AML Pts Research Articles

Allogeneic Stem Cell Transplantation from Two Loci Mismatched (≤6/8) Unrelated Donors in Acute Leukemia: On Behalf of the ALWP of the EBMT

Background Data on outcome of allogeneic transplantation (HSCT) from mismatched unrelated donors (MMUD) (≤6/8) in leukemic patients (pts) are limited. Methods We assess HSCT results in pts with AML/ALL in CR transplanted between 2000 and 2017 from ≤6/8 MMUD (2-4 HLA mismatches at the allelic level at loci A, B, C and DR) reported to the EBMT. Results A total of 465 pts were allocated, AML-320 and ALL-145. Median age was 50.2 years (range, 18-71.8) and 34.8 years (range, 18.2-62.9); 54% and 64% were males, respectively. Median F/U was 63 and 75 months, respectively. 69% and 66% were in CR1, while 31% and 34% were in CR2. 40% of AML pts had intermediate risk cytogenetics, 10% poor risk and 5% good risk (missing 45%),respectively. 37% of ALL pts were Ph positive, 22% Ph negative and 18% T ALL (17% B ALL with no Ph data,6% missing data). The number of HLA mismatches (HLAMM) was 6/8 - in 82% and 85%,5/8- in 11.5% and 12% and 3-4 in 6% and 3% of AML and ALL pts, respectively. 85% of AML pts and 77% of ALL pts received PBSC graft. Conditioning regimen was myeloablative in the majority of pts (89% of AML and 61% of ALL pts). 82% and 77% underwent in vivo TCD, respectively. GVHD prophylaxis was CSA/MTX in 51% and 67% and CSA/MMF in 21% and 10% of AML and ALL pts, respectively. Engraftment was achieved in 97% and 95% of pts, respectively. The incidence of acute (a) GVHD grade (Gr) II-IV and Gr III-IV was 34% and 41% and 14% and 21% for AML and ALL pts, respectively. Total and extensive chronic(c) GVHD rates at 2y were 38% and 38% and 23% and 14%, respectively. The main causes of death were disease recurrence (37% in both), GVHD (29% and 22%) and infections (22% and 26%).The 2 and 5y outcomes in the entire population were: RI-28% and 33%, NRM-28% and 30%; LFS-44% and 37%, OS- 50% and 41% and GRFS- 33% and 27%, respectively. More than 2 HLA mismatches were associated with a higher incidence of aGVHD Gr II-IV (29% vs 15%, respectively).In MVA, RI was lower for ALL vs AML HR (95% CI) 0.60, p=0.02. Disease status (CR2 vs CR1) was poor prognostic factor for RI, LFS and OS. Age was prognostic factor for NRM, LFS and OS. HLA mismatch at locus DR was poor prognostic factor, giving increased NRM: HR (95% CI) 1.68, p=0.02, and lower LFS: HR (95% CI), 1.42, p=0.03and OS HR (95% CI) 1.46, p=0.03and higher GVHD Gr II-IV HR (95% CI) 1.48, p=0.048. Results of MVA in AML pts in CR1 were similar. GVHD prophylaxis CSA/MMF in comparison to CSA/MTX resulted in higher NRM HR (95% CI) 2.2,p= 0.005 and lower GRFS HR (95% CI) 1.58, p=0.02.Notably, in 154 pts with AML in CR1 transplanted from ≤6/8 UD with T cell depletion c mismatches was associated with higher incidence of cGVHD HR (95% CI) 2.52, p=0.002. Summary and Conclusions HSCT from ≤6/8 MMUD transplantation can provide 40% 5y OS, 37% LFS and GRFS of 27% in leukemic pts. DR mismatch is a poor prognostic factor. cGVHD incidence at 5y is 41% with 21% being severe and is associated in AML pts with HLA C mismatches. CSA and MTX is the preferred GVHD prophylaxis.

