Allogeneic hematopoietic stem cell transplantation for advanced mycosis fungoides and Sézary syndrome. An updated experience of the Lymphoma Working Party of the European Society for Blood and Marrow Transplantation.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment option in advanced-stage mycosis fungoides (MF) and Sézary syndrome (SS). This study presents an updated analysis of the initial experience of the Lymphoma Working Party of the European Society for Blood and Marrow Transplantation (EBMT) describing the outcomes after allo-HSCT for MF and SS, with special emphasis on the impact of the use of unrelated donors (URD). METHODS AND PATIENTS: Eligible for this study were patients with advanced-stage MF or SS who underwent a first allo-HSCT from matched HLA-identical related or URD between January/1997 and December/2011. Sixty patients have been previously reported. RESULTS: 113 patients were included [77 MF (68%)]; 61 (54%) were in complete or partial remission, 86 (76%) received reduced-intensity protocols and 44 (39%) an URD allo-HSCT. With a median follow up for surviving patients of 73 months, allo-HSCT resulted in an estimated overall survival (OS) of 38% at 5 years, and a progression-free survival (PFS) of 26% at 5 years. Multivariate analysis demonstrated that advanced-phase disease (complete remission/partial remission >3, primary refractory or relapse/progression in patients that had received 3 or more lines of systemic treatment prior to transplant or the number of treatment lines was not known), a short interval between diagnosis and transplant (<18 months) were independent adverse prognostic factors for PFS; advanced-phase disease and the use of URDs were independent adverse prognostic factors for OS. CONCLUSIONS: This extended series supports that allo-HSCT is able to effectively rescue over one third of the population of patients with advanced-stage MF/SS. High relapse rate is still the major cause of failure and needs to be improved with better strategies before and after transplant. The negative impact of URD is a matter of concern and needs to be further elucidated in future studies.

'Off-the-shelf' allogeneic CAR T cells: development and challenges.

Autologous chimeric antigen receptor (CAR) T cells have changed the therapeutic landscape in haematological malignancies. Nevertheless, the use of allogeneic CAR T cells from donors has many potential advantages over autologous approaches, such as the immediate availability of cryopreserved batches for patient treatment, possible standardization of the CAR-T cell product, time for multiple cell modifications, redosing or combination of CAR T cells directed against different targets, and decreased cost using an industrialized process. However, allogeneic CAR T cells may cause life-threatening graft-versus-host disease and may be rapidly eliminated by the host immune system. The development of next-generation allogeneic CAR T cells to address these issues is an active area of research. In this Review, we analyse the different sources of T cells for optimal allogeneic CAR-T cell therapy and describe the different technological approaches, mainly based on gene editing, to produce allogeneic CAR T cells with limited potential for graft-versus-host disease. These improved allogeneic CAR-T cell products will pave the way for further breakthroughs in the treatment of cancer.

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.

Late treatment-related mortality versus competing causes of death after allogeneic transplantation for myelodysplastic syndromes and secondary acute myeloid leukemia.

The causes and rates of late patient-mortality following alloHCT for myelodysplastic syndromes or secondary acute myeloid leukemia were studied, to assess the contribution of relapse-related, treatment-related, and population factors. Data from EBMT on 6434 adults, who received a first alloHCT from January 2000 to December 2012, were retrospectively studied using combined land-marking, relative-survival methods and multi-state modeling techniques. Median age at alloHCT increased from 49 to 58 years, and the number of patients aged ≥65 years at alloHCT increased from 5 to 17%. Overall survival probability was 53% at 2 years and 35% at 10 years post-alloHCT. Survival probability at 5 years from the 2-year landmark was 88% for patients <45-year old and 63% for patients ≥65-year old at alloHCT. Cumulative incidence of nonrelapse mortality (NRM) for patients <45-year old at transplant was 7% rising to 25% for patients aged ≥65. For older patients, 31% of NRM-deaths could be attributed to population mortality. Favorable post-alloHCT long-term survival was seen; however, excess mortality-risk for all age groups was shown compared to the general population. A substantial part of total NRM for older patients was attributable to population mortality, information which aids the balanced explanation of post-HCT risk and helps improve long-term care.

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.

