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Background: We recently reported results of the prospective, open‐label HOVON‐100 trial in 334 adult patients with acute lymphoblastic leukemia (ALL) randomized to first‐line treatment with or without clofarabine (CLO). No improvement of event‐free survival (EFS) was observed, while a higher proportion of patients receiving CLO obtained minimal residual disease (MRD) negativity. Aim: In order to investigate the effects of CLO in more depth, two multi‐state models were developed to identify why CLO did not show a long‐term survival benefit despite more MRD‐negativity. Methods: The first model evaluated the effect of CLO on going off‐protocol (not due to refractory disease/relapse, completion or death) as a proxy of severe treatment‐related toxicity, while the second model evaluated the effect of CLO on obtaining MRD negativity. The subsequent impact of these intermediate events on death or relapsed/refractory disease was assessed in both models. Results: Overall, patients receiving CLO went off‐protocol more frequently than control patients (35/168 [21%] vs. 18/166 [11%], p = 0.019; HR 2.00 [1.13–3.52], p = 0.02), especially during maintenance (13/44 [30%] vs. 6/56 [11%]; HR 2.85 [95%CI 1.08–7.50], p = 0.035). Going off‐protocol was, however, not associated with more relapse or death. Patients in the CLO arm showed a trend towards an increased rate of MRD‐negativity compared with control patients (HR MRD‐negativity: 1.35 [0.95–1.91], p = 0.10), which did not translate into a significant survival benefit. Conclusion: We conclude that the intermediate states, i.e., going off‐protocol and MRD‐negativity, were affected by adding CLO, but these transitions were not associated with subsequent survival estimates, suggesting relatively modest antileukemic activity in ALL. [ABSTRACT FROM AUTHOR]

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. Addition of antithymocyte globulin (ATG) or post‐transplantation cyclophosphamide (PTCY) to standard immunosuppressive agents in patients who received a transplant from an HLA‐identical sibling donor is feasible and allows low rates of graft‐versus‐host disease (GVHD).When compared with PTCY, the use of ATG is associated with lower cumulative incidence of chronic GVHD. [ABSTRACT FROM AUTHOR]

Limited data are currently available on the outcome of patients with acute myeloid leukemia (AML) undergoing allogeneic stem cell transplantation (allo‐SCT) with a reduced performance status. We herein present the results of a registry study on 2,936 AML patients undergoing allo‐SCT in first remission (CR1) with a Karnofsky Performance Status (KPS) score less than or equal to 80%. Two‐year leukemia‐free survival (LFS), overall survival (OS) and graft‐versus‐host disease (GVHD)‐free, and relapse‐free survival (GRFS) rates were 54%, 59%, and 41%, respectively. In multivariable analysis, patients with a KPS score = 80% had lower non‐relapse mortality (NRM) and superior OS in comparison to patients with a KPS score <80% (p < 0.001). In the subgroup of patients with a KPS score =80%, a reduced‐intensity conditioning (RIC) regimen was associated with an increased risk of relapse (p = 0.002) and lower GRFS (p < 0.001) compared to myeloablative conditioning (MAC). Differently, in patients with a KPS score <80%, a RIC regimen resulted in lower NRM (p < 0.001), whereas relapse incidence did not differ, thus leading to an improved GRFS (p = 0.008) as compared to MAC. A transplant from a matched sibling donor (MSD) was associated with a reduced incidence of grade III‐IV acute GVHD (p < 0.01) and NRM (p < 0.01) in comparison to other donor types. In conclusion, allo‐SCT appears feasible in AML patients with a jeopardized KPS score. Survival is significantly affected by the conditioning intensity, which should be adjusted according to the severity of KPS impairment. [ABSTRACT FROM AUTHOR]

