Outcomes of hematopoietic stem cell transplantation in 813 pediatric patients with Fanconi anemia.

ABSTRACT: Allogeneic hematopoietic stem cell transplantation (HSCT) is the only established curative option for Fanconi anemia (FA)-associated bone marrow failure (BMF)/aplastic anemia (AA) and acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS). We performed a retrospective multicenter study on 813 children with FA undergoing first HSCT between 2010 and 2018. Median duration of follow-up was 3.7 years. Median age at transplant was 8.8 years (IQR, 6.5-18.1). Five-year overall survival (OS), event-free survival (EFS), and graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) were 83% (95% confidence interval [CI], 80-86), 78% (95% CI, 75-81), and 70% (95% CI, 67-74), respectively. OS was comparable between matched family donor (MFD; n = 441, 88%) and matched unrelated donor (MUD; n = 162, 86%) and was superior to that of mismatched family donor (MMFD) or mismatched unrelated donor (MMUD; n = 144, 72%) and haploidentical donor (HID; n = 66, 70%; P < .001). In multivariable analysis, a transplant indication of AML/MDS (vs AA/BMF), use of MMFD/MMUD and HID (vs MFD), and fludarabine-cyclophosphamide (FluCy) plus other conditioning (vs FluCy) independently predicted inferior OS, whereas alemtuzumab vs antithymocyte globulin was associated with better OS. Age ≥10 years was associated with worse EFS and GRFS. Cumulative incidences (CINs) of primary and secondary graft failure were 2% and 3% respectively. CINs of grade 3 to 4 acute GVHD and chronic GVHD were 12% and 8% respectively. The 5-year CIN of secondary malignancy was 2%. These data suggest that HSCT should be offered to patients with FA with AA/BMF at a younger age in the presence of a well-matched donor.

Mismatched related donor allogeneic haematopoietic cell transplantation compared to other donor types for Ph+ chronic myeloid leukaemia: A retrospective analysis from the Chronic Malignancies Working Party of the EBMT.

Allogeneic haematopoietic cell transplantation (allo-HCT) remains an option for tyrosine kinase inhibitor-resistant chronic myeloid leukaemia (CML) in first chronic phase (CP1) and high-risk patients with advanced disease phases. In this European Society for Blood and Marrow Transplantation (EBMT) registry-based study of 1686 CML patients undergoing first allo-HCT between 2012 and 2019, outcomes were evaluated according to donor type, particularly focusing on mismatched related donors (MMRDs). Median age at allo-HCT was 46 years (IQR 36-55). Disease status was CP1 in 43%, second CP (CP2) or later in 27%, accelerated phase in 12% and blast crisis in 18%. Donor type was matched related (MRD) in 39.2%, MMRD in 8.1%, matched unrelated (MUD) in 40.2%, and mismatched unrelated (MMUD) in 12.6%. In 4 years, overall survival (OS) for MRD, MMRD, MUD and MMUD was 61%, 56%, 63% and 59% (p = 0.21); relapse-free survival (RFS) was 48%, 42%, 52% and 46% (p = 0.03); cumulative incidence of relapse (CIR) was 33%, 37%, 27% and 30% (p = 0.07); non-relapse mortality (NRM) was 19%, 21%, 21% and 24% (p = 0.21); and graft-versus-host disease (GvHD)-free/relapse-free survival (GRFS) was 16%, 18%, 22% and 15% (p = 0.05) respectively. On multivariate analysis, MMRD use associated with longer engraftment times and higher risk of graft failure compared to MRD or MUD. There was no statistical evidence that MMRD use associated with different OS, RFS and incidence of GvHD compared to other donor types.

