Acute Myelogenous Leukemia In Remission Research Articles

Influence of Conditioning Regimen Intensity on Outcomes Post-Allogeneic Transplantation for AML in Complete Morphological Remission

Introduction: Acute myelogenous leukemia (AML) is a major indication for allogeneic hematopoietic cell transplantation (alloHCT). Myeloablative (MAC) regimens are preferred for their intensity, however, reduced intensity conditioning regimens (RIC) have been increasingly used to permit older patients and patients with comorbidities to undergo transplant. The literature is conflicting regarding the comparison of outcomes between RIC and MAC patients. While MAC regimens are associated with less relapse, non-relapse mortality (NRM) is higher. RIC regimens on the other hand, demonstrate less NRM but higher relapse rates. We sought to compare RIC vs MAC regimens at our centre for alloHCT of AML in complete remission (CR). Methods: We retrospectively analyzed the outcomes of 451 patients that underwent alloHCT for AML at the Princess Margaret Cancer Centre (PMCC) with either RIC or MAC using various donors between the years 2015-2020. Primary endpoint was 2-year overall survival (OS), secondary endpoints included cumulative incidence of relapse (CIR), cumulative NRM, and GVHD free/relapse free survival (GRFS). Conditioning regimen intensity was determined as defined by Bacigalupo et al (BBMT 2009). Of the total cohort 331 patients received RIC and 121 MAC. Among MAC regimens, 59% received FLU(4)Bu(4) (Fludarabine 140mg/m2 + Busulfan 12.8mg/m2). Among RIC patients 71% received Flu(4)Bu(2)TBI(200) (Fludarabine 140mg/m2+ Busulfan 6.4 mg/m2 + TBI 200cGy). Results: Median age at transplant was 48 years (range: 19-67) for MAC recipients and 61 (range: 18-75) for RIC recipients (p<0.001). Other patient characteristics are described in Table 1. For the entire cohort at 2 years, the incidence of NRM was 19.1% for MAC (95% CI: 12.4-26.8) and 22.5% for RIC (95% CI: 18.1-27.1) (p=0.44). Two-year CIR was 19.8% (95% CI: 12.9-27.8) for MAC recipients and 24.5% (95% CI: 20.0-29.4) for RIC recipients (p=0.15). Two-year OS was 61% and 53% for MAC and RIC, respectively (p=0.02). Acute GVHD occurred in 58.3% of MAC recipients versus 46.8% of RIC recipients. Chronic GVHD occurred in 43.3% of the MAC recipients versus 38% of the RIC recipients. At two years GRFS was 40.8% (95% CI: 35.4-46.1) for MAC and 33.7% (95% CI: 25.0-42.6) for RIC, p=0.30. When examining the Disease Risk Index (DRI) for the entire cohort, OS for high risk was 43.3% (95% CI: 32.5-53.5) vs 66.6% (95% CI: 61-71) and 64% (95% CI: 38-80) for intermediate risk and low risk respectively, p<0.001. A propensity score (PS) matched analysis was done matching patients for age, HLA matching (mismatched vs full match), DRI (low, intermediate, high risk) and in vivo T cell depletion (yes vs no). Two-year OS was 67% for the MAC recipients (95% CI: 57-76) and 66% for the RIC recipients (95% CI: 56-75), p=0.95 (Figure 1a). NRM for MAC was 22% (95% CI: 14-30) versus 14% (95% CI: 8-22) for RIC, p=0.19. CIR at 2 years was 18.5% for MAC (95% CI 11-27) and 24.3% for RIC (95% CI: 16-33), p=0.22. GRFS at 2 years was 36% (95% CI: 26.4-45.7) for MAC and 48.3% (95% CI: 38-58) for RIC recipients, p=0.17. In the subgroup analysis examining matched related donor (MRD) recipients in particular, the OS at 2 years was for MAC 83.6% (95% CI: 66.8-91.3) vs 57.3% (95% CI: 45.1-67.7) for RIC, p=0.006 (Figure 1b) Two-year NRM was 10.3% for MAC vs 23.4% for the RIC group, p=0.14. CIR at 2 years was 12.2% for MAC vs 23.4% for RIC in the MRD setting, p=0.11. Conclusions: Our study shows that in the MRD setting there is a statistically significant improved survival, especially in patients with low and intermediate DRI scores. In other donor settings, there is no significant difference in outcomes between patients that undergo alloHCT with MAC vs RIC regimens. MAC conditioning regimens should continue to be the preferred choice of intensity for patients that may tolerate it. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Randomized Phase II Study to Assess the Role of Nivolumab As Single Agent to Eliminate Minimal Residual Disease and Maintain Remission in Acute Myelogenous Leukemia (AML) Patients after Chemotherapy (NCI9706 protocol; REMAIN Trial)

Randomized Phase II Study to Assess the Role of Nivolumab As Single Agent to Eliminate Minimal Residual Disease and Maintain Remission in Acute Myelogenous Leukemia (AML) Patients after Chemotherapy (NCI9706 protocol; REMAIN Trial)

Relationship Between Pretransplantation Nutritional Status and Outcome in Adults with Acute Myelogenous Leukemia Undergoing Allogeneic Hematopoietic Cell Transplantation

