G-CSF-Mobilized Blood and Bone Marrow Grafts as the Source of Stem Cells for HLA-Identical Sibling Transplantation in Patients with Thalassemia Major

As an inherited anemia, thalassemia major (TM) is currently only curable with allogeneic hematopoietic stem cell transplantation (allo-HSCT). Here we report an allo-HSCT protocol for patients with TM who received a combination of granulocyte colony-stimulating factor-primed bone marrow and peripheral blood stem cells (G-BM & PBSCs) from a matched sibling donor (MSD). The conditioning regimen consisted of i.v. busulfan, cyclophosphamide, fludarabine, and antithymocyte globulin. Chimerism analysis was performed for all patients. Immunosuppressive treatment was terminated if rejection was suspected, and donor lymphocyte infusion was administered once no response was observed. A total of 184 patients with TM were enrolled in the study between July 2007 and July 2018. The cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) was 13.1%, and that of moderate or severe chronic GVHD was 5.7%. The cumulative incidence of graft rejection was .6%. In the total cohort, the 3-year overall survival, thalassemia-free survival, and GVHD-free, relapse-free survival were 97.8%, 97.3%, and 89.5%, respectively. Collectively, our results indicate that G-BM & PBSCs from an MSD is be a good stem cell source for patients with TM undergoing allo-HSCT.     

Partial T Cell-Depleted Peripheral Blood Stem Cell Transplantation from HLA-Identical Sibling Donors for Patients with Severe Aplastic Anemia

We analyzed the outcomes of 26 consecutive patients with acquired severe aplastic anemia (SAA) undergoing peripheral blood stem cell transplantation (PBSCT) with partial ex vivo T cell depletion with a targeted T cell dose from HLA-identical sibling donors. The median patient age was 37 years (range, 3 to 63 years). Four patients with uncontrolled pneumonia at the time of transplantation died, on days +1, +2, +21, and +26. All evaluable patients engrafted, with a median time to neutrophil recovery of 11 days (range, 10 to 14 days) and a median time to platelet recovery of 19 days (range, 8 to 53 days). Two patients had transient grade I acute graft-versus-host disease (GVHD) with skin involvement, but no patients developed grade II-IV acute GVHD. Two patients had mild skin chronic GVHD, and 1 patient had moderate chronic GVHD with ocular involvement. No relapse was observed after a median follow-up of 114 months (range, 4 to 233 months). The overall cumulative incidence of TRM at 10 years was 19%, whereas it was 5% for those with a Karnofsky Performance Status (KPS) score >60 at the time of transplantation. Disease-free survival, overall survival, and GVHD and relapse-free survival at 10 years were 81%, 81%, and 80%, respectively, for all patients and 95%, 95%, and 90%, respectively, for patients with a KPS score >60 at transplantation. Our data indicate that PBSCT with partial ex vivo T cell-depleted targeted cell dose grafts from an HLA-identical sibling donor is a feasible, safe, and effective approach to reduce GVHD and cure patients with SAA.     

Donor Selection for Killer Immunoglobulin-like Receptors B Haplotype of the Centromeric Motifs Can Improve the Outcome after HLA-Identical Sibling Hematopoietic Stem Cell Transplantation

After hematopoietic stem cell transplantation (HSCT), natural killer (NK) cell alloreactivity in HLA cells of recipients is regulated by killer immunoglobulin-like receptors (KIRs) on donor NK cells. The effect of KIRs on HSCT outcomes is controversial, particularly in those undergoing HLA-identical sibling HSCT. In this study, effects of KIR and HLA genotypes on the HSCT outcome were investigated in a 5-year retrospective study comprising 219 patient-donor pairs undergoing HLA-identical sibling HSCT for myeloid and lymphoid malignancies. We found that 39.7% (87 of 219) of these pairs, which were KIR mismatched, had better overall survival (OS) and reduced grade III to IV acute graft-versus-host disease (aGVHD), especially in acute myeloid leukemia (AML) patients. Bx1 donor KIR genotype with haplotype B on a telomeric region was a risk factor for the OS and relapse-free survival (RFS). Donor centromeric (c) and telomeric (t) KIR haplotype analysis showed that donor KIR cB-tA/tB was associated with improved OS and RFS compared with cA-tA or cA-tB. Furthermore, donor KIR B haplotype of the centromeric motifs (Cen-B) was an independent beneficial factor in improving OS and RFS and in protecting from relapse after HSCT. In AML patients, the occurrence of aGVHD was significantly lower in HLA-C1 group compared with that in HLA-C2 group, although such effect was not observed in patients with acute lymphoblastic leukemia or chronic myelogenous leukemia. Our results suggest that KIR could impact outcome and donor KIR haplotype with Cen-B confer significant survival benefits to HLA-identical sibling HSCT.     