Lower relapse incidence with haploidentical versus matched sibling or unrelated donor hematopoietic cell transplantation for core-binding factor AML patients in CR2: A study from the Global Committee and the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

Allogeneic hematopoietic cell transplantation (allo-HCT) is recommended for core-binding factor mutated (CBF) AML patients achieving second complete remission (CR2). However, approximately 20% of patients may relapse after transplant and donor preference remains unclear. We compared in this EBMT global multicenter registry-based analysis the allo-HCT outcomes using either haploidentical (Haplo), matched siblings donors (MSD), or 10/10 matched unrelated donors (MUD). Data from 865 de novo adult CBF AML patients in CR2 receiving allo-HCT in 227 EBMT centers from 2010 to 2022 were analyzed, in which 329 MSD, 374 MUD, and 162 Haplo-HCTs were included. For the entire cohort, 503 (58%) patients were inv(16)/CBFB-MYH11 and 362 patients (42%) were t(8;21)/RUNX1-RUNX1T1 AML. On multivariate analysis, Haplo-HCT was associated with a lower Relapse Incidence (RI) compared to either MSD (hazard ratio [HR] = 0.56, 95% CI 0.32-0.97; p < .05) or MUD (HR = 0.57, 95% CI: 0.33-0.99, p < .05). No significant difference was observed among the 3 types of donors on LFS, OS and GRFS. CBF-AML with t(8;21) was associated with both higher RI (HR = 1.79, 95% CI 1.3-2.47; p < .01) and higher NRM (HR = 1.58, 95% CI 1.1-2.27; p < .01) than CBF-AML with inv(16), which led to worse LFS, OS and GRFS. To conclude, for CBF-AML patients in CR2, Haplo-HCTs were associated with a lower RI compared to MSD and MUD allo-HCTs. There was no difference on LFS, OS or GRFS. CBF AML patients with inv(16) had a better progonosis than those with t(8;21) after allo-HCT in CR2.

Successful Allogeneic Peripheral Blood Stem Cell Transplantation in 4 Wiskott-Aldrich Syndrome Patients.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation is a potential curative treatment in Wiskott-Aldrich syndrome (WAS). Here, we analyzed the outcomes in 4 WAS patients who underwent this procedure with peripheral blood stem cell (PBSC) in our center. PATIENTS AND METHODS: Four patients with severe WAS phenotype have received allogeneic hematopoietic stem cell transplantation between January 2014 and December 2019 from matched sibling donors with PBSC. Two different preparative conditioning regimens were provided: the first associated busulfan-cyclophosphamide (2 patients) and the second with busulfan-fludarabine administered to the others. Cyclosporine gave as preferred graft-versus-host disease prophylaxis with a short course of methotrexate. RESULTS: All patients achieved engraftment after PBSC with a median CD34+ cell count: 13.6×106/kg (8 to 24.9×106/kg). Chronic graft-versus-host disease developed in 2 patients treated by cyclosporine-steroids with complete resolution. Chimerism for all the patients was fully donor (>95% donor). After a median follow-up of 41 months (8 to 74 mo), all patients (100%) are alive, healthy, with complete clinical, immunologic, and hematologic recovery, without signs of WAS. CONCLUSION: This limited study with high-dose PBSC transplantation approach for WAS, demonstrated a safe and effective treatment option, with rapid engraftment, without complications, excellent long-term outcomes, independent of conditioning regimen.

Post-transplantation cyclophosphamide versus antithymocyte globulin in patients with acute myeloid leukemia undergoing allogeneic stem cell transplantation from HLA-identical sibling donors: A retrospective analysis from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

BACKGROUND: Graft-versus-host disease (GVHD) is a major complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Addition of antithymocyte globulin (ATG) or post-transplantation cyclophosphamide (PTCY) to standard immunosuppressive agents reduces GVHD in different donor settings. METHODS: We compared the outcomes of adults with acute myeloid leukemia undergoing allo-HSCT from HLA-identical sibling donors after the use of PTCY (n = 197) or ATG (n = 1913). RESULTS: Patients in the PTCY group were younger than those in the ATG group (median age, 47 vs 54 years; P < .01). Peripheral blood was the most frequently used stem cell source, being significantly more frequent in the ATG group than in the PTCY group (95% vs 70% P < .01). The conditioning regimen was more frequently myeloablative in the PTCY group than in the ATG group (59% vs 48%; P < .01). Time to neutrophil engraftment was shorter in the ATG group than in the PTCY group (17 vs 20 days; P < .01). No differences were observed according to the other transplantation outcomes, except for chronic GVHD of all grades and extensive chronic GVHD at 2 years, which were significantly lower in the ATG group compared with the PTCY group (P < .02). CONCLUSION: PTCY is feasible in an HLA-identical sibling setting, and despite similar outcomes, ATG may be associated with lower incidence of chronic GVHD.

