), intermediate-1/low risk MDS (P < .001), <5% blasts (overall P < .001), very low/low/intermediate risk International Prognostic Scoring System-revised karyotype (P = .018), and having Medicare/Medicaid health insurance (P < .001). In multivariate analysis adjusting for all of the previous factors, age ≥65 (P = .021), presence of ≥2 comorbidities (P = .018), and <5% blasts (overall P = .011) were associated with a lower likelihood of undergoing transplantation. The results highlight that transplantation for MDS remains underutilized, particularly for candidates over the age of 65.

Prognostic pre-transplant factors in myelodysplastic syndromes primarily treated by high dose allogeneic hematopoietic stem cell transplantation: a retrospective study of the MDS subcommittee of the CMWP of the EBMT

Many pre-transplant factors are known to influence the outcome of allogeneic stem cell transplantation (SCT) treatment in myelodysplastic syndromes (MDS). However, patient cohorts are often heterogeneous by disease stage and treatment modalities, which complicates interpretation of the results. This study aimed to obtain a homogeneous patient cohort by including only de novo MDS patients who received upfront allogeneic SCT after standard high dose myelo-ablative conditioning. The effect of pre-transplant factors such as age, disease stage, transfusions, iron parameters and comorbidity on overall survival (OS), non-relapse mortality (NRM), and relapse incidence (RI) was evaluated in 201 patients. In this cohort, characterized by low comorbidity and a short interval between diagnosis and transplantation, NRM was the most determinant factor for survival after SCT (47 % after 2-year follow-up). WHO classification and transfusion burden were the only modalities with a significant impact on overall survival after SCT. Estimated hazard ratios (HR) showed a strongly increased risk of death, NRM and RI, in patients with a high transfusion-burden (HR 1.99; P = 0.006, HR of 1.89; P = 0.03 and HR 2.67; P = 0.03). The HR's for ferritin level and comorbidity were not significantly increased.

Up-to-date tools for risk assessment before allogeneic hematopoietic cell transplantation

Cure of malignant and non-malignant hematological diseases is potentially possible after allogeneic hematopoietic stem cell transplantation (HCT). Accurate evaluation of the risk-benefit ratio for an individual patient could improve the decision-making process about transplant, which ultimately would increase the likelihood of success. Several transplant-related models were designed in an effort to optimize decision-making about suitable candidates for allogeneic HCT. In 1998, The European Society for Blood and Marrow Transplantation (EBMT) developed a five-component pretransplantation risk scoring system for patients with CML. The EBMT score was later tested in patients with various hematological disorders, and it was shown to stratify risks of mortality after allogeneic HCT. More recent research efforts focused on models that assess health status before HCT. A HCT-specific comorbidity index was designed to assign weights to 17 relevant comorbidities that were shown to independently predict non-relapse mortality. Performance status scales and comprehensive geriatric assessment tools might uncover additional overall health limitations that affect long-term survival among older recipients of allogeneic HCT. Other models include the pretransplantation assessment of mortality score that summarizes the impacts of eight different pretransplantation patient- and disease-specific variables into a 50-point model that predicts survival. The disease-risk index captures the impact of primary diagnoses and disease status on relapse and survival following allogeneic HCT. The values and limitations of each model are discussed herein. We also provide insight on how to use these models in the clinic to decide about offering allogeneic HCT with the most suitable conditioning regimen intensity.

Safety and efficacy of azacitidine in Belgian patients with high-risk myelodysplastic syndromes, acute myeloid leukaemia, or chronic myelomonocytic leukaemia: results of a real-life, non-interventional post-marketing survey

OBJECTIVES

We evaluated azacitidine (Vidaza(®)) safety and efficacy in patients with myelodysplastic syndrome (MDS), acute myeloid leukaemia (AML), and chronic myelomonocytic leukaemia (CMML), in a real-life setting. Treatment response, dose, and schedule were assessed.