Allogeneic Hematopoietic Cell Transplantation for Chemotherapy-Unresponsive Mantle Cell Lymphoma: A Cohort Analysis from the Center for International Blood and Marrow Transplant Research

Patients with chemorefractory mantle cell lymphoma (MCL) have a poor prognosis. We used the Center for International Blood and Marrow Transplant Research database to study the outcome of 202 patients with refractory MCL who underwent allogeneic hematopoietic cell transplantation (allo-HCT) using either myeloablative (MA) or reduced-intensity/nonmyeloablative conditioning (RIC/NST), during 1998-2010. We analyzed nonrelapse mortality (NRM), progression/relapse, progression-free survival (PFS), and overall survival (OS). Seventy-four patients (median age, 54 years) received MA, and 128 patients (median age, 59 years) received RIC/NST. Median follow-up after allo-HCT was 35 months in the MA group and 43 months in the RIC/NST group. At 3 years post-transplantation, no significant between-group differences were seen in terms of NRM (47% in MA versus 43% in RIC/NST; P = .68), relapse/progression (33% versus 32%; P = .89), PFS (20% versus 25%; P = .53), or OS (25% versus 30%; P = .45). Multivariate analysis also revealed no significant between-group differences in NRM, relapse, PFS, or OS; however, receipt of a bone marrow or T cell–depleted allograft was associated with an increased risk of NRM and inferior PFS and OS. Our data suggest that despite a refractory disease state, approximately 25% of patients with MCL can attain durable remission after allo-HCT, and conditioning regimen intensity does not influence outcome of allo-HCT.     

Comparable Long-Term Outcome after Allogeneic Stem Cell Transplantation from Sibling and Matched Unrelated Donors in Patients with Acute Myeloid Leukemia Older Than 50 Years: A Report on Behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Allogeneic stem cell transplantation (SCT) is potentially curative therapy in acute myeloid leukemia (AML). Marked improvement has been achieved with SCT from matched unrelated donors (MUDs) in recent years. However, there are limited data comparing the long-term outcomes (beyond 10 years) after SCT from sibling donors and MUDs in older patients with AML. We analyzed these outcomes in a large cohort of patients with AML (n = 1134), age ≥50 years, who were alive and leukemia-free 2 years after SCT from matched siblings (n = 848) or MUDs (n = 286), with a median follow-up of 8.9 years. The median age was 56 and 58 years after SCT from siblings and MUDs, respectively (P = .005). In the sibling group, 77%, 12%, and 11% were in first complete remission (CR1), second complete remission (CR2), and active leukemia at SCT compared with 50%, 25%, and 25% in the MUD group, respectively (P < .001). Sixty-one percent of siblings and 62% of MUDs had reduced-intensity conditioning (P = .78). The 10-year leukemia-free survival (LFS) of patients surviving leukemia-free 2 years after SCT was 72% and 62%, respectively (P = .30). Multivariate analysis identified active leukemia at SCT (hazard ratio [HR], 1.86; P = .0001) or CR2 (HR, 1.51; P = .02) compared with CR1, female recipients (HR, 0.71; P = .006), adverse cytogenetics (HR, 2.52; P = .01), and prior graft-versus-host disease (HR, 1.31; P = .04) as independent factors predicting LFS. Donor and conditioning type were not significant. The cumulative incidence was 15% and 17% (P = .97) for late relapse mortality and 13% and 21% for late nonrelapse mortality, respectively (P = .15). In conclusion, long-term LFS is similar, and patients who are leukemia-free 2 years after SCT can expect favorable outcomes with both donor types.     