Preclinical modeling of myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) represent a heterogeneous group of hematological clonal disorders. Here, we have tested the bone marrow (BM) cells from 38 MDS patients covering all risk groups in two immunodeficient mouse models: NSG and NSG-S. Our data show comparable level of engraftment in both models. The level of engraftment was patient specific with no correlation to any specific MDS risk group. Furthermore, the co-injection of mesenchymal stromal cells (MSCs) did not improve the level of engraftment. Finally, we have developed an in vitro two-dimensional co-culture system as an alternative tool to in vivo. Using our in vitro system, we have been able to co-culture CD34+ cells from MDS patient BM on auto- and/or allogeneic MSCs over 4 weeks with a fold expansion of up to 600 times. More importantly, these expanded cells conserved their MDS clonal architecture as well as genomic integrity.

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.

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.

Comparison of Intensive Chemotherapy and Hypomethylating Agents before Allogeneic Stem Cell Transplantation for Advanced Myelodysplastic Syndromes: A Study of the Myelodysplastic Syndrome Subcommittee of the Chronic Malignancies Working Party of the European Society for Blood and Marrow Transplant Research.

The European Society for Blood and Marrow Transplant Research data set was used to retrospectively analyze the outcomes of hypomethylating therapy (HMA) compared with those of conventional chemotherapy (CC) before hematopoietic stem cell transplantation (HSCT) in 209 patients with advanced myelodysplastic syndromes. Median follow-up was 22.1 months and the median age of the group was 57.6 years with 37% of the population older than > 60 years. The majority of patients (59%) received reduced-intensity conditioning and 34% and 27% had intermediate-2 and high international prognostic scoring system (IPSS) scores. At time of HSCT, 32% of patients did not achieve complete remission (CR) and 13% had primary refractory disease. On univariate analysis, outcomes at 3 years were not significantly different between HMA and CC for overall survival (OS), relapse-free survival (RFS), cumulative incidence of relapse (CIR), and nonrelapse mortality (NRM): OS (42% versus 35%), RFS (29% versus 31%), CIR (45% versus 40%), and NRM (26% versus 28%). Comparing characteristics of the groups, there were more patients < 55 years old, more patients in CR (68% versus 32%), and fewer patients with primary refractory disease in the CC group than in the HMA group (10% versus 19%, P < .001). Patients with primary refractory disease had worse outcomes than those in CR with regard to OS (hazard ratio [HR], 2.42; 95% confidence interval [CI], 1.41 to 4.13; P = .001), RFS (HR, 2.27; 95% CI, 1.37 to 3.76; P = .001), and NRM (HR, 2.49; 95% CI, 1.18 to 5.26; P = .016). In addition, an adverse effect of IPSS-R cytogenetic risk group was evident for RFS. In summary, outcomes after HSCT are similar for patients receiving HMA compared with those receiving CC, despite the higher proportion of patients with primary refractory disease in the HMA group.

Clinical significance of acquired somatic mutations in aplastic anaemia.

Aplastic anaemia (AA) is frequently associated with other disorders of clonal haemopoiesis such as paroxysmal nocturnal haemoglobinuria (PNH), myelodysplastic syndrome (MDS) and T-large granular lymphocytosis. Certain clones may escape the immune attack within the bone marrow environment and proliferate and attain a survival advantage over normal haemopoietic stem cells, such as trisomy 8, loss of heterozygosity of short arm of chromosome 6 and del13q clones. Recently acquired somatic mutations (SM), excluding PNH clones, have been reported in around 20-25 % of patients with AA, which predispose to a higher risk of later malignant transformation to MDS/acute myeloid leukaemia. Furthermore, certain SM, such as ASXL1 and DNMT3A are associated with poor survival following immunosuppressive therapy, whereas PIGA, BCOR/BCORL1 predict for good response and survival. Further detailed and serial analysis of the immune signature in AA is needed to understand the pathogenetic basis for the presence of clones with SM in a significant proportion of patients.

Impact of TP53 mutation variant allele frequency on phenotype and outcomes in myelodysplastic syndromes.

Although next-generation sequencing has allowed for the detection of somatic mutations in myelodysplastic syndromes (MDS), the clinical relevance of variant allele frequency (VAF) for the majority of mutations is unknown. We profiled TP53 and 20 additional genes in our training set of 219 patients with MDS or secondary acute myeloid leukemia with findings confirmed in a validation cohort. When parsed by VAF, TP53 VAF predicted for complex cytogenetics in both the training (P=0.001) and validation set (P<0.0001). MDS patients with a TP53 VAF > 40% had a median overall survival (OS) of 124 days versus an OS that was not reached in patients with VAF <20% (hazard ratio (HR), 3.52; P=0.01) with validation in an independent cohort (HR, 4.94, P=0.01). TP53 VAF further stratified distinct prognostic groups independent of clinical prognostic scoring systems (P=0.0005). In multivariate analysis, only a TP53 VAF >40% was an independent covariate (HR, 1.61; P<0.0001). In addition, SRSF2 VAF predicted for monocytosis (P=0.003), RUNX1 VAF with thrombocytopenia (P=0.01) and SF3B1 with ringed sideroblasts (P=0.001). Together, our study indicates that VAF should be incorporated in patient management and risk stratification in MDS.