METHODS

This non-interventional, post-marketing survey included 49/50 patients receiving azacitidine at 14 Belgian haematology centres from 2010-2012. Treatment-emergent adverse events (TEAEs), including treatment-related TEAEs, and serious TEAEs (TESAEs) were recorded throughout the study. Treatment response [complete response (CR), partial response (PR), haematological improvement (HI), stable disease (SD), treatment failure (TF)) and transfusion-independence (TI) were evaluated at completion of a 1-year observation period (1YOP) or at treatment discontinuation, and overall survival (OS), at study conclusion.

RESULTS

The median age of patients was 74·7 (range: 43·9-87·8) years; 69·4% had MDS, 26·5% had primary or secondary AML, and 4·1% had CMML. Treatment-related TEAEs, grade 3-4 TEAEs, and TESAEs were reported in 67·3%, 28·6%, and 18·4% of patients, respectively. During 1YOP, patients received a median of 7 (1-12) treatment cycles. Treatment response was assessed for 38/49 patients. Among MDS and CMML patients (n = 29), 41·4% had CR, PR, or HI, 41·4% had SD, and 17·2% had TF. Among AML patients (n = 9), 44·4% had CR or PR, 33·3% had SD, and 22·2% had TF. TI was observed in 14/32 (43·8%) patients who were transfusion-dependent at baseline. Median (95% confidence interval) OS was 490 (326-555) days; 1-year OS estimate was 0·571 (0·422-0·696).

CONCLUSIONS

Our data support previous findings that azacitidine has a clinically acceptable safety profile and shows efficacy.

Some aspects of allogeneic stem cell transplantation in patients with myelodysplastic syndrome: advances and controversy

Myelodysplastic syndrome (MDS) is a heterogeneous group of myeloid disorders. MDS remains a disease of elderly patients; moreover, the incidence of high risk MDS is proportionally greater in elderly patients, with increased frequency of secondary acute myeloid leukemia, as well as adverse cytogenetic abnormalities. Allogeneic stem cell transplantation is a therapeutic approach with known curative potential for patients with MDS that allows the achievement of long-term disease control. Numerous controversies still exist regarding transplantation in MDS: timing of transplantation, disease status at transplantation and comorbidity, conditioning intensity, pretransplant therapy, and stem cell source. Various transplant modalities of different intensities and alternative donor sources are now in use. Current advances in transplant technology are allowing the consideration of older patients. This should result in a greater number of older patients benefiting from this potentially curative treatment modality. Despite advances in transplantation technology, there is still considerable morbidity and mortality associated with this approach. Nevertheless, with the introduction of reduced-intensity conditioning and thereby reduced early mortality, transplant numbers in MDS patients have significantly increased. Moreover, recent new developments with innovative drugs, including hypomethylating agents, have extended the therapeutic alternatives for MDS patients. Hypomethylating agents allow the delay of allogeneic stem cell transplantation by serving as an effective and well-tolerated means to reduce disease burden.

Beyond hypomethylating agents failure in patients with myelodysplastic syndromes

PURPOSE OF REVIEW

Although hypomethylating agents (HMAs) significantly improve outcomes in myelodysplastic syndromes (MDS), only half the patients achieve objective responses, and most responders lose response within 1-2 years. Azacitidine prolongs survival by a median of only 9.5 months. Failure of HMA therapy is associated with a very dismal prognosis. Therefore, novel therapeutic approaches are clearly needed.

RECENT FINDINGS

The sequential use of the alternative HMA after failure of first line HMA is associated with modest efficacy. The improved understanding of the biologic underpinnings of the disease have opened the door to study investigational agents that target disrupted molecular pathways critical to the pathogenesis of MDS. Combination treatment strategies using an azacitidine backbone are demonstrating promising early results. Expanding the applicability of allogeneic stem cell transplantation (alloSCT), the only curative modality, by reducing toxicity and relapse rates is another area of active research.

SUMMARY

Sequential switching to the alternative HMA, clinical trials of novel targeted therapies, azacitidine-based combination therapeutic strategies, and improvements in the alloSCT platform are the main directions in improving outcomes of MDS post HMA failure.