Pretransplantation nutritional status may impact outcome after allogeneic hematopoietic cell transplantation (HCT). Various simple screening tools have been developed and used to identify patients at risk of malnutrition; however, how best to use these screening tools is unclear, and their accuracy for the prediction of adverse outcomes is unknown. To investigate how these different measures contribute to outcome prediction, we examined a large cohort of adults with acute myelogenous leukemia (AML) who underwent allogeneic HCT in first or second remission at our institution between April 2006 and May 2021. We assessed the prognostic role of the Nutrition Risk Index (NRI), which combines weight loss and serum albumin, in 970 adults with AML in first or second remission who had usual body weight information available at AML diagnosis or relapse and before HCT. A low NRI at the time of conditioning for HCT was associated with higher nonrelapse mortality (hazard ratio [HR], .97; 95% confidence interval [CI], .95 to .98; P < .001) and relapse risk (HR, .98; 95% CI, .96 to .99; P < .001) and decreased relapse-free survival (HR, .97; 95% CI, .96 to .98; P < .001) and overall survival (HR, .97; 95% CI, .96 to .98; P < .001), as was a low pre-HCT serum albumin level. After multivariable adjustment, NRI, but not weight loss alone, was associated with outcome. The predictive ability of NRI was overall relatively low and comparable to that of serum albumin, with a C-statistic not exceeding .59. Taken together, our data indicate that pre-HCT level of serum albumin, an acute-phase protein recognized to more accurately reflect the severity of the inflammatory response compared with poor nutritional status, but not weight loss, is independently associated with post-HCT outcome in patients with AML. © 2022 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Comparison of Outcomes after Unrelated Double-Unit Cord Blood and Haploidentical Peripheral Blood Stem Cell Transplantation in Adults with Acute Myelogenous Leukemia: A Study on Behalf of Eurocord and the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Unmanipulated haploidentical hematopoietic stem cell transplantation (HCT) with post-transplantation cyclophosphamide as graft-versus-host disease (GVHD) prophylaxis (haplo-PTCY) and unrelated double-unit umbilical cord blood transplantation (dUCBT) are feasible options for treating patients with high-risk acute myelogenous leukemia (AML). This study compared outcomes after dUCBT and haplo-HCT using peripheral blood stem cells (PBSCs) in adult patients with AML in complete remission (CR) who underwent transplantation in European Society for Blood and Marrow Transplantation (EBMT)-affiliated centers. In a population of adults with de novo AML in first or second CR, we compared outcomes after dUCBT (n = 165) and after haplo-PTCY PBSC (n = 544) performed between January 2013 and December 2018. Patients receiving in vivo antithymocyte globulin, Campath, or ex vivo T cell depletion were excluded. The median follow-up was 33 months for the haplo-PTCY arm and 52 months for the dUCBT arm. No statistically significant differences were observed between the 2 arms in the rates of grade II-IV acute graft-versus-host disease (GVHD) (hazard ratio [HR], 1.31; P = .18), grade III-IV acute GVHD (HR, 1.17; P = .56), chronic GVHD (HR, .86; P = .48), relapse (HR, 1.07; P = .77), nonrelapse mortality (NRM) (HR, .94; P = .77), leukemia-free survival (LFS) (HR, .99; P = .95), or overall survival (OS) (HR, .99; P = .97). Favorable cytogenetic risk was the sole factor predictive of lower relapse incidence (RI). Younger age at transplantation was associated with lower NRM and higher LFS and OS. Both dUCBT and haplo-PTCY with PBSCs can be considered valid approaches for adult AML patients in CR. New strategies should be investigated in both settings to define the most appropriate conditioning regimen and potentially decrease RI and NRM through better immune reconstitution and optimal supportive care.

Impact of the Addition of Antithymocyte Globulin to Post-Transplantation Cyclophosphamide in Haploidentical Transplantation with Peripheral Blood Compared to Post-Transplantation Cyclophosphamide Alone in Acute Myelogenous Leukemia: A Retrospective Study on Behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

The use of haploidentical hematopoietic cell transplantation (haplo-HCT) with peripheral blood stem cells (PBSCs) to treat acute myelogenous leukemia (AML) is increasing. We explored whether the addition of antithymocyte globulin (ATG) to post-transplantation cyclophosphamide (PTCy) allows better outcomes compared with PTCy alone in haplo-HCT with PBSCs (haplo-PBSCT). We included 441 adult patients undergoing a first haplo-PBSCT for AML in first or second complete remission; graft-versus-host disease (GVHD) prophylaxis contained either PTCy alone (n=374) or ATG plus PTCy (n=67), in addition to cyclosporine A (CsA) and mycophenolate mofetil (MMF) as other immunosuppressive agents. All transplantations were performed between 2011 and 2019. No major imbalances were observed between the 2 groups. For both groups, the median patient age was 56 years, and the median year of haplo-PBSCT was 2017. Most patients received a reduced-intensity conditioning regimen (57% in the PTCy group and 61% in the ATG+PTCy group; P=.54). The median follow-up was 19 months in the PTCy group versus 15 months in the ATG+PTCy group (P=.59), and the rate of neutrophil engraftment in the 2 groups was 97% and 98%, respectively. In univariate analysis, there were no statistical differences in transplantation outcomes between the 2 groups. In multivariate analysis, ATG+PTCy was associated with a lower risk of chronic GVHD compared with PTCy alone (hazard ratio, .46; 95% confidence interval, .23 to .93; P=.03). No between-group differences in the other transplantation outcomes were seen. In haplo-PBSCT, the addition of ATG to PTCy (with CsA and MMF) is feasible and better at preventing chronic GVHD and is associated with survival and transplantation outcomes comparable to those with PTCy alone, without increasing transplantation toxicity, mortality, or relapse incidence.

A CASE OF CARDIAC MYELOID SARCOMA POST-ALLOGENEIC TRANSPLANTATION

TYPE: Late Breaking Abstract TOPIC: Cardiovascular Disease INTRODUCTION: Extramedullary relapse of acute myelogenous leukemia (AML) has been reported in a small percentage of patients who received hematopoietic stem cell transplantation. Among the sites of involvement, cardiac myeloid sarcoma or cardiac chloroma is an exceedingly rare presentation. We present a case of a right atrial chloroma without medullary involvement in a patient with AML in remission. CASE PRESENTATION: A 53-year-old woman with a background of AML with myelodysplasia-related features status post-induction chemotherapy followed by an allogeneic hematopoietic stem cell transplant came to the emergency department with chest pain and shortness of breath. The patient was noted to have pericarditis and treatment was initiated. Transthoracic echocardiogram showed a right atrial mass extending into the pericardium, which was confirmed by cardiac magnetic resonance imaging (MRI). Initial right heart catheterization with tissue biopsy was indeterminate and a second one showed atypical cells with immunohistochemical stains consistent with myeloid sarcoma. Bone marrow biopsy did not show evidence of AML and treatment with Azacitidine and Venetoclax was indicated. DISCUSSION: The five-year survival rate for AML is 29.5% and the majority of patients die from infection or hemorrhage. The presence of cardio-respiratory symptoms in our patient led to an early diagnosis of cardiac myeloid sarcoma. It is a rare presentation that is usually diagnosed at autopsy with an incidence <1%. CONCLUSIONS: A high index of suspicion is a cornerstone in the early diagnosis and timely management of cardiac myeloid sarcoma. DISCLOSURE: No significant relationships. KEYWORD: chloroma

Autoimmune Hemolytic Anemia: A Case Study Presentation.

