EBMT prospective observational study on allogeneic hematopoietic stem cell transplantation in T-prolymphocytic leukemia (T-PLL).

Preliminary data suggest that allogeneic stem cell transplantation (allo-SCT) may be effective in T-prolymphocytic leukemia (T-PLL). The purpose of the present observational study was to assess the outcome of allo-SCT in patients aged 65 years or younger with a centrally confirmed diagnosis of T-PLL. Patients were consecutively registered with the EBMT at the time of transplantation and followed by routine EBMT monitoring but with an extended dataset. Between 2007 and 2012, 37 evaluable patients (median age 56 years) were accrued. Pre-treatment contained alemtuzumab in 95% of patients. Sixty-two percent were in complete remission (CR) at the time of allo-SCT. Conditioning contained total body irradiation with 6 Gy or more (TBI6) in 30% of patients. With a median follow-up of 50 months, the 4-year non-relapse mortality, relapse incidence, progression-free (PFS) and overall survival were 32, 38, 30 and 42%, respectively. By univariate analysis, TBI6 in the conditioning was the only significant predictor for a low relapse risk, and an interval between diagnosis and allo-SCT of more than 12 months was associated with a lower NRM. This study confirms for the first time prospectively that allo-SCT can provide long-term disease control in a sizable albeit limited proportion of patients with T-PLL.

Genomic prediction of relapse in recipients of allogeneic haematopoietic stem cell transplantation.

Allogeneic haematopoietic stem cell transplantation currently represents the primary potentially curative treatment for cancers of the blood and bone marrow. While relapse occurs in approximately 30% of patients, few risk-modifying genetic variants have been identified. The present study evaluates the predictive potential of patient genetics on relapse risk in a genome-wide manner. We studied 151 graft recipients with HLA-matched sibling donors by sequencing the whole-exome, active immunoregulatory regions, and the full MHC region. To assess the predictive capability and contributions of SNPs and INDELs, we employed machine learning and a feature selection approach in a cross-validation framework to discover the most informative variants while controlling against overfitting. Our results show that germline genetic polymorphisms in patients entail a significant contribution to relapse risk, as judged by the predictive performance of the model (AUC = 0.72 [95% CI: 0.63-0.81]). Furthermore, the top contributing variants were predictive in two independent replication cohorts (n = 258 and n = 125) from the same population. The results can help elucidate relapse mechanisms and suggest novel therapeutic targets. A computational genomic model could provide a step toward individualized prognostic risk assessment, particularly when accompanied by other data modalities.

Trends in patient outcome over the past two decades following allogeneic stem cell transplantation for acute myeloid leukaemia: an ALWP/EBMT analysis.

BACKGROUND: Outcomes for patients with acute myeloid leukaemia (AML) undergoing allogeneic stem cell transplantation (allo-SCT) have significantly improved in recent years. OBJECTIVES: To assess the incremental improvement of transplanted AML patients in the last two decades. METHODS: Patients included in this analysis were adult AML patients who underwent allo-SCT from an HLA-matched sibling donor (MSD) or HLA-matched unrelated donor (MUD) in first remission. Patient outcomes were assessed between three cohorts according to the year of transplant (1993-2002, 2003-2007 and 2008-2012). RESULTS: The analysis comprised a total of 20 187 patients of whom 4763 were transplanted between 1993 and 2002, 5835 in 2003 and 2007, and 9589 in 2008 and 2012. In multivariate analysis, leukaemia-free survival (LFS) rates were significantly improved in more recently transplanted patients compared to patients transplanted in 1993-2002 [Hazard ratio (HR) = 0.84, confidence interval (CI) 95%, 0.77-0.92; P = 0.003], a benefit which also extended to improved overall survival (OS; HR = 0.8, CI 95%, 0.73-0.89; P < 0.0001), and decreased nonrelapse mortality (NRM) rates (HR = 0.65, CI 95%, 0.56-0.75; P < 0.0001). Subset analysis revealed that in MSD, the rates of LFS, NRM and OS significantly improved in patients in the more recent cohort with similar results also seen in MUD. Finally, the incidence of acute graft-versus-host disease (GVHD) was significantly reduced leading to improved GVHD-free/relapse-free survival (GRFS) rates in more recently transplanted patients. CONCLUSION: Outcome of allo-SCT for AML patients has markedly improved in the last two decades owing to decreased nonrelapse mortality and improved rates of leukaemia-free survival resulting in significantly longer survival.