Two decades of experience in a combined adult/pediatric allogeneic hematopoietic stem cell transplantation center in Algiers, Algeria.

Hematopoietic stem cell transplantation (HSCT) has evolved from an experimental to a successful treatment modality reaching worldwide 80.000 HSCT/year. Distribution and trends of HSCT, however, remain heterogeneous. Activities range from none to more than 511/10 million population between countries and regions. Here, we report on a successful autologous and allogeneic HSCT program for adult and pediatric patients started two decades ago in Northern Africa. From 1998 to December 2017, a total of 2828 HSCT was performed of which 2059 were allo-HSCT (1474 adults and 585 children). The activities were analyzed according to indication, donor type, stem cell source, and trends over time. There was a significant difference in indications according to age. Adult patients were transplanted more often for hematological malignancies. In children, the indications were distributed equally between malignant and non-malignant diseases. Overall activities increased substantially in AML and to a lower extent in ALL and CLL despite sharp reduction of activity in CML after 2005. Finally, a higher transplantation rate (33/10 million population) was reached as compared to most regions of the world except Europe and USA/Canada. Overall survival in children with AML was 56.0% at 15 years, in adults 61.3% at 5 years, and in patients with CML 55.5% at 15 years without difference between reduced intensity condition (RIC) and myeloablative conditioning (MAC). Patients with Ph+ ALL had the lowest survival reaching 26.7% at 5 years. Highest survival was observed in patients with aplastic anemia, Fanconi anemia, and thalassemia reaching 77.3%, 73.5%, and 75.7% at 15 years respectively. Long distances and late referral remain a challenge for this large country.

Peripheral Blood Stem Cell Mobilization and Collection in Pediatric Healthy Sibling Donors Weighing 20 Kilograms or Less; Algerian Experience.

Peripheral blood stem cells (PBSC) are the source of allogeneic hematopoietic stem cell transplants currently used for malignant and non-malignant hematological diseases. PBSC harvest may be difficult in young children who are donors. Extracorporeal separator line priming by red blood cells or albumin alone is usually required to improve haemodynamic tolerance and efficacy of collection. We present our experience with 29 children weighing 20 kg or less mobilised between January 2005 and June 2018. The median age and weight at the time of apheresis were 5 years and 18 kg, respectively. A total of 54 PBSC were performed. The median cell yield per apheresis was 5.9 × 106 CD34+cells/kg (2,5-13,9) recipient body weight (RBW). Despite their low weight, insertion of a femoral catheter was avoided in 58.6% of children. Nineteen donors required 2 or 3 apheresis sessions without any major complication. Twenty-nine pts with hemopathies have successfully benefited from PBSC except one case of rejection with aplastic anemia.

Worldwide Network for Blood and Marrow Transplantation Recommendations for Establishing a Hematopoietic Stem Cell Transplantation Program in Countries with Limited Resources, Part II: Clinical, Technical, and Socioeconomic Considerations.

The development of hematopoietic stem cell transplantation (HSCT) programs can face significant challenges in most developing countries because such endeavors must compete with other government health care priorities, including the delivery of basic services. Although this is may be a limiting factor, these countries should prioritize development of the needed expertise to offer state-of-the-art treatments, including transplantation, by providing financial, technological, legal, ethical, and other needed support. This would prove beneficial in providing successful programs customized to the needs of their population and potentially provide long-term cost savings by circumventing the need for their citizens to seek care abroad. The costs of establishing an HSCT program and the costs of the HSCT procedure itself can be substantial barriers in developing countries. In addition, socioeconomic factors intrinsic to specific countries can influence access to HSCT, patient eligibility for HSCT, and timely utilization of HSCT center capabilities. This report describes recommendations from the Worldwide Network for Blood and Marrow Transplantation for establishing HSCT programs, with a specific focus on developing countries, and identifies challenges and opportunities for providing this specialized procedure in resource-constrained settings.

