High-risk AML Research Articles

Maintenance 5-Azactidine May Improve Outcomes after Allogeneic Stem-Cell Transplantation in High-Risk AML and MDS Patients

Introduction: Allogeneic stem-cell transplantation (SCT) is curative therapy in patients with AML or MDS. However, disease recurrence is the major cause of treatment failure. 5-Azacytidine has been used in the standard treatment of MDS and also in the treatment of AML patients not eligible for standard chemotherapy. There is limited data on the safety and efficacy of Azacytidine after SCT. We explored the use of low-dose Azacytidine maintenance therapy for the prevention of relapse of AML/MDS after SCT. Methods: Patients considered to be at high risk for relapse after SCT were given Azacytidine at 32-50 mg/m2 for 5 days every 28 days for a planned duration of 2 years. Transplantation outcomes were compared with a historical group matched for patient age, disease, status at SCT, cytogenetics, conditioning and donor type. To reduce bias, control patients were required to be alive and in remission for at least the time until the start of Azacytidine prophylaxis in their counterparts. Patients relapsing after SCT and achieving second CR with chemotherapy were also eligible for secondary Azacytidine prophylaxis. The control patients for these patients were also matched for the time from SCT to relapse. Results: Forty patients, median age 62 years (25-74), 24 male and 16 female, were given azacytidine after SCT from HLA-matched sibling (n=8) or matched-unrelated (n=32) donors. Diagnosis was AML (n=32) or MDS (n=8). The conditioning regimen was myeloablative (n=20) or reduced-intensity (n=20). The status at SCT was untreated MDS/ secondary AML (n=10), CR1 (n=19), CR2 (n=4), refractory AML (n=7). 15 had normal karyotype, 9 complex karyotype and 16 other cytogenetic abnormalities (12 of them high-risk). Fifteen patients were in CR after SCT but at high-risk for relapse due to active disease (n=7) or positive MRD (n=3) at SCT, or poor-risk cytogenetics (n=5). Eight patients were given Azacytidine as secondary prevention after achieving CR with chemotherapy for post-transplant relapse. 17 patients were given Azacytidine pre-emptively for mixed-chimerism (n=9) or positive measurable residual disease (n=8) after SCT. The estimated leukemia-free survival (LFS) in this group of patients is less than 20%. Patients started Azacytidine in a median of 2.2 months (1.2-6.9) after SCT and received a median of 14 courses (1-50). Three patients were also given donor-lymphocyte infusions concomitantly with Azacytidine. 18 patients are still on therapy, 16 died or progressed, 3 stopped after long remission, 2 stopped due to regulatory issues and only 1 had to discontinue due to toxicity. 12 of 23 patients given prophylactic Azacytidine remained in CR, 11 relapsed and 7 of them died. 15 of 17 patients given Azacytidine preemptively achieved a response (10 CR) and 7 remained in CR. 9 died of disease progression and one of non-relapse cause. With a median follow-up of 22.5 months (10.2-45.2), the estimated 3-year overall survival (OS) and LFS rates are 53.9% (95%CI, 29.5-78.4) and 40.0% (95%CI, 21.2-58.6), respectively. In the matched control group, 8 patients are alive, 26 died of relapse and 6 of non-relapse causes. The estimated 3-year OS and LFS rates are 27.1% (95%CI, 13.2-41.0, P=0.002, Figure 1) and 19.7% (95%CI, 7.9-32.1, P=0.005, Figure 2), respectively. The relapse rates were 57.6% (95%CI, 41.6-79.8) and 65.3% (95%CI, 52.0-82.0) in the Azacytidine and control groups, respectively (P=0.04, Figure 3). The median time to relapse was 9.1 months (0.7-25.5) and 4.9 months (1.1-35.9), respectively. The non-relapse mortality (NRM) rates were 2.5% (95%CI, 0.3-17.3) and 15.0 (7.1-31.4), respectively (P=0.01). Conclusions: Azacytidine is safe and effective therapy when used prophylactically or preemptively in high-risk AML/MDS patients to prevent relapse. Azacytidine maintenance may reduce but more often delay relapse in this high-risk patient group. Azacytidine may also reduce NRM and improve survival in this patient group and should be further explored, possibly in combination with other methods to prevent relapse. Figure 1 Disclosures No relevant conflicts of interest to declare.

Azacitidine (AZA) with Nivolumab (Nivo), and AZA with Nivo + Ipilimumab (Ipi) in Relapsed/Refractory Acute Myeloid Leukemia: A Non-Randomized, Prospective, Phase 2 Study

Azacitidine (AZA) with Nivolumab (Nivo), and AZA with Nivo + Ipilimumab (Ipi) in Relapsed/Refractory Acute Myeloid Leukemia: A Non-Randomized, Prospective, Phase 2 Study

Venetoclax Is Safe and Efficacious in Relapsed/ Refractory AML

Introduction: On November 2018 the FDA approved the treatment of venetoclax together with hypomethylating agent (HMA) or low dose cytarabine (LDAC) for newly diagnosed AML patients who cannot tolerate intensive chemotherapy. There is limited data regarding the efficacy and safety of venetoclax in the setting of relapsed/refractory patients who received intensive chemotherapy for their disease. Methods: In this study, data were collected retrospectively from Israeli medical centers where venetoclax was used as an advanced line of treatment after intensive chemotherapy. Venetoclax was given as a combination with HMA or LDAC or as monotherapy. Results: 40 patients with AML were included in the study, 60% were Males. The median age at time of diagnosis was 67 years (range, 21-82). 27 (67.5%) patients had de-novo AML and 13 (32.5%) had secondary disease; 7 (17.5%) patients had a history of MDS and 6 (15%) of MPN. 37% of the patients had normal karyotype (20% of them had FLT3-ITD mutation), 23% had complex karyotype. Based on the 2017 ELN risk classification, 12.5% had favorable risk, 42.5% - intermediate and 45% had high risk. At presentation, 87.5% of the patients received the '7+3' protocol as induction therapy but only 45% achieved a CR. Ultimately, 57.5% of the patients achieved a CR post consolidation/ salvage therapy. 42.5% underwent allogeneic hematopoietic cell transplant (HCT); 71% received myeloablative conditioning and the others reduced intensity. The median time from diagnosis to starting venetoclax was 6 (1-64) months. Patients received venetoclax after a median of 2 (range, 1-4) prior lines of treatment (not including HCT). The median age at starting venetoclax was 68.5 years (range, 22-83). The ECOG performance status at starting venetoclax was 0-1 in 67.5% of the patients, 2 in 22.5% and 3 in 10% of the patients. The median daily dose of venetoclax was 400 mg (range: 100-800 mg). Venetoclax was given together with HMA (mostly azacitidine) in 62.5% of the patients and with LDAC in 22.5%. In 12.5% of the patients it was given as monotherapy and in 1 patient it was given with the FLAG-IDA regimen. The median number of cycles of venetoclax that were given so far is 2.75 (range: 0.5-14). None of the patients experienced tumor lysis syndrome (TLS). 27.5% of the patients did not survive more than 2 months. Of the 29 patients who survived longer than 2 months, 76% achieved neutrophil recovery and 77% of them recovered also their platelet count. In 52% of those who survived more than 2 months, CR/CRi was confirmed by bone marrow (BM) examination. Taken together, 76% of the patients who survived more than 2 months achieved blood cell count recovery and in 68% of them it was confirmed as CR/CRi by BM examination. At a median follow-up of 5.5 months, 35% of the patients are still alive and 57% of them are still on venetoclax. The leading cause of death (81%) was disease progression. The median OS from starting venetoclax of all the patients and of those who survived more than 2 months was 5.5 and 6.5 months, respectively (Figure 1). Conclusions: Venetoclax was given to high risk AML patients with relapsed/refractory disease after intensive chemotherapy and in around 40% of the patients also after HCT. The treatment was tolerable and no patient developed TLS. Among those who survived more than 2 months, the CR/CRi rate, or at least blood cell count recovery rate, was high (76%) and the median OS was 6.5 months. These retrospective data, albeit in a heterogeneous group of previously treated patients with AML, demonstrate that the combination of venetoclax with HMA or LDAC is safe and active also in AML patients with advanced disease. Its precise role for patients who relapse after intensive chemotherapy needs to be evaluated in a prospective clinical trial. Figure 1 Disclosures Wolach: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Speaker; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Speaker. Rowe:BioSight: Consultancy. OffLabel Disclosure: Venetoclax for relapsed/ refractory AML