Autoimmune hemolytic anemia (AIHA) is a rare and potentially life-threatening condition. This article presents a case study of AIHA in a patient with a history of acute myelogenous leukemia in remission. Differentiating the cause and type of HA (extrinsic versus intrinsic) will be discussed, along with information on follow-up and refractory AIHA. Advanced practice RNs (APRNs) play an essential role in the early recognition of HA, as well as the diagnosis, referral, and management of the condition.

Safety and Efficacy of Pembrolizumab Prior to Allogeneic Stem Cell Transplantation for Acute Myelogenous Leukemia

Programmed death 1 (PD-1) is an integral component of acute myelogenous leukemia (AML) immune evasion, chemotherapy resistance, and disease progression. PD-1 inhibitors are being investigated as treatment for AML in combination with hypomethylating agents and cytotoxic chemotherapy with encouraging findings. Although allogeneic stem cell transplantation (alloSCT) remains the most established curative treatment for patients with relapsed and refractory AML in complete remission, there are limited data on the clinical outcomes and safety of immune checkpoint inhibitors (ICIs) prior to alloSCT in AML. In the present study, we compared clinical outcomes of 9 patients with AML receiving high-dose cytarabine followed by pembrolizumab in a phase II clinical trial (NCT02768792) prior to alloSCT versus a historical control group of 18 AML patients who underwent alloSCT without prior ICI exposure. The nonparametric Jonckheere-Terpstra test was used to test for a difference in the ordered severity categories of acute graft-versus-host disease (GVHD) within 100 days of transplantation. Time-to-event estimates for overall survival and relapse-free survival were calculated using the Kaplan-Meier method and compared using a log-rank test. One-year survival was not significantly different between the treatment groups (67% versus 78%; P=.34). 100-day mortality was 0% in the ICI group versus 17% in the control group, and there was no increase in grade III-IV acute GVHD in patients treated with pembrolizumab prior to alloSCT. No chronic GVHD was seen in patients treated with pembrolizumab prior to alloSCT and who received post-transplantation cyclophosphamide (PTCy) as part of their conditioning regimen. These findings reinforce the safety and feasibility of ICI therapy prior to alloSCT in patients with AML, and suggest that PTCy may abrogate GVHD risk and severity in patients who receive ICI prior to undergoing alloSCT for AML.

Thiotepa-Busulfan-Fludarabine in Comparison to Busulfan-Cyclophosphamide As Myeloablative Conditioning Regimen Pre Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia: A Study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation (EBMT)

Background. Busulfan plus Cyclophosphamide (BuCy) is the traditional myeloablative conditioning (MAC) regimen pre allogeneic stem cell transplantation (SCT) for acute myelogenous leukemia (AML). The Thiotepa, Busulfan, Fludarabine (TBF) protocol was initially developed for cord blood SCT and subsequently employed in haploidentical SCT; however, there is limited data assessing the TBF regimen in SCT from sibling (MSD) and unrelated donor (URD) for AML and no comparison between the two preparative protocols has been performed.Patients and methods. We analyzed transplantation outcomes of 2523 adult patients (pts) with AML in remission (CR1, CR2+) aged 18-50 years that underwent a first SCT from MSD or URD between 2007 and 2015 and reported to the ALWP of the EBMT. One hundred and three patients received TBF and 2370 pts received BuCy. Pts who received oral busulfan, manipulated grafts, or transplant from <=8/10 HLA-matched donor were excluded. All pts received MAC regimen (defined by Busulfan dose>=9.6 mg/kg). As compared to BuCy, the TBF group included significantly older pts, who were transplanted more recently, had longer interval from diagnosis to transplant, and were more likely to have received BM as stem cell source and URD as donor type. In order to minimize the bias due to differences in pts characteristics, a 1:3 pair-matched analysis was performed. One hundred and forty-six pts receiving TBF were compared with 438 pts receiving BuCy; matching factors included age, year of SCT, disease status at SCT, interval from diagnosis to SCT, donor type, CMV serostatus of both the donor and patient, stem cell source, GVHD prophylaxis and use of anti-thymocyte globulin.Results. With a median follow-up of 22 months, incidence of grade II-IV and III-IV aGVHD after TBF vs BuCy was 29% vs 23% (p=0.23) and 15% vs 8% (p=0.04), respectively. The 5-year cumulative incidence of cGVHD and severe cGVHD was 36% vs 43% (p=0.66) and 16% vs 22% (p=0.72) for TBF vs BuCy, respectively. The 1-year and 5-year non-relapse mortality (NRM) rates were 10% and 22% for TBF vs 9% and 13% for BuCy, respectively (p=0.36). The 1-year and 5-year relapse incidence (RI) rates were 17% and 25% for TBF vs 21% and 37% for BuCy, respectively (p=0.32). No significant difference was observed in leukemia-free survival (LFS), being the 1-year and 5-year LFS rates 73% and 53% for TBF vs 70% and 50% for BuCy, respectively (p=0.56). Overall survival (OS) was also similar, being 80% and 54% for TBF vs 79% and 59% for BuCy, respectively (p=0.88). The composite endpoint graft-vs-host disease-free, relapse-free survival (GRFS) at 5 years was 48% for TBF and 40% for BuCy (p=0.48). Notably, when the analysis was restricted to pts in CR1, a significant difference in RI rate was observed (1-year and 5-year RI: 10% and 18% for TBF vs 20% and 38% for BuCy, respectively, p=0.003) leading to a trend for better LFS for TBF as compared to BuCy (1-year and 5-year LFS: 78% and 57% for TBF vs 72% and 50% for BuCy, respectively, p=0.07), with no difference in OS. When examining separately pts receiving SCT from MSD or URD, no significant difference was observed between TBF and BuCy regimens in terms of transplant outcome. In multivariate analysis, TBF was associated with lower RI compared to BuCy (HR 0.6, p=0.02), while no difference was observed in terms of NRM, LFS, OS and GRFS (HR 0.8, p=0.12 for GRFS). TBF was also associated with lower incidence of cGVHD (HR 0.7, p=0.04) and a trend for lower incidence of severe cGVHD (HR 0.6, p=0.1); on the contrary we observed a trend for higher incidence of grade III-IV aGVHD following TBF as compared to BuCy (HR 1.79, p=0.06).Conclusions. These results suggest that TBF is a valid myeloablative conditioning pre MSD or URD SCT for AML pts < 50 years of age and in remission, with similar transplantation outcome as compared to the traditional BuCy preparative regimen. These data may serve as the scientific background for a well designed randomized two arm study comparing TBF to BuCy as MAC pre SCT in AML pts below the age of 50 years in CR. [Display omitted] DisclosuresSavani:Jazz Pharmaceuticals: Speakers Bureau.

