J Perry

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.

Recipient/donor HLA and CMV matching in recipients of T-cell-depleted unrelated donor haematopoietic cell transplants

Improving haematopoietic cell transplantation outcomes by selection of an HLA-matched unrelated donor is best practice; however, donor selection by secondary characteristics is controversial. We studied 1271 recipients with haematological malignancies who underwent T-cell-depleted allografts and had complete data on HLA-matching status for six loci (HLA-A, -B, -C, -DRB1, -DQB1, -DPB1) and clinical outcome data. Five-year overall survival was 40.6%. HLA mismatching (at HLA-A, -B, -C, -DRB1, -DQB1) relative risk (RR) 1.22, 95% confidence interval (CI) 1.2–1.5, P=0.033 for 1 mismatch and RR 1.46, 95% CI 1.1–1.9, P=0.009 for >1 mismatch) and CMV mismatching (RR 1.37, 95% CI 1.2–1.6, P<0.001) were significantly associated with inferior survival. Donors aged <30 years showed a trend towards better survival. The multivariate model for mortality, combining CMV and HLA-match status, found an RR of 1.36 (95% CI 1.1–1.7, P=0.003) for HLA matched/CMV mismatched, an RR of 1.22 (95% CI 0.99–1.5, P=0.062) for HLA mismatched/CMV matched and an RR of 1.81 (95% CI 1.4–2.3, P=<0.001) for HLA/ CMV mismatched, compared with the HLA/CMV-matched recipients. These data suggest that HLA and CMV matching status should be considered when selecting unrelated donors and that CMV matching may abrogate the effect of an HLA mismatch.

Evidence for a GVL effect following reduced-intensity allo-SCT in ALL: a British Society of Blood and Marrow Transplantation study

Myeloablative allo-SCT decreases relapse incidence (RI) in ALL. Reduced intensity conditioning (RIC) may extend allo-SCT to older and less fit patients. Sixty-nine ALL patients reported to the BSBMT underwent fludarabine-based RIC allo-SCT, 38 from unrelated donors (UD). Forty-four patients received alemtuzumab. ALL was in CR in 64 patients (93%). This was a second or third SCT in 23 patients. Two-year OS and PFS were 36% and 32%, respectively. In multivariate analysis male recipients demonstrated better OS and PFS (hazard ratio (HR)=0.42, P=0.008 and HR=0.45, P=0.012, respectively). Two-year TRM was 29%: higher with younger age (HR=0.97/year, P=0.041), female recipient (HR=2.55, P=0.049) and increasing grade of acute GVHD (HR=1.87, P=0.001). Two-year RI was 38% and was lower in patients with acute and chronic GVHD (HR=0.62 per increasing grade, P=0.035 and HR=0.52, P=0.025, respectively). Long-term ALL-free survival is achievable following fludarabine-based RIC allo-SCT. The association between GVHD and decreased RI suggests the presence of a GVL effect.

Allogeneic stem cell transplantation for refractory acute myeloid leukemia in pediatric patients: the UK experience

We report outcomes for 44 children who underwent stem cell transplantation (SCT) for refractory AML in the UK between 2000 and 2012. Median age at SCT was 11.5 years. Twenty-three patients had primary refractory and 21 relapsed refractory AML. Refractory disease was confirmed by cytogenetics/molecular genetics in 24 cases. Median follow-up of the whole cohort is 6.8 years (2.1–14.9 years). Thirty patients (68%) achieved a CR following SCT. Transplant-related mortality at 1 year was 18%. Acute GVHD incidence was 52% (grade ⩾III 19%), chronic 7%. Relapse was the major cause of treatment failure and occurred in 32% of patients at a median of 61 days post SCT. Five-year overall survival and leukemia-free survival (LFS) were 43% (95% CI 31–61%). All patients with favorable cytogenetics (n=6) are alive in CR. Outcomes in patients with primary refractory disease were equivalent to those with relapsed refractory AML. Blast percentage ⩽30% in the BM pre-SCT, myeloablative conditioning and acute GVHD proved to be favorable prognostic features. We could stratify patients according to age ⩾10 years and >30% blasts in BM pre-SCT. Patients with none/one of these risk factors were highly salvageable (5 years LFS 53%) whereas those with both factors had a very poor prognosis (5 years LFS 10%). This may facilitate decision making on whether it is appropriate to consider transplant in such patients.