Title: SNP Microarray Reveals Predicted Outcomes of a Novel High Risk AML Subgroup with ERG Amplification

Increased expression of ERG (ETS-related gene), a proto-oncogene within the ETS (erythroblast transformation specific) family, is associated with an unfavorable clinical outcome in AML patients. A mechanism for ERG over-expression is ERG amplification. ERG amplification is present in 4-6% of adult AML. This study investigates the genetic profile of ERG-amplified AML by assessment of genomic copy number changes and mutational status of AML-related genes and how this correlates to treatment response and overall outcome. Currently copy number analysis is not recommended by ELN or WHO as a diagnostic standard in AML. An institutional retrospective review of 205 adult AML cases from 2015 to 2018 provided two cohorts: a discovery cohort and control cohort. The discovery cohort includes 11 cases (4%) with ERG amplification. All cases in the discovery cohort include either TP53 mutation and/or loss/LOH of 17p. Thus, we developed a control cohort of 39 cases with TP53 abnormalities without ERG amplifications to determine the role TP53 plays in the observed outcomes. The 179 adult AML cases from the TCGA public database comprises the validation cohort, which incorporates both copy number and molecular sequencing data. Approximately 4% of AML cases in the TCGA dataset show ERG amplification. For our discovery and control cohorts, genomic DNA was extracted (Maxwell, Promega, Madison, WI) from fresh bone marrow aspirates. Copy number/LOH analysis was performed using the CytoSNP microarray (Illumina, San Diego, CA). Sequence variants were evaluated in hotspot regions of 49 genes using the ThunderBolts Myeloid Panel library preparation (RainDance Technologies, Billerica, MA) and paired-end sequencing (MiSeq, Illumina, San Diego, CA). Alignment and variant calling was performed with MiSeq Reporter (Illumina) and NextGene (Soft Genetics, State College, PA) and sequences were annotated using VarSeq (Golden Helix, Bozman, MT). SNP microarray analysis of the discovery cohort revealed a distinct pattern of complex cytogenetics including chromothripsis, TP53 loss/LOH and loss of 5q. Molecular sequencing was available for 10 of 11 patients. All specimens analyzed for mutational status demonstrated TP53 loss of function mutations. The majority of cases (9/11) demonstrated complete loss of function of TP53 by mutation in conjunction with a "second hit" in the form of loss due to deletion or LOH of 17p. These nine patients failed to achieve any response with chemotherapy with a median survival time of 3.8 months. The two surviving patients had a single TP53 mutation with an intact second allele. Both of these patients are post-allogeneic stem cell transplant with no evidence of relapse. There is an association of ERG amplification with MDS as 8 of the 11 patients transformed from very-high risk MDS. The interaction between ERG and TP53 allows one to predict treatment response and outcomes based on the presence or absence of an intact TP53 allele. Within the control group, there were no significant differences in survival or response to treatment based on number of intact TP53 alleles. The validation cohort of TCGA patients confirmed the strong positive correlation between ERG amplification and TP53 mutations. There were 8 cases with ERG amplification. Of these, 6 cases had a similar genetic pattern found in the discovery cohort including TP53 mutations, loss of 5q and complex cytogenetics. The median overall survival (OS) of this cohort of ERG amplified + TP53 mutation was 2.5 months. ERG amplification classifies a high-risk population of AML detected by copy number/LOH analysis with a distinct genetic signature including loss of 5q, complex cytogenetics including chromothripsis and loss of function TP53 mutation. The successive loss of the second TP53 allele in the setting of ERG amplification identifies a subset of patients with resistance to cytarabine and a very poor prognosis. These patients are unlikely to benefit from cytotoxic chemotherapy and may have improved outcomes with alternative regimens and/or clinical trial. ERG amplification is associated with AML that transforms from very-high risk MDS. Recognizing these patients before transforming to AML could allow for early transplant. This high-risk subgroup is currently un-recognized by standard cytogenetics and genetic mutation profiling; therefore, we recommend that copy number/LOH analysis become part of the standard diagnostic testing for MDS and AML. Disclosures No relevant conflicts of interest to declare.

Prophylactic or Preemptive Low-Dose Azacitidine (AZA) and Donor Lymphocyte Infusion (DLI) Prevent Disease Relapse Following Allogeneic Transplantation in High Risk Acute Myeloid Leukemia and Myelodysplastic Syndrome

Introduction: Despite therapeutic advances in recent years, disease relapse is still observed in up to 50-60% of the patients (pts) receiving allogeneic transplantation for high risk AML and MDS. In an initial Phase II trial of 30 pts treated with prophylactic low-dose AZA and escalated doses of DLI to prevent relapse, we reported that such prophylactic treatment can be safely administered and compared favorably to patients receiving no post-transplant maintenance. We here update 16 pts from our center, included in that protocol, as well as a larger cohort of additional patients treated with combined epigenetic and cellular therapy and the resultant effect on their event-free survival and their overall survival. Patients and methods: Fifty-nine pts (median age 59 yrs (range, 37-70); 30 M/29 F), comprising 40 pts with AML and 19 pts with MDS, were treated. Among the AML pts (ELN classification FAV n=2, INT n=17, ADV n=21), high risk criteria were as follows: 15 had complex karyotypes, 7 Flt3-ITD, 1 MECOM (EVI1) rearr., 3 monosomies, 2 t(9;11), and 1 t(11;19)); 9 were in CR≥2, 4 were refractory, and 13 had 2ary AML to MDS/chemotherapy/or MPS. Among the MDS pts, high risk criteria included 6 pts with complex caryotypes, 2 monosomies, 1 MECOM (EVI1) rearr., and 4 had 2ary MDS. IPSS-R median was 5.5 (3 - 7.5). MDS pre-transplant status included 7 CR1, 1 CR2, 5 PR, 1 relapse, 4 upfront, and 1 refractory. The therapeutic protocol administered to the initial 16 pts consisted of AZA, starting between d56 and d100 post-transplant, at a dose of 32 mg/m²/d SC, for 5 consecutive days, every 28 days, for up to a total of 12 cycles followed by DLI commencing after 3 cycles of AZA and 4 weeks following discontinuation of immunosuppressive prophylaxis. Two additional DLI were scheduled every 8 weeks following the 1st DLI. The doses of DLI 1, 2 and 3 were, respectively, 5x106, 1x107, and 5x107 CD3+ cells/kg for matched related donor (MRD), and 1x106, 5x106, and 1x107 CD3+ cells/kg for unrelated donor (UD). In the extended patient cohort, presented here, we slightly modified the schedule: DLI could be given earlier (after one or two cycles of AZA) and haploidentical pts could receive AZA/DLI as well, with DLI at the escalated doses of 1x105, 5x105, and 1x106 CD3+ cells/kg. Immunosuppression included cyclosporine A (CsA) in case of MRD, CsA and mycophenolate mofetil (MMF) in case of UD or haplo. MMF was progressively reduced during the first 2 months. CsA was tapered starting at day 60-100 post-transplant. Patients could start AZA while they were still receiving CsA. The conditioning regimens consisted of MAC for 5 pts, RIC for 46 pts and sequential for 8 pts. Donors were MRD, MUD, UD 9/10, and haplo for 20, 30, 1 and 8 pts respectively. Results: The median number of cycles AZA was 7 (range 1-12), 17 pts received 12 cycles of AZA, while 42 pts (71%) received at least one DLI. The median number of DLI was 1 (range 0-4), 15 pts received ≥ 3 DLI. The median time for the first post-transplant AZA injection was 83 days (range 56-145 d) and the median time post-transplant for those pts who received a first DLI was 148 days (range 78-245 d). The median pt-follow-up was 17 months (range 2-83). Eight pts (13%) relapsed (7 AML and 1 MDS). The cumulative incidence of relapse and NRM at 1 year was 12% and 11.5% respectively. Fifteen pts (25%) died. Causes of death included relapse in 6 pts, infection in 7 pts, myocardial infarction in 1 pt, and GvHD in 1 pt. Overall survival and event free survival for the entire group at 2 years was 71% (95% CI 54-82%) and 67% (95% CI 50-80%) respectively. The cumulative incidence of acute GvHD grade 1-4 and chronic GvHD were 32% (95% CI 16-49%) and 39% (95% CI 20-58%). Among the 8 pts who developed grade 3 acute GvHD, 4 occurred in pts who had received DLI. One pt died from grade 4 digestive GvHD post-AZA alone. Conclusion: We conclude that, despite their very high risk disease, prophylactic/preemptive low-dose AZA and DLI can be readily and safely administered with an acceptable incidence of subsequent GvHD to the AML and MDS pts described here. Significantly, in the poor-prognosis pts under study, the incidence of relapse is lower than expected. Furthermore, considering the immune escape mechanisms prophylactic or pre-emptive either AZA or DLI might be associated to additive non-cross reactive interventions, such as checkpoint inhibitors, in order to further decrease disease relapse and increase overall survival. Disclosures Peterlin: Jazz Pharma: Consultancy; Astellas: Consultancy; Daiichi-Sankyo: Consultancy; AbbVie Inc: Consultancy. Orvain:Novartis: Honoraria; Incyte: Honoraria. Chevallier:Jazz Pharmaceuticals: Honoraria; Daiichi Sankyo: Honoraria; Incyte: Consultancy, Honoraria.