Autologous Bone Marrow Transplantation in Acute Myelogenous Leukemia: In Vitro Treatment With Myeloid Cell-Specific Monoclonal Antibodies

Second or third chemotherapy-induced remissions in acute myelogenous leukemia (AML) are limited by early relapse of the leukemia. We developed monoclonal antibodies (MoAbs) that are cytotoxic to myeloid leukemia cells to treat bone marrow from these patients ex vivo for autologous transplantation. In this pilot study, bone marrow was harvested from ten patients with AML in remission, treated with one or two complement-fixing MoAbs, PM-81 and AML-2-23, which react with myeloid differentiation antigens, incubated with rabbit complement, and cryopreserved. These MoAbs were chosen because they have broad reactivity with AML cells but not with pluripotent progenitor cells. At the time of transplant, 6 patients were in second complete remission, 1 each was in third complete or partial remission, and 2 were in early first relapse. The patients were treated with cyclophosphamide (60 mg/kg a day for 2 days) and total body irradiation (200 cGy twice a day for 3 days) and given infusions of MoAb-treated bone marrow. Full bone marrow reconstitution was observed in eight patients; two patients did not recover platelets. Seven of the ten patients are surviving and disease-free at 21.0, 15.0, 13.0, 10.0, 6.0, 3.0, and 2.0 months posttransplant. Treating bone marrow with MoAbs to myeloid differentiation antigens does not interfere with pluripotential stem cell engraftment. Longer follow-up and a controlled study are necessary to prove that the apparent efficacy of this therapeutic approach in some patients is attributable to MoAb-mediated killing of leukemia cells.

Less Is More: Superior Graft-versus-Host Disease-Free/Relapse-Free Survival with Reduced-Intensity Conditioning and Dual T Cell Depletion in Acute Myelogenous Leukemia.

In this study, we compared the outcomes of patients with acute myelogenous leukemia (AML) in complete remission treated with myeloablative conditioning (MAC) and those treated with reduced-intensity conditioning (RIC) before allogeneic hematopoietic stem cell transplantation (allo-HCT). In addition, we explored the efficacy of dual T cell depletion using anti-thymocyte globulin (ATG) and post-transplantation cyclophosphamide (PTCy) for the prevention of graft-versus-host disease (GVHD) in patients undergoing RIC allo-HCT. Our study cohort comprised 356 adults with AML in complete remission who underwent allo-HCT between 2013 and 2018. One hundred eleven patients (31.2%) received a MAC regimen, and 245 (68.8%) received an RIC regimen. One hundred seventy-one of the patients who received an RIC regimen (68.4%) received ATG, PTCy, and cyclosporine (ATG-PTCY-CsA) for GVHD prophylaxis in accordance with our institutional protocol. Data were collected retrospectively and updated in July 2019. With a median follow-up of 14.5 months (range, 0 to 76 months), 161 patients (45.2%) died, and 66 (18.5%) relapsed. Two-year overall survival (OS), relapse-free survival (RFS), and GVHD-free/RFS (GRFS) were 55%, 52.6%, and 35%, respectively. The intensity of the conditioning regimen, with or without ATG-PTCY-CsA, did not have a significant impact on OS and RFS. However, RIC in combination with ATG-PTCY-CsA was associated with a significantly lower cumulative incidence of acute GVHD and chronic GVHD. The use of RIC with ATG-PTCy-CsA was a significant predictor for higher GRFS secondary to the reduction of clinically relevant GVHD (P= .0001). In patients with AML, RIC allografts and dual T cell modulation with ATG and PTCy led to superior GRFS. The use of this GVHD prophylaxis strategy, along with mitigation of conditioning toxicity using RIC, may result in better long-term quality of life for allo-HCT recipients.

Long-Term Outcomes of Patients with Acute Myelogenous Leukemia Treated with Myeloablative Fractionated Total Body Irradiation TBI-Based Conditioning with a Tacrolimus- and Sirolimus-Based Graft-versus-Host Disease Prophylaxis Regimen: 6-Year Follow-Up from a Single Center.

Cyclophosphamide (Cy)/etoposide combined with fractionated total body irradiation (FTBI) or i.v. busulfan (Bu) has been the main conditioning regimens for allogeneic hematopoietic cell transplantation (alloHCT) for young patients with acute myelogenous leukemia (AML) eligible for a myeloablative conditioning (MAC) regimen. Recent data has suggested that i.v. Bu could be the preferred myeloablative regimen in patients with myeloid malignancies. However, Bu-based regimens are associated with higher rates of sinusoidal obstruction syndrome. Here we report long-term survival outcomes of patients with AML receiving FTBI combined with Cy or etoposide before undergoing alloHCT at City of Hope (COH). We obtained a retrospective review of a prospectively maintained institutional registry of clinical outcomes in 167 patients (median age, 41 years; range, 18 to 57 years) with AML in first or second complete remission who underwent alloHCT at COH between 2005 and 2015. Eligible patients received a MAC regimen with FTBI (1320 cGy) and Cy (120 mg/kg) for unrelated donor transplantation or etoposide (60 mg/kg) for related donor transplantation. Graft-versus-host disease (GVHD) prophylaxis was provided with tacrolimus and sirolimus. In this retrospective study, 6-year overall survival was 60% and nonrelapse mortality was 15%. The GRFS rate was 45% at 1 year and 39% at 2 years. We also describe late metabolic effects and report the cumulative incidence of secondary malignancies (9.5%). Overall, in this young adult patient population, our results compare favorably to chemotherapy-based (i.v. Bu) conditioning regimens without significant long-term toxicity arising from TBI-based regimens.

Autologous Hematopoietic Stem Cell Transplantation in Acute Myelogenous Leukemia.

