Upfront allogeneic blood stem cell transplantation for patients with high-risk myelodysplastic syndrome or secondary acute myeloid leukemia using a FLAMSA-based high-dose sequential conditioning regimen

Current challenges in conditioning regimens for MDS transplantation

Myelodysplastic syndrome (MDS) is a very heterogeneous clonal disorder. Patients with "higher-risk" MDS, defined by specific recurrent genetic abnormalities, have a poor prognosis because of a high risk of progression to secondary acute myeloid leukemia with low chemosensitivity. Allogeneic hematopoietic stem cell transplantation remains the only treatment that offers durable disease control because the donor immune system allows graft-versus-MDS effects. In terms of preparation steps before transplantation, targeting the malignant clone by increasing the conditioning regimen intensity is still a matter of intense debate. MDS is mainly diagnosed in older patients, and high toxicity related to common myeloablative conditioning regimens has been reported. Efforts to include new drugs in the conditioning regimen to achieve the best malignant clone control without increasing toxicity have been made over the past 20 years. We summarized these retrospective and prospective studies and evaluated the limitations of the available evidence to delineate the ideal conditioning regimen.

Sequential vs myeloablative vs reduced intensity conditioning for patients with myelodysplastic syndromes with an excess of blasts at time of allogeneic haematopoietic cell transplantation: a retrospective study by the chronic malignancies working party of the EBMT

The optimal conditioning for patients with higher risk MDS receiving potentially curative allogeneic haematopoietic stem cell transplant(allo-HCT) remains to be defined. This is particularly the case for patients with excess of blasts at time of allo-HCT. Sequential (Seq) conditioning, whereby chemotherapy is followed rapidly by transplant conditioning, offers an opportunity to decrease disease burden, potentially improving outcomes allo-HCT outcomes. Herein we present the only analysis comparing Seq to myeloablative (MAC) and reduced intensity conditioning (RIC) specifically focussed on MDS patients with excess of blasts at allo-HCT. 303 patients were identified in the EBMT registry, receiving RIC (n = 158), Seq (n = 105), and MAC (n = 40). Median follow-up was 67.2 months and median age at allo-HCT was 59.5 years (IQR 53.5-65.6). For the entire cohort, 3 y overall survival (OS) was 50% (95% CI 45-56%) and relapse free survival (RFS) 45% (95% CI 40-51%). No significant differences in OS (log-rank p = 0.13) and RFS (log-rank p = 0.18) were observed between conditioning protocols. On multivariable analysis, lower performance status, worse IPSS-R cytogenetics, sibling donor (compared to 8/8 MUD) and ≥20% blasts at allo-HCT were associated with worse outcomes. In conclusion, the Seq protocol did little to influence the outcome in this high-risk group of patients, with outcomes mostly determined by baseline disease risk and patient characteristics such as performance status.

Smart Conditioning with Venetoclax-Enhanced Sequential FLAMSA + RIC in Patients with High-Risk Myeloid Malignancies

Up to 50% of patients with high-risk myeloid malignancies die of relapse after allogeneic stem cell transplantation. Current sequential conditioning regimens like the FLAMSA protocol combine intensive induction therapy with TBI or alkylators. Venetoclax has synergistic effects to chemotherapy. In a retrospective survey among German transplant centers, we identified 61 patients with myeloid malignancies that had received FLAMSA-based sequential conditioning with venetoclax between 2018 and 2022 as an individualized treatment approach. Sixty patients (98%) had active disease at transplant and 74% had genetic high-risk features. Patients received allografts from matched unrelated, matched related, or mismatched donors. Tumor lysis syndrome occurred in two patients but no significant non-hematologic toxicity related to venetoclax was observed. On day +30, 55 patients (90%) were in complete remission. Acute GvHD II°-IV° occurred in 17 (28%) and moderate/severe chronic GvHD in 7 patients (12%). Event-free survival and overall survival were 64% and 80% at 1 year as well as 57% and 75% at 2 years, respectively. The off-label combination of sequential FLAMSA-RIC with venetoclax appears to be safe and highly effective. To further validate these insights and enhance the idea of smart conditioning, a controlled prospective clinical trial was initiated in July 2023.