What is the outcome in patients with acute leukaemia who survive severe acute graft-versus-host disease?

BACKGROUND: Acute graft-versus-host disease (aGVHD) is a major complication of allogeneic haematopoietic stem cell transplantation (HSCT). With new promising therapies, survival may improve for severe aGVHD. OBJECTIVES: We wanted to analyze the long-term outcome in patients who survive severe aGVHD. METHODS: This study was a landmark analysis of 23 567 patients with acute Leukaemia who survived for more than 6 months after HSCT, 2002-2014. Patients alive after severe aGVHD (n = 1738) were compared to controls. RESULTS: Patients with severe aGVHD had higher non-relapse mortality (NRM) and higher rate of extensive chronic GVHD (cGVHD) than the controls (P < 10-5 ). The probability of relapse was significantly lower in the severe aGVHD group, but Leukaemia-free survival (LFS) and overall survival were significantly lower than for the controls (P < 10-5 ). Five-year LFS in patients with severe aGVHD was 49%, as opposed to 61% in controls with no or mild GVHD and 59% in patients with moderate GVHD. CONCLUSIONS: HSCT patients who survive severe aGVHD have higher risk of developing extensive cGVHD, a higher NRM, a lower relapse probability, and lower LFS than other HSCT patients. This study is a platform for outcome analysis in patients treated with novel therapies for acute GVHD.

Distinct factors determine the kinetics of disease relapse in adults transplanted for acute myeloid leukaemia.

BACKGROUND: Disease recurrence remains the major cause of death in adults with acute myeloid leukaemia (AML) treated using either intensive chemotherapy (IC) or allogenic stem cell transplantation (allo-SCT). AIMS: The timely delivery of maintenance drug or cellular therapies represent emerging strategies with the potential to reduce relapse after both treatment modalities, but whilst the determinants of overall relapse risk have been extensively characterized the factors determining the timing of disease recurrence have not been characterized. MATERIALS AND METHODS: We have therefore examined, using a series of sequential landmark analyses, relapse kinetics in a cohort of 2028 patients who received an allo-SCT for AML in CR1 and separately 570 patients treated with IC alone. RESULTS: In the first 3 months after allo-SCT, the factors associated with an increased risk of relapse included the presence of the FLT3-ITD (P < 0.001), patient age (P = 0.012), time interval from CR1 to transplant (P < 0.001) and donor type (P = 0.03). Relapse from 3 to 6 months was associated with a higher white cell count at diagnosis (P = 0.001), adverse-risk cytogenetics (P < 0.001), presence of FLT3-ITD mutation (P < 0.001) and time interval to achieve first complete remission (P = 0.013). Later relapse was associated with adverse cytogenetics, mutated NPM1, absence of chronic graft-versus-host disease (GVHD) and the use of in vivo T-cell depletion. In patients treated with IC alone, the factors associated with relapse in the first 3 months were adverse-risk cytogenetics (P < 0.001) and FLT3-ITD status (P = 0.001). The factors predicting later relapse were the time interval from diagnosis to CR1 (P = 0.22) and time interval from CR1 to IC (P = 0.012). DISCUSSION AND CONCLUSION: Taken together, these data provide novel insights into the biology of disease recurrence after both allo-SCT and IC and have the potential to inform the design of novel maintenance strategies in both clinical settings.

Validation of the revised IPSS at transplant in patients with myelodysplastic syndrome/transformed acute myelogenous leukemia receiving allogeneic stem cell transplantation: a retrospective analysis of the EBMT chronic malignancies working party.

The International Prognostic Scoring System has been revised (IPSS-R) to predict prognosis of patients with myelodysplastic syndromes at diagnosis. To validate the use of the IPSS-R assessed before transplant rather than at diagnosis we performed a retrospective analysis of the EBMT database. A total of 579 patients had sufficient information available to calculate IPSS-R at transplant. Median overall survival (OS) from transplant was significantly different according to IPSS-R: very low 23.6 months, low 55.0 months, intermediate 19.7 months, high 13.5 months, very high 7.8 months (P<0.001). In a multivariate Cox model the following parameters were significant risk factors for OS: IPSS-R, graft source, age and prior treatment. Median relapse free survival also showed significant differences according to IPSS-R: very low: 23.6 months, low: 24.8 months, intermediate 10.6 months, high 7.9 months, very high 5.5 months (P<0.001). Multivariate risk factors for relapse-free survival (RFS) were: IPSS-R, reduced intensity conditioning, graft source and prior treatment. A trend for an increased relapse incidence was noted for very high risk IPSS-R. We conclude that the IPSS-R at transplant is a useful prognostic score for predicting OS and RFS after transplantation, capturing both disease evolution and response to prior treatment before transplant.