Lenalidomide Plus Hypomethylating Agent as a Treatment Option in Acute Myeloid Leukemia With Recurrent Genetic Abnormalities—AML With inv(3)(q21.3q26.2) or t(3;3)(q21.3;q26.2); GATA2, MECOM

IntroductionAcute myeloid leukemia (AML) is a heterogeneous clonal hematopoietic neoplasm. The cytogenetic changes associated with AML affect the response rate and survival and are one of the most important independent prognostic factors. AML with inv(3)(q21.3q26.2) or t(3;3)(q21.3;q26.2); GATA2, MECOM accounts for 1% to 2% of all forms of AML and has been associated with a younger age at diagnosis, a poor response to standard induction chemotherapy, and very poor long-term prognosis. Patients and MethodsWe performed a single-center, retrospective cohort study comparing the outcomes with hypomethylating agent (HMA) plus lenalidomide to those with standard intensive induction therapies for newly diagnosed and relapsed/refractory AML with inv(3). ResultsOf the 15 patients, 4 (26.7%) had received lenalidomide and HMA as primary therapy. The overall response rate (ORR) was 100% for the 4 patients who had received lenalidomide with HMA as first-line induction therapy. The ORR was 27.3% (3 of 11) for the patients who had received other induction regimens (P = .0256). The duration of response for first induction therapy was an average of 7.4 months after lenalidomide plus an HMA and a mean of 1.5 months after induction with other chemotherapy regimen (P = .057). The ORR for induction and reinduction therapy was also assessed, with an ORR of 21.4% (6 of 28) for alternative chemotherapy regimens and an ORR of 75% (6 of 8) for induction and reinduction with lenalidomide plus HMA (P = .0046). ConclusionsThe high ORR and reasonable duration of response could allow for potentially curative allogeneic hematopoietic cell transplantation for these patients with high-risk AML. Our initial data suggest that lenalidomide plus HMA is a promising approach for patients with AML with inv(3).

Novel Strategies in High-Risk AML

Novel Strategies in High-Risk AML

EPO and EPOR Expression in Patients with Acute Leukemia and Its Clinical Significance

To investigate the expression of erythropoietin (EPO) and erythropoietin receptor (EPOR) in patients with acute leukemia (AL) and its clinical significance. The levels of EPO and EPOR in plasma were determined by ELISA kit. mRNA expression levels of EPO and EPOR were determined by RT-RCR. The protein expression levels of EPO and EPOR were detected by Western blot. The EPO protein levels in marrow plasma of ALL and AML group were significantly higher than those in the control group (P＜0.05), EPOR protein levels in ALL and AML group were significantly lower than those in the control group (P＜0.05). The mRNA levels of EPO and EPOR in ALL and AML groups were significantly higher than those in the control group (P＜0.05). The mRNA levels of EPO and EPOR in the high risk ALL and AML groups were significantly higher than those in the medium, low risk group and the control group (P＜0.05). The protein expression levels of EPO and EPOR in ALL and AML groups were significantly higher than that in control group (P＜0.05). The mRNA levels of EPO and EPOR in ALL and AML groups did not correlate with hemoglobin level and erythrocyte count (P＞0.05). The expressions of EPO and EPOR is higher in ALL and AML patients. The expression levels of EPO and EPOR relate with the risk of ALL and AML. High risk patients have higher expression levels of EPO and EPOR, however, the expression levels of EPO and EPOR do not correlate with hemoglobin level and erythrocyte counting.

PS1055 NEGATIVE MINIMAL RESIDUAL DISEASE STATUS BY MULTICOLOUR FLOW CYTOMETRY AFTER 1ST COURSE IS THE MOST PREDICTIVE FACTOR FOR AML PATIENTS

Background: In patients with relapsed or refractory acute myeloid leukemia (R/R AML) encouraging results have been reported after allogeneic hematopoietic stem cell transplantation (HSCT) following a conditioning regimen with sequential melphalan, fludarabine and total body irradiation (FMTBI) (Steckel et al., Br. J. Haematol. 2018; 180:840–853). However, non-relapse mortality (NRM) was up to 45% in elderly patients (>59 years) and higher age was associated with inferior survival. Aims: We hypothesized that in elderly patients with active disease or AML with unfavorable genetics, fludarabine and melphalan alone might enable similar long-term graft-versus-host-disease (GVHD) and relapse-free survival (GRFS) and be associated with lower NRM compared to FMTBI. Methods: Between 01/2011–02/2019, 106 consecutive high-risk AML patients received conditioning with FMTBI (n = 58), i.e. melphalan (140 mg/m2, day −11) preceding fludarabine (30 mg/m2days −5 to −2) and total body irradiation (2–8 Gy starting on day −1) or FM (n = 48), i.e. fludarabine day −6 to −2 and melphalan (140 mg/m2, day −3) and a T cell-repleted graft from an HLA-matched donor. GVHD prophylaxis consisted of cyclosporine A or tacrolimus plus mycophenolate mofetil; additional antithymocyte globulin was administered in the unrelated donor setting. Active disease was defined as ≥5% bone marrow blasts or extramedullary disease. Results: Prior to conditioning, 72% of patients had active (n = 48) or measurable residual disease (MRD, n = 29) and 18% were in complete remission (without MRD marker: n = 15; MRD negative: n = 4). MRD was determined by qPCR analysis of mutated NPM1 (n = 25), CBFB-MYH11 (n = 3), MLL-PTD (n = 4) and JAK-V617F (n = 1). In the FM group, patients were older (58 vs. 48 years, p = 0.09) and significantly more patients had a high-risk Hematopoietic Cell Transplantation-Comorbidity Index (56% vs 22%), p = 0.02). Genetic risk according to European Leukemia Network criteria 2017 did not differ between the FM and FMTBI group (low/intermediate/high: 19%/42%/39% vs 33%/27%/ 40%; p = 0.18). Twenty-nine patients (27%) were grafted from a matched related donor, 65 patients (61%) from a 10/10 matched unrelated donor (MUD), and 12 patients (11%) from a 9/10 MUD and the vast majority received peripheral blood stem cells (99%). All patients engrafted. With a median follow-up of 30.8 months (range, 1.6–95.3), probabilities of overall and relapse-free survival at 3 years were comparable between the FM and FMTBI group (65.0 ± 7.1% vs 72.8 ± 8.2%; p = 0.452, and 61.1 ± 7.2% vs 68.3 ± 8.1%; p = 0.573, respectively). Similarly, non-relapse mortality at 3 years (15% vs. 4%; p = 0.11), cumulative incidences of acute GVHD grade 3–4 at day +100 (10% vs 5%; p = 0.31) and chronic severe GvHD at 1 year (19% vs 11%; p = 0.47) did not differ between groups. The combined endpoint GRFS was 51.2 ± 7.3 in the FM group and 49.9 ± 9.2% in the FMT group (p = 0.109), respectively.Summary/Conclusion: Conclusion: Our data suggest that FM is well tolerated and associated with similar outcomes compared to FMT in our AML patients of whom >70% proceded to transplant with active or measurable residual disease. Especially elderly patients, who face a high risk of NRM, might not benefit from additional TBI. Thus, FM is a valid option for this vulnerable patient cohort resulting in a median GRFS of 40 months.