Outcome of Allogeneic Hematopoietic Stem Cell Transplantation in Patients Age >69 Years with Acute Myelogenous Leukemia: On Behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Reduced-intensity conditioning (RIC) allows for the use of allogeneic hematopoietic stem cell transplantation (HSCT) in older patients with acute myelogenous leukemia (AML). We compared outcomes between 713 patients age ≥70 years and 16,161 patients age 50 to 69 years who underwent HSCT between 2004 and 2014. A higher proportion of the older patients were male and had secondary AML, active disease, a peripheral blood stem cell graft, a matched unrelated donor, an RIC regimen, and a lower Karnofsky Performance Status (KPS) score (P< .001). In multivariate analysis, the incidences of acute and chronic graft-versus-host disease and relapse were similar in the 2 age groups. Nonrelapse mortality at 2 years was 34% (95% confidence interval [CI], 31% to 38%) in patients age ≥70 years and 24% (95% CI, 25% to 32%) in those age 50 to 69 years (P< .001). Survival at 2 years in the 2 groups was 38% (95% CI, 34% to 42%) and 50% (95% CI, 49% to 50%), respectively (P< .001). In patients with active disease, the corresponding percentages were 35% (95% CI, 29% to 41%) in those age ≥70 years and 33% (95% CI, 31% to 34%) in those age <70 years (P = .36). In patients age ≥70 years, a KPS score of ≥80% was associated with improved survival (hazard ratio, 1.53; 95% CI, 1.14 to 2.06; P = .003). In summary, patients age ≥70 years had worse outcomes, except for those with active AML.     

Maintenance Tyrosine Kinase Inhibitors Following Allogeneic Hematopoietic Stem Cell Transplantation for Chronic Myelogenous Leukemia: A Center for International Blood and Marrow Transplant Research Study

It remains unknown whether the administration of tyrosine kinase inhibitors (TKIs) targeting BCR-ABL1 after allogeneic hematopoietic cell transplantation (HCT) is associated with improved outcomes for patients with chronic myelogenous leukemia (CML). In this registry study, we analyzed clinical outcomes of 390 adult patients with CML who underwent transplantation between 2007 and 2014 and received maintenance TKI following HCT (n = 89) compared with no TKI maintenance (n = 301), as reported to the Center for International Blood and Marrow Transplant Research. All patients received TKI therapy before HCT. The majority of patients had a disease status of first chronic phase at HCT (n = 240; 62%). The study was conducted as a landmark analysis, excluding patients who died, relapsed, had chronic graft-versus-host disease, or were censored before day +100 following HCT. Of the 89 patients who received TKI maintenance, 77 (87%) received a single TKI and the other 12 (13%) received multiple sequential TKIs. The most common TKIs used for maintenance were dasatinib (n = 50), imatinib (n = 27), and nilotinib (n = 27). As measured from day +100, the adjusted estimates for 5-year relapse (maintenance, 35% versus no maintenance, 26%; P = .11), leukemia-free survival (maintenance, 42% versus no maintenance, 44%; P = .65), or overall survival (maintenance, 61% versus no maintenance, 57%; P = .61) did not differ significantly between patients receiving TKI maintenance or no maintenance. These results remained unchanged in multivariate analysis and were not modified by disease status before transplantation. In conclusion, our data from this day +100 landmark analysis do not demonstrate a significant impact of maintenance TKI therapy on clinical outcomes. The optimal approach to TKI administration in the post-transplantation setting in patients with CML remains undetermined.     