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.

Long-term follow-up of a retrospective comparison of reduced-intensity conditioning and conventional high-dose conditioning for allogeneic transplantation from matched related donors in myelodysplastic syndromes.

This study shows the long-term updated outcomes of a multicenter retrospective study which analyzed 843 patients with myelodysplastic syndrome (MDS) who underwent transplantation with an HLA-identical sibling donor with either reduced-intensity conditioning (RIC) in 213 patients, or standard myeloablative conditioning (MAC) in 630 patients. In multivariate analysis, the 13-year relapse rate was significantly increased after RIC (31% after MAC vs 48% in RIC; HR, 1.5; 95% CI, 1.1-1.9; P=0.04), but with no differences in overall survival (OS) (30% after MAC vs 27% in RIC; P=0.4) and PFS (29 vs 21%, respectively, P=0.3). Non-relapse mortality was higher in MAC (40 vs 31%; P=0.1), especially in patients older than 50 years (50 vs 33%, P<0.01). In addition, long-term follow-up confirms the importance of other variables on 13-year OS, mainly MDS risk category, disease phase, cytogenetics and receiving a high donor cell dose, irrespective of the conditioning regimen used.

Risk factors for treatment failure after allogeneic transplantation of patients with CLL: a report from the European Society for Blood and Marrow Transplantation.

For young patients with high-risk CLL, BTK-/PI3K-inhibitors or allogeneic stem cell transplantation (alloHCT) are considered. Patients with a low risk of non-relapse mortality (NRM) but a high risk of failure of targeted therapy may benefit most from alloHCT. We performed Cox regression analyses to identify risk factors for 2-year NRM and 5-year event-free survival (using EFS as a surrogate for long-term disease control) in a large, updated EBMT registry cohort (n= 694). For the whole cohort, 2-year NRM was 28% and 5-year EFS 37%. Higher age, lower performance status, unrelated donor type and unfavorable sex-mismatch had a significant adverse impact on 2-year NRM. Two-year NRM was calculated for good- and poor-risk reference patients. Predicted 2-year-NRM was 11 and 12% for male and female good-risk patients compared with 42 and 33% for male and female poor-risk patients. For 5-year EFS, age, performance status, prior autologous HCT, remission status and sex-mismatch had a significant impact, whereas del(17p) did not. The model-based prediction of 5-year EFS was 55% and 64%, respectively, for male and female good-risk patients. Good-risk transplant candidates with high-risk CLL and limited prognosis either on or after failure of targeted therapy should still be considered for alloHCT.

Long-term survival of patients with CLL after allogeneic transplantation: a report from the European Society for Blood and Marrow Transplantation.

Even with the availability of targeted drugs, allogeneic hematopoietic cell transplantation (allo-HCT) is the only therapy with curative potential for patients with CLL. Cure can be assessed by comparing long-term survival of patients to the matched general population. Using data from 2589 patients who received allo-HCT between 2000 and 2010, we used landmark analyses and methods from relative survival analysis to calculate excess mortality compared with an age-, sex- and calendar year-matched general population. Estimated event-free survival, overall survival and non-relapse mortality (NRM) 10 years after allo-HCT were 28% (95% confidence interval (CI), 25-31), 35% (95% CI, 32-38) and 40% (95% CI, 37-42), respectively. Patients who passed the 5-year landmark event-free survival (N=394) had a 79% probability (95% CI, 73-85) of surviving the subsequent 5 years without an event. Relapse and NRM contributed equally to treatment failure. Five-year mortality for 45- and 65-year-old reference patients who were event-free at the 5-year landmark was 8% and 47% compared with 3% and 14% in the matched general population, respectively. The prospect of long-term disease-free survival remains an argument to consider allo-HCT for young patients with high-risk CLL, and programs to understand and prevent late causes of failure for long-term survivors are warranted, especially for older patients.