Impact of T-cell depletion strategies on outcomes following hematopoietic stem cell transplantation for idiopathic aplastic anemia: A study on behalf of the European blood and marrow transplant severe aplastic anemia working party.

We retrospectively analyzed the outcomes of 1837 adults and children with severe aplastic anemia (SAA) who underwent matched sibling donor (MSD) and matched unrelated donor (MUD) hemopoietic stem cell transplantation (HSCT) between 2000 and 2013. Patients were grouped by transplant conditioning containing either anti-thymocyte globulin (ATG) (n = 1283), alemtuzumab (n = 261), or no serotherapy (NS) (n = 293). The risks of chronic GvHD were significantly reduced when ATG or alemtuzumab were compared with NS (P = .021 and .003, respectively). Acute GVHD was significantly reduced in favor of alemtuzumab compared with ATG (P = .012) and NS (P < .001). By multivariate analysis, when compared with ATG, alemtuzumab was associated with a lower risk of developing acute (OR 0.262; 95% CI 0.14-0.47; P < .001) and chronic GVHD (HR 0.58; 95% CI 0.35-0.94; P = .027). OS was significantly better in ATG and alemtuzumab patients compared with NS (P = .010 and .025). Our data shows inclusion of serotherapy in MSD and MUD HSCT for patients with SAA reduces chronic GVHD and provides a survival advantage over patients not receiving serotherapy. Notably, alemtuzumab reduced the risk of acute and chronic GvHD compared with ATG and indicates that alemtuzumab might be the serotherapy of choice for MSD and MUD transplants for SAA.

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.

Efficacy and outcome of allogeneic transplantation in IgD and nonsecretory myeloma. A report on behalf of the Myeloma Subcommittee of the Chronic Malignancies Working Party of the European Group for Blood and Marrow Transplantation.

We have recently reported on the outcome of autologous transplantation in the rare myelomas (IgD, IgE, IgM, and nonsecretory [NS]) but there is no real information on the outcome of these conditions after allogeneic transplantation. We used the European Group for Blood and Marrow Transplantation myeloma database to compare the outcomes after allogeneic transplantation of 1354 common myelomas (IgG, IgA, and light chain myeloma) with the outcome in 26 IgD myelomas and 52 NS myelomas. There was little difference between common and the IgD and NS myeloma patients with respect to prognostic factors although the IgD group had a higher beta 2 microglobulin at diagnosis, shorter time to transplantation, and more T cell depletion. IgD and NS patients had a significantly greater achievement of complete remission at conditioning but this did not translate into equivalent progression-free survival and overall survival for the IgD patients although the NS outcome was very similar to that of common myeloma. The PFS and OS of IgD, common, and NS myelomas appear similar after allogeneic transplantation, despite a tendency for higher early relapse rate in IgD myeloma. Allogeneic transplantation may, therefore, be an option to investigate in prospective observational studies.

Risk of complications during hematopoietic stem cell collection in pediatric sibling donors: a prospective European Group for Blood and Marrow Transplantation Pediatric Diseases Working Party study.

We investigated prospectively factors influencing the safety of hematopoietic stem cell (HSC) collection in 453 pediatric donors. The children in the study donated either BM or peripheral blood stem cells (PBSCs) according to center policy. A large variability in approach to donor issues was observed between the participating centers. Significant differences were observed between BM and PBSC donors regarding pain, blood allotransfusion, duration of hospital stay, and iron supplementation; however, differences between the groups undergoing BM vs PBSC donation preclude direct risk comparisons between the 2 procedures. The most common adverse event was pain, reported mainly by older children after BM harvest, but also observed after central venous catheter (CVC) placement for PBSC collection. With regard to severe adverse events, one patient (0.7%) developed a pneumothorax with hydrothorax after CVC placement for PBSC collection. The risk of allotransfusion after BM harvest was associated with a donor age of < 4 years and a BM harvest volume of > 20 mL/kg. Children < 4 years were at higher risk than older children for allotransfusion after BM harvest and there was a higher risk of complications from CVC placement before apheresis. We conclude that PBSC and BM collection are safe procedures in children.

