Allogeneic haematopoietic stem cell transplant in patients with lower risk myelodysplastic syndrome: a retrospective analysis on behalf of the Chronic Malignancy Working Party of the EBMT

This corrects the article DOI: 10.1038/bmt.2016.266.

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.

Allogeneic hematopoietic stem cell transplantation in solid organ transplant recipients: a retrospective, multicenter study of the EBMT

We conducted a questionnaire survey of the 565 European Society for Blood and Marrow Transplantation centers to analyze the outcome of allogeneic hematopoietic stem cell transplantation (alloSCT) in recipients of solid organ transplantation (SOT). We investigated 28 patients with malignant (N = 22) or nonmalignant diseases (N = 6), who underwent 31 alloSCT procedures: 12 after kidney, 13 after liver and 3 after heart transplantation. The incidence of solid organ graft failure at 60 months after first alloSCT was 33% (95% confidence interval [CI], 16-51%) for all patients, 15% (95% CI, 2-40%) for liver recipients and 50% (95% CI, 19-75%) for kidney recipients (p = 0.06). The relapse rate after alloSCT (22%) was low following transplantation for malignant disorders, despite advanced stages of malignancy. Overall survival at 60 months after first alloSCT was 40% (95% CI, 19-60%) for all patients, 51% (95% CI, 16-86%) for liver recipients and 42% (95% CI, 14-70%) for kidney recipients (p = 0.39). In summary, we show that selected SOT recipients suffering from hematologic disorders may benefit from alloSCT and experience enhanced long-term survival without loss of organ function.

High numbers of mobilized CD34+ cells collected in AML in first remission are associated with high relapse risk irrespective of treatment with autologous peripheral blood SCT or autologous BMT

The faster hematopoietic recovery after autologous peripheral blood SCT (APBSCT) in patients with AML may be offset by an increased relapse risk as compared with autologous BMT (ABMT). The EORTC and GIMEMA Leukemia Groups conducted a trial (AML-10) in which they compared, as second randomization, APBSCT and ABMT in first CR patients without an HLA compatible donor. A total of 292 patients were randomized. The 5-year DFS rate was 41% in the APBSCT arm and 46% in the ABMT arm with a hazard ratio (HR) of 1.17; 95% confidence interval=0.85-1.59; P=0.34. The 5-year cumulative relapse incidence was 56% vs 49% (P=0.26), and the 5-year OS 50% and 55% (P=0.6) in the APBSCT and ABMT groups, respectively. APBSCT was associated with significantly faster recovery of neutrophils and platelets, shorter duration of hospitalization, reduced need of transfusion packed RBC and less days of intravenous antibiotics. In both treatment groups, higher numbers of mobilized CD34+ cells were associated with a significantly higher relapse risk irrespective of the treatment given after the mobilization. Randomization between APBSCT and ABMT did not result in significantly different outcomes in terms of DFS, OS and relapse incidence.

Reduced intensity-conditioned allogeneic stem cell transplantation for multiple myeloma relapsing or progressing after autologous transplantation: a study by the European Group for Blood and Marrow Transplantation

Outcomes and prognostic factors of reduced intensity-conditioned allo-SCT (RIC allo-SCT) for multiple myeloma (MM) relapsing or progressing after prior autologous (auto)-SCT are not well defined. We performed an analysis of 413 MM patients who received a related or unrelated RIC allo-SCT for the treatment of relapse/progression after prior auto-SCT. Median age at RIC allo-SCT was 54.1 years, and 44.6% of patients had undergone two or more prior auto-SCTs. Median OS and PFS from the time of RIC allo-SCT for the entire population were 24.7 and 9.6 months, respectively. Cumulative non-relapse mortality (NRM) at 1 year was 21.5%. In multivariate analysis, CMV seronegativity of both patient and donor was associated with significantly better PFS, OS and NRM. Patient-donor gender mismatch was associated with better PFS, fewer than two prior auto-SCT was associated with better OS, and shorter time from the first auto-SCT to the RIC allo-SCT was associated with lower NRM. The results of this study identify patient and donor CMV seronegativity as the key prognostic factor for outcome after RIC allo-SCT for MM relapsing or progressing after prior auto-SCT.