The clinical outcomes of autologous hematopoietic stem cell transplantation (ASCT) in acute myelogenous leukemia (AML) have improved over time. Indeed, numerous studies have demonstrated that ASCT is associated with a lower relapse rate and acceptable nonrelapse mortality compared with chemotherapy alone in patients with AML. In addition, ASCT is also associated with comparable overall survival outcomes to those of allogeneic hematopoietic stem cell transplantation in some patients with AML. To date, age, cytogenetic and molecular risk stratification, and minimal residual disease (MRD) status have been shown to be closely related to clinical outcomes following ASCT. ASCT is recommended for patients with favorable-risk and intermediate-risk AML in first complete remission and patients with acute promyelocytic leukemia in second complete remission for whom a matched sibling donor is not available. MRD status pre-ASCT is the most important factor to consider when determining whether a patient is eligible for ASCT and can effectively predict clinical outcomes after ASCT. Advanced age is not an absolute contradiction for ASCT. In this review, we describe the literature and clinical trials evaluating the outcomes of ASCT in patients with AML and discuss the indications for ASCT therapy. Because the greatest concern in ASCT recipients is early relapse, important factors that should be monitored before ASCT and future perspectives in this area are also presented.

Impact of Total Body Irradiation on Successful Neutrophil Engraftment in Unrelated Bone Marrow or Cord Blood Transplantation

[Background]Total body irradiation (TBI) has been thought to help donor cell engraftment in allogeneic hematopoietic cell transplantation (HCT) from alternative donors by killing recipientfs T cells. On the other hand, it might increase non-relapse adverse events due to induction or deterioration of inflammatory states following conditioning, leading in organ damages. However, the clinical significance of TBI may be changed by recent progress of HCT strategies, including donor selection algorithms, conditioning intensity, prophylaxis of graft-versus-host disease (GVHD), practical antibiotics usage during febrile neutropenia, and various supportive cares. Thus, the impact of TBI on neutrophil engraftment following HCT was retrospectively analyzed, using Japanese transplant registry database.[Patients and methods]We retrospectively analyzed 3933 adult recipients (>15 y.o.) who underwent HCT between 2006 and 2013 from 8/8 HLA-matched unrelated bone marrow donor (MUD, n=1367), HLA-mismatched unrelated bone marrow donor (MMUD, n=1102), and unrelated cord blood (UCB, n=1464). HCT using unrelated peripheral blood stem cells was excluded because it was currently too small in Japan. Only standard-risk leukemia patients were included: 1st or 2nd complete remission of acute myelogenous leukemia or acute lymphoblastic leukemia, 1st or 2nd chronic phase of chronic myeloid leukemia, and myelodysplastic syndrome other than refractory anemia with excess blasts. Conditioning regimens were divided into 5 groups: High-TBI (>=12Gy) myeloablative conditioning (MAC), fludarabine (Flu)-based Low-TBI (<=8Gy) MAC, no-TBI MAC, Flu-based Low-TBI (<=8Gy) reduced-intensity conditioning (RIC), and Flu-based no-TBI RIC.First, the impact of TBI on cumulative neutrophil engraftment was individually analyzed in overall MUD, MMUD, and UCB cohorts. Next, we evaluated the effects of TBI in UCB subgroups stratified according to conditioning intensity, number of HLA-mismatch, and the presence of anti-HLA antibodies.[Results]Neutrophil engraftment was sufficiently achieved among the High-TBI-MAC, Low-TBI-MAC, no-TBI-MAC, Low-TBI-RIC, and no-TBI-RIC groups both in MUD (>95% in all regimens at day 30) and MMUD (>92% in all regimens at day30) (Figure 1), and TBI was not significantly associated with prompt neutrophil engraftment in multivariate analyses. On the other hand, in UCB, no-TBI-MAC and -RIC groups had lower neutrophil engraftment compared with TBI-regimens (86% in High-TBI-MAC vs. 87% in Low-TBI-MAC vs. 70% in no-TBI-MAC vs. 85% in Low-TBI-RIC vs. 76% in no-TBI-RIC at day-60, P<0.001, Figure1). In multivariate analyses, TBI-regimens in UCB were significantly associated with successful neutrophil engraftment (HR 1.41, P=0.021 in High-TBI-MAC; HR 1.90 in Low-TBI-MAC, P<0.001; HR 1.57 in Low-TBI-RIC, P<0.01), after adjusting for age, gender, performance status, disease type, GVHD prophylaxis, use of in vivo T-cell depletion, infused cell doses, and use of granulocyte-colony stimulating factor. This beneficial effect on engraftment from TBI-based regimens was also observed in the UCB subgroups stratified according to conditioning intensity. Therefore, we subsequently focused only on HCT from UCB, and assessed the beneficial effect of TBI on neutrophil engraftment in the subgroups stratified according to number of HLA allele match, and the presence of anti-HLA antibodies.In the subgroups by number of HLA allele match, TBI-regimens were significantly associated with successful neutrophil engraftment only in recipients who received UCB with 4/6 or less HLA allele match, while the beneficial effect by TBI was not observed in those with 6/6 or 5/6 HLA allele match (Figure 2).Additionally, focusing on recipients who had anti-HLA antibodies (n=173, Figure 3), TBI-based regimens were significantly associated with successful neutrophil engraftment (HR 2.38 in High-TBI regimens, P=0.017; HR 2.23 in Low-TBI regimens, P=0.016).[Conclusion]TBI-regimens had neither impact on neutrophil engraftment in the current practice of unrelated bone marrow transplantation. However, in UCB transplantation, TBI is still necessary to enhance engraftment, no matter what conditioning intensity is selected. Especially, recipients from UCB with two or more allele mismatches or with anti-HLA antibodies may benefit from adding TBI into conditioning. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

TCR Clonal Evolution in AML Patients in Morphologic Remission Treated with Anti-PD1 Antibody, Nivolumab