Current status of pretransplant intensive chemotherapy or hypomethylating agents for myelodysplastic syndrome

Myelodysplastic syndrome is a heterogeneous disease with survival probabilities ranging from a few months to several years. Allogeneic hematopoietic cell transplantation (HCT) remains the only curative treatment. Although access (up to 75 years) and outcome of HCT have improved steadily in recent years, high relapse rates and, to a lower extent, treatment related mortalities are a persisting problem. Reduction of tumor burden before HCT has been shown to decrease relapse incidence and often overall survival (OS) in hematological malignancies but the role of pretransplant therapy in MDS remains controversial. We reviewed the role of pretransplant therapy on outcome in MDS patients. No prospective randomized trial addressed this issue so far. Retrospective studies have shown that pretransplant therapy reduces the risk of relapse, but does not improve survival. In addition, registry studies from diagnosis with standard protocols are proposed in order to exclude patient selection. With the availability of new, more effective and low-toxicity therapies, it may be possible to achieve a significant improvement of OS in the future.

Fludarabine/busulfan versus busulfan/cyclophosphamide as myeloablative conditioning for myelodysplastic syndrome: a propensity score-matched analysis

Myeloablative conditioning with fludarabine/busulfan (Flu/Bu4) prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT) is effective for acute myeloid leukemia. However, the effectiveness of Flu/Bu4 for myelodysplastic syndrome (MDS) remains poorly understood. Therefore, we retrospectively analyzed nationwide registry data in Japan from 2006 to 2018 and compared transplant outcomes of adult MDS patients receiving Flu/Bu4 and busulfan/cyclophosphamide (Bu4/Cy) using propensity score (PS) matching. The primary endpoint was overall survival (OS). Among 2,482 MDS patients, 153 patients were assigned each to the Flu/Bu4 and Bu4/Cy groups. The 3-year OS rates were 52.7% (95% confidence interval [CI], 43.8-60.8%) and 49.5% (95% CI, 40.8-57.6%) in the Flu/Bu4 and Bu4/Cy group, respectively (P = 0.548). The 3-year progression-free survival (P = 0.858), the cumulative incidence of relapse (P = 0.536), and cumulative incidence of non-relapse mortality (P = 0.684) were not significantly different between the two groups. According to the findings of subgroup analyses, no patient had a favorable OS when using either of the two regimens. In conclusion, although our PS-matched cohort mainly comprised older patients who had a low hematopoietic cell transplantation-comorbidity index and low-risk disease status, Flu/Bu4 could be an alternative to Bu4/Cy for MDS patients prior to allo-HSCT.

On Behalf of the SFGM-TC: Retrospective Comparison of Reduced and Higher Intensity Conditioning for High-Risk Myelodysplastic Syndrome Treated With Allogeneic Stem-Cell Transplantation

BACKGROUND

Allogeneic hematopoietic stem-cell transplantation (allo-HSCT) remains the best curative option for high-risk myelodysplastic syndrome . We retrospectively compared patient outcomes after allo-HSCT according to the intensity of the conditioning regimen.

PATIENTS AND METHODS

Three conditioning regimens were compared in 427 patients allografted for high-risk myelodysplastic syndrome: reduced-intensity conditioning (RIC), fludarabine (150-160 mg/m²) and busulfan (6.4 mg/kg); sequential FLAMSA-RIC, fludarabine, amsacrine, and aracytine followed by RIC; and myeloablative with reduced toxicity (RTC), fludarabine and busulfan (9.6 mg/kg or 12.8 mg/kg).

RESULTS

The patients in the 3 conditioning groups were different in regards to the number of treatment lines (P< .001), percentage of blasts in bone marrow (P< .001), and disease status at transplantation (P< .001). No significant differences in outcomes (overall survival, progression-free survival, nonrelapse mortality, relapse incidence, and graft versus host disease relapse-free survival) were observed between the 3 groups. Using propensity score analysis to overcome baseline imbalances, we compared 70 patients receiving FLAMSA-RIC to 260 patients receiving RIC, and compared 83 patients receiving RTC to 252 patients receiving RIC. The only factor influencing overall and progression-free survival was cytogenetic risk at transplantation. After the covariate adjustment using propensity score to reduce baseline imbalances, the only factor influencing overall and progression-free survival was still cytogenetic risk at transplantation.