Comparison of conditioning regimens of various intensities for allogeneic hematopoietic SCT using HLA-identical sibling donors in AML and MDS with <10% BM blasts: a report from EBMT

In this multicenter retrospective study, the long-term outcomes of 878 adults with AML and refractory anemia with excess blasts (RAEB) with BM blasts <10% who underwent transplantation with an HLA-identical sibling donor between 1998 and 2004 were analyzed according to four regimens of conditioning intensity: reduced-intensity conditioning (RIC) (either intermediate RIC (IntermRIC) or non-myeloablative (NMA) RIC), and myeloablative conditioning (MC) in 718 patients (either conventional MC or hyperintense MC. In multivariate cox analysis, patients undergoing NMA transplantation had lower non-relapse mortality risk in the first 100 days after transplantation (P<0.01), but a higher risk beyond day +100 (P=0.02), as well as higher relapse incidence in the first 12 months (P<0.01), but the risk was similar in all groups beyond 12 months. The probabilities of PFS and OS up to 7 years were significantly lower only in the NMA subgroup (P0.01 for both). The 7-year OS was 53%, 29%, 56% and 51%, respectively. Our data suggest that prospective studies comparing RIC regimens (especially IntermRIC) with MC are appropriate in patients with AML and RAEB who are in a non-advanced disease status.

Allogeneic stem cell transplantation for older advanced MDS patients: improved survival with young unrelated donor in comparison with HLA-identical siblings

We investigated whether a young human leukocyte antigen (HLA)-matched unrelated donor (MUD) should be preferred as donor to an HLA-identical sibling (MRD) for older patients with myelodysplastic syndrome (MDS) (≥ 50 years) who underwent allogeneic stem cell transplantation (AHSCT). Outcomes of 719 MDS patients with a median age of 58 years (range, 50-73 years) who received AHSCT from related (n=555) or unrelated (n=164) donors between 1999 and 2008 and reported to the European Group for Blood and Marrow Transplantation were analyzed. The median donor age of the MRD was 56 years (range: 35-78), in contrast to 34 years (range: 19-64) for the MUDs. Influence of donor's age on survival was not observed for MRD (hazard ratio (HR): 1.01 (95% confidence interval (CI): 0.99-1.02), P=0.2), but there was a significant impact of MUD's age on outcome (HR: 1.03 (95% CI: 1.01-1.06); P=0.02). Transplantation from younger MUDs (<30 years) had a significant improved 5-year overall survival in comparison with MRD and older MUDs (>30 years): 40% vs 33% vs 24% (P=0.04). In a multivariate analysis, AHSCT from young MUD (<30 years) remained a significant factor for improved survival in comparison with MRD (HR: 0.65 (95% CI: 0.45-0.95), P=0.03), which should be considered in donor selection for older patients.

The EBMT activity survey: 1990-2010

A total of 654 centers from 48 countries were contacted for the 2010 survey. In all, 634 centers reported a total of 33 362 hematopoietic SCT (HSCT) with 30 012 patients receiving their first transplant (12 276 allogeneic (41%) and 17 736 autologous (59%)). Main indications were leukemias: 9355 (31%; 93% allogeneic), lymphoid neoplasias specifically Non Hodgkin's lymphoma, Hodgkin's lymphoma and plasma cell disorders: 17 362 (58%; 12% allogeneic), solid tumors: 1585 (5%; 6% allogeneic) and non-malignant disorders: 1609 (6%; 88% allogeneic). There were more unrelated donors than HLA-identical sibling donors (53% versus 41%); the proportion of peripheral blood as stem cell source was 99% for autologous and 71% for allogeneic HSCT. Cord blood was primarily used in allogeneic transplants (6% of total) with three autologous cord blood HSCT being reported. The number of transplants has increased by 19% since 2005 (allogeneic 37% and autologous 9%) and continued to increase by about 1100 HSCT per year since 2000. Patterns of increase were distinct and different. The data show the development of transplantation in Europe since 1990, with the number of patients receiving a HSCT increasing from 4200 to over 30 000 annually. The most impressive trend seen is the steady increase of unrelated donor transplantation, in parallel to the availability of unrelated donors through donor registries.

Prophylaxis and treatment of GVHD after allogeneic haematopoietic SCT: a survey of centre strategies by the European Group for Blood and Marrow Transplantation

Recommendations on indications for allogeneic haematopoietic SCT have been presented, but transplantation techniques remain poorly standardized. Pre-transplant risk factors are well defined, and reported outcomes vary markedly among patients with similar risk characteristics. It would be of importance to know the impact of differences in treatment procedures. To study properly the different components of allogeneic transplantation, standardization of at least some central procedures would be needed. As the first step, the European Group for Blood and Marrow Transplantation (EBMT) performed a survey among all its 372 member centres performing allogeneic transplantations about their strategies in preventing and treating GVHD. Responses from 79 centres (21% return) from 25 countries (60% return) were received. Although some trends toward more uniform policies compared with a survey carried out 15 years earlier were observed, the present survey still showed marked variability in the GVHD prophylaxis and treatment strategies. On the basis of these findings, EBMT is developing a consensus process aiming at a standardized strategy.