We are conducting a clinical trial titled "Randomized Phase II Study to Assess the Role of Nivolumab as Single Agent to Eliminate Minimal Residual Disease and Maintain Remission in Acute Myelogenous Leukemia (AML) Patients After Chemotherapy" (REMAIN trial) (NCT02275533).A critical barrier in developing immunotherapies is the identification of predictive biomarkers of response to therapy. T lymphocytes play critical roles in response to immunotherapies but their clonality and temporal changes in the T cell repertoire during treatment have not been well investigated. Recent advances in deep sequencing technology make it possible to characterize the T cell receptor (TCR) repertoire generated following immunotherapy.In this study, we characterized T cell repertoire in peripheral blood and/or bone marrow samples of three AML patients on the REMAIN trial before and after nivolumab treatment. Using Illumina MiSeq sequencer and total RNA from each sample, we conducted deep sequencing of TCR-α and -β chains, and calculated the diversity index (inverse Simpson’s index) in their CDR3 sequences to assess overall clonality of T cells. We obtained total CDR3 clonotypes of 420,765 ± 155,449 (average ± standard deviation) for TCR-α and 410,786 ± 115,219 for TCR-β per each sample. Interestingly, we found that certain TCR-α and -β clonotypes were drastically enriched in the bone marrow samples after nivolumab treatment. Many of these enriched TCR clonotypes were minimal or undetectable before nivolumab treatment, indicating that nivolumab might induce expansion of anti-AML T cell subclones. Particularly, nivolumab treatment led to marked reduction of TCR diversity indexes in both peripheral blood and bone marrow samples of one AML patient, who had shown a clearance of minimal residual disease as detected by WT1 qRT-PCR.Our results thus far indicate the feasibility of this type of comprehensive analysis of TCR repertoire in the context of immunotherapy for AML. Preliminary results suggest that such analysis may be utilized to predict response of immune checkpoint blockade, and could also be useful to identify high-affinity TCRs for adaptive T cell therapy approaches. DisclosuresLiu:BMS: Research Funding; Karyopharm: Research Funding. Odenike:Incyte: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Suneisis: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Geron: Research Funding; CTI/Baxter: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Spectrum: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Algeta: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Sanofi-Aventis: Honoraria, Membership on an entity’s Board of Directors or advisory committees. Stock:ADC Therapeutics: Honoraria; Amgen: Honoraria; Gilead Sciences: Honoraria; Sigma-Tau: Honoraria, Research Funding; Royalties for a chapter in Up to Date: Patents & Royalties.

Early Infection Attenuates Hematologic Malignant Disease Relapse Following Initial Allogeneic Hematopoietic Cell Transplantation

Background: Primary malignant disease relapse, graft-versus-host disease (GvHD) and infection are the most common causes of death following allogeneic hematopoietic cell transplantation (alloHCT). We investigated whether infection following initial alloHCT influenced subsequent risk for hematologic malignant disease relapse.Methods: Consecutive adult patients (N=324) with acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML) or myelodysplasia (MDS) who received initial matched sibling (MSD) or unrelated donor (MUD) bone marrow (BM, n=33), peripheral blood stem cell (PBSC, n=253) or umbilical cord blood (UCB, n=38) grafts from January 2010 through December 2014 at The Ohio State University Comprehensive Cancer Center were included. Patient-, transplant-, and infection-related data were retrospectively obtained. Categories for microbiologically-documented infections included bacterial blood stream infection (BSI), viral reactivation (VRA), invasive fungal infection (IFI), and respiratory viral infection (RVI). Correlation between development of infection and relapse was assessed using multi-variable (MV) proportional sub-distribution hazards models, where infection was treated as a time‐dependent covariate and death from any cause as a competing risk. Landmark analyses (LMA) at D14, D28, D56 and D100, which included only those patients who survived without relapse at the indicated time and infection status as a covariate, were performed to predict future relapse.Results: Most transplant recipients had first complete remission AML, received MUD PBSC grafts following myeloablative conditioning, and were given methotrexate and calcineurin-based GvHD prophylaxis. Following alloHCT, 107 (33%) patients experienced disease relapse. Median progression-free survival (PFS) for the entire patient cohort was nearly two years (703 days). Grades 2-4 acute GvHD developed in 164 (51%) patients, and 145 (45%) patients developed limited or extensive chronic GvHD. One- and three-year overall survival (OS) rates for the entire cohort were 63% and 45%, respectively.Cumulative incidence of infection, overall and by infection type, is depicted in Table 1. Patient- and transplant-related factors affecting development of infection are listed in Table 2. Patients who developed infection post-transplant had future relapse risk that was 46% (HR 0.54, 95% CI: 0.36-0.80, p=0.003) less than those patients who did not develop infection, regardless of infection type, in MV proportional sub-distribution hazards model analyses. LMA showed similar patterns in reduced risk for relapse following infection. Although not all reached statistical significance, LMA showed reduced relapse risk associated with early infection: D14 (HR 0.54, 95% CI: 0.27-1.05, p=0.07), D28 (HR 0.53, 95% CI: 0.30-0.93, p=0.03), D56 (HR 0.57, 95% CI: 0.37-0.90, p=0.01), and D100 (HR 0.63, 95% CI: 0.37-1.09, p=0.10).Using infection as a time-dependent covariate, patients with infection had higher risk for infection-related mortality (IRM, HR 2.10, 95% CI: 1.45-3.05, p<0.0001) and non-relapse mortality (NRM, HR 6.42, 95% CI: 3.17-12.99, p<0.0001) versus patients not developing infection, but no difference in risk for relapse-related mortality (RRM, HR 0.97, 95% CI: 0.62-1.51, p=0.89). Interestingly, LMA at early post-HCT time points showed that infection may actually be protective for RRM: D14 (HR 0.69, 95% CI: 0.37-1.30, p=0.25), D28 (HR 0.59, 95% CI: 0.35-0.99, p=0.05), D56 (HR 0.57, 95% CI: 0.37-0.87, p=0.01), and D100 (HR 0.71, 95% CI 0.46-1.11, p=0.13).Conclusion: Early infection post-alloHCT may confer protection against hematologic malignant disease relapse, but also increases NRM and IRM. Further investigation is required to define underlying immunologic mechanisms that may mediate such putative protection in order to promote presumed enhancement in graft-versus-leukemia effect. [Display omitted] DisclosuresAuletta:Shire Pharmaceuticals: Consultancy. Lozanski:Boehringer Ingelheim: Research Funding; Genentech: Research Funding; Beckman Coulter: Research Funding; Stemline Therapeutics Inc.: Research Funding. Hofmeister:Arno Therapeutics, Inc.: Research Funding; Janssen: Pharmaceutical Companies of Johnson & Johnson: Research Funding; Celgene: Research Funding; Incyte, Corp: Membership on an entity’s Board of Directors or advisory committees; Signal Genetics, Inc.: Membership on an entity’s Board of Directors or advisory committees; Karyopharm Therapeutics: Research Funding; Takeda Pharmaceutical Company: Research Funding; Teva: Membership on an entity’s Board of Directors or advisory committees. Andritsos:Hairy Cell Leukemia Foundation: Research Funding.