CONCLUSION

Overall survival appears to be similar with the 3 conditioning regimens. The only factor influencing survival is cytogenetic risk at transplantation, suggesting that new promising drugs in the conditioning and/or early interventions after transplantation are needed to improve outcomes in these patients.

Eligibility for clinical trials is unsatisfactory for patients with myelodysplastic syndromes, even at a tertiary referral center

Participation in clinical trials may allow patients with MDS to gain access to therapies not otherwise available. However, access is limited by strict inclusion and exclusion criteria, reflecting academic or regulatory questions addressed by the respective studies. We performed a simulation in order to estimate the average proportion of MDS patients eligible for participation in a clinical trial. The simulation drew upon 1809 patients in the Düsseldorf MDS Registry whose clinical data allowed eligibility screening for a wide range of clinical trials. This cohort was assumed to be alive and available for study participation. The simulation also posited that all MDS trials (n = 47) conducted in our center between 1987 and 2016 were open for recruitment. In addition, study activities in the year 2016 were analyzed to determine the proportion of patients eligible for at least one of the 9 MDS trials open at that time. On average, each clinical trial was suitable for about 18 % of patients in the simulation cohort. Conversely, 34 % of the patients were eligible for at least one of the 9 clinical studies in 2016. Inclusion/exclusion criteria of studies initiated by the pharmaceutical industry excluded more than twice the fraction of patients compared with investigator initiated trials (potential inclusion of 10 % vs. 21 %, respectively). Karyotype (average exclusion rate 58 %), comorbidities (40 %), and prior therapies (55 %) were the main reasons for exclusion. We suggest that in- and exclusion criteria should be less restrictive, in order to meet the needs of the real-life population of elderly MDS patients.

FLAMSA-RIC for Stem Cell Transplantation in Patients with Acute Myeloid Leukemia and Myelodysplastic Syndromes: A Systematic Review and Meta-Analysis

Reduced-intensity conditioning (RIC) regimens are established options for hematopoietic stem cell transplantation (HSCT) for patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). However, the efficacy of RIC regimens for patients with high-risk disease is limited. The addition of a fludarabine, amsacrine, and cytarabine (FLAMSA)-sequential conditioning regimen was introduced for patients with high-risk MDS and AML to combine a high anti-leukemic activity with the advantages of RIC. The current systematic literature review and meta-analysis was conducted with the aim of identifying all cohort studies of patients with AML and/or MDS who received FLAMSA-RIC to determine its efficacy and toxicity. Out of 3044 retrieved articles, 12 published studies with 2395 overall patients (18.1–76.0 years; 96.8% AML and 3.2% MDS; follow-up duration of 0.7–145 months; 50.3% had active AML disease before HSCT) met the eligibility criteria and were included in the meta-analysis. In the pooled analysis, the 1- and 3-year overall survival (OS) rates were 59.6% (95% confidence interval (CI), 47.9–70.2%) and 40.2% (95% CI, 28.0–53.7%), respectively. The pooled 3-year OS rate of the patients who achieved CR1 or CR2 prior to HSCT was 60.1% (95% CI, 55.1–64.8%) and the percentage of those with relapse or refractory disease was 27.8% (95% CI, 23.3–32.8%). The pooled 3-year leukemia-free survival (LFS) rate was 39.3% (95% CI, 26.4–53.9%). Approximately 29% of the patients suffered from grades 2–4 acute graft-versus-host disease (GVHD), while 35.6% had chronic GVHD. The pooled 1- and 3-year non-relapse mortality (NRM) rates were 17.9% (95% CI, 16.1–19.8%) and 21.1% (95% CI, 18.8–23.7%), respectively. Our data indicates that the FLAMSA-RIC regimen is an effective and well-tolerated regimen for HSCT in patients with high-risk AML and MDS.