Reduced-Intensity Hematopoietic Cell Transplantation for Patients with Primary Myelofibrosis: A Cohort Analysis from the Center for International Blood and Marrow Transplant Research

We evaluated outcomes and associated prognostic factors in 233 patients undergoing allogeneic hematopoietic cell transplantation (HCT) for primary myelofibrosis (MF) using reduced-intensity conditioning (RIC). The median age at RIC HCT was 55 yr. Donors were a matched sibling donor (MSD) in 34% of RIC HCTs, an HLA well-matched unrelated donor (URD) in 45%, and a partially matched/mismatched URD in 21%. Risk stratification according to the Dynamic International Prognostic Scoring System (DIPSS) was 12% low, 49% intermediate-1, 37% intermediate-2, and 1% high. The probability of survival at 5 yr was 47% (95% confidence interval [CI], 40% to 53%). In a multivariate analysis, donor type was the sole independent factor associated with survival. Adjusted probabilities of survival at 5-yr were 56% (95% CI, 44% to 67%) for MSD, 48% (95% CI, 37% to 58%) for well-matched URD, and 34% (95% CI, 21% to 47%) for partially matched/mismatched URD (P = .002). The relative risk (RR) for NRM was 3.92 (P = .006) for well-matched URD and 9.37 (P < .0001) for partially matched/mismatched URD. Trends toward increased NRM (RR, 1.7; P = .07) and inferior survival (RR, 1.37; P = .10) were observed in DIPSS intermediate-2/high-risk patients compared with DIPSS low/intermediate-1 risk patients. Our data indicate that RIC HCT is a potentially curative option for patients with MF, and that donor type is the most important factor influencing survival in these patients.     

Outcomes of Related Donor HLA-Identical or HLA-Haploidentical Allogeneic Blood or Marrow Transplantation for Peripheral T Cell Lymphoma

The role of allogeneic blood or marrow transplantation (alloBMT) for peripheral T cell lymphoma (PTCL) remains to be defined. There is growing interest in reduced-intensity conditioning (RIC) regimens and/or utilization of human leukocyte antigen haploidentical (haplo) grafts given concerns about treatment-associated toxicities and donor availability. We reviewed the outcomes of 44 consecutive, related donor alloBMTs for PTCL performed at Johns Hopkins Hospital from 1994 to 2011, including 18 RIC/haplo alloBMTs. Patients receiving RIC (n = 24) were older, with median age of 59 years (range, 24 to 70), than patients receiving myeloablative conditioning (MAC, n = 20), with median age of 46 years (range, 18 to 64), P = .01. The median age at RIC/haplo alloBMT was 60 years. The estimated 2-year progression-free survival (PFS) was 40% (95% confidence interval [CI], 26% to 55%) and overall survival (OS) was 43% (95% CI, 28% to 59%). In older patients (≥60, n = 14), the estimated 2-year PFS and OS were 38% (95% CI, 18% to 79%) and 45% (95% CI, 24% to 86%), respectively. On unadjusted analysis, there was a tendency toward superior outcomes for alloBMT in first remission versus beyond first remission, with an estimated 2-year PFS of 53% (95% CI, 33% to 77%) versus 29% (95% CI, 9% to 45%), P = .08. On competing risk analysis, the 1-year cumulative incidence of relapse was 38% for MAC/HLA-identical alloBMTs and 34% for RIC/haplo alloBMTs. Estimated 1-year nonrelapse mortality was 10% for MAC and 8% for RIC (11% for RIC/haplo alloBMT). On unadjusted landmark analysis, patients with acute grade II-IV or chronic graft-versus-host disease (GVHD) had a 17% probability of relapse (95% CI, 0% to 39%), compared with 66% (95% CI, 48% to 84%) in patients without GVHD, P = .04. Utilization of RIC and alternative donors expands treatment options in PTCL to those who are older and unable to tolerate high-dose conditioning, with outcomes comparable with approaches using myeloablative regimens and HLA-matched donors. AlloBMT may be appropriate in first remission in select high-risk cases.     