Outcome of Two Loci Mismatched (≤6/8) Unrelated Donor Hematopoietic Cell Transplantation for Acute Leukemia: ALWP of the EBMT Study

Outcome of Two Loci Mismatched (≤6/8) Unrelated Donor Hematopoietic Cell Transplantation for Acute Leukemia: ALWP of the EBMT Study

Exceptional Responders to Hypomethylating Agents in Myeloid Neoplasms: The Miami Experience

Exceptional Responders to Hypomethylating Agents in Myeloid Neoplasms: The Miami Experience

Durable Responses Observed in Elderly AML Patients Unfit for Intensive Chemotherapy with First-in Class Selective AXL Inhibitor Bemcentinib (BGB324) in Combination with LDAC: Phase II Open-Label Study

Durable Responses Observed in Elderly AML Patients Unfit for Intensive Chemotherapy with First-in Class Selective AXL Inhibitor Bemcentinib (BGB324) in Combination with LDAC: Phase II Open-Label Study

Primary Antigen Aberrations and Immunophenotype Shifts of Blasts in AML Patients during the Treatment and at the Time of Relapse

Introduction. Presence of measurable by flow cytometry (FC) residual disease (MRD) is a well-known risk factor in AML patients (pts), which is associated with adverse prognosis. The main idea in MRD by FC is searching for leukemia-associated immunophenotype (LAIP) which is based on «different from normal (DfN) approach». DfN approach allows to capture any immuphenotypic (IP) shifts during the therapy. LAIP may change in 16-91% AML cases. There are some ELN recommendations for monoclonal antibodies (mAbs) which allows todetect "mandatory (most frequent)" aberrations. But each laboratory uses its own tactics for MRD detection, taking into account the capabilities and equipment, and approved standardized panel still does not yet exist. Aim. To find the most common and adverse IP aberrations of blast cells in the onset of AML, and to determine the frequency of IP shifts during treatment and in relapse. Patients and methods. From March 2016 to February 2018 71 newly diagnosed AML (18-79 y.o.) pts were included in the initial LAIP (before any treatment) detection in hematology department of National Research Center for hematology, Moscow, Russia. MRD was detected in bone marrows by FC with BD FACS Canto II. The standard panel included mAbs against CD19, CD7, CD2, CD38, CD65, CD66b, CD99 (FITC); CD56, CD15, CD11b, CD13 (PE); CD33 (APC); HLA-DR, CD14, CD16, CD117 (PerCP-Cy 5.5); CD45 (APC-H7) and CD34 (PE-Cy7). MRD was determined after 1st and 2nd treatment course and in relapse. Pts received different treatment strategy due to age, comorbid status, severe infectious complications and type of AML. Most common for 80% of pts was induction course «7+3». Next cycles differed by intensity. The threshold value of 0.01% was estimated for long-term prognosis in our research. Results. The distribution of aberrations of blasts in the AML onset is shown in pic. 1. The most common aberration was "reduced /absence expression": in 60% of pts it was observed in the combination CD34+/HLA-DRlow (HLA-DR-). The appearance of this aberration and its preservation during the course of therapy were also more common (10% - 15%) than others (pic 1). When analyzing the results of long-term survival, it was shown that low expression of CD38 and/or CD117, as well as increased expression of CD13 in combination with CD34+ on blast cells in AML onset, is associated with bad prognosis (pic.2). CD117 and CD38low are the earliest markers of progenitor cells and show the region for identifying stem cells and leukemic stem cell. When analyzing the remaining groups of aberrant combinations (overexpression, asynchronous and non-linear expression), no correlation with the long-term prognosis was revealed. From 15 relapses of AML, the change of the primary LAIP was detected in 40%. Of the 7 refractory AML pts, the change of primary LAIP was detected in 57%. Complete replacement of the primary LAIP - in 18% from those with relapse and refractoriness (pic 3). Conclusion. The immunophenotyping shifts in AML pts is a very common phenomenon. In our study 60% of LAIP in relapse remained the same and 43% was the identical in refractory pts. LAIP shifts during chemotherapy reflects the biology of the tumor and its low sensitivity to therapy, but eventually leads to relapse development. To cover all potential changes in the IP and early suspect the relapse development to change the tactics of therapy, it is necessary to use the complex standardized mAbs panel, which allows determining as many aberrancies, as possible. Figure Disclosures No relevant conflicts of interest to declare.

Olutasidenib (FT-2102), an IDH1m Inhibitor As a Single Agent or in Combination with Azacitidine, Induces Deep Clinical Responses with Mutation Clearance in Patients with Acute Myeloid Leukemia Treated in a Phase 1 Dose Escalation and Expansion Study

Olutasidenib (FT-2102), an IDH1m Inhibitor As a Single Agent or in Combination with Azacitidine, Induces Deep Clinical Responses with Mutation Clearance in Patients with Acute Myeloid Leukemia Treated in a Phase 1 Dose Escalation and Expansion Study

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.