Treatment of MDS

The heterogeneous nature of myelodysplastic syndromes (MDS) demands a complex and personalized variety of therapeutic approaches. Among them, allogeneic hematopoietic stem cell transplantation remains the only potentially curative option and is accessible to only a small number of fit patients. For the majority of patients with MDS, treatment strategies are nonintensive and risk-adapted (by the revised version of the International Prognostic Scoring System), ranging from iron chelation and growth factors to lenalidomide and hypomethylating agents. These approaches are noncurative and aimed instead at improving cytopenias and quality of life and delaying disease progression. These limitations underpin the need for more translational research-based clinical trials in well-defined subgroups of patients with MDS. Indeed, much progress has been made over the past decade in understanding the complex molecular mechanisms underlying MDS. Unfortunately, this has not yet translated into approval of novel treatment options. There is a particularly urgent medical need in patients failing current first-line therapies, such as with erythropoiesis-stimulating or hypomethylating agents. Nevertheless, actual developments are expected to pave the way for exciting novel therapeutic opportunities. This review provides an overview of the current therapeutic landscape in MDS focusing on recent advances in clinical and translational research.

Upfront allogeneic hematopoietic cell transplantation (HCT) versus remission induction chemotherapy followed by allogeneic HCT for acute myeloid leukemia with multilineage dysplasia: A propensity score matched analysis

The efficacy of induction chemotherapy before allogeneic hematopoietic cell transplantation (HCT) for patients with acute myeloid leukemia with multilineage dysplasia (AML-MLD) is unclear. Some patients with AML-MLD have received upfront HCT without prior induction chemotherapy. To compare the transplant outcomes between patients who received upfront HCT and those who received induction chemotherapy followed by allogeneic HCT for AML-MLD, we retrospectively analyzed the Japanese registration data of 1445 adult patients who had received allogeneic HCT between 2007 and 2016. Propensity score matching identified 269 patients in each cohort. There were no significant differences in overall survival between the two groups. The cumulative incidence of leukemia-related mortality was significantly lower in patients who received upfront HCT than those who received induction chemotherapy before HCT. In the subgroup analyses, upfront HCT had a significantly reduced incidence of leukemia-related mortality among patients aged between 60 and 70 years, those with a lower white blood cell count at diagnosis (<3000/μL), and poor cytogenetic risk, and those who received myeloablative conditioning and cord blood transplantation. Our results suggested that induction chemotherapy before HCT did not have any benefits of survival after HCT for AML-MLD. Upfront HCT contributed to the reduced incidence of leukemia-related mortality after HCT. Upfront HCT should be considered for patients with AML-MLD who are eligible for allogeneic HCT.

Current and Future Treatment Options for Myelodysplastic Syndromes: More Than Hypomethylating Agents and Lenalidomide?

Myelodysplastic syndromes are a heterogeneous group of bone marrow disorders that result in cytopenias and a propensity to develop secondary leukemia. While allogeneic transplantation still remains the only potential curative treatment option, it can only be offered to a limited number of patients. For the majority, who are not transplant candidates, treatment strategies cover iron chelation, growth factors, lenalidomide, and hypomethylating agents to improve cytopenia and potentially delay disease progression. These limited options underpin the urgent need for more translational research-based clinical trials in well-defined subgroups of patients with myelodysplastic syndromes. Indeed, myelodysplastic syndromes are a moving target with maximum innovation in the understanding of the complex molecular pathways during the last decade. Compared with other hematological diseases such as myeloma, this has unfortunately not yet translated into approval of novel treatment options. Given the current developments in the field, we are optimistic that recent frustrations will be overcome shortly and this will pave the way for exciting opportunities, especially for patients not responding to first-line therapeutic options.

Induction chemotherapy followed by allogeneic HCT versus upfront allogeneic HCT for advanced myelodysplastic syndrome: A propensity score matched analysis

To reduce post-transplant relapse, acute myeloid leukemia (AML) type remission induction chemotherapy has been attempted to reduce disease burden before allogeneic hematopoietic cell transplantation (HCT) in patients with advanced myelodysplastic syndrome (MDS). However, the efficacy of induction chemotherapy before HCT is unclear. We retrospectively analyzed the Japanese registration data of 605 adult patients, who had received allogeneic HCT for advanced MDS between 2001 and 2016, to compare the post-transplant relapse between patients who received induction chemotherapy followed by allogeneic HCT and those who received upfront HCT. Propensity score matching identified 230 patients from each cohort. There were no significant differences in overall survival and non-relapse mortality between the two groups. The cumulative incidence of relapse was significantly higher in patients who received induction chemotherapy than those who received upfront HCT. In the subgroup analyses, upfront HCT had a significantly reduced relapse incidence among patients with poor cytogenetics, those with higher international prognostic scoring system at diagnosis, and those who received reduced-intensity conditioning. Our results suggested that AML type remission induction chemotherapy before HCT did not improve post-transplant relapse and survival for adult patients with advanced MDS. Upfront HCT is preferable for patients with a poor karyotype.