Carmustine, Etoposide, Cytarabine, and Melphalan (BEAM)–Campath Allogeneic Stem Cell Transplantation for Aggressive Non-Hodgkin Lymphoma: An Analysis of Outcomes from the British Society of Blood and Marrow Transplantation

The role of allogeneic stem cell transplantation (SCT) in the management of aggressive non-Hodgkin lymphoma (NHL) remains to be defined, but the number of procedures performed continues to increase. We report here the outcomes of allogeneic SCT using carmustine, etoposide, cytarabine, and melphalan (BEAM)-Campath (Genzyme Corporation, Cambridge, MA) conditioning for aggressive NHL as reported to the British Society of Blood and Marrow Transplantation (BSBMT). This retrospective study identified 46 patients who reported to the BSBMT registry as having undergone BEAM-Campath conditioned allogeneic SCT for aggressive NHL between 1999 and 2010. Disease histology was diffuse large B cell lymphoma (DLBCL, n = 25), DLBCL/Burkitt lymphoma (n = 5), and T cell lymphoma (n = 16). At diagnosis, the median age was 42.5 (range, 17 to 59), 37 had advanced stage disease (Ann Arbor III/IV), 28 had 2 or more extra-nodal sites of disease, and 23 had elevated lactate dehydrogenase. International prognostic index was high or high/intermediate in 58%. The median number of prior therapies was 3 (range, 1 to 5) and 5 patients had previously undergone transplantation (4 autologous, 1 allogeneic). The median age at transplantation was 44.8 (range, 18 to 59), with 34 patients demonstrating chemo-sensitive disease and 22 undergoing transplantation in first response. Performance score was good in 40 patients and all engrafted with a median of 14 days (range, 11 to 27) to neutrophil recovery. At latest follow-up, 20 patients were alive with 17 in complete remission. Acute graft-versus-host disease (GVHD) developed in 7 patients and chronic GVHD developed in 13 (7 limited, 6 extensive). Five patients died from nonrelapse causes, with a cumulative incidence of nonrelapse mortality of 7% at 100 days and 11% at 3 and 5 years. Twenty-one patients died after lymphoma relapse, with a cumulative incidence of relapse/progression of 51% at 1 year and 53% at 5 years. Disease status at transplantation had no impact on relapse rate. Progression-free survival was 41% at 1 year and 36% at 5 years. Overall survival was 54% at 1 year and 42% at 5 years. Overall, BEAM-Campath-conditioned allogeneic SCT is well tolerated and able to deliver durable disease-free survival to a subset of patients with aggressive NHL. However, the high relapse rates indicate further investigation is needed to identify those patients most likely to benefit.

Polymorphism in TGFB1 is associated with worse non-relapse mortality and overall survival after stem cell transplantation with unrelated donors

Transforming growth factor β-1, encoded by the TGFB1 gene, is a cytokine that plays a central role in many physiological and pathogenic processes. We have sequenced TGFB1 regulatory region and assigned allelic genotypes in a large cohort of hematopoietic stem cell transplantation patients and donors. In this study, we analyzed 522 unrelated donor-patient pairs and examined the combined effect of all the common polymorphisms in this genomic region. In univariate analysis, we found that patients carrying a specific allele, ‘p001’, showed significantly reduced overall survival (5-year overall survival 30.7% for p001/p001 patients vs. 41.6% others; P=0.032) and increased non-relapse mortality (1-year non-relapse mortality: 39.0% vs. 25.4%; P=0.039) after transplantation. In multivariate analysis, the presence of a p001/p001 genotype in patients was confirmed as an independent factor for reduced overall survival [hazard ratio=1.53 (1.04–2.24); P=0.031], and increased non-relapse mortality [hazard ratio=1.73 (1.06–2.83); P=0.030]. In functional experiments we found a trend towards a higher percentage of surface transforming growth factor β-1-positive regulatory T cells after activation when the cells had a p001 allele (P=0.07). Higher or lower production of transforming growth factor β-1 in the inflammatory context of hematopoietic stem cell transplantation may influence the development of complications in these patients. Findings indicate that TGFB1 genotype could potentially be of use as a prognostic factor in hematopoietic stem cell transplantation risk assessment algorithms.

Impact of pre-transplant co-morbidities on outcome after alemtuzumab-based reduced intensity conditioning allo-SCT in elderly patients: A British Society of Blood and Marrow Transplantation study

The advent of reduced intensity conditioning (RIC) regimens has permitted the extension of allo-SCT to selected patients into their eighth decade but GVHD remains a major cause of morbidity and mortality. Alemtuzumab is increasingly used to reduce the risk of severe GVHD, but there are concerns that T-cell depletion may compromise outcome particularly in older patients. We therefore studied the impact of pre-transplant factors on the outcome of 187 patients with a haematological malignancy over the age of 60 transplanted using an alemtuzumab-based RIC regimen of whom co-morbidity scoring was possible in 169. Of the patients, 120 had a haematopoietic cell transplantation co-morbidity index (HCT-CI) of 0 or 1 and 49 had a score of 2 or more. The 5-year OS was 33%. In multivariable analysis, OS was determined by co-morbidity score (P=0.001) and disease status at transplant (P=0.004) but not by patient age. Non-relapse mortality was determined by co-morbidity score (P=0.001). Two-year OS for patients with a HCT-CI of 0–1 was 59 versus 6% for patients with a higher score. Alemtuzumab-based RIC allografts can be delivered safely in patients aged over 60 but co-morbidity scoring is mandatory to identify patients who will benefit.