Unrelated donor hematopoietic stem cell transplantation for pediatric de novo acute myeloid leukemia with intermediate- or high-risk cytogenetics.

The role of unrelated donor HSCT for children with de novo AML in CR1 is controversial. We performed this study to investigate the feasibility of unrelated donor HSCT who initially had intermediate- or high-risk cytogenetics. We retrospectively reviewed medical records of patients with AML who received unrelated HSCT in CR1 at Samsung Medical Center between November 2001 and January 2012. Patients were allocated based on karyotype at diagnosis as follows: (a) low-risk: inv(16), t(16;16), t(8;21), and t(15;17); (b) high-risk: -5, 5q-, -7, 3q abnormalities, t(8;16), t(6;9), t(6;11), t(6;21), t(10;11), complex karyotype (≥3 abnormalities), and acute megakaryocytic leukemia without t(1;22); and (c) IR: all the other karyotypes including normal. Patients in intermediate- or high-risk group who were transplanted with either unrelated CB or matched unrelated BM/mobilized PB in their CR1 were included in this study. The projected OS and EFS rates were 74.9% and 71.1%, respectively, with a median follow-up of 87.3months after transplantation. The EFS was 70.1%, 80.7%, and 73.9% for CB, BM, and mobilized PB groups, respectively (P=0.89), and 73.9% and 70.6% for IR and high-risk groups (P=0.76). The leading cause of death was relapse (n=8), and only one patient died from non-relapse cause. Unrelated donor HSCT seems a feasible approach for children with intermediate- or high-risk AML in CR1. Relapse remains the leading cause of treatment failure among these patients.

Efficacy and Safety of Decitabine Combined with CAG (Cytarabine, Aclarubicin, G-CSF) for Patients with Intermediate or High Risk Myelodysplastic Syndrome and Acute Myeloid Leukemia: a Meta-Analysis

To systematically evaluate the efficacy and safety of DCAG regimen for treating the intermediate or high risk MDS and AML. PubMed, EMbase, The Cochrane Library, WanFang Data and CNKI databases were searched to collect randomized controlled trials (RCTs) of decitabine combined with CAG regimen for intermediate or high risk MDS and AML from inception to March, 2018. The quality of each RCT was evaluated by the Cochrane collaboration´s tool for assessing the risk of bias.Then, the data were analyzed by using RevMan 5.3. Twenty-four RCTs were included in the meta-analysis, containing 1 557 patients with intermediate or high-risk MDS and AML, of whom 594 were AML patients and 590 were MDS patients. The patients treated with the DCAG regimen were enrolled in DCAG group, and the patients treated with single-agent decitabine or CAG regimen were enrolled in control group. The results of meta-analysis showed that compared with other therapies, the complete remission rate of DCAG regimen in patients with intermediate or high-risk MDS and AML was high (RR=1.63，95% CI=1.43-1.85，P＜0.000 01), and the overall response rate was also high (RR=1. 35，95% CI=1.24-1.46，P＜0.000 01); Subgroup analysis results showed that DCAG regimen was better than CAG regimen in the complete remission rate (RR=1.71，95% CI=1.49-1.97，P＜0.000 01), and slightly better than single-agent decitabine group (RR=1.43，95% CI=1.08-1.91，P=0.01). In terms of adverse reactions, there was no statistically significant difference in the rates of myelosuppression, pulmonary infection, gastrointestinal reactions, and bleeding events between the 2 groups (P＞0.05). DCAG regimen has significant efficacy in the treatment of intermediate or high-risk MDS and AML, and is superior to CAG regimen and single-agent dicitabine regimen. As compared with control group, there was no significant difference in adverse events. Due to limited quantity and quality of the included studies, more high quality studies are needed to verify above mentioned conclusion.

Distinct Gene Expression Patterns of Minimal Residual Disease (MRD) Cells in High-Risk AML Patients Identified By RNA-Sequencing

INTRODUCTIONEvolving techniques have made possible the direct detection, physical isolation, and study of AML minimal residual disease (MRD) after treatment. This could allow for better identification of therapeutic vulnerabilities in AML. Prior studies have focused on cells that initiate leukemia in mouse models, known as leukemia-initiating cells (LIC), generally with a foundational CD34+CD38- immunophenotype. LIC are typically derived from diagnostic samples of untreated patients. Such stem-like cells do not necessarily represent the residual fraction of AML after treatment. Relapse may originate from non-LIC, and the presence of phenotypically and molecularly defined MRD is now firmly established as a critical prognostic factor for patients. High-risk AML is characterized by relapse, despite morphologic complete remission with initial therapy in most cases. RNA-sequencing was performed on pre- and post-treatment AML subpopulations, including MRD, from high-risk patients, to determine differences in gene expression.METHODSMatched primary AML samples were collected from marrow and peripheral blood of patients with high-risk AML (including patients with unfavorable karyotype and/or TP53 mutation) at diagnosis and after treatment. Mononuclear cells were flow-sorted for bulk (CD45dim) and LIC (Lin-CD34+CD38-CD123+) from diagnostic samples. Post-treatment samples were sorted for bulk mononuclear cells (MNC) and MRD, based on difference-from-normal/MRD immunophenotype specific for each patient as determined from established 20-marker clinical flow cytometry analysis. RNA was isolated using low-input methodology, and RNA-sequencing was performed using Illumina HiSeq 2000. Gene expression was assessed using GO-Elite, and differences between patients and subpopulations were assessed using rank product method.RESULTSGene expression in MRD was analyzed by RNA-sequencing in comparison to diagnostic samples in eight patients with high-risk AML. Four patients had unfavorable karyotype, including two with TP53 mutations. Patients had additional high-risk features, such as FLT3-ITD or RUNX1 mutations, or secondary/therapy-related AML. Treatment consisted of chemotherapy (6/8) or hypomethylating agents (2/8), with or without other targeted drugs. Residual leukemia was detected in post-treatment samples in all study patients. Significant differences in gene expression were detected between MRD and other sorted populations, including diagnostic bulk AML and LIC. Relevant MRD pathways included those with strong interactions with the microenvironment. Anti-apoptotic mechanisms, cytoskeletal, and cell adhesion related genes, WNT/beta-catenin signaling, and TGFbeta signaling ranked among the most relevant processes in AML MRD subpopulations (Figure 1A, GO-Elite interactome of highly expressed genes in AML MRD). To identify potentially critical and unique MRD-specific genes, rank product method was applied using 1) the most highly expressed genes in AML MRD, 2) the most differential expressed genes between MRD and bulk AML at diagnosis, and 3) the most differentially expressed genes between MRD and bulk MNC after treatment. Among the top 50 scoring genes using this approach (Figure 1B), 16 genes were among the top 5% of genes expressed in MRD among all patients and 20 genes have cell surface gene-products (shown in yellow). Several potential leukemia- and cancer-related genes of interest were identified (shown in bold).CONCLUSIONSKey differences exist between the gene expression profiles of post-treatment MRD from high-risk AML patients, in comparison to other populations and subpopulations of sorted cells before and after treatment. The highlighted differences suggest that MRD relies on specific intrinsic gene expression changes and microenvironmental interactions, and therefore may be targetable after elimination of bulk AML with initial therapy. Accessible surfacesome targets are among top hits. [Display omitted] DisclosuresKonopleva:cellectis: Research Funding; Immunogen: Research Funding; abbvie: Research Funding; Stemline Therapeutics: Research Funding. Andreeff:Astra Zeneca: Research Funding; Amgen: Consultancy, Research Funding; Jazz Pharma: Consultancy; Celgene: Consultancy; Reata: Equity Ownership; SentiBio: Equity Ownership; Aptose: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; United Therapeutics: Patents & Royalties: GD2 inhibition in breast cancer ; Eutropics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Oncolyze: Equity Ownership; Daiichi-Sankyo: Consultancy, Patents & Royalties: MDM2 inhibitor activity patent, Research Funding; Oncoceutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

HLA-Haploidentical Hematopoietic Cell Transplantation after TCR-Alpha Beta and CD45RA+ Depletion Following Reduced Intensity Conditioning in Adults and Children with Hematological Malignancies