High concordance of genomic and cytogenetic aberrations between peripheral blood and bone marrow in myelodysplastic syndrome (MDS).

Bone marrow (BM) genetic abnormalities in myelodysplastic syndrome (MDS) have provided important biological and prognostic information; however, frequent BM sampling in older patients has been associated with significant morbidity. Utilizing single-nucleotide polymorphism array (SNP-A) and targeted gene sequencing (TGS) of 24 frequently mutated genes in MDS, we assessed the concordance of genetic abnormalities in BM and peripheral blood (PB) samples concurrently from 201 MDS patients. SNP-A karyotype in BM was abnormal in 108 (54%) and normal in 93 (46%) patients, with 95% (190/201) having an identical PB karyotype. The median copy number (CN) for deletions was significantly lower in BM (CN:1.4 (1-1.9)) than in PB (CN:1.5 (1-1.95), P<0.001). Using TGS, 71% (130/183) patients had BM somatic mutations with 95% (124/130) having identical mutations in PB. The mutant allele burden was lower in PB (median 27% (1-96%)) compared with BM (median 29% (1-100%); P=0.14) with no significant difference in the number, types of mutations or World Health Organization subtype. In all patients with discordant SNP (n=11) and mutation (n=6) profiles between BM and PB, shared abnormalities were always present irrespective of treatment status. Overall, 86% of patients had a clonal aberration with 95% having identical SNP-A karyotype and mutations in PB, thus enabling frequent assessment of response to treatment and disease evolution especially in patients with fibrotic or hypocellular marrows.

The relationship of TP53 R72P polymorphism to disease outcome and TP53 mutation in myelodysplastic syndromes.

Nonsynonymous TP53 exon 4 single-nucleotide polymorphism (SNP), R72P, is linked to cancer and mutagen susceptibility. R72P associations with specific cancer risk, particularly hematological malignancies, have been conflicting. Myelodysplastic syndrome (MDS) with chromosome 5q deletion is characterized by erythroid hypoplasia arising from lineage-specific p53 accumulation resulting from ribosomal insufficiency. We hypothesized that apoptotically diminished R72P C-allele may influence predisposition to del(5q) MDS. Bone marrow and blood DNA was sequenced from 705 MDS cases (333 del(5q), 372 non-del(5q)) and 157 controls. Genotype distribution did not significantly differ between del(5q) cases (12.6% CC, 38.1% CG, 49.2% GG), non-del(5q) cases (9.7% CC, 44.6% CG, 45.7% GG) and controls (7.6% CC, 37.6% CG, 54.8% GG) (P=0.13). Allele frequency did not differ between non-del(5q) and del(5q) cases (P=0.91) but trended towards increased C-allele frequency comparing non-del(5q) (P=0.08) and del(5q) (P=0.10) cases with controls. Median lenalidomide response duration increased proportionate to C-allele dosage in del(5q) patients (2.2 (CC), 1.3 (CG) and 0.89 years (GG)). Furthermore, C-allele homozygosity in del(5q) was associated with prolonged overall and progression-free survival and non-terminal interstitial deletions that excluded 5q34, whereas G-allele homozygozity was associated with inferior outcome and terminal deletions involving 5q34 (P=0.05). These findings comprise the largest MDS R72P SNP analysis.

Life coaching following haematopoietic stem cell transplantation: a mixed-method investigation of feasibility and acceptability.

Haematopoietic stem cell transplantation (HSCT) cures many haematological cancers. Recovery post-HSCT is physically and psychologically challenging, lasting several months. Beyond the first post-transplant year, a fifth report difficulties encompassing practical, social and emotional domains, including finance and employment. We investigated the feasibility, acceptability and impact of a life coaching intervention designed to address psychosocial 'survivor' concerns of HSCT recipients and facilitate transition to life post-treatment. A concurrent embedded experimental mixed-method design was employed. Pre- and post-intervention data collection comprised qualitative semi-structured telephone interviews and quantitative postal questionnaires. Seven purposively sampled HSCT recipients (<18 months) participated, reporting on one-to-one life coaching delivered by a professional life coach fortnightly over 8 weeks. Participants reported less anxiety, depression and fewer survivor concerns post-intervention, with a trend for lower social difficulties and increased functional well-being. Perceived self-efficacy was unchanged. Life coaching was feasible to deliver and acceptable to the participants who indicated it was a positive experience, with benefits described in diverse areas including work, lifestyle and hobbies. Life coaching within cancer services potentially offers the means to address psychosocial concerns and support transition to life after treatment, enabling patients to reach their potential, e.g. returning to employment and financial independence. Further investigation of this intervention in cancer survivors is warranted.