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

Outcomes of AML Patients Treated with Gemtuzumab-Ozogamicin Based Therapies: A Cue to Optimal Chemotherapy Backbone

Several therapeutic approvals in recent years have resulted in a change in the paradigm for standard treatment of patients with newly diagnosed and relapsed/refractory (r/r) AML. Gemtuzumab ozogamicin (GO) was resurrected in 2017 for CD33+ newly diagnosed or relapsed/refractory AML using a safer fractionated dosing regimen. Since its re-approval it has been incorporated in combination with standard 7+3 (cytarabine 100mg/m2 + daunorubicin 60mg/m2; Castaigne S et al, Lancet 2012) as upfront therapy for good and intermediate risk AML patients (pts) treated at institutions with access to rapid risk stratification (molecular/cytogenetic results) including ours (Roswell Park; RP). In the five randomized studies of GO combinations for newly diagnosed AML, varied doses of cytarabine and anthracyclines were used (Lancet Oncol, 2014). In these, cytarabine doses ranged from (100-200 mg/m2), daunorubicin doses ranged from 45-60 mg/m2. These studies did not intensify daunorubicin beyond 60mg/m2 and did not incorporate FLT3 inhibitors. Previous work has demonstrated that anthracycline dose intensification (90mg/m2) provides a recognized survival advantage for younger AML pts (Luskin MR et al, 2016.), particularly those with mutations in FLT3. Optimal combination approach(s) including GO for the management of patient with AML are unclear. Adaptation of GO in combination with 7+3 for upfront AML management has led to the evolution of institutional standards to optimize early identification of good/intermediate risk AML pts. Unfortunately, there is limited data on the safety and efficacy of higher doses of daunorubicin in combination with GO and/or FLT3 inhibitors. Here we present outcomes and adverse events (AEs) using varied upfront treatment regimens in combination with GO at RP. We additionally present a cohort of r/rAML pts treated with GO alone or in combinations under an expanded access protocol (NCT02312037) at RP prior to re-approval in 2017. R/R AML pts treated on expanded access had AEs collected prospectively, all other cases were identified by retrospective chart review in accordance to IRB approval. 218 patients with a diagnosis of AML and a median age of 66.5 years were seen at RP since GO approval. Of these all good risk and 45% of intermediate risk AML underwent induction chemotherapy. During 2015-2017 r/rAML patients were treated with GO based therapy (N=32) on NCT02312037 trial. Since FDA approval another 48 pts have been treated with GO at our institution. Of the 80 patients in this cohort, N=25 underwent GO based induction therapy (Table 1). The most frequently used other combinations were: (i) daunorubicin 60mg/m2 and cytarabine 200mg/m2 (N=17), (ii) daunorubicin 90mg/m2 + cytarabine 100mg/m2, N=4), (iii) FLAG-GO (used in patients with cardiac comorbidities; N=2) and hypomethylating agents combined with GO (N=10), monotherapy was used in 45 pts. The ORR (CR+Cri) for patients treated with GO based induction was 88%. The overall (OS) and event free survival (EFS) were 48 and 17 months for induction-treated pts respectively. The most common AEs were febrile neutropenia (60%), infusion reactions (30%), transaminitis (20%), cytopenias beyond 30 days from induction (10%). The most common reason for change of therapy was disease progression. Toxicity was not higher in those patients receiving higher doses (>60mg/m2) of daunorubicin or cytarabine (200mg/m2). Two patients received GO+7+3+FLT3 inhibitors; this was well- tolerated in a very small sample. In the R/R cohort, pts received a median of 2 cycles of therapy, the ORR was 18%. GO had no activity in those treated with >2 prior regimens for relapsed disease. In conclusion, anthracycline intensification as part of a 7+3 combination with GO was not associated with increased toxicity. Although the number was small, FLT3 inhibitors following 7+3+GO were also well tolerated. These data require confirmation in a larger cohort. Our results confirm the EFS reported in the literature (18 months in ALFA 0701 study), and suggest a higher mean OS of 40 months compared with conventional 7+3 induction. The response rate for GO monotherapy in r/rAML is low and was exceedingly poor for heavily pretreated pts. Disclosures Thota: Incyte, Inc.: Speakers Bureau. Griffiths:Novartis Inc.: Consultancy; Appelis Pharmaceuticals: Other: PI on a clinical trial; Onconova Therapeutics: Other: PI on a clinical trial; Partner Therapeutics: Consultancy; Astex Phramaceuticals/Otsuka Pharmaceuticals: Consultancy, Research Funding; Astex Phramaceuticals/Otsuka Pharmaceuticals: Consultancy, Research Funding; New Link Genetics: Consultancy; New Link Genetics: Consultancy; Persimmune: Consultancy; Persimmune: Consultancy; Boston Scientific: Consultancy; Boston Scientific: Consultancy; Abbvie, Inc.: Consultancy; Partner Therapeutics: Consultancy; Novartis Inc.: Consultancy; Appelis Pharmaceuticals: Other: PI on a clinical trial; Abbvie, Inc.: Consultancy, PI on a clinical trial; Celgene, Inc: Consultancy, Research Funding; Celgene, Inc: Consultancy, Research Funding; Onconova Therapeutics: Other: PI on a clinical trial; Genentech, Inc.: Research Funding; Genentech, Inc.: Research Funding. Wang:Agios: Other: Advisory role; Abbvie: Other: Advisory role; Kite: Other: Advisory role; Jazz: Other: Advisory role; Amgen: Other: Advisory role; Daiichi: Other: Advisory role; Astellas: Other: Advisory role, Speakers Bureau; celyad: Other: Advisory role; Pfizer: Other: Advisory role, Speakers Bureau; Stemline: Other: Advisory role, Speakers Bureau.