Post-transplant cyclophosphamide, calcineurin inhibitor, and mycophenolate mofetil compared to anti-thymocyte globulin, calcineurin inhibitor, and methotrexate combinations as graft-versus-host disease prophylaxis post allogeneic stem cell transplantation from sibling and unrelated donors in patients with acute myeloid leukemia: a study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

Post-transplant cyclophosphamide plus calcineurin inhibitor (CNI)(tacrolimus or cyclosporine A) plus mycophenolate mofetil (PTCy/TAC or CSA/MMF) and anti-thymocyte globulin plus CNI (tacrolimus or cyclosporine A) plus methotrexate (ATG/TAC or CSA/MTX) are common graft-versus-host disease (GVHD) prophylaxis regimens. We compared the two regimens in patients with acute myeloid leukemia (AML) undergoing allogeneic transplantation from matched siblings or unrelated donors. 402 received PTCy/TAC or CSA/MMF and 5648 received ATG/TAC or CSA/MTX. Patients in the PTCy-based group were younger (48.7 vs. 51.5 years, p = 0.024) and there was a higher frequency of patient cytomegalovirus seropositivity and female donor to male patient combination in this group (77.8% vs. 71.8%, p = 0.009 and 18.4% vs. 14.4%, p = 0.029, respectively). More patients in the PTCy-based group received reduced-intensity conditioning (51.5% vs. 41%, p < 0.0001). No differences were observed in the incidence of acute GVHD grade II-IV and III-IV (21.2% vs. 20.4%, p = 0.92 and 8.1% vs. 6%, p = 0.1) or 2-year total and extensive chronic GVHD (33.7% vs. 30%, p = 0.09 and 10.7% vs. 11.2%, p = 0.81) between the groups. In the multivariate analysis, all transplant outcomes did not differ between the groups. PTCy/CNI/MMF and ATG/CNI/MTX are alternative regimens for GVHD prophylaxis in AML patients.

In the era of Bortezomib-based Induction, intensification of Melphalan-based conditioning with Bortezomib does not improve Survival Outcomes in newly diagnosed Multiple Myeloma: a study from the Chronic Malignancies Working Party of the EBMT.

Bortezomib (Vel)- Melphalan 200 mg/m2 (Mel200) (Vel-Mel) has been utilised to intensify conditioning in autologous hematopoietic stem cell transplantation (AHCT) for multiple myeloma (MM). This EBMT registry-based study compared Vel-Mel with Mel200 during upfront AHCT. Between 2010 and 2017, MM patients who received Vel-Mel (n = 292) conditioning were compared with 4,096 Mel200 patients in the same 58 centres. Pre-AHCT, compared to Mel200 patients, Vel-Mel patients had similar International Staging System (ISS) scores and cytogenetic risk profiles; a similar proportion had received bortezomib-based induction (85% and 87.3%, respectively) though they were younger with a better performance status. Vel-Mel patients were more likely to achieve CR post-induction (40.6% vs 20.3%, p < 0.001) and by day 100 of AHCT (CR/VGPR: 70.2 % vs. 57.2%, p < 0.001). There was no difference in 3-year PFS (49% vs 46%, p = 0.06) or early post-AHCT mortality. In multivariable analysis, Vel-Mel associated with inferior PFS (HR: 1.69 (1.27-2.25, p < 0.001) and OS (HR:1.46 (1.14-1.86,p = 0.002), similar to negative effects on PFS of advanced ISS (HR:1.56 (1.33-1.83, p < 0.001), high-risk cytogenetics (HR:1.43(1.18-1.74, p < 0.001) and poor post-induction response(<=PR)(HR: 1.43(1.25-1.62, p < 0.001) Overall, despite superior pre- and post-AHCT responses, there was no improvement in PFS or OS following Vel-Mel. This data supports the findings of the smaller prospective IFM study.

Outcomes of allogeneic haematopoietic cell transplantation for myelofibrosis in children and adolescents: the retrospective study of the EBMT Paediatric Diseases WP.