The impact of HLA matching on long-term transplant outcome after allogeneic hematopoietic stem cell transplantation for CLL: a retrospective study from the EBMT registry

We analyzed 368 chronic lymphocytic leukemia patients who underwent allogeneic hematopoietic stem cell transplantation reported to the EBMT registry between 1995 and 2007. There were 198 human leukocyte antigen (HLA)-identical siblings; among unrelated transplants, 31 were well matched in high resolution ('well matched' unrelated donor, WMUD), and 139 were mismatched (MM), including 30 matched in low resolution; 266 patients (72%) received reduced-intensity conditioning and 102 (28%) received standard. According to the EBMT risk score, 11% were in scores 1-3, 23% in score 4, 40% in score 5, 22% in score 6 and 4% in score 7. There was no difference in overall survival (OS) at 5 years between HLA-identical siblings (55% (48-64)) and WMUD (59% (41-84)), P=0.82. In contrast, OS was significantly worse for MM (37% (29-48) P=0.005) due to a significant excess of transplant-related mortality. Also OS worsened significantly when EBMT risk score increased. HLA matching had no significant impact on relapse (siblings: 24% (21-27); WMUD: 35% (26-44), P=0.11 and MM: 21% (18-24), P=0.81); alemtuzumab T-cell depletion and stem cell source (peripheral blood) were associated with an increased risk. Our findings support the use of WMUD as equivalent alternative to HLA-matched sibling donors for allogeneic HSCT in CLL, and justify the application of EBMT risk score in this disease.

Solid organ transplantation after allogeneic hematopoietic stem cell transplantation: a retrospective, multicenter study of the EBMT

To analyze the outcome of solid organ transplantation (SOT) in patients who had undergone allogeneic hematopoietic stem cell transplantation (HSCT), a questionnaire survey was carried out within 107 European Group of Blood and Marrow Transplantation centers. This study covered HSCT between 1984 and 2007 in Europe. Forty-five SOT in 40 patients were reported. Fifteen liver, 15 renal, 13 lung, 1 heart and 1 skin transplantations were performed in 28 centers. Overall survival (OS) of patients after SOT was 78% at 5 years (95% confidence interval [CI], 64% to 92%). OS at 5 years was 100% for renal, 71% (95% CI, 46% to 96%) for liver and 63% (95% CI, 23% to 100%) for lung transplant recipients. The 2-year-incidence of SOT failure was 20% (95% CI, 4% to 36%) in patients with graft-versus-host disease (GvHD) and 7% (95% CI, 0% to 21%) in patients without GvHD before SOT. The relapse incidence for underlying malignant diseases was 4% at 5 years (95% CI, 0% to 12%). In summary, this study shows that selected patients receiving SOT after HSCT have a remarkably good overall and organ survival. These data indicate that SOT should be considered in selected patients with single organ failure after HSCT.

Thalidomide and lenalidomide in primary myelofibrosis

Primary myelofibrosis is a clonal haematopoietic stem cell disease, characterised by marrow stromal fibrosis, extramedullary haematopoiesis, splenomegaly, hepatomegaly and progressive cytopenia. Therapeutic options once cytopenia has developed are limited to supportive care, such as erythrocyte transfusions and growth factors. The aetiology has become more clear, especially since JAK-2 mutations were found, resulting in increased production of cytokines. The immune-modulating drug thalidomide and its derivative lenalidomide have shown to be effective in reducing cytopenia, most probably by inhibiting the cytokine responses. In some patients the bone marrow fibrosis disappears. We describe the experience with these drugs in a cohort of 14 patients for thalidomide and seven for lenalidomide (in six patients lenalidomide was given after thalidomide and one patient received lenalidomide upfront). Thalidomide gave clinical improvement in 6/14 patients, but its use was limited mainly due to toxicity, especially the development of neuropathy. The drug could be given for a median period of 15.5 months in responding patients. Lenalidomide was effective in 4/7 of the patients, in some patients with no response on thalidomide. Due to the more favourable toxicity profile, the median duration of therapy was 19 months, with 3/4 patients on therapy longer than 19 months. These data are discussed in view of the clinical studies published. We conclude that lenalidomide is preferred in myelofibrosis, given a higher response rate and more favourable toxicity profile. If no response the addition of prednisone can be considered. In some patients it can normalise haemoglobin and make them transfusion independent.