The VITAL Trial: Phase II Trial of Vosaroxin and Infusional Cytarabine for Frontline Treatment of acute Myeloid Leukemia

The VITAL Trial: Phase II Trial of Vosaroxin and Infusional Cytarabine for Frontline Treatment of acute Myeloid Leukemia

Isolated Trisomy 11 in Patients with Myeloid Malignancies - Is the Prognosis Not As Grim As Previously Thought?

Isolated Trisomy 11 in Patients with Myeloid Malignancies - Is the Prognosis Not As Grim As Previously Thought?

Clinical and Immunologic Activity of Ipilimumab Following Decitabine Priming in Post-Allogeneic Transplant and Transplant-Naïve Patients with Relapsed or Refractory Myelodysplastic Syndromes and Acute Myeloid Leukemia: A Multi-Center Phase 1, Two-Arm, Dose-Escalation Study

Clinical and Immunologic Activity of Ipilimumab Following Decitabine Priming in Post-Allogeneic Transplant and Transplant-Naïve Patients with Relapsed or Refractory Myelodysplastic Syndromes and Acute Myeloid Leukemia: A Multi-Center Phase 1, Two-Arm, Dose-Escalation Study

Venetoclax-Based Salvage Therapy for Post-Hematopoietic Cell Transplantation Relapse in Acute Myeloid Leukemia

Venetoclax-Based Salvage Therapy for Post-Hematopoietic Cell Transplantation Relapse in Acute Myeloid Leukemia

Distinct Gene Expression Profiles and Mutations Associate with Outcome in Younger Adults with De Novo Cytogenetically Normal Acute Myeloid Leukemia (CN-AML) (Alliance)

Distinct Gene Expression Profiles and Mutations Associate with Outcome in Younger Adults with De Novo Cytogenetically Normal Acute Myeloid Leukemia (CN-AML) (Alliance)

Determinants of Outcomes of FLT3mut Acute Myeloid Leukemia with First Salvage Therapy

Determinants of Outcomes of FLT3mut Acute Myeloid Leukemia with First Salvage Therapy

Poor-Risk AML with Complex, Monosomal Karyotype: In Vivo Therapeutic Efficacy of Decitabine (DAC) in Patient-Derived Xenograft (PDX) Mouse Models