Background: The use of post-transplant cyclophosphamide (PTCy) is highly effective in preventing graft-versus-host disease (GVHD) in the haploidentical (Haplo) transplant setting and is being increasingly used in matched sibling (MSD) and matched unrelated (MUD) transplants. There is no information on the impact of donor types using homogeneous prophylaxis with PTCy. Methods: We retrospectively compared outcomes of adult patients with acute myeloid leukemia (AML) in first complete remission (CR1) who received a first allogeneic stem cell transplantation (SCT) with PTCy as GVHD prophylaxis from MSD (n = 215), MUD (n = 235), and Haplo (n = 789) donors registered in the EBMT database between 2010 and 2017. Results: The median follow-up was 2 years. Haplo-SCT carried a significantly increased risk of acute grade II–IV GVHD (HR 1.6; 95% CI 1.1–2.4) and NRM (HR 2.6; 95% CI 1.5–4.5) but a lower risk of relapse (HR 0.7; 95% CI 0.5–0.9) that translated to no differences in LFS (HR 1.1; 95% CI 0.8–1.4) or GVHD/relapse-free survival (HR 1; 95% CI 0.8–1.3). Interestingly, the use of peripheral blood was associated with an increased risk of acute (HR 1.9; 95% CI 1.4–2.6) and chronic GVHD (HR 1.7; 95% CI 1.2–2.4) but a lower risk of relapse (HR 0.7; 95% CI 0.5–0.9). Conclusions: The use of PTCy in patients with AML in CR1 receiving SCT from MSD, MUD, and Haplo is safe and effective. Haplo-SCT had increased risk of acute GVHD and NRM and lower relapse incidence but no significant difference in survival. [ABSTRACT FROM AUTHOR]

Reduced-intensity conditioning ( RIC)-allo SCT is increasingly used for acute myelogenous leukemia. Limited data are available for the comparison of peripheral blood stem cells with bone marrow for RIC-allo SCT. We used the European Group for Blood and Marrow Transplantation ( EBMT) ALWP data to compare the outcome of mobilized peripheral blood stem cells ( PBSC) ( n = 1430) vs. bone marrow ( BM) ( n = 107) for acute myelogenous leukemia ( AML) patients with complete remission that underwent RIC-allo SCT from compatible sibling donors. The leukemia features, the disease status, and the time from diagnosis were similar between the two groups. Engraftment was achieved in 99% and 93% in the PBSC and BM groups, respectively ( P < 0.0001). The day of engraftment was significantly earlier for the PBSC vs. the BM group, 15 (1-59) and 19 (5-69), respectively ( P < 0.001). Acute GVHD, severe GVHD (grade III-IV) and chronic GVHD did not differ between the groups. leukemia-free survival ( LFS), relapse, and non-relapsed mortality ( NRM) were 51 ± 2%, 32 ± 1%, and 17 ± 1% vs. 50 ± 6%, 38 ± 6%, and 12 ± 3% for the PBSC and BM groups, respectively. Our results indicate faster engraftment, but no difference in GVHD, LFS, relapse, and NRM when comparing PBSC to BM grafts from sibling donors following RIC conditioning. This is the first study comparing PBSC to BM grafts in the RIC setting, analyzing a homogeneous population of patients with AML in remission. Whether PBSC should be preferred for advanced phases of the disease, where the outcome is dominated by relapse incidences, needs further investigation. [ABSTRACT FROM AUTHOR]

High-dose cytarabine is currently used in combination with anthracycline in the treatment of acute myeloblastic leukaemia (AML). Moreover, high-dose cytarabine has been reported to produce long-term disease-free survival in a proportion of patients, especially in certain subtypes of AML. However, it remains unknown whether the outcome of patients undergoing allogeneic or autologous stem cell transplantation is influenced by previous treatment with high-dose cytarabine. To this end, 1672 patients with AML in first remission who were reported to the Acute Leukaemia Working Party registry of the European Group for Blood and Marrow Transplantation (EBMT) and who were transplanted between 1980 and 1995 were analysed according to the dose intensity of cytarabine given at induction and/or consolidation. Autologous stem cell transplantation (ABMT) was performed in 846 patients and allogeneic bone marrow transplantation (BMT) in 826 patients. This study shows that the dose of cytarabine (Ara-C) given at induction and/or consolidation did not influence the relapse incidence in patients subsequently allografted or autografted. In addition, it did not give any advantage in terms of overall outcome. Therefore, high-dose (HD) Ara-C may not be needed for patients who have a planned stem cell transplantation (SCT) as post-remission therapy. Nevertheless, HD Ara-C may be utilized in certain subtypes of AML that are believed to be curable by chemotherapy alone. [ABSTRACT FROM AUTHOR]