Impact of HLA Alleles on Outcomes of Allogeneic Transplantation for B Cell Non-Hodgkin Lymphomas: A Center for International Blood and Marrow Transplant Research Analysis

Even in the modern era of targeted therapies, allogeneic hematopoietic stem cell transplantation (allo-HCT) can offer a chance of extended survival in B cell non-Hodgkin lymphoma (B-NHL) patients who relapse after or are deemed ineligible for autologous transplantation. A better understanding of the factors influencing the graft-versus-lymphoma (GVL) response would be useful in identifying B-NHL patients who may benefit from allo-HCT. Based on prior single-center reports, we hypothesized that certain HLA alleles, or haplotypes, may be associated with superior GVL compared with others after allo-HCT. To test this possibility we retrospectively evaluated whether the presence of HLA-A2, HLA-C1C1, HLA-DRB1*01:01, or HLA-DRB1*13 alleles or the presence of HLA-A1+, HLA-A2-, and HLA-B44- haplotypes is associated with outcomes in a cohort of 1314 HLA-8/8 matched sibling or unrelated donor HCT for relapsed/refractory B-NHL. We observed no significant association between any HLA allele or haplotype and overall survival or any of the secondary endpoints. In conclusion, this study represents the largest reported series of allo-HCT outcomes of B-NHL patients based on HLA type. Identification of other variables will be required to delineate the immunologic impact of donor–host interactions on outcomes of allo-HCT for B-NHL.     

Hematopoietic Stem Cell Transplantation in Patients with Lymphomatoid Granulomatosis: A European Group for Blood and Marrow Transplantation Report

Lymphomatoid granulomatosis (LG) is a very rare, Epstein-Barr virus–associated lymphoproliferative disorder of B cells. Prognosis is poor, particularly after relapse and no curative treatment exists. We report the results of high-dose therapy and autologous stem cell transplantation (ASCT) or reduced-intensity conditioning and allogeneic stem cell transplantation (alloSCT) in patients with multiply relapsed LG. A European Group for Blood and Marrow Transplantation survey identified 10 patients who had received 9 ASCT and 4 alloSCT. All patients had active disease at the time of transplantation. With a median follow-up of 5.1 (range, 1.4 to 6.3) years, 6 patients are alive and disease-free. Two ASCT patients died of septicemia early after transplantation, and 1 committed suicide after being in continuous complete remission 19 months after ASCT. Another patient allografted 4 years after ASCT remained disease-free but died of severe graft-versus-host disease 3 months after alloSCT. High-dose therapy followed by ASCT and alloSCT are effective therapeutic options and should be considered in all patients with refractory and multiply relapsed LG.     

Real-World Issues and Potential Solutions in Hematopoietic Cell Transplantation during the COVID-19 Pandemic: Perspectives from the Worldwide Network for Blood and Marrow Transplantation and Center for International Blood and Marrow Transplant Research Health Services and International Studies Committee

The current COVID-19 pandemic, caused by SARS-CoV-2, has impacted many facets of hematopoietic cell transplantation (HCT) in both developed and developing countries. Realizing the challenges as a result of this pandemic affecting the daily practice of the HCT centers and the recognition of the variability in practice worldwide, the Worldwide Network for Blood and Marrow Transplantation (WBMT) and the Center for International Blood and Marrow Transplant Research's (CIBMTR) Health Services and International Studies Committee have jointly produced an expert opinion statement as a general guide to deal with certain aspects of HCT, including diagnostics for SARS-CoV-2 in HCT recipient, pre- and post-HCT management, donor issues, medical tourism, and facilities management. During these crucial times, which may last for months or years, the HCT community must reorganize to proceed with transplantation activity in those patients who urgently require it, albeit with extreme caution. This shared knowledge may be of value to the HCT community in the absence of high-quality evidence-based medicine.© 2020 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.     

