A. van Biezen

Treatment-related mortality and graft-versus-leukemia activity after allogeneic stem cell transplantation for chronic lymphocytic leukemia using intensity-reduced conditioning.

Allogeneic stem cell transplantation (SCT) using reduced-intensity conditioning (RIC) has potential to be a promising treatment of aggressive chronic lymphocytic leukemia (CLL). Since available clinical data obtained with this novel approach are very limited, we have performed a survey on this issue. Data of 77 patients were collected from 29 European Group for Blood and Marrow Transplantation centers. Median age was 54 (30–66) years, and the median number of previous chemotherapy regimens was 3 (0–8). HLA-identical sibling donors were used in 81% of the cases. Moderate conditioning regimens (mainly low-dose total body irradiation (TBI) or fludarabine–cyclophosphamide combinations) were administered to 56% of the patients, whereas the remainder received more intense conditioning consisting of fludarabine–busulfan or high-dose melphalan combinations. In 40% of the patients, in vivo T-cell depletion (TCD) with anti-thymocyte globulin or CAMPATH-1H was part of the conditioning regimen. Cumulative treatment-related mortality (TRM) was 18% (95% CI 9; 27) after 12 months. Complete chimerism as well as best response was not achieved immediately post-transplant but took a median of 3 months to develop. The 2-year probability of relapse was 31% (95% CI 18; 44), with no event occurring later than 12 months post transplant in the absence of TCD. With one exception, relapses were not observed after onset of chronic graft-versus-host disease. Event-free and overall survival at 24 months were 56% (95% CI 43; 69) and 72% (95% CI 61; 83), respectively. The median follow-up was 18 (1–44) months. Donor lymphocyte infusions or secondary transplants were performed in 19 patients with insufficient disease control and/or incomplete donor chimerism post-transplant, leading to a response in seven patients (37%). Preliminary multivariate analysis identified less than PR at transplant (hazard ratio (HR) 3.5; P<0.01) and alternative donor (HR 3.1; P=0.02) as significant risk factors for relapse, whereas number of previous regimens >2 (HR 5.4; P=0.03), TBI (HR 2.5; P=0.05), and alternative donor (HR 2.3; P=0.08) were risk factors for survival. We conclude that RIC might favorably influence the outcome after allogeneic SCT for CLL by reducing TRM while preserving graft-versus leukemia activity.

Bone marrow transplantation from HLA-identical siblings as first-line treatment in patients with myelodysplastic syndromes: early transplantation is associated with improved outcome

Allogeneic bone marrow transplantation (BMT) offers a potential cure for younger patients with myelodysplastic syndromes (MDS) or secondary acute myeloid leukemia (sAML). More than 600 patients from 50 European centers have now been reported to the European Group for Blood and Marrow Transplantation (EBMT). We retrospectively analyzed 131 patients reported to the Chronic Leukemia Working Party of the EBMT who underwent BMT from HLA-identical siblings without prior remission induction chemotherapy. At the time of BMT 46 patients had refractory anemia (RA) or RA with ringed sideroblasts, 67 patients had more advanced MDS subtypes and 18 patients had progressed to sAML. The 5-year disease-free (DFS) and overall survival (OS) for the entire group of patients was 34 and 41%, respectively. Fifty patients died from transplant-related complications, most commonly graft-versus-host disease and/or infections. Relapse occurred in 28 patients between 1 and 33 months after BMT, resulting in an actuarial probability of relapse of 39% at 5 years. DFS and OS were dependent on pretransplant bone marrow blast counts. Patients with RA/RARS, RAEB, RAEB/T and sAML had a 5-year DFS of 52, 34, 19 and 26%, respectively. The 5-year OS for the respective patient groups was 57, 42, 24 and 28%. In a multivariate analysis, younger age, shorter disease duration, and absence of excess of blasts were associated with improved outcome. From these data we conclude that patients with myelodysplasia who have appropriate marrow donors, especially those aged less than 40 years and those with low medullary blast cell count should be treated with BMT as the primary treatment early in the course of their disease. Transplantation early after establishing the diagnosis of MDS may improve prognosis due to a lower treatment-related mortality and a lower relapse risk.

Reduced-intensity conditioning lowers treatment-related mortality of allogeneic stem cell transplantation for chronic lymphocytic leukemia: a population-matched analysis

To elucidate whether reduced-intensity conditioning (RIC) decreases treatment-related mortality (TRM) after allogeneic stem cell transplantation (allo-SCT) for chronic lymphocytic leukemia (CLL), we retrospectively compared 73 RIC cases from a recent EBMT survey with 82 patients from the EBMT database who had undergone standard myeloablative conditioning (MC) for CLL during the same time period. The two populations were matched by adjusting the primary risk factor, the conditioning regimen, in a series of Cox models for age, sex, donor type, remission status at transplant and analyzed for its effect on TRM, relapse incidence, event-free (EFS) and overall survival (OS). After adjustment, a significant reduction of TRM became evident for the RIC population (hazard ratio (HR) 0.4 (95% confidence interval 0.18–0.9); P=0.03). On the other hand, RIC was associated with an increased relapse incidence (HR 2.65 (0.98–7.12); P=0.054). There was no significant difference between RIC and MC in terms of EFS (HR 0.69 (0.38–1.25); P=0.22) and OS (HR 0.65 (0.33–1.28); P=0.21). We conclude that RIC appears to favorably influence TRM after allo-SCT for CLL. This observation, as well as possible detrimental effects of RIC on relapse risk, should be confirmed by prospective studies.