Female-versus-male alloreactivity as a model for minor histocompatibility antigens in hematopoietic stem cell transplantation

H-Y encoded gene products were the first to be recognized as clinically relevant minor histocompatibility antigens. Compared to other gender combinations, female donor/male recipient (FDMR) transplants are associated with increased graft-versus-host disease (GvHD), increased transplant-related mortality (TRM) and reduced risk of relapse. Still, their relative impact on transplant outcome remains controversial. We analyzed donor/recipient sex combination in 53,988 patients treated with allogeneic hematopoietic stem cell transplantation (HSCT) between 1980 and 2005. We found a strong increase in chronic GvHD and late TRM and decreased survival in FDMR transplants irrespective of underlying disease. Conversely, FDMR patients had lower relapse rates. The negative effect on survival decreased with advancing disease stage as relapse protection became more important. Effects of H-Y alloreactivity were most pronounced in patients transplanted from HLA-matched donors and in those receiving transplants from an adult donor. Adjustment for acute and chronic GvHD only partially corrected the effects of H-Y alloreactivity. Analysis of the FDMR proportion over time indicated that the frequency of this gender combination has declined in unrelated transplants over the last 10 years. These data define the role of H-Y mismatching in allogeneic HSCT and support the current practice of avoiding female donors for male patients, if possible.

Dynamics in chimerism of T cells and dendritic cells in relapsed CML patients and the influence on the induction of alloreactivity following donor lymphocyte infusion

Donor lymphocyte infusion (DLI) after allogeneic SCT induces complete remissions in approximately 80% of patients with relapsed CML in chronic phase, but some patients do not respond to DLI. We studied absolute numbers of dendritic cell (DC) subsets and chimerism in T cells and two subsets of blood DCs (myeloid DCs (MDCs) and plasmacytoid DCs (PDCs)) in relation to DLI-induced alloreactivity. Based on T cell and DC chimerism, we identified three groups. Four patients were completely donor chimeric in T cells and DC subsets. These patients had an early stage of relapse, and three of the four patients attained complete molecular remission (CMolR) without significant GVHD. Six patients were completely donor in T cells and mixed chimeric in DC subsets. All patients entered CMolR, but this was associated with GVHD in four and cytopenia in three patients. Five patients had mixed chimerism in T cells and complete recipient chimerism in MDC; only two patients entered CMolR. Our data suggest that the combination of donor T cells and mixed chimerism in DC subsets induces a potent graft-versus-leukemia (GVL) effect in association with GVHD. DLI in patients with an early relapse and donor chimerism in both T cells and DC subsets results in GVL reactivity without GVHD.

A retrospective comparison of autologous and unrelated donor hematopoietic cell transplantation in myelodysplastic syndrome and secondary acute myeloid leukemia: a report on behalf of the Chronic Leukemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT)

Hematopoietic cell transplantation (HCT) is an effective treatment for myelodysplasia (MDS) and secondary acute myeloid leukemia (sAML). In this study, outcome of 593 patients with MDS/sAML after autologous and allogeneic HCT from a matched unrelated donor (MUD) were compared. A total of 167 (28%) patients received HCT from MUD without prior chemotherapy (MUD-U). The rest received HCT in first complete remission (CR1) (Autologous (Auto-CR1), n=290 (49%), HCT from MUD (MUD-CR1), n=136 (23%)). Survival at 3 years was best in MUD-CR1 (50%) compared to Auto-CR1 (41%) and MUD-U (40%) (P=0.01). Similarly, disease-free survival was 44% for MUD-CR1 compared to Auto-CR1 (28%) and MUD-U (34%) (P=0.03). Treatment-related mortality was 17% in Auto-CR1 compared to MUD-CR1 (38%) and MUD-U (49%) (P<0.001). Relapse for Auto-CR1 was 62% compared to 24 and 30% for MUD-CR1 and MUD-U, respectively (P<0.001). Outcome was best for patients with low tumor burden transplanted 6-12 months after diagnosis. Factors influencing outcome at 3 years were mainly significant in the first 6 months. Only, relapse after autologous HCT remained constant over time. Outcomes after allogeneic HCT in patients of 20-40 and >40 years were similar. Autologous and Allogeneic HCT from MUD offer the possibility of long-term survival to patients with MDS/sAML.

Determining mucosal barrier injury to the oesophagus using CT scan

INTRODUCTION

Oral mucositis is recognised as one of the most debilitating complications of high-dose cytostatic chemotherapy used to prepare for haematopoietic stem cell transplantation (HSCT), but very little is known about oesophageal mucositis, as endoscopy is not routinely performed.