A multicentre UK study of GVHD following DLI: rates of GVHD are high but mortality from GVHD is infrequent.

DLIs are frequently used following haematopoietic SCT (HSCT) in patients with risk of relapse but data on GVHD following DLI are scarce. We report on 68 patients who received DLI following HSCT. Most patients developed GVHD following DLI (71%), which was acute in 22 patients (32%) almost half of whom had grade III-IV acute GVHD (aGVHD). Thirty patients (44%) developed cGVHD which followed aGVHD in four patients and was graded severe in nine patients. Corticosteroids were the most common first-line therapy for both acute and chronic GVHD. A wide range of second/third-line agents included cyclosporin, mycophenolate, tacrolimus, imatinib, infliximab and ECP. Relapse of initial malignancy occurred in 37%. Relapse was significantly less frequent in those receiving pre-emptive DLI. Relapse rates were also lower in those with GVHD (31%) than those without GVHD (50%), but this did not reach statistical significance. At 55 months post DLI, 34% of patients had died most commonly from relapse and 22% had on-going GVHD. Although GVHD was an important cause of morbidity post DLI (71%), only 6% died from GVHD. Although most patients develop GVHD post DLI and may require consecutive therapies, mortality from GVHD is infrequent. DLI remains an important option for relapse post transplant and manipulation of the GVT effect needs to be optimised to induce remission without morbidity from GVHD.

Retrospective study of alemtuzumab vs ATG-based conditioning without irradiation for unrelated and matched sibling donor transplants in acquired severe aplastic anemia: a study from the British Society for Blood and Marrow Transplantation.

This retrospective national study compared the use of alemtuzumab-based conditioning regimens for hematopoietic SCT (HSCT) in acquired severe aplastic anemia with antithymocyte globulin (ATG)-based regimens. One hundred patients received alemtuzumab and 55 ATG-based regimens. A matched sibling donor (MSD) was used in 87 (56%), matched unrelated donor (MUD) in 60 (39%) and other related or mismatched unrelated donor (UD) in 8 (5%) patients. Engraftment failure occurred in 9% of the alemtuzumab group and 11% of the ATG group. Five-year OS was 90% for the alemtuzumab and 79% for the ATG groups, P=0.11. For UD HSCT, OS of patients was better when using alemtuzumab (88%) compared with ATG (57%), P=0.026, although smaller numbers of patients received ATG. Similar outcomes for MSD HSCT using alemtuzumab or ATG were seen (91% vs 85%, respectively, P=0.562). A lower risk of chronic GVHD (cGVHD) was observed in the alemtuzumab group (11% vs 26%, P=0.031). On multivariate analysis, use of BM as stem cell source was associated with better OS and EFS, and less acute and cGVHD; young age was associated with better EFS and lower risk of graft failure. This large study confirms successful avoidance of irradiation in the conditioning regimens for MUD HSCT patients.

Allogeneic stem cell transplantation using alemtuzumab-containing regimens in severe aplastic anemia.

Alemtuzumab, a humanized anti-CD52, IgG1 monoclonal antibody, is used to reduce graft-versus- host disease (GVHD) and aid engraftment after allogeneic haemopoietic stem cell transplant (HSCT). Its associated low incidence of GVHD makes it an attractive alternative to anti-thymocyte globulin (ATG) in transplant conditioning regimen for severe aplastic anaemia (SAA). We have reviewed the use of alemtuzumab-based conditioning regimen for HSCT in SAA and show that it results in sustained haematological engraftment, a very low incidence of chronic GVHD without an increase in viral infections. Intriguingly, alemtuzumab appears to induce tolerance post-HSCT with the findings of stable mixed T cell chimerism with full donor myeloid chimerism and the absence of chronic GVHD, and which persist on withdrawal of post-graft immunosuppression. Finally, its low toxicity profile may permit future application of HSCT to older patients with SAA who fail to respond to immunosuppressive therapy.