• Marked improvement has been achieved in recent years in stem cell transplantation (SCT) from unrelated donors. • Long-term outcome is equivalent after SCT from unrelated and sibling donors. • Patients who are leukemia-free 2 years after SCT can expect a favorable outcome. 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. [ABSTRACT FROM AUTHOR]

Purpose: Total-body irradiation (TBI) is a major constituent of myeloablative conditioning regimens. The standard technique consists of 12 Gy in 6 fractions over a period of 3 days. The Standard-fractionation compAred to one-daily fRaction total body irrAdiation prior to tranSplant In LEUkemia patieNts (SARASIN) study aimed to compare standard fractionation with once-daily fractionation before transplant in leukemia.Methods and Materials: We retrospectively compared TBI regimens delivered in 2993 patients from the European Society for Blood and Marrow Transplantation database, who underwent transplantation between 2000 and 2014 for acute lymphoblastic leukemia (ALL, n = 1729) or acute myeloid leukemia (AML, n = 1264). TBI was delivered as either 12 Gy in 6 fractions (group 1, considered the reference group; 1362 ALL and 857 AML patients), 9 to 12 Gy in 2 fractions (group 2, 173 ALL and 256 AML patients), or 12 Gy in 3 to 4 fractions (group 3, 194 ALL and 151 AML patients).Results: The median follow-up was 60 and 84 months in ALL and AML patients, respectively. At 5 years, the leukemia-free survival rate, overall survival rate, relapse incidence, and nonrelapse mortality rate were 46.6%, 50.4%, 28.8%, and 24.6%, respectively, in ALL patients and 46.6%, 48.9%, 29.7%, and 23.6%, respectively, in AML patients. In multivariate analyses, the outcomes of groups 2 and 3 were not statistically different from those in group 1. The cumulative incidence of secondary malignancies (SMs) was significantly higher in group 2 (7.2%; P < 10-6 for group 2 vs group 1). However, group 2 was not associated with an increase in SMs when we considered non-T-cell-depleted transplant patients.Conclusions: We showed that the 12-Gy fractionated TBI dose delivered either in 2 fractions or in 1 fraction per day over a period of 3 to 4 days resulted in nonsignificant differences in disease control and survival. However, 1-day fractionation may be associated with a higher risk of mucositis and hemorrhagic cystitis. The absence of a significant difference in the SM incidence in the non-T-cell-depleted group should be interpreted with caution in the context of a retrospective study design. Our findings are important to consider for radiation therapy department organization. In-depth analyses of other nonlethal toxicities and late effects are required. [ABSTRACT FROM AUTHOR]

Usually, after double umbilical cord blood transplantation (DUCBT), only 1 of the transplanted units persists in the long term. The characteristics of the winning cord blood unit (W-CBU) that determine unit dominance and how they influence the outcomes of DUCBT remain unclear. We retrospectively analyzed 347 patients with acute leukemia transplanted with a DUCBT (694 CBU) from 2005 to 2013 who had documented neutrophil engraftment and a W-CBU identified by chimerism analysis, to identify unit characteristics impacting on dominance. Median age at DUCBT was 40 years and median follow-up was 35 months. Among W-CBUs, 41% were ≥5/6 HLA matched to the recipient and 59% were ≤4/6. Multivariate analysis indicated that ≤4/6 HLA-matched W-CBUs led to lower leukemia-free survival (44% versus 56%; hazard ratio [HR], 1.5; P  = .032) and overall survival (49% versus 62%; HR, 1.5; P  = .028), increased nonrelapse mortality (26% versus 18%; HR, 1.9; P  = .027), and acute graft-versus-host disease (46% versus 35%; HR, 1.7; P  = .013). We were unable to predict unit dominance, but we demonstrated that outcomes were strongly influenced by the degree of HLA mismatch between W-CBU and recipient. Therefore, selection of both units with the lower number of HLA mismatches with the recipient is indicated. [ABSTRACT FROM AUTHOR]