MATERIALS AND METHODS

We incorporate the computed tomography (CT) scan in the diagnostic workup of fever during neutropenia to detect evidence of pulmonary complications. This allowed us to evaluate whether mucosal barrier injury to the oesophagus can be determined. We selected 46 patients without oesophageal cancer or immune suppression (controls), who had a normal oesophagus, and measured the mucosal thickness at the upper part (UP), middle part (MP) and lower part (LP) of the oesophagus. Next, we selected 30 patients having a CT scan done for diagnostic purposes within 14 days after HSCT and measured mucosal thickness at the same levels. We also scored oral mucositis and gut toxicity.

RESULTS

The mucosal thickness of the UP, MP and LP, respectively, for the controls (mean +/- SD) was 4.1 mm (+/-1.1), 4.2 mm (+/-1.2) and 4.8 mm (+/-1.3), and the corresponding values for the subjects were 5.9 mm (+/-2.2), 5.9 mm (+/-2.0) and 7.7 mm (+/-3.0). Analysis of variance showed statistically significant differences between subjects and controls at all oesophageal levels. All patients suffered from severe oral mucositis at the time.

CONCLUSION

Hence, mucosal barrier injury to the oesophagus can be objectively measured using CT scan.

Non-infusional vs intravenous consolidation chemotherapy in elderly patients with acute myeloid leukemia: final results of the EORTC-GIMEMA AML-13 randomized phase III trial

In this trial, acute myeloid leukemia patients (pts) aged 61-80 years received MICE (mitoxantrone, etoposide and cytarabine) induction chemotherapy in combination with different schedules of granulocyte colony-stimulating factor administration. Pts in complete remission were subsequently randomized for two cycles of consolidation therapy: mini-ICE regimen (idarubicin, etoposide and cytarabine) given according to either an intravenous (i.v.) or a 'non-infusional' schedule. Among the 346 pts randomized for the second step, 331 pts received consolidation-1 and 182 consolidation-2. A total of 290 events (255 relapses, 35 deaths in first CR) have been reported. The median follow-up was 4.4 years. No significant differences were detected in terms of disease-free survival (median 9 vs 10.4 months, P=0.15, hazard ratio (HR) =1.18, 95% confidence interval (CI) 0.94-1.49) - primary end point - and survival (median 15.7 vs 17.8 months, P=0.19, HR=1.17, 95% CI 0.92-1.50). In the 'non-infusional' arm grade 3-4 vomiting (10 vs 2%; P=0.001) and diarrhea (10 vs 4%; P=0.03) were higher than in the 'i.v.' arm, whereas time to platelet recovery >20 x 10(9)/l (median: 19 vs 23 days; P=0.02) and duration of hospitalization (mean: 15 vs 27 days; P<0.0001) was shorter. The 'non-infusional' consolidation regimen resulted in an antileukemic effect similar to the intravenous regimen, which was less myelosuppressive and associated with less hospitalization days.

Autologous stem cell transplantation for therapy-related acute myeloid leukemia and myelodysplastic syndrome

We report the results of 65 patients with treatment-related myelodysplastic syndrome (MDS)/acute myelogenous leukemia (AML) who were transplanted from an autograft and reported to the EBMT. The median age was 39 years (range, 3-69), and stem cell source was bone marrow (n = 31), or peripheral blood progenitor cells (n = 30), or the combination of both (n = 4). The primary disease was solid tumors (n = 37), Hodgkin's disease (n = 13), non-Hodgkin's lymphoma (n = 10), acute lymphoblastic leukemia (n = 2) or myeloproliferative syndromes (n = 3). The types of MDS were as follows: RAEB (n = 1; 2%), RAEB-t (n = 3; 5%), or AML (n = 56; 87%). The median time between diagnosis and transplantation was 5 months (range, 3-86). The Kaplan-Meier estimates of the probability of 3-year overall and disease-free survival were 35% (95% CI: 21-49%) and 32% (95% CI: 18-45%), respectively. The median leukocyte engraftment was faster after transplantation with peripheral blood stem cells than with bone marrow: 12 (range, 9-26) vs 29 (range, 11-67) days (P<0.001). The cumulative incidence of relapse was 58% (95% CI: 44-72%) and of treatment-related mortality 12% (95% CI: 6-38%). Lower relapse rate was seen in patients transplanted in first complete remission (CR1 vs non-CR1: 3 years: 48 vs 89%; P = 0.05). Furthermore, age beyond 40 years resulted in a higher treatment-related mortality (47 vs 7%; P = 0.01). In a multivariate analysis, transplantation in CR1 age as well as their interaction influenced overall survival significantly. Autologous transplantation may cure a substantial number of patients with treatment-related MDS/AML, especially if they are in CR1 and of younger age.