Idarubicin-Intensified Hematopoietic Cell Transplantation Improves Relapse and Survival of High-Risk Acute Leukemia Patients with Minimal Residual Disease

The optimal conditioning regimen of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for high-risk patients with minimal residual disease (MRD) remains controversial. We studied the results in 98 high-risk acute leukemia patients transplanted with idarubicin (IDA)-intensified conditioning regimens between 2012 January and 2017 January. Among these patients, 31 (31.6%) had more than 5% marrow blasts at time of transplantation and 67 patients were in morphologic remission: MRD negative status at time of conditioning was achieved in 39 patients (39.8%), whereas 28 (28.6%) remained carriers of any other positive MRD level in the bone marrow. Three-year relapse estimates of patients with MRD-positive remission was 22.0%, which was remarkably lower than patients with active disease (45.4%, P = .027) but approximate to that of patients in MRD-negative remission (15.5%, P = .522). There were no significant differences in terms of 3-year estimated overall survival (OS) and disease-free survival (DFS) between MRD-positive remission and MRD-negative remission groups (71.4% versus 79.1% [P = .562] and 67.9% versus 76.9% [P = .634], respectively). Moreover, the estimated rates of 3-year OS and DFS of patients in MRD-positive remission were significantly better than those in patients with active disease (71.4% versus 41.9% [P = .033] and 67.9% versus 38.7% [P = .037], respectively). These data indicate that IDA-intensified conditioning allo-HSCT could overcome the negative prognostic impact of MRD.

Sequential intensified conditioning followed by prophylactic DLI could reduce relapse of refractory acute leukemia after allo-HSCT

The major obstacle is leukemia relapse for refractory leukemia undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). We previously introduced a strategy of sequential intensified conditioning and early rapid immunosupressant withdrawal for refractory leukemia undergoing allo-HSCT, with 5-year overall survival (OS) and 3-year relapse rate of 44.6% and 33.3%. To reduce leukemia relapse, prophylactic donor lymphocyte infusion (DLI) was administered based on our historical strategy. A total of 153 refractory advanced acute leukemia patients were enrolled in this prospective study. According to the availability of donor lymphocytes and the criteria for DLI, 144 patients surviving day +60 were divided into two groups (80 DLI versus 64 non-DLI). The relapse rate was less and OS was better in patients receiving DLI than in those not receiving DLI (22.7% vs 33.9%, P=0.048; 58.1% vs 54.9%, P=0.043). The non-relapse mortality (NRM) was similar between DLI and non-DLI groups (P=0.104). Overall, the 5-year overall and disease-free survival post-transplantation were 51.1%±5.7% and 49.2%±5.3%. The 5-year relapse rate and NRM were 27.3%±4.4% and 29.7%±5.3%. Multivariate analysis revealed that lower bone marrow blasts on day 0, DLI and chronic graft-versus-host disease were associated with less relapse and better OS. The strategy of sequential intensified conditioning followed by early immunosupressant withdrawal and DLI could reduce relapse of refractory acute leukemia after allo-HSCT and improve survival.

Durable graft-versus-leukaemia effects without donor lymphocyte infusions - results of a phase II study of sequential T-replete allogeneic transplantation for high-risk acute myeloid leukaemia and myelodysplasia