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.

We report a retrospective analysis of 246 myelodysplastic syndrome (MDS) patients in the EBMT (The European Society for Blood and Marrow Transplantation) database who were transplanted for International Prognostic Scoring System (IPSS) low or intermediate-1 disease. The majority of these patients (76%) were reclassified as intermediate or higher risk according to R-IPSS. The 3-year overall survival (OS) and PFS were 58% and 54%, respectively. In a multivariate analysis, adverse risk factors for PFS were marrow blast percentage (hazard ratio (HR): 1.77, P=0.037), donor/recipient CMV serostatus (donor-/recipient+: HR: 2.02, P=0.011) and source of stem cells (marrow and non-CR: HR: 5.72, P<0.0001, marrow and CR: HR: 3.17, P=0.027). Independent risk factors for OS were disease status at time of transplant and the use of in vivo T-cell depletion (TCD). Patients who did not receive TCD and were transplanted from an unrelated donor had worse OS (HR: 4.08, P<0.0001). In conclusion, 'lower' risk MDS patients have better outcome than those with 'higher risk' after haematopoietic stem cell transplant (HSCT). Selecting the right source of stem cells, a CMV-positive donor for CMV-positive patients and using in vivo TCD results in the best outcome in these patients. More studies are needed to evaluate the role of HSCT in these patients as compared with conventional treatment.

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 cell transplantation for multiple myeloma in Europe: trends and outcomes over 25 years. A study by the EBMT Chronic Malignancies Working Party.

We describe the use and outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for multiple myeloma (MM) in Europe between January 1990 and December 2012. We identified 7333 patients, median age at allo-HSCT was 51 years (range: 18-78), of whom 4539 (62%) were males. We distinguished three groups: (1) allo-HSCT upfront (n=1924), (2) tandem auto-allo-HSCT (n=2004) and (3) allo-HSCT as a second line treatment and beyond (n=3405). Overall, there is a steady increase in numbers of allo-HSCT over the years. Upfront allo-HSCT use increased up to year 2000, followed by a decrease thereafter and represented 12% of allo-HSCTs performed in 2012. Tandem auto-allo-HSCT peaked around year 2004 and contributed to 19% of allo-HSCTs in 2012. Allo-HSCT as salvage after one or two or three autografts was steadily increasing over the last years and represented 69% of allo-HSCTs in 2012. Remarkable heterogeneity in using allo-HSCT was observed among the different European countries. The 5-year survival probabilities from time of allo-HSCT for the three groups after year 2004 were 42%, 54% and 32%, respectively. These results show that the use of allo-HSCT is increasing in Europe, especially as second line treatment and beyond. There is an unmet need for well-designed prospective studies investigating allo-HSCT as salvage therapy for MM.

Conflicting HLA assignment by three different typing methods due to the apparent loss of heterozygosity in the MHC region.

Loss of heterozygosity (LOH) has been reported to cause false human leukocyte antigen (HLA) homozygous typing results in pre-transplant patients suffering from haematological malignancies, who in fact are HLA heterozygous. This poses a challenge for histocompatibility testing, as a stem cell graft from a genuinely HLA homozygous donor to a mistyped patient may lead to acute life-threatening graft-vs-host disease. LOH in the HLA region on chromosome 6 is known to be quite common in solid tumours, helping malignant cells to escape T-cell surveillance, but the incidence in haematological malignancies is less well known and the estimates vary. Here we report LOH in the HLA region of five patients with haematological malignancy. We found considerable differences in sensitivity between the three different HLA typing methods used in our laboratory: SSP was clearly the most sensitive method for detecting the lost haplotype, followed by rSSO, while SBT was the least sensitive technique. A subsequent, retrospective genotyping of 65 HLA homozygous haematological patients by SSP method showed no mistyped LOH cases in our laboratory in the past 10 years. The frequency of HLA homozygosity was found to be similar between haematological patients and control groups. It is important for an HLA laboratory to be aware of the differences in various HLA typing techniques' sensitivity for detecting an under-represented haplotype between HLA typing techniques when genotyping patients with haematological diseases. It is advisable for HLA laboratories to have at least two different methods with different sensitivities in their repertoire to be able to retype samples when a false homozygous result is suspected.