Should elderly patients with higher-risk myelodysplastic syndromes undergo allogeneic hematopoietic stem cell transplantation?

Myelodysplastic syndromes (MDS) include a group of hematopoietic malignancies characterized by dysplastic changes, ineffective hematopoiesis and variable risk of leukemic progression. At diagnosis, 86% of MDS patients are ≥60 years. Azacitidine, the only drug that prolongs life in high-risk (HR)-MDS patients, adds a median of only 9.5 months to life. Allogeneic stem cell transplantation (alloSCT) remains the only potentially curative approach. Despite recent improvements including use of reduced intensity conditioning (RIC) that decrease transplant-related mortality, alloSCT continues to be used rarely in elderly MDS. There is paucity of data regarding outcomes of RIC alloSCT in elderly MDS patients, especially in direct comparison with azanucleosides. In this paper, the authors discuss the recent Markov decision analysis by Koreth et al. in which investigators demonstrated superior survival of patients with HR-MDS aged 60-70 years who underwent RIC alloSCT in comparison with those who were treated with azanucleosides.

Current therapy of myelodysplastic syndromes

After being a neglected and poorly-understood disorder for many years, there has been a recent explosion of data regarding the complex pathogenesis of myelodysplastic syndromes (MDS). On the therapeutic front, the approval of azacitidine, decitabine, and lenalidomide in the last decade was a major breakthrough. Nonetheless, the responses to these agents are limited and most patients progress within 2 years. Allogeneic stem cell transplantation remains the only potentially curative therapy, but it is associated with significant toxicity and limited efficacy. Lack or loss of response after standard therapies is associated with dismal outcomes. Many unanswered questions remain regarding the optimal use of current therapies including patient selection, response prediction, therapy sequencing and combinations, and management of resistance. It is hoped that the improved understanding of the underpinnings of the complex mechanisms of pathogenesis will be translated into novel therapeutic approaches and better prognostic/predictive tools that would facilitate accurate risk-adaptive therapy.

A disease risk index for patients undergoing allogeneic stem cell transplantation

The outcome of allogeneic HSCT varies considerably by the disease and remission status at the time of transplantation. Any retrospective or prospective HSCT study that enrolls patients across disease types must account for this heterogeneity; yet, current methods are neither standardized nor validated. We conducted a retrospective study of 1539 patients who underwent transplantation at Dana-Farber Cancer Institute/Brigham and Women's Hospital from 2000 to 2009. Using multivariable models for overall survival, we created a disease risk index. This tool uses readily available information about disease and disease status to categorize patients into 4 risk groups with significantly different overall survival and progression-free survival on the basis of primarily differences in the relapse risk. This scheme applies regardless of conditioning intensity, is independent of comorbidity index, and was validated in an independent cohort of 672 patients from the Fred Hutchinson Cancer Research Center. This simple and validated scheme could be used to risk-stratify patients in both retrospective and prospective HSCT studies, to calibrate HSCT outcomes across studies and centers, and to promote the design of HSCT clinical trials that enroll patients across diseases and disease states, increasing our ability to study nondisease-specific outcomes in HSCT.

[Allogeneic hematopoietic stem cell transplantation in elderly]

Most of patients with hematological malignancies are elderly (more than 60  years). Allogeneic stem cell transplantation is an important and effective treatment for most of these diseases. However, the toxicity and the supposed frailty of elderly patients, have limited the applicability of allogeneic transplantation for these patients. Elderly patients are at high risk to develop life-threatening complications, if allogeneic transplantation is performed with myeloablative conditioning regimens and using bone marrow stem source. Since more than 10 years, reduced intensity conditioning regimen have been developed, allowing to overcome the age as contra-indication for allogeneic transplantation. On the other hand, it is the presence of comorbidities which identify frail patients. For these subjects, allogeneic transplantation should be not indicated. Furthermore, advances in the supportive care and the development of new molecules could allow to reduce the toxicity of myeloablative conditioning regimens and thus to offer more intensive regimens before transplantation also in elderly population.