Low-dose cytosine arabinoside (LD-AraC) vs LD-AraC plus granulocyte/macrophage colony stimulating factor vs LD-AraC plus Interleukin-3 for myelodysplastic syndrome patients with a high risk of developing acute leukemia: final results of a randomized phase III study (06903) of the EORTC Leukemia Cooperative Group

In this randomized phase III study of the EORTC Leukemia Cooperative Group, patients with myelodysplastic syndromes (MDS) with 10-30% bone marrow blasts and hematopoietic failure were treated with low-dose cytosine arabinoside (LD-AraC) (2 x 10 mg/m2/day subcutaneously (s.c.) days 1-14) either alone or in combination with rhGM-CSF or interleukin-3 (IL-3) both given s.c. at a dose of 150 microg/day from day 8 to 21. A total of 180 evaluable patients with a median age of 65 years and refractory anemia with an excess of blasts (RAEB, n = 107) or RAEB in transformation (RAEBt, n = 73) were randomized. There were no differences among the three treatment regimens with respect to numbers of courses applied or treatment delays. Hemorrhage occurred in approximately 40% in all arms, whereas infection rates were higher in the granulocyte/macrophage colony stimulating factor (GM-CSF)- or IL3-containing arm. The overall response rate was 38.6% with no statistically significant difference among the three arms. In summary, a substantial proportion of patients had achieved relatively durable responses in all the three arms. No influence of either growth factor was detected on the grade of cytopenia. Thus, the combination of LD-AraC with GM-CSF or IL-3 cannot be recommended for routine use in a high-risk MDS population.

Gemtuzumab ozogamicin (Mylotarg®) as single-agent treatment for frail patients 61 years of age and older with acute myeloid leukemia: final results of AML-15B, a phase 2 study of the European Organisation for Research and Treatment of Cancer and Gruppo Italiano Malattie Ematologiche dell'Adulto Leukemia Groups

The therapeutic activity and toxicity profile of gemtuzumab ozogamicin were assessed in 40 patients >60 years of age with acute myeloid leukemia (AML) who were not considered eligible for conventional chemotherapy because of advanced age or poor performance status. The drug was administered at the dose of 9 mg/m2 as a single 2-h i.v. infusion on days 1 and 15. Patients who achieved a complete remission (CR/CRp) were to receive a consolidation with two additional injections of the immunotoxin at the same dose. The overall CR/CRp rate was 17% (95% CI, 8-32%). The CR/CRp rate in patients 61-75 years old was 33% (6/18), and 5% (1/22) in patients older than 75 years. Induction death occurred in seven patients (17%), all aged above 75 years. Overall survival was significantly longer in patients aged 61-75 years than in older individuals (P=0.05), and in CD33+ cases than in CD33- cases (P=0.05). We conclude that the dose/schedule of gemtuzumab ozogamicin used in this trial is too toxic in the age group over 75 years. For these patients, additional studies with reduced doses of the immunotoxin are warranted.

ID1 and ID2 are retinoic acid responsive genes and induce a G0/G1 accumulation in acute promyelocytic leukemia cells

Acute promyelocytic leukemia (APL) is uniquely sensitive to treatment with all-trans retinoic acid (ATRA), which results in the expression of genes that induce the terminal granulocytic differentiation of the leukemic blasts. Here we report the identification of two ATRA responsive genes in APL cells, ID1 and ID2. These proteins act as antagonists of basic helix-loop-helix (bHLH) transcription factors. ATRA induced a rapid increase in ID1 and ID2, both in the APL cell line NB4 as well as in primary patient cells. In addition, a strong downregulation of E2A was observed. E2A acts as a general heterodimerization partner for many bHLH proteins that are involved in differentiation control in various tissues. The simultaneous upregulation of ID1 and ID2, and the downregulation of E2A suggest a role for bHLH proteins in the induction of differentiation of APL cells following ATRA treatment. To test the relevance of this upregulation, ID1 and ID2 were overexpressed in NB4 cells. Overexpression inhibited proliferation and induced a G0/G1 accumulation. These results indicate that ID1 and ID2 are important retinoic acid responsive genes in APL, and suggest that the inhibition of specific bHLH transcription factor complexes may play a role in the therapeutic effect of ATRA in APL.