This retrospective study evaluated 35 children (median age 5.2 years; range 0.4-18) with myelofibrosis (MF), including 33 with primary myelofibrosis and 2 with secondary myelofibrosis transplanted from matched sibling donor (MSD) (n = 17) or non-MSD (n = 18) between 2000 and 2022. Conditioning was usually chemotherapy-based (n = 33) and myeloablative (n = 32). Fifteen patients received bone marrow (BM), 14 haematopoietic cells (HC) from peripheral blood (PB), and 6 from cord blood (CB). Day +100 acute GvHD II-IV incidence was significantly lower after MSD-haematopoietic cell transplantation (MSD-HCT) than after non-MSD-HCT [18.8% (4.3-41.1) vs 58.8% (31-78.6); p = 0.01]. Six-year non-relapse mortality (NRM) was 18% (7.1-32.8), relapse incidence was 15.9% (5.6-30.9), progression-free survival (PFS) was 66.1% (47-79.7), GvHD-free relapse-free survival was 50% (30.6-66.7), and overall survival (OS) was 71.1% (51.4-84). Six-year PFS and OS were significantly higher after BM transplantation compared to HCT from other sources [85.1% (52.3-96.1) vs 50.8% (26.3-71), p = 0.03, and 90.9% (50.8-98.7) vs 54% (28.1-74.2), p = 0.01, respectively], whereas NRM was significantly lower [0% vs 32% (12.3-53.9); p = 0.02]. This first multicentre study on outcomes of allogeneic HCT in children with myelofibrosis proves feasibility and curative effect of transplantation in these children, suggests that bone marrow transplantation is associated with better outcomes, and indicates the need for further studies.

Outcomes of patients undergoing allogeneic haematopoietic stem cell transplantation for congenital amegakaryocytic thrombocytopenia; a study on behalf of the PDWP of the EBMT.

Congenital amegakaryocytic thrombocytopenia is a rare, inherited bone marrow failure syndrome. Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is currently the only curative treatment. In this retrospective study, we analysed 66 patients with allo-HSCT, reported in the European Society for Blood and Marrow Transplantation (EBMT) registry. Bone marrow (BM) was the most widely used stem cell source (n = 40; 61%) followed by peripheral blood (PB) (n = 18; 27%), and unrelated umbilical cord blood (UCB) (n = 8; 12%). Most frequently was a HLA-matched graft from related (n = 26; 39%) and unrelated (n = 15; 23%) donors after a myeloablative busulfan-based conditioning regimen. GvHD prophylaxis was mostly cyclosporine and methotrexate (53%). The 6-year cumulative incidence of graft-failure and second transplant were 25% and 17%, respectively. The 6-year disease-free survival (DFS) and overall survival (OS) were 66.9% and 85.6%, respectively. The 6-year transplant-related mortality (TRM) was 8.0%. In conclusion, most patients with CAMT benefit from allo-HSCT, but with many graft failures.

Total body irradiation plus fludarabine versus busulfan plus fludarabine as a myeloablative conditioning for adults with acute myeloid leukemia treated with allogeneic hematopoietic cell transplantation. A study on behalf of the Acute Leukemia Working Party of the EBMT.

Cyclophosphamide is frequently substituted with fludarabine (Flu) in conditioning regimens before allogeneic hematopoietic cell transplantation (allo-HCT). We aimed to compare retrospectively, total body irradiation (12 Gy) plus Flu (FluTBI12) versus busulfan (Bu) plus Flu (FB4) as a myeloablative conditioning before allo-HCT in patients with acute myeloid leukemia (AML). Out of 3203 patients who met the inclusion criteria, 109 patients treated with FluTBI12 and 213 treated with FB4 were included in a final matched-pair analysis. In both groups, median patient age was 41 years, first or second complete remission (CR1/CR2) proportion was 78%/22%, allo-HCT from an unrelated donor was performed in 78% of patients. The probabilities of leukemia-free survival and overall survival at 2 years in FluTBI12 and FB4 groups were 65% vs. 60% (p = 0.64) and 70% vs. 72% (p = 0.87), respectively. The cumulative incidence of relapse was 19% vs. 29% (p = 0.11), while non-relapse mortality was 16% vs. 11%, respectively (p = 0.13). There were no statistical differences in both acute and chronic graft-versus-host disease (GVHD) incidence. The probability of GVHD-free, relapse-free survival (GRFS) was 49% for both groups. FluTBI12 and FB4 are comparable myeloablative regimens before allo-HCT in AML patients transplanted in CR1 and CR2.