Reduced intensity allogeneic stem cell transplantation for follicular lymphoma relapsing after an autologous transplant achieves durable long-term disease control: an analysis from the Lymphoma Working Party of the EBMT†.

BACKGROUND: Patients with follicular lymphoma (FL) relapsing after an autologous transplant (autoSCT) may be treated with a variety of therapies, including a reduced intensity allogeneic transplant (RICalloSCT). We conducted a retrospective analysis of a large cohort of patients undergoing RICalloSCT for FL in this setting. PATIENTS AND METHODS: A total of 183 patients, median age 45 years (range 21-69), had undergone an autoSCT at a median of 30 months before the RICalloSCT. Before the RICalloSCT, they had received a median of four lines (range 3-10) of therapy and 81% of patients had chemosensitive disease and 16% had chemoresistant disease. Grafts were donated from sibling (47%) or unrelated donors (53%). RESULTS: With a median follow-up of 59 months, the non-relapse mortality (NRM) was 27% at 2 years. The median remission duration post-autoSCT and RICalloSCT was 14 and 43 months, respectively. The 5-year relapse/progression rate, progression-free survival and overall survival were 16%, 48% and 51%, respectively, and were associated with age and disease status at RICalloSCT. CONCLUSION: These data suggest that an RICalloSCT is an effective salvage strategy in patients with FL recurring after a prior autoSCT and might overcome the poor prognostic impact of early relapse after autoSCT.

Conditioning intensity in middle-aged patients with AML in first CR: no advantage for myeloablative regimens irrespective of the risk group-an observational analysis by the Acute Leukemia Working Party of the EBMT.

In recipients of allogeneic hematopoietic stem cell transplantation with AML in CR1, reduced intensity (RIC) conditioning regimens are usually given to older patients and myeloablative regimens (MAC) to younger patients. We analyzed whether in middle-aged patients aged 40-60 years, MAC was superior to RIC in cytogenetically higher risk AML. Among 2974 patients, 1638 had MAC and 1336 RIC transplants. Cytogenetics were high risk in 508, intermediate risk in 2297 and low risk in 169. Overall survival (OS) was higher in patients with RIC with low-risk cytogenetics but not in the intermediate- or poor-risk AML. Relapse incidence was lower with MAC in poor- and intermediate-risk AML. Nonrelapse mortality (NRM) was higher in MAC in all cytogenetic risk groups. Multivariate analysis confirmed a significant leukemia-free survival and OS advantage for RIC in low risk but no advantage of MAC in intermediate- and poor-risk leukemia. In patients aged 40-60 years, MAC has no advantage over RIC. We confirm lower relapse but higher NRM risks with MAC. MAC is not superior in patients with higher risk cytogenetics, but is inferior to RIC in the small cohort of AML patients with low-risk cytogenetics.

Outcome of allogeneic hematopoietic stem-cell transplantation for adult patients with AML and 11q23/MLL rearrangement (MLL-r AML).

Acute myeloid leukemia (AML) with 11q23/MLL rearrangement (MLL-r AML) is allocated to the intermediate- or high-risk cytogenetic prognostic category depending on the MLL fusion partner. A more favorable outcome has been reported in patients receiving an allogeneic hematopoietic stem-cell transplantation (alloHSCT), but this has not been confirmed in large series. We analyzed the outcome of alloHSCT among adult patients reported to the Acute Leukemia Working Party between 2000 and 2010. We identified 159 patients with 11q23/MLL rearranged AML allografted in first complete remission (CR1, n=138) or CR2, mostly corresponding to t(9;11), t(11;19), t(6;11) and t(10;11) translocations. Two-year overall survival (OS), leukemia-free survival (LFS), relapse incidence and non-relapse mortality were 56±4%, 51±4%, 31±3% and 17±4%, respectively. The outcome differed according to 11q23/MLL rearrangement, being more favorable in patients with t(9;11) and t(11;19) compared with t(10;11) and t(6;11) (2-year OS: 64±6% and 73±10% vs 40±13% and 24±11%, respectively; P<0.0001). Multivariate analysis for OS identified t(6;11), t(10;11), age>40 years and CR2 as unfavorable features, whereas t(6;11), t(10;11), CR2 and the use of reduced-intensity conditioning regimen affected poorly the LFS. This study confirms the potential role of alloHSCT for adult patients with 11q23/MLL rearranged AML in CR1.