Allogeneic haematopoietic stem-cell transplantation remains the only curative treatment for relapsed/refractory acute myeloid leukaemia (AML) and high-risk myelodysplasia but has previously been limited to patients who achieve remission before transplant. New sequential approaches employing T-cell depleted transplantation directly after chemotherapy show promise but are burdened by viral infection and require donor lymphocyte infusions (DLI) to augment donor chimerism and graft-versus-leukaemia effects. T-replete transplantation in sequential approaches could reduce both viral infection and DLI usage. We therefore performed a single-arm prospective Phase II clinical trial of sequential chemotherapy and T-replete transplantation using reduced-intensity conditioning without planned DLI. The primary endpoint was overall survival. Forty-seven patients with relapsed/refractory AML or high-risk myelodysplasia were enrolled; 43 proceeded to transplantation. High levels of donor chimerism were achieved spontaneously with no DLI. Overall survival of transplanted patients was 45% and 33% at 1 and 3 years. Only one patient developed cytomegalovirus disease. Cumulative incidences of treatment-related mortality and relapse were 35% and 20% at 1 year. Patients with relapsed AML and myelodysplasia had the most favourable outcomes. Late-onset graft-versus-host disease protected against relapse. In conclusion, a T-replete sequential transplantation using reduced-intensity conditioning is feasible for relapsed/refractory AML and myelodysplasia and can deliver graft-versus-leukaemia effects without DLI.

Allogeneic hematopoietic stem cell transplantation for MDS and CMML: recommendations from an international expert panel

An international expert panel, active within the European Society for Blood and Marrow Transplantation, European LeukemiaNet, Blood and Marrow Transplant Clinical Trial Group, and the International Myelodysplastic Syndromes Foundation developed recommendations for allogeneic hematopoietic stem cell transplantation (HSCT) in myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML). Disease risks scored according to the revised International Prognostic Scoring System (IPSS-R) and presence of comorbidity graded according to the HCT Comorbidity Index (HCT-CI) were recognized as relevant clinical variables for HSCT eligibility. Fit patients with higher-risk IPSS-R and those with lower-risk IPSS-R with poor-risk genetic features, profound cytopenias, and high transfusion burden are candidates for HSCT. Patients with a very high MDS transplantation risk score, based on combination of advanced age, high HCT-CI, very poor-risk cytogenetic and molecular features, and high IPSS-R score have a low chance of cure with standard HSCT and consideration should be given to treating these patients in investigational studies. Cytoreductive therapy prior to HSCT is advised for patients with ≥10% bone marrow myeloblasts. Evidence from prospective randomized clinical trials does not provide support for specific recommendations on the optimal high intensity conditioning regimen. For patients with contraindications to high-intensity preparative regimens, reduced intensity conditioning should be considered. Optimal timing of HSCT requires careful evaluation of the available effective nontransplant strategies. Prophylactic donor lymphocyte infusion (DLI) strategies are recommended in patients at high risk of relapse after HSCT. Immune modulation by DLI strategies or second HSCT is advised if relapse occurs beyond 6 months after HSCT.

Preparing Patients With Myelodysplastic Syndrome for Transplant When Is Pre-transplant Cytoreductive Therapy Appropriate?

To date, the only treatment option with curative potential for patients suffering from myelodysplastic syndromes (MDS) is allogeneic stem cell transplantation (allo-SCT). However, patient selection for this procedure as well as the choice of the appropriate pre-transplant regime remain challenging. This review discusses both intensive chemotherapy and hypomethylating agents (HMAs) as debulking strategies. Current evidence on the use of AML-like intense chemotherapy suggests that this represents a valuable option especially in fitter and younger MDS patients with aggressive disease, whereas HMAs seem especially indicated in patients presenting with certain mutations and less proliferative disease in order to bridge them to transplant. The actual need for pre-transplant cytoreduction strongly depends on donor availability and disease progression: upfront allo-SCT might be considered for patients with slowly progressing MDS if a donor is readily available. Common to the data discussed in this review is their retrospective nature, making clear recommendations in terms of debulking strategy difficult. Prospective randomized trials are required to explicitly answer this question in the future.