▪Background: Haploidentical (Haplo) hematopoietic cell transplantation (HCT) provides an alternative option for patients without HLA-matched donor. GVHD, engraftment failure, and infectious complications continue to be the main causes of non-relapse mortality (NRM). We hypothesized that selective depletion of TCRαβ+ and CD45RA+ naïve T cells subset will permit hematopoietic engraftment, while effectively reducing GVHD, and provide improved donor immune reconstitution through adoptive transfer of donor's mature NK and γδ T cells and CD45RA- memory T cells.Methods: GCSF +/- plarixefor (N=13) mobilized PBSC apheresis product were divided into two fractions in 9:1 ratio, and depleted using CliniMACS device after labeling with TCRαβ and CD45RA reagents (Miltenyi Biotec, Bergish-Gladbach, Germany), respectively. The conditioning regimen consisted of total nodal irradiation 6 - 7.5 Gy over 3 equal fractions, 160 mg/m2 Fludarabine divided daily over 4 days, Thiotepa 10 mg/kg divided twice daily for 1 day and Melphalan 70-140 mg/m2 for 1 day. Short term GVHD prophylaxis for 30 days was given to 1 patient using MMF, 11 using tacrolimus or 2 using Sirolimus.Results: We transplanted 20 adults (median age 42 years, range 20 - 68 ) and 3 children (age range 7-14 years) with high risk AML (n=14), ALL (n=6), MDS (n=2), myeloma (N=1). The patients were infused with TCRαβ and CD45RA depleted graft containing a median of 9.94 x 106 (range, 5.58 - 20.78) CD34+ cells/kg, 0.19 x 104 (range 0 - 8.53) CD45RA+CD3+ cells/kg, and 4.21 x 106 (range, 0.15 - 11.67) CD45RO+CD3+ cells/kg. In addition, the TCRαβ depleted graft fraction contained a median of 0.19 x 104 (range 0 - 8.53) TCRαβ+ cells/kg, and 8.87 x 106 (range 1.73 - 29.74) TCRγδ + cells/kg. All patients except 1 had engraftment of ANC > 500 cells/µL at a median of 11 day (range, 8 - 19) and PLT > 20,000 cells/µL at a median of 12 day (range, 7 - 19). Complete donor chimerism was seen at the time of engraftment in all patients with primary engraftment. Only 1 patient experienced primary graft failure. There was no secondary graft failure.Eleven patients developed acute GVHD of grade II-IV, with the day 100 cumulative incidence (C.I.) of acute GVHD of Gd II-IV, and Gd III-IV of 50% (95% CI 27.3 - 69.0%) and 17.9 % (95% CI 5.3- 36.4%), respectively. One patient experienced chronic GVHD. Day 180 C.I. of NRM and relapse were 23.9 % (95% 8.3-43.9%) and 5.6 % (95% CI 0.3-23.3%), respectively. NRM was attributed to aGVHD in 3 of the 6 deaths. Viral reactivation included CMV (n=7), HHV6 (N=4), EBV (N=3) and adenovirus (N=2), with no fatal viral infection occurred within 100 days. Two patients had fatal blood stream infection within 100 days. With a median follow up of 306 days (range 18 - 551 days) in surviving patients, the 6 month and 1 year overall survival (OS) were 76.9% (95% CI 52.9-89.7%) and 71 % (95% CI 46-85.9%), respectively. (Figure 1).Conclusions: Our preliminary results suggest that RIC haplo-HCT with TCRαβ and CD45RA+ depleted grafts allows successful allograft in high-risk patients lacking a suitable matched donor. NRM due to GVHD remains the major obstacle for the successful HCT. Fine adjustment of T cell dose with short course of immunosuppressant may reduce GVHD while preserving antitumor and antimicrobial immunocompetence. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Favorable Outcome of Sequential HLA-Haploidentical Transplantation Using Ptcy As GvHD Prophylaxis in High Risk AML and MDS of the Elderly

Sequential conditioning regimens, comprising cytoreductive chemotherapy shortly applied prior to reduced intensity conditioning are successfully used for high-risk (HR) AML/MDS in matched related and unrelated donor hematopoietic stem cell transplantation. However, few data are available for sequential conditioning in the context of HLA-haploidentical transplantation (haplo-HSCT), especially in the elderly. To investigate the relative merits of sequential haplo-HSCT in the elderly we retrospectively analyzed the outcome of thirty-five patients (pts) with advanced AML/MDS (>=50 years old).Thirty-three pts suffering from HR AML, defined by refractory, relapsed or secondary leukemia, or complete remission with adverse-risk genetics according to ELN criteria and two pts with HR MDS according to IPSS-R, who underwent T-cell-replete haplo-HSCT at our institution between January 2009 and November 2016 were included. Disease was active in 29 pts while 6 had achieved CR. Pre-transplantation risk factors were scored using the hematopoietic cell transplantation-specific comorbidity index (HCT-CI) which was ≥3 in 13 pts (median HCT-CI:2, range 0-8). A sequential therapeutic concept using either FLAMSA (n=26) or clofarabine (n=9) for cytoreduction was used prior to RIC in all pts. Bone marrow (54%) and peripheral blood stem cells (46%) were both used as graft source. Post-grafting immunosuppression consisted of high-dose cyclophosphamide, tacrolimus and MMF in all pts.Median age was 60 years (50-70). One graft rejection occurred. Three pts died early in aplasia. Neutrophil and platelet engraftment was achieved in 95% and 77% of evaluable pts, respectively at a median of 16,5 (13-89) and 31,5 (11-103) days.Acute GvHD grade I-III occurred in 25/32 of the pts (grade III n=2); no patient developed grade IV aGvHD. Chronic GvHD was observed in 13/29 pts and was most frequently assessed as mild (n=6) or moderate (n=5) while 2 pts developed severe cGvHD. No GvHD related death was observed. CI of NRM at day 100, 1-year and 3-years was 11%, 23% and 23%, respectively. CI of relapse at 1- and 3-years was 15% and 27%, with a median time to relapse of 152 days (20-413). At a median follow up of 27 months (4-74), estimated one- and three-year overall survival (OS) was 62% and 52% respectively. One- and three-year leukemia-free survival (LFS) was 59% and 52%.Our results suggest that using a sequential therapeutic concept in PTCY-based haplo-HSCT is safe and properly tolerated while it provides a favorable disease control when treating elderly HR MDS/AML pts. Thus, sequential haplo-HSCT seems to be a valuable alternative in pts who lack a conventional donor or are in urgent need for prompt transplantation. DisclosuresTischer:Jazz Pharmaceuticals: Other: Jazz Advisory Board.

Higher Expression of PALB2 Predict Poor Prognosis in AML Patients and Identifies Potential Targets of Synthetic Lethal Therapies