Stem cell transplantation from identical twins in patients with myelodysplastic syndromes

In a multicentre retrospective EBMT database study, we analysed factors influencing outcome in 38 patients with MDS/sAML who were transplanted with stem cells from their syngeneic twin and compared those to 1444 patients who were transplanted from an HLA-identical sibling. The median time to leukocyte and platelet engraftment was faster in the twin group: 14 vs 17 (P=0.02) and 16 vs 26 days (P=0.09), respectively. The 5 years cumulative incidence of treatment-related mortality (TRM) was higher in the sibling than in the twin group (38 vs 27%; P=0.05). The 5 year cumulative incidence of relapse was 32% (95% CI: 29-35%) for the siblings and 39% (95% CI: 26-60%; P=0.6) for the twins. A trend for better 5-years disease-free and overall survival was observed in the twin group: 34% (95% CI: 14-54%) vs 28% (95% CI: 25-31%; P=0.2) and 36% (95% CI: 15-57%) vs 32% (95% CI: 29-35%; P=0.09), respectively. In a multivariate analysis, stem cell transplantation from identical twins had a lower TRM: HR: 0.4 (95% CI: 0.2-0.9; P=0.03). The relapse rate was similar for both groups with a HR of 1.2 (95% CI: 0.07-2.1; P=0.5), with a better survival for the twins: HR 0.6 (95% CI: 0.4-1.0; P=0.07). We conclude that twin transplantation in MDS/sAML is associated with a similar relapse risk, a lower TRM and a trend for better overall survival in comparison to transplantation from HLA-identical siblings.

Inhibitor of apoptosis proteins: new therapeutic targets in hematological cancer?

Apoptosis is an essential process for the selection and survival of lymphocytes. Resistance to apoptosis can promote malignant transformation of hematopoietic cells. Proteins that regulate apoptosis may therefore be critically involved in the development of hematological cancer. A delicate balance between pro- and antiapoptotic mechanisms determines whether a cell death signal can activate the execution of the apoptotic cell death program. The family of inhibitor of apoptosis (IAP) proteins is a recently identified, novel category of apoptosis-regulatory proteins. IAPs can inhibit the activation of caspases that are the executioners of apoptosis, activated by both the extrinsic and intrinsic pathway. IAPs may thereby set the threshold for apoptosis-activation and play a key role in the regulation of apoptotic cell death. IAPs themselves are also subject to strict regulation through feedback mechanisms. This paper focuses on the role of IAP family proteins in the regulation of apoptosis and discusses implications for their involvement in cancer and possible use for cancer therapy, especially in leukemias and lymphomas.

The presence of an HLA-identical sibling donor has no impact on outcome of patients with high-risk MDS or secondary AML (sAML) treated with intensive chemotherapy followed by transplantation: results of a prospective study of the EORTC, EBMT, SAKK and GIMEMA Leukemia Groups (EORTC study 06921)

This report used the framework of a large European study to investigate the outcome of patients with and without an HLA-identical sibling donor on an intention-to-treat basis. After a common remission-induction and consolidation course, patients with an HLA-identical sibling donor were scheduled for allogeneic transplantation and patients lacking a donor for autologous transplantation. In all, 159 patients alive at 8 weeks from the start of treatment were included in the present analysis. In total, 52 patients had a donor, 65 patients did not have a donor and in 42 patients the availability of a donor was not assessed. Out of 52 patients, 36 (69%) with a donor underwent allogeneic transplantation (28 in CR1). Out of 65 patients, 33 (49%) received an autograft (27 in CR1). The actuarial survival rates at 4 years were 33.3% (s.e. = 6.7%) for patients with a donor and 39.0% (s.e. = 6.5%) for patients without a donor (P = 0.18). Event-free survival rates were 23.1% (s.e. = 6.2%) and 21.5% (s.e. = 5.3%), respectively (P = 0.66). Correction for alternative donor transplants did not substantially alter the survival of the group without a donor. Also, the survival in the various cytogenetic risk groups was not significantly different when comparing the donor vs the no-donor group. This analysis shows that patients with high-risk myelodysplastic syndrome and secondary acute myeloid leukemia may benefit from both allogeneic and autologous transplantation. We were unable to demonstrate a survival advantage for patients with a donor compared to patients without a donor.