We analyzed 661 adult patients who underwent single-unit (n = 226) or double-unit (n = 435) unrelated cord blood transplantation (UCBT) following a reduced-intensity conditioning (RIC) consisting of low-dose total body irradiation (TBI), cyclophosphamide, and fludarabine (Cy/Flu/TBI200). Eighty-two patients received rabbit antithymocyte globulin (ATG) as part of the conditioning regimen (ATG group), whereas 579 did not (non-ATG group). Median age at UCBT was 54 years, and diagnoses were acute leukemias (51%), myelodysplastic syndrome/myeloproliferative neoplasm (19%), and lymphoproliferative diseases (30%). Forty-four percent of patients were transplanted with advanced disease. All patients received ≥4 antigens HLA-matched UCBT. Median number of collected total nucleated cells was 4.4 × 107/kg. In the ATG group, on 64 evaluable patients, ATG was discontinued 1 (n = 27), 2 (n = 20), or > 2 days before the graft infusion (n = 17). In multivariate analyses, the use of ATG was associated with decreased incidence of acute graft-versus-host disease (hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.17-0.55; P < .0001), higher incidence of nonrelapse mortality (HR, 1.68; 95% CI, 1.16-2.43; P = .0009), and decreased overall survival (HR, 1.69; 95% CI, 1.19-2.415; P = .003). Collectively, our results suggest that the use of ATG could be detrimental, especially if given too close to graft infusion in adults undergoing UCBT following Cy/Flu/TBI200 regimen. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate results of high-dose total-body irradiation (TBI) regimens for hematopoietic stem cell transplantation. Methods and Materials: A total of 1,032 patients underwent TBI in one or two fractions before autologous or allogeneic hematologic stem cell transplantation for acute leukemia and non-Hodgkin''s lymphoma. The TBI regimens were normalized by using the biological effective dose (BED) concept. The BED values were divided into three dose groups. Study end points were relapse incidence (RI), non-relapse mortality (NRM), relapse-free survival (RFS), and overall survival (OS). Multivariate analysis was performed, stratified by disease. Results: In the highest TBI dose group, RI was significantly lower and NRM was higher vs. the lower dose groups. However, a significant influence on RFS and OS was not found. Relapses in the eye region were found only after shielding to very low doses. Age was of significant influence on OS, RFS, and NRM in favor of younger patients. The NRM of patients older than 40 years significantly increased, and OS decreased. There was no influence of age on RI. Men had better OS and RFS and lower NRM. Type of transplantation significantly influenced RI and NRM for patients with acute leukemia and non-Hodgkin''s lymphoma. There was no influence on RFS and OS. Conclusions: Both RI and NRM were significantly influenced by the size of the BED of single-dose or two-fraction TBI regimens; OS and RFS were not. Age was of highly significant influence on NRM, but there was no influence of age on RI. Hyperfractionated TBI with a high BED might be useful, assuming NRM can be reduced. [Copyright &y& Elsevier]