Background: DNA-hypomethylating agents (HMAs) show an encouraging but not yet well-understood activity in AML/MDS patients (pts) with adverse cytogenetics, such as -7/del(7q) embedded in a complex, monosomal karyotype (MK). We have noted that MK pts with multiple monosomies responded better to DAC treatment than pts with only one monosomal autosome (Blum, Greve and Lübbert, Curr Opin Hematol. 2017). This important characteristic of HMAs differentiates them from cytarabine (AraC, lacking DNMT-inhibitory activity) as shown in randomized studies with DAC (Wierzbowska et al., Am. J. Hematology 2018) and AZA (Döhner et al., Leukemia 2018). The mechanism of action is currently under investigation and may involve preferential gene reactivation on monosomic chromosomes by DAC (Greve et al., ASH Annual Meeting 2017, #2612). In order to address this important difference between DAC and AraC, we compared their antileukemic activity in PDX models representing cytogenetically normal (CN) AML and adverse cytogenetics AML (complex, monosomal karyotypes including del(7q) and 1 or more monosomies). Materials and Methods: PDX models were generated for 5 CN and 3 MK AML pts with a median age of 68 years (range 55-80), a median WBC of 3.0 x 103/µl (range 1.4-139.7) and a median of 42% bone marrow (BM) blasts (range 5-97). 7/8 pts were sampled at diagnosis, i.e. prior to first-line treatment (3 pts received DAC, 3 pts induction and 1 pt upfront allografting); 1/8 pt had had multiple relapses. T-cell depleted peripheral blood or bone marrow cells (3x106 cells/mouse) were injected into NSG (NOD/Shi-scid/IL-2Rγnull) mice. Leukemic cell engraftment was determined by flow cytometry (FC) in BM, peripheral blood (PB) and spleen during the course of the experiment and at the end of a study. Leukemic cells were transplanted serially at least 4-5 times to propagate and ensure full leukemic potential of the cells. Mice were treated with low-toxic concentrations of DAC (1 mg/kg/day given intraperitoneally), AraC (15 mg/kg/day given intravenously) or vehicle (PBS) for 5 consecutive days (one cycle). Drug doses were titrated to be equitoxic and as potent as possible without causing side effects. Treatment commenced upon disease onset, as evaluated by FC positivity for human CD33, increased WBC in PB and weight loss. Overall survival served as the read-out. The study was carried out in accordance with the recommendations by the Society of Laboratory Animal Science in an AAALCA accredited animal facility. The animal experiments were approved by the regional council (Regierungspräsidium Freiburg, ref. 35, permit no. G-12/86). Results: We successfully established well-characterized PDX from pts with CN (n = 5), and with MK (n = 3) with a median of 2 autosomal monosomies (range 1-6; of chromosomes 4, 6, 7 [2x], 15, 17 [2x], 18, 21). TP53 (mutational status available for 6/8 pts) was wildtype in 4 CN pts and 1 MK pt, and mutated in 1 MK pt. All models were treated with either DAC, AraC or vehicle. Across both cytogenetic cohorts, DAC treatment significantly prolonged median survival by 36 days when compared to vehicle administration (p = 0.0002, see Fig 1A). Specifically, DAC increased median survival of CN PDX by 33 days (p = 0.0104, range 61-105 days with DAC, compared to 43-65 days with vehicle, Fig 1B), and in MK PDX by 40 days (p = 0.0197; range 72-105 days with DAC, compared to 39-50 days with vehicle, Fig 1C). Notably, disease progression in two DAC-treated PDX (one CN, one MK with 6 monosomies) was delayed to 105 days (Fig 1, marked with ⋆). AraC treatment also resulted in longer median survival across both cohorts compared to vehicle, albeit not as pronounced as with DAC, by an average of 20 days (p = 0.0066). In more detail, AraC increased median survival of CN PDX by 19 days (p = 0.0025, range 53-82 days), and, though not significantly, of MK PDX by 15 days (p = 0.2048, range 46-92 days). Conclusion: In this PDX study recapitulating two different cytogenetic risk groups of AML, DAC showed encouraging activity also in models with complex, monosomal karyotype, even in the presence of 6 autosomal monosomies, and was superior to AraC in extending survival. These data lend further support to the treatment of such adverse genetics AML patients with HMAs. Disclosures No relevant conflicts of interest to declare.

Next-Generation RNA Sequencing-Based Analysis Identifies a Novel Set of Prognostic Micrornas (miRs) in Cytogenetically Normal Acute Myeloid Leukemia (CN-AML)

Next-Generation RNA Sequencing-Based Analysis Identifies a Novel Set of Prognostic Micrornas (miRs) in Cytogenetically Normal Acute Myeloid Leukemia (CN-AML)

Targeted Treatment and Survival Following Relapse after Allogeneic Hematopoietic Cell Transplantation for Acute Leukemia and MDS in the Contemporary Era