Background - Partner and localizer of BRCA2 (PALB2) plays a key role in the DNA damage repair (DDR). Genomic alterations of DDR genes rarely occur in AML, while their deregulation at transcriptional level is a known mechanism exploited by leukemic cells in order to sustain the high genetic instability and to continue proliferation.Aim - We aimed to characterize the role of PALB2 in AML by investigating its expression levels and its prognostic value, in order to evaluate its potential as target of therapies based on a synthetic lethality approaches.Methods - Gene expression profiling (GEP, Affymetrix) was performed on bone marrow cells of 7 healthy donors (HD) and 60 AML patients with more than 80% blast cells. K-means clustering of patients according to the expression of PALB2 was performed and differences in survival were assessed d by Kaplan-Meier survival analysis.Results - Our cohort was characterized by a median age at diagnosis of 60 years-old. Twelve out of 43 patients harbored a mutation in FLT3 (27.9%, 17 patients not tested); 8 patients were NPM1 mutated (27.6%, 31 patients not tested); 2 patients were TP53 mutated (3%, all patients tested). According to ELN2017 guidelines, 17 cases were high-risk AML, 38 cases were intermediate, 3 cases had low-risk classification and 2 cases were not classified due to the lack of prognostic markers. We detected variable levels of PALB2 mRNA (range 52.90-244.37) in AML patients and its median expression was higher compared to HD (129.26 vs 67.85, respectively; p=.019). We clustered our patients according to PALB2 expression and we defined 2 groups of patients: cluster H and L with higher and lower expression levels of PALB2, respectively (cluster centers 158.86 and 105.41, respectively; figure A). Notably, HD revealed PALB2 expression values comparable with the cluster L (range 52.90-99.60). No differences were detected in term of incidence mutations in FLT3 and NPM1, white blood cell count at diagnosis, age at diagnosis and prevalence of karyotype alterations. Patients were treated with best supportive therapy (n=11/58, therapy data missing for 2 patients), hypomethylating agents (n=2/58) and intensive chemotherapy ( n=45/58). Within patients treated with intensive chemotherapy, we compared complete remission rate after induction and we found no differences between H and L. However, patients with higher expression of PALB2 had worst overall survival than patients in cluster L (median survival group H=397 days; CI 95%=288.9-505.0, L=not reached; p=.045; figure B). Notably, we confirmed worst prognosis in patients in cluster H when considering 33 out of 45 patients with intermediate/low risk karyotype (i.e. normal karyotype, t(8;21) or less than 3 aberrations according to ELN2017; p=.026).Conclusion - We identified a subgroup of AML patients with higher expression of PALB2, which predicted poorer prognosis in patients treated with curative intent and it associated with poorer prognosis in patients with low/intermediate risk. While patients carrying mutations in PALB2 (and BRCA1/2) are candidate for PARP inhibitors (PARPi) therapies in breast cancers, few clinical trials with PARPi are available in AML and the frequency of mutations is very low. Our data opens a new scenario in which PALB2 may be a target of therapies in AML based on synthetic lethal approaches targeting the DDR pathway. However, a better understanding of the biological role of PALB2 in AML and its interaction with other alterations is needed.Supported by Fondazione Del Monte [Display omitted] DisclosuresCavo:Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees. Soverini:Novartis: Consultancy; Bristol Myers Squibb: Consultancy; Incyte Biosciences: Consultancy. Martinelli:Roche: Consultancy; Celgene: Consultancy, Speakers Bureau; Janssen: Consultancy; Ariad/Incyte: Consultancy; Amgen: Consultancy; Pfizer: Consultancy, Speakers Bureau; Abbvie: Consultancy; Jazz Pharmaceuticals: Consultancy; Novartis: Speakers Bureau.

Allogeneic Hematopoietic Cell Transplantation (HCT) Vs. Non-HCT Consolidation Therapies in Acute Myeloid Leukemia (AML) Patients 60-75 Years of Age in First Complete Remission (CR1): An Alliance (A151509), SWOG, ECOG-ACRIN and CIBMTR Study

Introduction: The preferred post-remission therapy for older patients (pts) with AML remains uncertain. We compared outcomes for older AML pts in CR1 receiving HCT reported to the CIBMTR to older AML pts achieving CR1 on National Clinical Trials Network induction and non-HCT consolidation therapy (CT) trials.Methods: This study focused on pts 60-75 years of age treated between 2004 to 2013. CT pts (n=211) underwent induction and consolidation on Alliance for Clinical Trials in Oncology, ECOG-ACRIN or SWOG clinical trials for initial therapy for newly diagnosed AML; the CIBMTR provided data for HCT pts (n=431). CT patients received at least one cycle of CT on study and were excluded if HCT occurred at any time. Time to event started at CR1 and pts entered at CT or HCT, respectively, using left-truncation to account for differential entry times.Results: For the CT cohort, first consolidation included standard therapy (e.g., cytarabine or a hypomethylating agent) and additional study drug (e.g., bortezomib, dasatinib, sorafenib, and Zosuquidar, gemtuzumab) or tipifarnib alone. Among HCT pts, the donor was a HLA-matched sibling or unrelated donor (URD) in 66% and the others were partially HLA-matched/mismatched URD (10%) or cord blood (24%). HCT pts were younger and more frequently had high-risk AML (high WBC, secondary AML and unfavorable cytogenetics) (Table). The median time from CR1 to HCT and CT was 3.2 and 0.5 months, respectively.Allogeneic HCT showed worse overall survival (OS) (HR=1.52, p=0.02) prior to 9 months and better OS thereafter (HR= 0.53, p <0.0001) relative to CT (figure 1A). Treatment-related mortality (TRM) was worse after HCT in the first 9 months (HR=2.8, CI: 1.5 -5.2, p=.0009), while relapse was less frequent beyond 9 months after treatment (HR = 0.42, CI: 0.29 to 0.61, p<.0001). Despite higher early TRM, HCT recipients went on to manifest superior OS [5 year OS: HCT 29% (24-34%), CT 13.8% (9 -22%)] (Figure 1A). The benefit of HCT for survival after 9 months was more prominent in those with unfavorable cytogenetics (Figure 1B). Multivariate analysis for OS showed no statistically significant effect of age or performance status, while unfavorable cytogenetics were detrimental (HR=1.74, p<.0001).Conclusions. Allogeneic HCT led to heightened early risks from TRM, but resulted in superior long-term survival in older AML pts receiving HCT relative to CT by reducing relapse. Efforts to attenuate early TRM after allogeneic HCT may further improve HCT outcomes for older pts. [Display omitted] DisclosuresUstun:novartis: Speakers Bureau. Attar:Agios: Employment, Equity Ownership. Larson:Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BristolMyers Squibb: Consultancy, Research Funding; Ariad/Takeda: Consultancy, Research Funding. Roboz:Roche/Genentech: Consultancy; Eisai: Consultancy; Cellectis: Research Funding; Aphivena Therapeutics: Consultancy; Sandoz: Consultancy; Janssen Pharmaceuticals: Consultancy; Otsuka: Consultancy; Jazz Pharmaceuticals: Consultancy; Sandoz: Consultancy; AbbVie: Consultancy; Celltrion: Consultancy; Cellectis: Research Funding; Eisai: Consultancy; Astex Pharmaceuticals: Consultancy; Argenx: Consultancy; Pfizer: Consultancy; Celgene Corporation: Consultancy; Novartis: Consultancy; Jazz Pharmaceuticals: Consultancy; Bayer: Consultancy; Bayer: Consultancy; Roche/Genentech: Consultancy; Orsenix: Consultancy; Astex Pharmaceuticals: Consultancy; Celgene Corporation: Consultancy; Daiichi Sankyo: Consultancy; Pfizer: Consultancy; Janssen Pharmaceuticals: Consultancy; Otsuka: Consultancy; Orsenix: Consultancy; Daiichi Sankyo: Consultancy; Celltrion: Consultancy; Novartis: Consultancy; Aphivena Therapeutics: Consultancy; Argenx: Consultancy; AbbVie: Consultancy. Uy:GlycoMimetics: Consultancy; Curis: Consultancy. Stone:Fujifilm: Consultancy; Ono: Consultancy; Orsenix: Consultancy; Otsuka: Consultancy; Agios: Consultancy, Research Funding; AbbVie: Consultancy; Argenx: Other: Data and Safety Monitoring Board; Celgene: Consultancy, Other: Data and Safety Monitoring Board, Steering Committee; Arog: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Jazz: Consultancy; Astellas: Consultancy; Merck: Consultancy; Pfizer: Consultancy; Sumitomo: Consultancy; Amgen: Consultancy; Cornerstone: Consultancy. Foran:Agios: Research Funding; Xencor, Inc.: Research Funding. Weisdorf:Seattle Genetics: Consultancy; Equillium: Consultancy; FATE: Consultancy; SL Behring: Consultancy; Pharmacyclics: Consultancy.