Survival advantage of treosulfan plus fludarabine (FT14) compared to busulfan plus fludarabine (FB4) in active acute myeloid leukemia post allogeneic transplantation: an analysis from the European Society for Blood and Marrow Transplantation (EBMT) Acute Leukemia Working Party (ALWP).

We compared FT14 (fludarabine 150-160 mg/m2, treosulfan 42 g/m2) versus FB4 (fludarabine 150-160 mg/m2, busulfan 12.8 mg/kg) in acute myeloid leukemia (AML) transplanted at primary refractory/relapsed disease. We retrospectively studied: (a) adults diagnosed with AML, (b) recipients of first allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated/sibling donor (2010-2020), (c) HSCT with primary refractory/relapsed disease, (d) conditioning regimen with FT14 or FB4. We studied 346 patients, 113 transplanted with FT14, and 233 with FΒ4. FT14 patients were significantly older, more frequently had an unrelated donor and had received a lower dose of fludarabine. Cumulative incidence (CI) of acute graft-versus-host disease (GVHD) grade III-IV and extensive chronic GVHD was similar. With a median follow-up of 28.7 months, 2-year CI of relapse was 43.4% in FT14 versus 53.2% in FB4, while non-relapse mortality (NRM) was respectively 20.8% versus 22.6%. This led to 2-year leukemia-free survival (LFS) of 35.8% for FT14 versus 24.2% in FB4, and overall survival (OS) of 44.4% versus 34%. Adverse cytogenetics and conditioning regimen independently predicted CI of relapse. Furthermore, conditioning regimen was the only independent predictor of LFS, OS, and GVHD-free/relapse-free survival. Therefore, our real-world multicenter study suggests that FT14 is associated with better outcomes in primary refractory/relapsed AML.

The outcome of patients with Hodgkin lymphoma and early relapse after autologous stem cell transplant has improved in recent years.

Hodgkin lymphoma (HL) patients who relapse after autologous-stem-cell- transplantation (auto-SCT) have traditionally had a poor prognosis. We analyzed 1781 adult HL patients who relapsed between 2006 and 2017 after a first auto-SCT. The 4-year overall survival (OS) after relapse continuously increased from 32% for patients relapsing in 2006-2008, to 63% for patients relapsing in 2015-2017 (p = 0.001). The improvement over time was predominantly noted in patients who had an early relapse (within 12 months) after auto-SCT (p = 0.01). On multivariate analysis, patients who relapsed in more recent years and those with a longer interval from transplant to relapse had a better OS, whereas increasing age, poor performance status, bulky disease, extranodal disease and presence of B symptoms at relapse were associated with a worse OS. Brentuximab vedotin (BV), checkpoint inhibitors (CPI) and second transplant (SCT2; 86% allogeneic) were used in 233, 91 and 330 patients respectively. The 4-year OS from BV, CPI, and SCT2 use was 55%, 48% and 55% respectively. In conclusion, the outcome after post-transplant relapse has improved significantly in recent years, particularly in the case of early relapse. These large-scale real-world data can serve as benchmark for future studies in this setting.

Outcome of haploidentical versus matched sibling donors in hematopoietic stem cell transplantation for adult patients with acute lymphoblastic leukemia: a study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