Introduction: Relapse is the most frequent cause of treatment failure after allogeneic hematopoietic cell transplantation (alloHCT). While transplant-related mortality has decreased substantially over the last few decades, little progress has been made in outcomes and no standard of care exists for patients (pts) with post-alloHCT relapse. In the recent era, several new therapies, including targeted agents, have been approved for ALL, AML, and MDS. We conducted a study to evaluate outcomes of pts with these diseases who relapse after alloHCT in the contemporary period with routine availability of these newer therapeutic agents. Methods: We performed a single-institution retrospective cohort study to review treatment strategies and outcomes of relapse post-alloHCT. We identified 420 adult pts who received their first alloHCT in 2010-2018 using any conditioning regimen or donor source. Overall, 115 (27%) pts experienced relapse (ALL=17/64 [27%], AML=67/242 [28%], MDS=31/114 [27%]) and were included in the analysis. Results: Myeloablative (54%) matched-unrelated donor grafts (50%) were the most common types of HCTs. Peripheral blood stem cell graft (49%) and bone marrow graft (48%) were used the most. Median time from alloHCT to relapse was 5 (range 1-65) months, and 83% of relapses occurred within the first year. Only 24% and 11% of pts experienced grade II-IV acute and any chronic GVHD prior to relapse, respectively. Seven of 17 pts had Philadelphia chromosome positive ALL. Mutation panel was tested in 56% of AML and MDS. Median follow-up period after relapse was 19 (range 6-80) months. The estimated survival after relapse for all diseases was 32% (95% CI 24-41%) at 6 months, 21% (14-28%) at 12 months, and 14% (8-21%) at 24 months (Fig 1). Excluding pts treated with supportive care only, the majority received a combination of different treatments; pts with ALL received median 3 (range 1-5), pts with AML received median 2 (1-4), and pts with MDS received median 1 (1-3) agent. Targeted therapies used for ALL pts included blinatumomab (n=5) and BCR-ABL targeting tyrosine kinase inhibitors with (n=2) or without (n=4) chemotherapy. Among AML pts, targeted agents were used in 15 pts (sorafenib [n=7], 2 each with enasidenib, gemtuzumab ozagamicin, and ivosidenib, and 1 each with venetoclax and SEL24 [a dual pan-PIM/FLT3 inhibitor]). One pt each was treated with enasidenib, gemtuzumab ozagamicin, and PTC299 (an inhibitor of VEGFA mRNA translation) followed by SEL24 for MDS. Second alloHCTs (n=5) were performed median 5 (range 1-16) months after first HCT and median 1 month (range 0-5 months) after relapse. Two pts received no bridging therapy, while 3 pts received chemotherapy (n=2) or donor lymphocyte infusions (DLI [n=1]) prior to the second transplant. DLI without second transplant was used in 25 pts at a median of 20 (range 3-18) months after ALL relapse, median 2 (range 0-13) months after AML relapse, and median 3 (range 1-5) months after MDS relapse. Following DLI, 53% pts developed GVHD. Targeted therapy was associated with a trend towards better survival compared to other therapies (Fig 2, HR 0.65, 95% CI 0.41-1.03, p=0.06). Based on multivariable analysis, matched unrelated (vs. matched sibling, HR 1.70, p=0.027) or haploidentical donor grafts (HR 2.69, p=0.003), presence of grade II-IV acute GVHD before relapse (HR 2.46, p<0.001), and less than 12 months from HCT to relapse (<6 vs. >12 months, HR 6.34, p<0.001; 6-12 vs. >12 months, HR 3.16, p=0.005) were adverse prognostic features with survival after relapse post-alloHCT (Table 1). Conclusion: Outcomes of pts with ALL, AML, and MDS who relapse following alloHCT remain poor in the contemporary era when several newer therapies, including targeted agents, are available for their treatment. Targeted agents were used only in a minority of post-alloHCT relapses likely due to the combination of pt status, absence of the target mutation, the agents' availability, and other factors. Pts who developed grade II-IV acute GVHD and had shorter "disease-free" duration from unrelated or haploidentical donor grafts had the significantly shorter survival following relapse. More innovative treatment strategies to prevent and treat relapse post-alloHCT are needed. Disclosures Hill: Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celegene: Consultancy, Honoraria, Research Funding; Amgen: Research Funding; TG therapeutics: Research Funding; Genentech: Consultancy, Research Funding; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Takeda: Research Funding. Anwer:In-Cyte: Speakers Bureau; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Majhail:Atara Bio: Consultancy; Anthem, Inc.: Consultancy; Nkarta: Consultancy; Mallinckrodt: Honoraria; Incyte: Consultancy.