Risk of Invasive Fungal Infections in Patients with High-Risk MDS and AML Receiving Hypomethylating Agents

IntroductionAcute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) patients are at risk of invasive fungal infection (IFI) due to prolonged neutropenia related to the underlying diseases and the induction chemotherapy required to treat them. The risk of IFI specifically in AML or MDS patients treated with hypomethylating agents (HMA) has not been fully elucidated, with previous publications reporting various prophylaxis practices and IFI incidences from 3.3% to 14.4%. We sought to characterize the incidence of IFI in patients with MDS and AML who received azacitidine (AZA) or decitabine (DAC) at our institution.MethodsA retrospective cohort study was performed to evaluate the incidence of IFI in adults receiving between 10/1/10 and 10/1/17. Patients were included if they received at least two cycles of either drug and were diagnosed with AML, MDS with a revised international prognostic scoring system (R-IPSS) score of at least 3.5, or chronic myelomonocytic leukemia (CMML) categorized as intermediate 2 or higher risk using CMML-specific prognostic scoring system (CPSS). Patients were excluded if they received mold-active antifungal prophylaxis at any time during HMA therapy prior to the development of an IFI, or if they received mold-active antifungal treatment when starting a HMA. The primary endpoint was the incidence of IFI, defined as proven, probable, or possible using the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group criteria (EORTC).ResultsSix hundred and fifty-one consecutive patients were screened, and 203 patients met inclusion criteria. The three most common reasons for exclusion were incomplete data (n=158), receipt of fewer than two cycles of a HMA (n=138), and receipt of mold-active antifungal treatment at the time of HMA initiation or mold-active antifungal prophylaxis at any point during HMA therapy (n=86). Six patients had two distinct episodes of HMA therapy separated by either an allogeneic stem cell transplant or a treatment other than HMA; thus 209 episodes of treatment occurred amongst 203 patients. Overall, the study population was elderly with the median age of 69, and 59% of the patients were male. Fifty-one percent of patients had AML, while 49% had MDS or CMML; 72% received AZA. The median number of cycles of HMA utilized was five. Most patients were treatment-naïve (59% AML and 87% MDS had no prior therapy). A significant portion of the group (25.8%) was neutropenic on cycle 1 day 1 (C1D1) of HMA. Other pertinent baseline characteristics of the study population are displayed in Table 1. We identified 20 cases of IFI, with an overall incidence of 9.6%. Most IFI were possible cases according to the EORTC criteria (13/20, 65%), but there were 3 culture-proven cases. The possible cases all met the host criterion of neutropenia and 12 of 13 met the clinical criterion of lower respiratory tract infection based on imaging. Organisms isolated on culture included Aspergillus spp., Fusarium spp., and Scedosporium spp. A diagnosis of IFI was made at a median of 3 cycles of HMA, with the majority (85%) diagnosed within the first four cycles. Among the 20 cases of IFI, 12 were diagnosed while receiving AZA and 8 were receiving DAC. More than half of the patients who developed IFI were neutropenic on C1D1. These patients had a significantly higher risk of IFI compared to non-neutropenic patients (20.4% vs. 5.8%, p=0.0051). When other baseline characteristics were analyzed, patients with therapy-related MDS (t-MDS) compared to de novo MDS were more likely to have an IFI (20.8% vs. 5.1%, p=0.0314). Patients with de novo AML also had a higher incidence of IFI compared to AML from an antecedent MDS/MPN (15.4% vs. 2.4%), however this did not reach statistical significance (p=0.07). Additional comparisons are described in Table 2.ConclusionIFI occurred in 9.6% of patients treated with HMA, but was observed in 20.4% of those who were neutropenic on C1D1 of HMA. Another potential risk factor identified was t-MDS versus de novo MDS. Prospective evaluation of mold-active antifungal prophylaxis in patients with MDS or AML who are neutropenic at the start of HMA therapy is warranted. DisclosuresFrey:Novartis: Consultancy; Servier Consultancy: Consultancy. Perl:Arog: Consultancy; NewLink Genetics: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy; Novartis: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy; AbbVie: Membership on an entity's Board of Directors or advisory committees; Actinium Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Porter:Kite Pharma: Other: Advisory board; Novartis: Other: Advisory board, Patents & Royalties, Research Funding; Genentech: Other: Spouse employment.

The MRD-Negativity Rate Measured By Flow Cytometry after the 1st and the 2nd Induction Course Among CR AML Patients from Different Cytogenetic Subgroups Does Not Differ Though the Morphological CR Achievement Does

Background. The recent ELN recommendations (2017) have introduced new criteria of response in AML - complete remission with MRD-negativity (CR/MRD-neg). It's a well-known fact that AML with different cytogenetics has different chemosensitivity, and so - CR rate in patients with favorable, intermediate or poor cytogenetic markers substantially differs. MRD negativity corresponds to more favorable long-term results in CR patients, but it's not clear whether the MRD-negativity rate is the same in favorable, intermediate or poor risk AML pts. As it is still poorly understood whether the high risk AML patients need classical «7+3» induction, we introduced a new approach for this cohort of patients - prolonged low-dose cytostatic exposure after hypomethylating priming.Aim. To evaluate the MRD-negativity in CR AML patients from different cytogenetic subgroups after the first classical non-intensive induction: «7+3», «Aza+7+3», «Aza-Ida-Ara-C», and the second induction differed by intensity.Materials and patients. 83 AML patients with a median age of 37 y.o. (17-59), m/f 31/52, after achieving CR (69 pts) were included in the MRD study in the National Research Center for Hematology. From March 2016 till Dec 2017, 49 pts disregarding cytogenetic risk were treated with «7+3» as the first induction course (Dauno 60 mg/m2 1-3 days, Ara-C 100 mg/m2 bid 1-7 days). The second induction course for these pts was «7+3» with continuous Ara-C infusion (200 mg/m2 1-7 days). Since Dec 2017 till July 2018 in all patients epigenetic priming with 3 days of Azacitidine (75 mg/m2) was applied additionally in order to obtain the cytogenetic results prior to cytostatic exposure. All patients were tested by molecular markers (FLT3, CEBPa, mNPM1) but this data did not influence the treatment choice. 8 pts from favorable/intermediate cytogenetic risk group after Aza-prephase have got «7+3» (Dauno 60 mg/m2 4-6 days, Ara-C 200 mg/m2 by continuous infusion, 4-10 days), and 13 pts from poor cytogenetic risk group (complex, -7,-5, inv3, monosomy) after Aza-priming received prolonged low-dose schedule (Ida 3 mg/m2 4-10 days, Ara-C 10 mg/m2 bid sc 4-17 days). The second induction course for favorable/intermediate risk group was FLAG-Ida, for poor risk group - the same as the 1st induction. MRD testing was performed by 6-color flow cуtometry with FACS Canto II (BD) machine after 1st and 2nd chemotherapy courses. The rate of MRD-negativity was calculated among CR patients.Results. Totally among 83 patients CR was achieved in 83%, early death was registered in 6% and refractory AML was diagnosed in 11%. The induction and MRD testing results after the 1st and the 2nd induction course according to prognostic group and treatment arm are demonstrated in the Table.1. Morphological CR rate differs substantially in patients from favorable/intermediate and poor risk by any treatment approach (p=0,04). The prolonged low-dose induction with Aza-prephase induced the same numbers of CRs as the classical «7+3»: 69% vs 46% (p=0,42). Epigenetic priming provided identical MRD-negative CRs in all treatment and cytogenetic groups: 75% vs 62% in favorable/intermediate risk group (p=0,29), 67% vs 50% in poor risk (p=0,62). The second intensive induction with Flag-Ida in favorable/intermediate risk group did not increase the portion of MRD-neg CR pts in comparison with «7+3»: 88% vs 71% (р=0,14). Early relapse rate through all groups showed comparable results.Conclusion. Though the morphological CR achievement is highly influenced by cytogenetic subgroup in AML, the MRD-negativity rate among CR pts by flow cytometry after the 1st and the 2nd induction course is similar. The de-intensification of induction for poor risk group did not lead to the deterioration of therapy efficacy and provided the same rate of MRD-negativity. The 2nd intensified induction after «7+3» did not increase the MRD-negativity in CR pts. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Measurable Residual Disease Assay with WT1 Expression in Acute Myeloid Leukemia Who Underwent Allogeneic Hematopoietic Stem Cell Transplantation; Optimal Threshold, Time Points, and Candidates