BACKGROUND: Non-T-cell depleted haploidentical hematopoietic stem cell transplantation (HaploSCT) is being increasingly used in acute lymphoblastic leukemia (ALL) with improving patient outcomes. We have recently reported that outcomes of adult patients (pts) with ALL in complete remission (CR) receiving HaploSCT are comparable to unrelated donor transplants. We now compared HaploSCT and matched sibling donor (MSD) transplants in pts with ALL. AIM: To assess transplantation outcomes of HaploSCT and MSD transplants in pts with ALL in CR. METHODS: We retrospectively analyzed adult patients (≥ 18 years) with ALL who underwent their first allogeneic stem cell transplantation (alloSCT) in first or second CR between 2012 and 2018, either from a T cell replete Haplo or MSD donor, and whose data were reported to the Acute Leukemia Working Party (ALWP) of the European Society for Blood and Marrow Transplantation (EBMT). Multivariate analysis (MVA) adjusting for differences between the groups was performed using the Cox proportional hazards regression model. Propensity score matching was also performed to reduce confounding effects. RESULTS: The analysis comprised 2304 patients: HaploSCT-413; MSD-1891. Median follow-up was 25 months. Median age was 37 (range 18-75) and 38 (18-76) years in HaploSCT and MSD, respectively. HaploSCT patients were transplanted more recently than those transplanted from MSD (2016 vs 2015, p < 0.0001). A higher rate of HaploSCT was in CR2 (33.4% vs 16.7%, p < 0.0001), respectively, and fewer received myeloablative conditioning (68% vs 83.2%, p < 0.0001). Cytomegalovirus (CMV) seropositivity was lower in HaploSCT patients (22% vs 28%, p = 0.01) and donors (27.1% vs 33%, p < 0.02), and a higher proportion of the HaploSCTs were performed using a bone marrow (BM) graft (46.2% vs 18.6%, p < 0.0001). The 2 groups did not differ with regard to gender, Karnofsky performance status score, ALL phenotype, Philadelphia chromosome (Ph) positivity and pre-alloSCT measurable residual disease (MRD). Graft versus host disease (GVHD) prophylaxis was mainly post-transplant cyclophosphamide (PTCy) based (92.7%) in the HaploSCT setting, while it was mostly pharmacologic in the setting of MSD (18.7% received ATG). Cumulative incidence of engraftment at day 60 was higher in MSD transplants compared to HaploSCT (98.7% vs 96.3%, p = 0.001), respectively. Day 180 incidence of acute (a) GVHD II-IV and III-IV was higher in HaploSCT vs. MSD: 36.3% vs 28.9% (p = 0.002 and 15.2% vs 10.5% (p = 0.005), respectively. Conversely, the 2-year chronic (c) GVHD and extensive cGVHD were 32% vs 38.8% (p = 0.009) and 11.9% vs 19.5% (p = 0.001) in HaploSCT vs MSD, respectively. Main causes of death were leukemia (31.8% vs 45%), infection (33.1% vs 19.7%) and GVHD (16.6% vs 19.7%) for HaploSCT and MSD, respectively. Two-year relapse incidence (RI), non-relapse mortality (NRM), leukemia-free survival (LFS), overall survival (OS) and GVHD-free, relapse-free survival (GRFS) were 26% vs 31.6%, 22.9% vs 13%, 51% vs 55.4%, 58.8% vs 67.4% and 40.6% vs 39% for HaploSCT and MSD, respectively. In the MVA, RI was significantly lower in HaploSCT in comparison with MSD, hazard ratio (HR) = 0.66 (95% CI 0.52-0.83, p = 0.004), while NRM was significantly higher, HR = 1.9 (95% CI 1.43-2.53, p < 0.0001). aGVHD grade II-IV and grade III-IV were higher in HaploSCT than in MSD HR = 1.53 (95% CI 1.23-1.9, p = 0.0002) and HR = 1.54 (95% CI 1.1-2.15, p = 0.011), respectively. Extensive cGVHD was lower in HaploSCT compared with MSD, HR = 0.61 (95% CI 0.43-0.88, p = 0.007), while total cGVHD did not differ significantly, HR = 0.94 (95% CI 0.74-1.18, p = 0.58). LFS, OS and GRFS did not differ significantly between the 2 transplant groups, HR = 0.96 (95% CI 0.81-1.14, p = 0.66); HR = 1.18 (95% CI 0.96-1.43, p = 0.11) and HR = 0.93 (95% CI 0.79-1.09, p = 0.37), respectively. These results were confirmed in a matched-pair analysis. CONCLUSIONS: Outcomes of adult patients with ALL in CR receiving alloSCT from haploidentical donors are not significantly different from those receiving transplants from MSD in terms of LFS, OS and GRFS.