Unrelated bone marrow transplantation in patients with myelodysplastic syndromes and secondary acute myeloid leukemia: an EBMT survey

The Chronic Leukemia Working Party of the EBMT has collected data on 118 patients of median age 24 years (range 0.3 to 53 years) who underwent an allogeneic bone marrow transplantation from unrelated donors for treatment of MDS or secondary AML (RA/RARS, n = 24; RAEB, n = 26; RAEB-t, n = 34; CMML, n = 12; sAML, n = 22) between 1986 and 1996. The data were reported by 49 EBMT centers. Thirty-four of 118 patients are alive, relapse was the cause of death in 19 of 84 patients and the remaining patients died of transplant-related mortality. For the whole group the actuarial probability of survival at 2 years is 28%, disease-free survival 28%, relapse risk 35% and transplant-related mortality is 58%. The transplant-related mortality is significantly influenced by the age of the recipient (<18 years 40%, 18–35 years 61%, >35 years 81%). The relapse rate after BMT is influenced by FAB classification of the disease at BMT. Patients with a low blast count (RA, RAEB) have a lower probability of relapse (13%, 15%) compared to patients with RAEB-t or sAML (29%, 45%). Furthermore, we found evidence of a graft-versus-leukemia effect in MDS/sAML. Patients with acute GVHD, grade II–IV, had a probability of relapse of 26% vs 42% in patients with no acute GVHD or grade I only. Allogeneic transplantation with an HLA-matched, unrelated donor may be offered to younger patients (age <35 years) with poor risk myelodysplasia or secondary aml.

Autologous/reduced-intensity allogeneic stem cell transplantation vs autologous transplantation in multiple myeloma: long-term results of the EBMT-NMAM2000 study

Long-term follow-up of prospective studies comparing allogeneic transplantation to autologous transplantation in multiple myeloma is few and controversial. This is an update at a median follow-up of 96 months of the European Group for Blood and Marrow Transplantation Non-Myeloablative Allogeneic stem cell transplantation in Multiple Myeloma (NMAM)2000 study that prospectively compares tandem autologous/reduced intensity conditioning allogeneic transplantation (auto/RICallo) to autologous transplantation alone (auto). There are 357 myeloma patients up to age 69 years enrolled. Patients with an HLA-identical sibling were allocated to auto/RICallo (n = 108) and those without to auto alone (n = 249). At 96 months progression-free survival (PFS) and overall survival (OS) were 22% and 49% vs 12% (P = .027) and 36% (P = .030) with auto/RICallo and auto respectively. The corresponding relapse/progression rate (RL) was 60% vs 82% (P = .0002). Non-relapse mortality at 36 months was 13% vs 3% (P = .0004). In patients with the del(13) abnormality corresponding PFS and OS were 21% and 47% vs 5% (P = .026), and 31% (P = .154). Long-term outcome in patients with multiple myeloma was better with auto/RICallo as compared with auto only and the auto/RICallo approach seemed to overcome the poor prognostic impact of del(13) observed after autologous transplantation. Follow up longer than 5 years is necessary for correct interpretation of the value of auto/RICallo in multiple myeloma.

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.

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.

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.

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

N Kröger et al. recently reported the results of a retrospective analysis of 65 patients undergoing autologous stem cell transplantation for therapy-related acute myeloid leukemia (t-AML) and myelodysplastic syndrome (t-MDS). The authors analyzed European bone marrow transplantation registry data and showed that the Kaplan– Meier estimates of the probability of 3-year overall and disease-free survival were 35 and 32%, respectively. These figures exceed the results obtained with allogeneic stem cell transplantation and support the autologous approach as an alternative for patients with t-AML/t-MDS. The data presented in this publication, however, should be interpreted with caution. t-AML and t-MDS differ markedly from their de novo counterparts. Clonal chromosomal aberrations are detected in up to 97% of cases with t-AML/t-MDS and cytogenetic markers indicating a poor prognosis (7q-/-7, 5q-/-5, rearrangements involving 11q23 and complex aberrant karyotypes) predominate. In contrast, the patient collective described by Kröger et al. showed a normal karyotype in 14/34 (41%) cases with available cytogenetics and high-risk markers in only 7/34 (23%). Furthermore, 33/65 (51%) patients were younger than 40 years, indicating a lower median age than that reported in large t-AML/t-MDS studies which was uniformly over 50 years. Taken together, the favorable results obtained with autologous transplantation in patients with t-AML/tMDS may be – at least in part – attributable to a patient population with favorable clinical and biologic characteristics. Until there are prospective studies evaluating autologous transplantation, allogeneic transplantation should remain the preferred transplantation approach in patients with t-AML/t-MDS. H Sill, W Zinke-Cerwenka and A Berghold Division of Hematology, Medical University of Graz, Graz, Austria and Institute of Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria E-mail: heinz.sill@meduni-graz.at