Recently, an increasing number of patients with acute lymphoblastic leukemia with a poor Karnofsky Performance Status (KPS) score are considered for allogeneic hematopoietic stem cell transplantation (allo-HCT). Nevertheless, there is paucity of available data about outcome of this fragile population. We report here the results of a retrospective study designed to evaluate outcome of ALL patients undergoing allo-HCT with KPS score ≤80%. The analysis included ALL patients aged ≥18 years, undergoing allo-HCT in first remission between 2000 and 2018, with a KPS score of 50% to 80% at the time of transplant. A total of 1,010 patients were identified. Median age at transplant was 43 years (18-76 years). Median year of transplant was 2011. The KPS score was =80% in 83% of the patients and <80% in 17% of the patients. Diagnosis was Philadelphia chromosome (Ph) negative B-ALL, Ph positive B-ALL or T-ALL in 34%, 44% and 22% of the patients, respectively. Donor type was MSD or 10/10 UD in 60% and 40% of the patients, respectively. Conditioning was myeloablative (MAC) or reduced-intensity (RIC) in 78% and 22% of the patients, respectively, and it was TBI-based in 79% of the patients. Stem cell source was PBSC in 76% and BM in 24% of the patients, respectively. Cumulative incidence of grade II-IV and III-IV aGVHD was 32% and 9%, respectively. The 2-year cumulative incidence of chronic GVHD (cGvHD) and severe cGVHD was 43% and 18%, respectively. Non relapse mortality (NRM) and relapse incidence (RI) at 2 years were 18% and 28%, respectively. At 2 years, leukemia-free survival (LFS), overall survival (OS) and GVHD-free, relapse-free survival (GRFS) rates were 54%, 64% and 41%, respectively. On multivariate analysis, transplant from 10/10 UD was associated with higher incidence of aGVHD (HR 1.8, p<0.0001) and higher risk of NRM (HR 1.7, p<0.01) as compared to MSD. RIC conditioning was associated with higher risk of relapse (HR 1.2, p=0.02), lower LFS (HR 1.3, p=0.03) and lower GRFS (HR 1.3 p=0.02) as compared to MAC. NRM was not significantly different between MAC and RIC. Factors independently associated with improved OS were younger age at transplant, female sex, more recent year of transplant and Ph+ B ALL phenotype. Administration of ATG was associated with reduced risk of developing grade II-IV aGVHD (HR 0.6, p<0.001), cGVHD (HR 0.5, p<10−4) and severe cGVHD (HR 0.4, p<10−4). In conclusion, allo-HCT is feasible in patients with acute lymphoblastic leukemia in first remission and KPS score ≤80%, with acceptable NRM and survival rates. Transplant from a MSD was associated with reduced risk of NRM and aGVHD as compared to 10/10 UD. Interestingly, despite the poor KPS score of the patients included in the analysis, a MAC protocol was associated with similar NRM, lower relapse and better LFS and GRFS as compared to RIC in the selected population. Finally, administration of ATG was associated with reduced acute and chronic GVHD rates. [ABSTRACT FROM AUTHOR]

Acute myeloid leukemia bearing a RUNX1 gene mutation (RUNX1 + AML) has been proposed as a provisional entity in the 2016 WHO classification. Clinically, it has been associated with inferior response rates and outcome after conventional chemotherapy. Accordingly, RUNX1 + AML is allocated in the unfavorable prognostic category of the 2017 European Leukemia Net classification. Following allogeneic stem cell transplantation (alloSCT), RUNX1 was an unfavorable factor in one study in MDS/secondary AML, while data in de novo AML are scarce. Here, we present a retrospective study by the EBMT Acute Leukemia Working Party, aiming to elucidate the prognostic value of RUNX1 mutation in patients undergoing alloSCT for AML in first complete remission (CR1). Adults undergoing alloSCT for AML in CR1 from matched related or unrelated donors between 2013 and 2018 with complete information on conventional cytogenetics and RUNX1 mutational status were selected from the EBMT registry. Variables of interest were overall and leukemia-free survival (OS/LFS), GvHD/relapse free survival (GRFS), cumulative relapse incidence (RI), non-relapse mortality (NRM) and GvHD. Log rank test, Gray test and Cox regression models were used. 128 RUNX+ and 388 RUNX- patients were identified, >80% of both subgroups presenting as de novo AML. As expected, RUNX1+ patients rarely had co-mutations in NPM1 (6% vs. 26%, p=10−3), and showed a positive correlation with ASXL1 mutations (50% vs. 16%, p=10−4). Cytogenetic categories and other mutations (FLT3 -ITD, CEBPA) were equally distributed between the two groups, as were age, donor and graft type, CMV, conditioning and T cell depletion (TCD). Median follow-up was 16.4 (RUNX+) and 19.8 (RUNX-) months. 2y OS/LFS of the entire cohort were 64% [59-69]/57% [52-62], with no difference between RUNX1 + and RUNX1 - patients either in univariate or multivariate analysis (2y OS: 67.9% [57.3-78.5] vs. 63.1%v[57.4-68.7]p=0.15; 2y LFS: 57.6% [46.4-68.7] vs. 57% [51.4-62.6], p=0.38], figure 1). RUNX1 mutation neither had any impact among patients with normal karyotype (figure 2). Similarly, no other outcome parameter was influenced by RUNX1 mutational status. Instead, multivariate analysis revealed age and donor type as risk factors for OS, LFS and NRM. Poor cytogenetic was associated with higher RI and inferior LFS/GRFS, in vivo TCD with a lower rate of aGvHD II-IV, cGvHD, and better GRFS. Among patients with available information, FLT3 -ITD was an independent risk factor for relapse, LFS and GRFS. RUNX1 did not modify the role of FLT3 -ITD. Within the limits of a retrospective registry analysis, we could not find a negative influence of RUNX1 mutation on outcome after allogeneic SCT in CR1. Hence, transplantation in CR1 might overcome the unfavorable prognostic value of RUNX1 mutation and can be recommended as consolidation treatment in this entity. [ABSTRACT FROM AUTHOR]