Thiotepa-based versus total body irradiation-based myeloablative conditioning prior to allogeneic stem cell transplantation for acute myeloid leukaemia in first complete remission: a retrospective analysis from the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Thiotepa is an alkylating compound with an antineoplastic and myeloablative activity and can mimic the effect of radiation. However, it is unknown whether this new regimen could safely replace the long-established ones. This retrospective matched-pair analysis evaluated the outcome of adults with acute myeloid leukaemia in first complete remission who received myeloablative conditioning either with a thiotepa-based (n = 121) or a cyclophosphamide/total body irradiation-based (TBI; n = 358) regimen for allogeneic hematopoietic stem cell transplantation from an HLA-matched sibling or an unrelated donor. With a median follow-up of 44 months, the outcome was similar in both groups. Acute graft-versus-host disease grade II-IV was observed in 25% after thiotepa-containing regimen versus 35% after TBI (P = 0.06). The 2-yr cumulative incidence of chronic graft-versus-host disease was 40.5% for thiotepa and 41% for TBI (P = 0.98). At 2 yrs, the cumulative incidences of non-relapse mortality and relapse incidence were 23.9% (thiotepa) vs. 22.4% (TBI; P = 0.66) and 17.2% (thiotepa) vs. 23.3% (TBI; P = 0.77), respectively. The probabilities of leukaemia-free and overall survival at 2 yrs were not significantly different between the thiotepa and TBI groups, at 58.9% vs. 54.2% (P = 0.95) and 61.4% vs. 58% (P = 0.72), respectively. Myeloablative regimens using combinations including thiotepa can provide satisfactory outcomes, but the optimal conditioning remains unclear for the individual patient in this setting.

Myelodysplastic syndromes: diagnosis, prognosis, and treatment

BACKGROUND

Myelodysplastic syndromes (MDS) are malignant stem-cell diseases that are usually diagnosed in elderly patients who present with anemia or, less commonly, bi- or pancytopenia. Their incidence in persons over age 80 is above 50 new cases per 100,000 persons per year. Their clinical course is highly variable. About one-quarter of all patients with MDS develop acute leukemia. The median survival time from the moment of diagnosis is about 30 months.

METHOD

We selectively searched the PubMed database for pertinent articles and guidelines from the years 2000-2013. We used the search term "myelodysplastic syndromes."

RESULTS

MDS are diagnosed by cytology, with consideration of the degree of dysplasia and the percentage of blast cells in the blood and bone marrow, and on a cytogenetic basis, as recommended in the WHO classification. In particular, chromosomal analysis is necessary for prognostication. The Revised International Prognosis Scoring System (IPSS-R) enables more accurate prediction of the course of disease by dividing patients into a number of low- and high-risk groups. The median survival time ranges from a few months to many years. The approved treatments, aside from transfusion therapy, include iron depletion therapy for low-risk patients, lenalidomide for low-risk patients with a deletion on the long arm of chromosome 5, and 5-azacytidine for high-risk patients. High-risk patients up to age 70 who have no major accompanying illnesses should be offered allogenic stem-cell transplantation with curative intent. The cure rates range from 30% to 50%. Mucositis, hemorrhages, infections, and graft-versus-host diseases are the most common complications of this form of treatment.

CONCLUSION

Myelodysplastic syndromes are treated on an individualized, risk-adapted basis after precise diagnostic evaluation and after assessment of the prognosis. More studies are needed so that stage-adapted treatment can be improved still further.

Up-front allogeneic hematopoietic cell transplantation in acute myeloid leukemia arising from the myelodysplastic syndrome

In patients with secondary acute myeloid leukemia (s-AML) arising from the myelodysplastic syndrome (MDS), treatment outcome is unsatisfactory. We compared up-front allogeneic hematopoietic cell transplantation (HCT) to induction chemotherapy (IC) as an initial treatment in patients with s-AML arising from MDS. This retrospective study included 85 patients who were diagnosed with s-AML arising from MDS; 11 patients proceeded to up-front HCT without IC (HCT group) and 74 received IC (IC group) as an initial treatment for s-AML, 28 of whom subsequently underwent HCT. In the IC group, 41.9% achieved complete remission (CR) compared to 81.8% in the HCT group (p = 0.013). The HCT group showed a significantly longer event-free survival (EFS) than the IC group (median 29.2 vs. 5.2 months, p = 0.042). Overall survival of the HCT group was higher than that of the IC group, but the difference was not statistically significant (median 34.6 vs. 7.6 months, p = 0.149). After adjustment for other clinical factors, outcome in the HCT group was significantly better than in the IC group in terms of CR rate (hazard ratio, HR, 11.195; p = 0.007) and EFS (HR, 0.384; p = 0.029). Up-front HCT is a viable option in s-AML arising from MDS if an appropriate donor is available.