An EBMT registry matched study of allogeneic stem cell transplants for lymphoma: allogeneic transplantation is associated with a lower relapse rate but a higher procedure-related mortality rate than autologous transplantation

The role of allogeneic bone marrow transplantation in lymphoma remains uncertain. We have analyzed 1185 allogeneic transplants for lymphoma reported to the EBMT registry between 1982 and 1998 and compared the results with those of 14687 autologous procedures performed over the same period. Patients receiving allogeneic transplants were subdivided according to histology: low-grade non-Hodgkin's lymphoma (NHL) 231 patients; intermediate-grade NHL 147 patients; high-grade NHL 255 patients; lymphoblastic NHL 314 patients; Burkitt's lymphoma 71 patients; and Hodgkin's disease 167 patients. These patients received allogeneic transplants as their first transplant procedure. Actuarial overall survival (OS) at 4 years from transplantation was: low-grade NHL 51.1%; intermediate-grade NHL 38.3%; high-grade NHL 41.2%; lymphoblastic lymphoma 42.0% years; Burkitt's lymphoma 37.1%; and Hodgkin's disease 24.7% years. These outcomes are relatively poor because of the high procedure-related mortality associated with these procedures, particularly in patients with Hodgkin's disease (51.7% actuarial procedure-related mortality at 4 years). Multivariate analysis showed that for all lymphomas apart from Hodgkin's disease, status at transplantation significantly affected outcome. A matched analysis was performed: for all categories of lymphoma, OS was better for autologous than for allogeneic transplantation. Relapse rate was better in the allogeneic group for low-, intermediate- and high-grade, and lymphoblastic NHL. It was equivalent for Burkitt's lymphoma and worse in the allogeneic group for Hodgkin's disease. Allogeneic transplantation appears to be superior to autologous procedures in terms of producing a lower relapse rate. The toxicity of allogeneic procedures must however be reduced before this translates into an improvement in OS.

Quantification of donor and recipient hemopoietic cells by real-time PCR of single nucleotide polymorphisms

Analysis of changes in recipient and donor hemopoietic cell origin is extremely useful to monitor the effect of stem cell transplantation (SCT) and sequential adoptive immunotherapy by donor lymphocyte infusions (DLI). We developed a sensitive and accurate method to quantify the percentage of recipient and donor cells by real-time PCR using single nucleotide polymorphisms (SNPs) as markers. Allele-specific PCR of seven SNPs resulted in specific markers for donor or recipient in 97% of HLA-identical sibling pairs. Both, recipient- and donor-derived hemopoietic cells can be simultaneously analyzed in 67% sibling pairs. We expect this can be increased to approximately 99% by developing three additional SNP-PCR. Serial dilution of SNP-positive DNA into either SNP-negative DNA or water revealed a detection limit of 0.1-0.01% depending on the amount of input DNA and start C(t) of the used SNP-PCR. Application of our real-time SNP-PCR method for a CML patient treated by allogeneic SCT and DLI demonstrated its feasibility to follow donor T-cell chimerism and early detection of residual and recurrent autologous hemopoiesis in response to treatment. This detailed monitoring of the genetic origin of hemopoietic cells, in particular immune effector cells and target cells after SCT and DLI, may substantially contribute to understanding of the mechanisms that play a role in the success of treatment.

The stem cell mobilizing capacity of patients with acute myeloid leukemia in complete remission correlates with relapse risk: results of the EORTC-GIMEMA AML-10 trial

Variable numbers of CD34+ cells can be harvested from the blood of AML patients in CR after G-CSF supported mobilization following consolidation chemotherapy. We hypothesized that a decreased ability to mobilize stem cells reflects a chemotherapy-induced reduction in the number of normal and leukemic stem cells. We therefore analyzed whether the mobilizing capacity of these patients was of prognostic significance. 342 AML-patients in first CR received daily G-CSF from day 20 of the consolidation course and underwent 1-6 aphereses to obtain a minimum dose of 2 x 10(6) CD34+ cells/kg. Afterwards they were randomized for autologous bone marrow (BM) or blood SCT. As a surrogate marker for the mobilizing capacity, the highest yield of CD34+ cells of a single apheresis was adopted. Patients could be categorized into four groups: no harvest (n = 76), low yield (<1 x 10(6) CD34+/kg; n = 50), intermediate yield (1-6.9 x 10(6) CD34+ cells/kg; n = 128) and high yield (> or = 7 x 10(6) CD34+ cells/kg; n = 88). The median follow-up was 3.4 years; 163 relapses and 16 deaths in CR were reported. Autologous blood or BM SCT was performed in 36%, 64%, 81% and 88%, respectively, of the patients assigned to the no harvest, low, intermediate and high CD34+ yield group. The 3-year disease-free survival rate was 46.7%, 65.0%, 50.4% and 26.9% (P = 0.0002) and the relapse incidence was 47.5%, 30.1%, 43.1% and 71.9% (P < 0.0001). Multivariate Cox's proportional hazards model showed that the CD34+ yield was the most important independent prognostic variable (P = 0.005) after cytogenetics. Patients with the highest mobilizing capacity have a poor prognosis due to an increased relapse incidence.