We report here the results of a retrospective study designed to evaluate outcome of patients with AML with KPS score ≤80% following allo-SCT. The analysis included adult AML patients undergoing allo-SCT in CR1 between 2000 and 2018, with a KPS score at the time of transplant between 50% and 80%. A total of 2,963 patients were identified. Median age at transplant was 55 years (18-77 years). The KPS score was 80% in 85% of the patients and <80% in 15% of the patients. Cytogenetic risk was good, intermediate or poor in 6%, 68% and 26% of the patients, respectively. Donor type was sibling (MSD), matched (10/10 UD), mismatched (9/10 UD) unrelated, haploidentical (haplo) or cord blood (CB) in 47%, 35%, 8%, 6% and 4% of patients. Conditioning was myeloablative (MAC) or reduced-intensity (RIC) in 42% and 58% of patients. Stem cell source was PBSC or BM in 84% and 14% of the patients, respectively. Cumulative incidence of grade II-IV acute GVHD (aGvHD) and chronic GVHD (cGvHD) was 26% and 38%, respectively. Non-relapse mortality (NRM) and relapse incidence (RI) at 2 years were 19% and 27%. Leukemia-free survival (LFS), overall survival (OS) and GVHD-free, relapse-free survival (GRFS) rates were 54%, 59% and 41%, respectively. On multivariate analysis, transplant from a MSD was associated with a reduced risk of aGvHD (10/10 UD HR 1.8, 9/10 UD HR 2.4, haplo HR 1.9, CB HR 3.4, p<10−4) and NRM (10/10 UD HR 1.4, 9/10 UD HR 2.4, haplo HR 1.8, CB HR 2, p<10−3, MSD as reference) as compared to all other donor types. Patients with KPS score of 80% had significantly lower NRM and improved survival as compared to patients with KPS<80%. Other factors independently associated with improved OS were younger age, female sex, good or intermediate risk cytogenetics and de-novo AML. In order to compare outcome following MAC and RIC conditioning regimens the analysis was restricted to patients receiving transplant from MSD or UD. Patients with a KPS score of 80% or <80% were analyzed separately. In the group of patients with a KPS score of 80%, a RIC regimen was associated with higher RI (HR 1.4, p<0.01), higher incidence of severe cGVHD (HR 1.6, p<0.001), and inferior GRFS (HR 1.3, p<0.001) as compared to MAC. NRM was not significantly different following RIC or MAC in this population. In contrast, in patients with a KPS score <80%, RIC was associated with lower NRM (HR 0.3, p<0.0001) and better LFS (HR 0.6, p<0.01), OS (HR 0.5, p<0.0001) and GRFS (HR 0.6, p<0.01) as compared to MAC. In conclusion, allo-SCT is feasible in patients with acute myeloid leukemia in first remission and KPS score ≤80%, with acceptable NRM and survival rates. In patients with a KPS score of 80% a MAC regimen was associated with lower relapse rate, similar NRM and better GRFS as compared to RIC, while in patients with a KPS score <80% RIC was associated with reduced NRM and improved OS. In addition, transplant from a MSD was associated with reduced risk of NRM and aGVHD rates as compared to other donor types. [ABSTRACT FROM AUTHOR]