Does High-Dose Cytarabine Cause More Fungal Infection in Patients With Acute Myeloid Leukemia Undergoing Consolidation Therapy: A Multicenter, Prospective, Observational Study in China.

Invasive fungal infection (IFI) remains as a significant cause of morbidity and mortality in patients with acute myelogenous leukemia (AML). Here, we report the subgroup analysis of China Assessment of Antifungal Therapy in Haematological Disease (CAESAR) study to evaluate the risk of IFI in patients with AML in 1st remission receiving high-dose cytarabine (HiDAC) as consolidation. A total of 638 patients with AML in 1st complete remission were selected from the database. Among them, 130 patients received HiDAC alone with total dose of 2–3 g/m2 × 6 while 508 patients received multiple-agent combination chemotherapy (multiagent chemo group). The patients’ characteristics were generally not different but more patients in HiDAC group had peripherally inserted central catheter (61.5% vs 44.5%, P = 0.002). The median duration of neutropenia was 8.0 days in both HiDAC (2–20) and multiagent chemo group (2–28). Number of patients with prolonged neutropenia (>14 days) tended to be more in multiagent chemo group but not significant different (16.3% vs 8.8%, respectively). There was no significant difference between 2 groups in persistent neutropenic fever (40.8% vs 33.1%), antifungal treatment (11.5% vs 11.4%), and incidence of proven/probable IFI (4 probable in HiDAC vs 1 proven/4 probable in multiagent chemo, P = 0.35) or possible IFI. As to the clinical outcome in terms of duration of hospitalization and death in remission, there was a trend of shorter duration of hospitalization in HiDAC (19 days, 3–70) compare to multiagent chemo group (21 days, 1–367, P = 0.057) while no death documented in HiDAC group and only 2 patients died in the multiagent chemo group (0.4%). As to risk factors associated with IFI in all 638 patients, there was a trend of more IFI in patients with severe neutropenia (3.0%, P = 0.089) and previous history of IFI (3.85%, P = 0.086) while the antifungal prophylaxis was not associated significantly reduced IFI. Overall, our data support the perception that HiDAC alone as consolidation in first remission AML patients was well tolerated and not associated with increased hematological toxicity and IFI than conventional combination chemotherapy. Antifungal prophylaxis may not necessary except for patients with previous history of IFI.

Allogeneic Hematopoietic Cell Transplantation for Acute Myelogenous Leukemia in Remission - a Prospective Comparison of Three Different Donor Groups; Matched Sibling, Matched Unrelated, and Haploidentical Family Donors

Allogeneic hematopoietic cell transplantation (HCT) from HLA-matched sibling (MS) or unrelated donors (MU) is a well-established treatment for patients with intermediate/high-risk acute myelogenous leukemia (AML) in remission. When HLA-matched donors are not available, however, use of haploidentical family (HF) donors for HCT remains controversial.Therefore, we performed a prospective study, where patients with AML in complete remission (CR) underwent allogeneic HCT according to the donor priority of MS, MU, or HF donors. Conditioning regimen for MS-HCT was busulfan (3.2 mg/kg • 4 days)-cyclophosphamide (60 mg/kg • 2 days) or, for patients >55 years or with co-morbidity, busulfan (3.2 mg/kg • 2 days)-fludarabine (30 mg/m2 • 6 days)-Thymoglobulin (1.5 mg/kg • 3 days). Patients undergoing MU- or HF-HCT received busulfan (3.2 mg/kg • 2 days)-fludarabine (30 mg/m2 • 6 days)-Thymoglobulin (3 mg/kg • 3 days) (Lee K-H et al; Blood 2011;118:2609-2617; Am J Hematol 2011;86:399-405). Ex-vivo T cell depletion was not performed. GVHD prophylaxis included cyclosporine plus a short course of methotrexate.Between January 2010 and December 2014, 244 patients enrolled. Of those, 16 patients were excluded from the analysis (12 patients relapsed before HCT; 3 with major protocol violation; and 1 with incomplete data). Of remaining 228 patients, 81 underwent HCT from MS donors, 90 from MU donors, and 57 from HF donors. The donors for MU-HCT were younger and more male-dominant than those for MS- or HF-HCT. The characteristics of patients and their donors were summarized in Table 1.Table 1MS-HCT (n=81)UD-HCT (n=90)HF-HCT (n=57)P*Median age, yr (range)48 (19-66)43 (16-66)46 (17-69)Sex, male/female37/4444/4629/280.824CR1/CR276/582/847/100.098Chromosome risk,low**/intermediate/high/high-monosomal6/57/10/54/65/16/32/40/7/50.751Donor median age, yr (range)45 (18-63)28 (20-45)29 (15-58)Donor age, yrup to 2526-45over 454413629610193260.000Donor sex, male/female46/3576/1436/210.000Donor relation, parents/sibling/offspring7/24/26HLA allele mismatch/8 (GVH direction), 0/1/2/3/481/0/0/051/26/10/2/10/0/5/22/300.000Graft, bone marrow/peripheral blood28/530/900/570.000Median nucleated cell count, •108/kg (range)8.0 (0.9-19.0)10.8 (4.1-31.4)10.8 (5.1-19.3)Median CD34+ count, •106/kg (range)4.9 (0.8-18.0)8.0 (1.4-26.2)6.4 (2.4-25.7)*by Chi-square test; **Twelve patients with AML of low-risk chromosomal abnormality included 6 patients in CR2, 3 with c-kit mutation, and 3 with persistent aml1-eto or cbf beta-myh11 after induction chemotherapy.The median follow-up duration of 164 survivors in the study was 34.7 months (range, 3.7-63.6) after HCT. The donor-group effect on the HCT outcomes was described in Table 2. Patients who underwent MS-HCT showed slightly slower neutrophil engraftment and higher incidence of chronic GVHD. Otherwise, in terms of disease recurrence, NRM, graft failure, EFS, and OS, there was no significant difference according to the donor-type. For AML recurrence, cytogenetic risk was an independent prognostic factors (P =0.003; hazard ratio of low-risk to; intermediate-risk, 1.42; high-risk, 2.53; high-risk with monosomal karyotype, 5.47).Table 1MS-HCT (n=81)UD-HCT (n=90)HF-HCT (n=57)PCumulative incidence ( 95% confidence interval)*AML recurrence29% (19-40%)26% (17-36%)35% (20-51%)0.785Non-relapse mortality (NRM)8% (3-16%)7% (2%-16%)11% (4-21%)0.435Graft failure1% (0.1-6%)6% (2-12%)5% (1-13%)0.293ANC>500/uL median days (range)100% 13 (9-20)99%12 (10-45)98% 12 (6-22)0.049Platelet>20,000/uL median days (range)99% (86-100%) 14 (0-83)97% (88-99%) 13 (0-77)96% (83-99%) 14 (0-106)0.352Grades 2-4 acute graft-versus-host disease (GVHD)12% (6-21%)13% (7-21%)23% (13-34%)0.176Moderate to severe chronic GVHD39% (28-50%)22% (13-30%)23% (13-35%)0.04524-year survival**Event-free (EFS)63%69%54%0.381Overall (OS)62%74%64%0.077*compared by Gray's method; **compared by log-rank testOur study showed that, despite heterogeneity of baseline donor characteristics (age and sex), conditioning regimen, and graft source (bone marrow vs. peripheral blood), overall post-transplant outcomes were similar among recipients from MS-, MU-, and HF-donors. Therefore, for patients with AML in CR but without an HLA-matched donor available, HCT from a haploidentical family member may be considered. DisclosuresNo relevant conflicts of interest to declare.