Conditioning regimens in acute myeloid leukemia

Current intensive consolidation chemotherapy for patients with acute myeloid leukemia (AML) produces median remission duration of 12-18 months, with less than 30% of patients surviving 5 years free of disease. Post-remission therapy is necessary to prevent relapse in most patients with AML; therefore, the aim of post-remission treatment is to eradicate the minimal residual disease. Nevertheless, the optimal form of treatment is still under debate. The choice among the possible approaches (intensive chemotherapy, autologous or allogeneic hematopoietic stem cell transplantation) relies on two main factors: the expected risk of relapse, as determined by biological features, and expected morbidity and mortality associated with a specific option. In this review, we focus on the different preparative regimens before autologous and allogeneic hematopoietic stem cell transplantation in patients with AML, stressing the importance of an adequate conditioning regimen as a mandatory element of a successful AML therapy, in both the allogeneic and the autologous transplant setting.

When to transplant MDS, and what to do when transplant fails

Allogeneic hematopoietic stem cell transplantation (HCT) is still the only treatment modality with curative potential for patients with myelodysplastic syndromes. While early transplant-related mortality has improved during the last years, relapse risk following HCT still remains high, especially in older patients undergoing reduced-intensity conditioning. Therefore, when considering allogeneic HCT, in the absence of randomized data, emphasis should be put on patient selection and optimization of the pre-transplant and post-transplant period. In addition to a thorough comorbidity evaluation, risk stratification considering age, cytogenetics, grade of cytopenia, disease-related quality of life, as well as discussion of available treatment alternatives, are mandatory to decide when and how to perform allogeneic HCT. Since therapeutic options are often limited in patients relapsing after HCT, preventing relapse through maintenance strategies or minimal residual disease-directed therapy remains a central goal of current clinical research.

Risk assessment before allogeneic hematopoietic cell transplantation for older adults with acute myeloid leukemia

Acute myeloid leukemia (AML) most commonly affects patients older than 60 years. Outcomes of treatment of older AML patients have been poor. The advent of reduced-intensity conditioning (RIC) regimens made allogeneic hematopoietic cell transplantation (HCT) an available treatment option with curative intent for older AML patients. Because older patients are often excluded from clinical trials, little is known about the stratification of their risks before allogeneic HCT. While recent studies of RIC and allogeneic HCT have shown little impact of age on outcomes, other variables such as the recipient health status and the AML disease status and chromosomal aberrations have proven to be of prognostic significance. Here, the authors review recent studies of allogeneic HCT for older patients with AML with detailed evaluation of risk factors for relapse as well as non-relapse mortality. The authors have integrated the currently available information on transplant risks into a five-category risk-benefit system that could aid in the decision-making in this patient population.

Azacitidine and donor lymphocyte infusions as first salvage therapy for relapse of AML or MDS after allogeneic stem cell transplantation

The combination of azacitidine and donor lymphocyte infusions (DLI) as first salvage therapy for relapse after allogeneic transplantation (allo-HSCT) was studied in 30 patients with acute myeloid leukemia (AML; n=28) or myelodysplastic syndromes (MDS; n=2) within a prospective single-arm multicenter phase-II trial. Treatment schedule contained up to eight cycles azacitidine (100 mg/m(2)/day, days 1-5, every 28 days) followed by DLI (from 1-5 × 10(6) to 1-5 × 10(8) CD3(+)cells/kg) after every second azacitidine cycle. A median of three courses azacitidine (range 1-8) were administered, and 22 patients (73%) received DLI. Overall response rate was 30%, including seven complete remissions (CRs, 23%) and two partial remissions (7%). Five patients remain in CR for a median of 777 days (range 461-888). Patients with MDS or AML with myelodysplasia-related changes were more likely to respond (P=0.011), and a lower blast count (P=0.039) as well as high-risk cytogenetics (P=0.035) correlated with the likelihood to achieve CR. Incidence of acute and chronic graft-versus-host disease was 37% and 17%, respectively. Neutropenia and thrombocytopenia grade III/IV occurred during 65% and 63% of treatment cycles, while infections were the most common grade III/IV non-hematological toxicity. Azacitidine and DLI as salvage therapy is safe, induces long-term remissions and may become an alternative for patients with AML or MDS relapsing after allo-HSCT.