Influence of Age on Acute and Chronic GVHD in Children Undergoing HLA-Identical Sibling Bone Marrow Transplantation for Acute Leukemia: Implications for Prophylaxis

Relapse remains the major cause of mortality after hematopoietic cell transplantation (HCT) for pediatric acute leukemia. Previous research has suggested that reducing the intensity of calcineurin inhibitor-based graft-versus-host disease (GVHD) prophylaxis may be an effective strategy for abrogating the risk of relapse in pediatric patients undergoing matched sibling donor (MSD) HCT. We reasoned that the benefits of this strategy could be maximized by selectively applying it to those patients least likely to develop GVHD. We conducted a study of risk factors for GVHD, to risk-stratify patients based on age. Patients age <18 years with leukemia who received myeloablative, T cell-replete MSD bone marrow transplantation and calcineurin inhibitor-based GVHD prophylaxis between 2000 and 2013 and were entered into the Center for International Blood and Marrow Transplant Research registry were included. The cumulative incidence of grade II-IV acute GVHD (aGVHD) was 19%, that of grade II-IV aGVHD 7%, and that of chronic GVHD (cGVHD) was 16%. Compared with age 13 to 18 years, age 2 to 12 years was associated with a lower risk of grade II-IV aGVHD (hazard ratio [HR], .42; 95% confidence interval [CI], .26 to .70; P?=?.0008), grade II-IV aGVHD (HR, .24; 95% CI, .10 to .56; P?=?.001), and cGVHD (HR, .32; 95% CI, .19 to .54; P?<?.001). Compared with 2000-2004, the risk of grade II-IV aGVHD was lower in children undergoing transplantation in 2005-2008 (HR, .36; 95% CI, .20 to .65; P?=?.0007) and in 2009-2013 (HR, .24; 95% CI. .11 to .53; P?=?.0004). Similarly, the risk of grade III-IV aGVHD was lower in children undergoing transplantation in 2005-2008 (HR, .23; 95% CI, .08 to .65; P?=?.0056) and 2009-2013 (HR, .16; 95% CI, .04 to .67; P?=?.0126) compared with those doing so in 2000-2004. We conclude that aGVHD rates have decreased significantly over time, and that children age 2 to 12 years are at very low risk for aGVHD and cGVHD. These results should be validated in an independent analysis, because these patients with high-risk malignancies may be good candidates for trials of reduced GVHD prophylaxis.     

Intravenous Busulfan Compared with Treosulfan-Based Conditioning for Allogeneic Stem Cell Transplantation in Acute Myeloid Leukemia: A Study on Behalf of the Acute Leukemia Working Party of European Society for Blood and Marrow Transplantation

Dose intensity of the conditioning regimen has significant impact on the outcomes after stem cell transplantation (SCT) for acute myeloid leukemia. Most studies have shown more relapse, less nonrelapse mortality (NRM), and similar overall survival after reduced-intensity and myeloablative conditioning. There are limited data on the dose equivalence and expected outcomes of treosulfan-based compared with busulfan-based conditioning. We compared SCT outcomes after fludarabine with either intravenous busulfan at a myeloablative dose (FB4, 12.8?mg/kg, n?=?1265) or a reduced dose (FB2, 6.4?mg/kg, n?=?1456) or treosulfan at 42 g/m² (FT14, n?=?403) or 36 g/m² (FT12, n?=?168). Median patient age was 48, 60, 57, and 60 years in the FB4, FB2, FT14, and FT12 groups, respectively (P?<?.0001). Two-year overall survival was 58%, 53%, 53%, and 51%, respectively (P?=?.25). Multivariate analysis identified advanced age, advanced disease status, and secondary leukemia to be associated with worse survival. Relapse rate was 30%, 35%, 34%, and 40%, respectively. Relapse was more common after FB2, advanced age and disease status, secondary leukemia, and sibling donors. NRM was 17%, 18%, 21%, and 16%, respectively. NRM was least common after FT12 and more common with advanced age and disease status and unrelated donors. Treosulfan-based regimens were associated with lower rates of graft-versus-host disease. There was no difference in any outcome among patients in first complete remission at transplantation. However, there was better survival with treosulfan-based conditioning in advanced leukemia. In conclusion, survival is determined mostly by disease biology and is similar after various regimens. Treosulfan-based conditioning is more similar to myeloablative than to reduced-intensity conditioning but can be administered safely in older patients, with lower rates of graft-versus-host disease and possibly better outcomes in patients with active leukemia.