Reduced Intensity Versus Myeloablative Conditioning for Allogeneic Stem Cell Transplantation in Acute Myeloid Leukemia

▪IntroductionReduced intensity conditioning (RIC) regimens for allogeneic hematopoietic stem cell transplantation (SCT) offer a potential treatment for otherwise incurable cases of acute myelogenous leukemia (AML) with less associated toxicity compared to myeloablative conditioning (MAC). Eradication of malignant cells after RIC depends largely on the graft-versus leukemia effect (GVL). These regimens are becoming increasingly popular, particularly in older patients or those with comorbidities. They may also be offered to otherwise healthy patients based on personal or physician preference, as there is growing evidence that overall survival may be equivalent for both treatments. We retrospectively reviewed the charts of Saskatoon Cancer Centre patients receiving either RIC or MAC to compare the incidence and grade of graft versus host disease (GVHD), progression free survival (PFS), and overall survival (OS).MethodsWe identified 74 patients who underwent HSCT for AML in complete remission (CR) between January 2000- December 2013. Of these patients, 55 received MAC and 19 received RIC.Median age at HSCT was 48 years (range 18-68). In the group receiving MAC, 36% of patients were >50 years, whereas 74% of patients receiving RIC were >50 yrs of age.ResultsPatients receiving RIC experienced greater incidence of chronic GVHD (63% vs 41%, p=.09) and relapse (54% vs 30%, p=.07). Incidence of acute GVHD was the same for either regimen (53%).Median overall survival was similar (39 vs 38 months), with lower early mortality in RIC later overtaking MAC at 27 months. Progression free survival demonstrated a non-statistically significant advantage for MAC (median 43 vs 49 months).ConclusionRIC has been associated with greater incidence of chronic GVHD and relapse, with no difference in overall survival. Patients receiving RIC are more likely to be >50 years of age, making comparisons challenging. The results of this review suggest that MAC is the preferred regimen for patients who can tolerate its toxic effects due to reduced incidence of chronic GVHD and relapse, however the similarity in overall survival makes the choice of either conditioning regimen reasonable. Future studies to identify the best conditioning regimen are warranted.Overall Survival [Display omitted] Progression Free Survival [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Recovery Blasts in the Peripheral Blood in AML Patients Who Obtain a Complete Remission Is a Favorable Prognostic Indicator

Introduction: Many patients with Acute Myelogenous Leukemia (AML) will transiently develop blasts in the peripheral blood upon recovery of induction chemotherapy, despite going on to obtain a complete remission. These are presumably non-leukemic marrow blasts. Recovery blasts can sometimes reach over 20% in the peripheral blood in remission patients. The significance of recovery blasts cells after induction chemotherapy in patients with AML is not clear. We sought to define the incidence of recovery blastocytosis (RB) and determine if the presence of RB has prognostic relevance.Methods: We performed a retrospective analysis of 72 patients with newly diagnosed AML who underwent induction chemotherapy with 7+3 (cytarabine and daunorubicin) with or without etoposide between the years of 2006 and 2013 at our institution. Patients were included in the analysis as having RB only if their blasts resolved by day 14 of induction chemotherapy, blasts reappeared upon recovery after day 14, recovery blasts were > 5% in the peripheral blood of a duration of >5 days, and subsequently resolved by day 45 and remission was obtained. We recorded patient’s absolute and percentage peripheral blast counts on presentation, upon nadir and throughout recovery of induction chemotherapy. The incidence and level of RB in patients who achieved a remission was tabulated. This group (group 1) was compared to the patients who achieved a remission whom did not develop RB (group 2).Results: 45/77 AML patients obtained a CR after induction chemotherapy. Recovery blasts were seen in 9/45 (20%) remission patients (group 1), with a median RB of 9% for a median duration of 8 days. Of these 9 patients, 4 developed RB > 10%, and 2 developed RB >20 % Group 1 did not differ in respect to age, gender, cytogenetic profile, etoposide use, or whether the patient received 1 or 2 induction therapies from the 36/45 remission AML patients who did not develop RB (group 2). Median survival for group 1 was = 1,376 days, and 1,036 days for group 2 (p= .035).Conclusion: Recovery Blasts in the peripheral blood after induction chemotherapy is seen commonly in AML patients who obtain a complete remission. RB can be seen even as high as > 20% in remission patients. AML patients who develop RB on their way to remission after induction chemotherapy have a better overall survival then patients who do not develop RB. [Display omitted] Graph 1. Kaplan-Meier survival curves for AML patients with RB (group 1) and without RB (group 2). DisclosuresNo relevant conflicts of interest to declare.