BackgroundOverexpression of WT1 is a surrogate marker of abnormal myelopoiesis and has been evaluated as a potential tool to assess measurable residual disease (MRD) in myeloid malignancies. Given that lack of consensus on clinically relevant WT1 thresholds and time points in the allogeneic hematopoietic cells transplantation (allo-HSCT) setting, WT1 quantification has not yet gained widespread use despite several pieces of evidence demonstrating the possible role for MRD assessment with the limited numbers of patients. To investigate optimal threshold, time points, and candidates of WT1 quantification in AML, we retrospectively analyzed a large cohort of consecutive patients who underwent allo-HSCT at Catholic Hematology Hospital.Patients and methodsThis study included 425 consecutive patients with AML who underwent allo-HSCT at CR state from either a matched siblings (n=199), matched unrelated (n=117) or haploidentical family donors (n=109) from 2012 to 2016. Patients were in the first (n=400) or second (n=25) complete remission with a median age of 48 years (range, 18~70). Favorable, intermediate, poor risk groups by 2017 NCCN criteria were 28% (n=120), 49% (n=206), and 23% (n=99), respectively. Bone marrow WT1 levels before, and at 1 or 3 months after allo-HSCT were determined using real-time PCR using the ELN normalized method. We sought to clarify the prognostic relevance of the WT1 quantification regarding the cumulative incidence of relapse (CIR) and survival outcomes.ResultsWith a median follow-up of 39 months (range, two days to 73 months), the 4-year overall survival, disease-free survival, CIR and non-relapse mortality were 63.6%±2.6%, 61.5%±2.6%, 17.9%±2.1% and 24.7%±2.5%, respectively.Analysis of dynamic changes of WT1 levels demonstrated decreased levels at 1 (n=333, mean 86 copies, range 0~1800) and three months (n=346, mean 101 copies, range 0~1670) after allo-HSCT compared to before allo-HSCT (n=425, mean 219 copies, range 0~9630). Relapsed patients had significantly higher WT1 levels before (P=0.018) and at three months (P=0.041) after allo-HSCT, whereas no difference at one month after allo-HSCT (P=0.167). Even the ROC curve analysis revealed that WT1 levels before allo-HSCT were significantly available to predict CIR after allo-HSCT (P<0.001). Among various cut-off levels of WT1 expression (median, 25% from the top, and cut off by ELN), cutoff by ELN (250 copies) was most effective for predicting CIR. The CIR of MRD positive patients (³ 250 copies) before and at three months after allo-HSCT were 43% (vs. 14%, P<0.001) and 35% (vs. 11%, P<0.001), respectively. In multivariate analysis, the WT1-MRD positivity independently predicted the CIR (before, HR=3.5, P<0.001; at three months, HR=7.4, P<0.001), which translated into inferior disease-free survival (P<0.001) and overall survival (P<0.001). In a subgroup analysis with the WT1-MRD positive patients before allo-HSCT (n=44), the WT1-MRD positivity at three months was significantly effective to identify patients with a higher risk for relapse (100% vs. 26%, P<0.001).In subgroup analyses in each risk group by 2017 NCCN criteria, the WT1-MRD positivity before allo-HSCT was significantly effective to predict CIR in the intermediate risk group (57% vs. 12%, P<0.001), whereas no significance in both favorable and poor risk groups. On the other hand, the WT1-MRD positivity at three months after allo-HSCT was effective to predict CIR in the poor risk group (60% vs. 21%, P<0.001). In patients with normal karyotype without NPM1 mutations (n=117), the WT1-MRD positivity before allo-HSCT significantly predict CIR (32% vs. 8%, P=0.001), whereas no difference in patients with NPM1 mutations (n=66) or core-binding factor (CBF) AML (n=102).ConclusionsThese data suggest standardized bone marrow WT1 levels using the ELN threshold (250 copies) before and at three months after allo-HSCT provided relevant information to predict relapse in AML with intermediate and poor risk groups by 2017 NCCN criteria, respectively. The validated WT1 MRD assay by ELN was revealed to be particularly available in AML without specific MRD markers, such as NPM1 or CBF-AML, and different significance by times points should be considered for clinical applications to identify high-risk AML for relapse, potential candidates for various immunomodulatory approaches. DisclosuresKim:Pfizer: Research Funding; Ilyang: Research Funding; BMS: Research Funding; Novartis: Research Funding. Lee:Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding.

A Safety Study of the Addition of Omacetaxine to the Standard-of-Care Induction Regimen of Cytarabine and Idarubicin in Newly-Diagnosed AML Patients

Background: Omacetaxine mepesuccinate (OM) is a semi-synthetic form of Homoharringtonine (HH), a cephalotaxine alkaloid. OM induces cell apoptosis by inhibiting peptide bond formation during mRNA translation, with rapid loss of short-lived proteins, such as MCL-1, c-MYC, and Cyclin D1 (Lu, J Hematol Oncol. 2014, 7: 2). Notably, cytarabine synergizes with HH in causing apoptosis of leukemia cells in vitro. A phase III RCT in China of 620 patients with de novo AML demonstrated superior CR and 3-yr survival rates upon addition of HH to a standard 2-drug AML induction therapy (‘7 + 3‘; Jin, Lancet Oncol. 2013, 14:599). Thus, we hypothesized that OM, at an appropriate dose, would similarly enhance the efficacy of a 7 + 3 regimen. OM is FDA-approved for the treatment of TKI-resistant CML. The MTD of 1.25 mg/m2/d SQ for 14 days every 28 days, as determined in a phase I/II CML trial of OM (Quintás-Cardama, Cancer 2007, 109: 248), served as a basis for the dose escalation used in this study.Methods: The primary endpoint of this phase I safety trial was to determine the optimally safe and active dose (OD) of OM when added to a standard 7 + 3 induction regimen, cytarabine and idarubicin. OM was administered SQ q12h d1-7 with cytarabine (100mg/m2 CIV) d1-7 and idarubicin (12mg/m2 IV) d1-3. Four dose levels were tested, starting with OM 0.625 mg/m2 q12h (further dose levels: 1.25, 2.0, 3.0, and 4.2 mg/m2 q12h). All newly diagnosed, untreated de novo or secondary AML patients, aged 18-70y with ECOG PS of 0-3 were eligible for this study. Secondary endpoints included overall response rate (ORR) and overall and event free survival (OS, EFS). Hematologic toxicity (HT) was defined as incomplete hematologic recovery; ANC < 1.0 x 109/L or platelet count < 100 x 109/L present at d49, with the bone marrow documented to be free of leukemic infiltration. Dose escalation was based on the EffTox design (Biometrics 2004, 60:684), a Bayesian adaptive design which considers the trade-off between efficacy and toxicity in determining the OD for Phase II trials.Results: Twenty-two patients, median age 58 (range 25-69) years were enrolled from June 2015 to June 2018. 12 patients (54.5%) had adverse cytogenetics, 6 (27%) intermediate risk, 3 (13.7%) favorable risk and 1 patient's cytogenetic risk was unknown (fibrotic BM). Eight patients demonstrated disease evolution from myelodysplastic syndrome (MDS). Altogether 16 of the 22 patients (73%) were deemed high risk based on cytogenetics or MDS-AML evolution. The EffTox design was implemented until cohort 4 (3 mg/m2 q12h), where 2 of 3 patients experienced a grade 5 non-hematologic toxicity (NHT), resulting in a dose-limiting toxicity (DLT). Since no DLTs were observed in cohort 3, an additional 5 patients were thus enrolled at this dose level to ensure safety. The OD was determined to be the dose level used in cohort 3: OM 2 mg/m2. No HTs were observed in 21 of 22 patients, (one patient not evaluable). The most common non-hematologic treatment emergent adverse events (TEAEs) of any grade were fever (68%), nausea (64%), vomiting (55%), hyperglycemia (41%), diarrhea (41%), mucositis (36%), headache (36%), sinus tachycardia (32%), rash/dermatitis (32%), and abdominal pain (32%). The most prevalent non-hematologic grade 3/4 TEAEs were febrile neutropenia (23%), hypoxia (18%), hyperglycemia (18%), and dyspnea (18%). ORR (CR and CRi) was 45.5%. Median OS was 605 days and EFS was 100 days.Conclusion: In this population with predominantly high-risk AML, the combination of OM with a standard 7 + 3 regimen demonstrates a manageable safety profile with acceptable efficacy. As ~ 25% of patients achieving CR with ‘7 + 3‘ do so after a second induction (based on meta-analysis of 6 trials, n = 1980, see Cancer 2010, 116: 5012), the ORR here is comparable to those receiving a single standard of care induction. The results in this high-risk group are therefore promising and warrant further investigation in a phase II trial. At present, we are assessing leukemic blast MCL protein expression in stored pre-treatment samples to determine if this predicts OM efficacy.NCT02440568. Teva has performed a Medical Accuracy Review of this abstract. DisclosuresKhan:Teva: Speakers Bureau. Patel:Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen: Honoraria.