Safety, Efficacy and Biomarker Analysis of a Phase 1b/2 Study of Onvansertib (ONV), a Polo-like Kinase 1 (PLK1) Inhibitor, in Combination with Low-Dose Cytarabine (LDAC) or Decitabine (DEC) in Patients (pts) with Relapsed/Refractory Acute Myeloid Leukemia (R/R AML)

Safety, Efficacy and Biomarker Analysis of a Phase 1b/2 Study of Onvansertib (ONV), a Polo-like Kinase 1 (PLK1) Inhibitor, in Combination with Low-Dose Cytarabine (LDAC) or Decitabine (DEC) in Patients (pts) with Relapsed/Refractory Acute Myeloid Leukemia (R/R AML)

Characteristics and Outcome of Patients with Core Binding Factor Acute Myeloid Leukemia and FLT3-ITD: Results from an International Collaboration

Background: Core binding factor acute myeloid leukemia (CBF-AML) is defined by the presence of either t(8;21)(q22;q22) or inv(16)(p13.1q22)/t(16;16)(p13.1;q22) and is associated with a favorable outcome, particularly if treated with repetitive cycles of high-dose cytarabine as post-remission therapy. Long-time 10-year overall survival (OS) rate was reported of 58% in FLT3-ITD negative patients (pts; Allen et al. Leukemia 2013). Nevertheless, 30-40% CBF-AML pts experience relapse. FLT3-ITD mutations occur in roughly 5-10% of adult CBF-AML. However, their prognostic relevance is still controversial. Aims: To characterize CBF-AML with FLT3-ITD and compare outcomes according to their genetic background. Methods: We retrospectively studied 65 AML pts with CBF-AML and FLT3-ITD (median age at diagnosis, 54 years; range, 22-81 years) diagnosed between 1996 and 2018 within seven study groups/institutions of the US and Europe. Results: Thirty-two (49%) of the 65 pts harbored t(8;21). Median white blood cell and platelet counts at diagnosis of patients with t(8;21) and inv(16) were 18.3/nl (range, 1.8-202/nl) and 31/nl (range, 7-372/nl), respectively. AML diagnoses were de novo in 61 (94%) and therapy-related in 4 (6%) of the pts. Thirty (46%) pts were female. Cytogenetic analysis revealed additional abnormalities (abn) in 38 (58%) pts, most frequently loss of X or Y (n=13; n=12 associated with t(8;21)), complex karyotype (≥3 abn; n=12; n=7 occurring in t(8;21)), trisomy 22 (n=7, all associated with inv(16)) or trisomy 8 (overall n=6, n=5 occurring in inv(16)). Four pts were positive for both mutations, FLT3-ITD as well as FLT3-TKD. Median ITD allelic ratio were 0.44 (range, 0.003-50) and median ITD size 60 bp (range, 3-120 bp). Three older pts (median age, 75.5 years) were treated with either azacitidine + sorafenib, azacitidine + venetoclax or with etoposide + tipifarnib. All three patients receiving non-intensive therapy died within one year and were excluded from further analysis. Complete remission (CR) after anthracycline-based induction therapy was achieved in 98% (n=61/62) of patients fit for intensive treatment including two pts treated with 7+3 ± midostaurin within the RATIFY trial. One patient died during induction. Fifteen (24%) pts underwent allogeneic hematopoietic cell transplantation. Of those, 10 pts were transplanted in 1st and 5 pts in 2nd CR. Median follow-up for the entire cohort was 4.43 years (95%-CI, 3.35-8.97 years). Median and 4-year relapse-free survival (RFS) rates were 3.41 years (95%-CI, 1.26 years - not reached) and 44.9% (95%-CI, 32.9-61.4%). Median and 4-year overall survival rates (OS) were 4.48 years (95%-CI, 2.26 years - not reached) and 51.8% (95%-CI, 39.6.2-67.9%). Neither type of CBF-AML (p=0.60), nor additional chromosomal abn (p=0.80), nor presence of a complex karyotype (p=0.50) had a prognostic impact on OS. Higher age (≥60 years) was an in trend negative prognostic factor on RFS and OS (p=0.07, each). High allelic ratio (≥0.5) had no impact on RFS (p=0.3), but in trend on OS (p=0.10). Conclusions: Despite a high remission rate pts with FLT3-ITD had an inferior outcome as compared to previously published data on CBF-AML without FLT3-ITD. Thus, CBF-AML with FLT3-ITD should not be classified within the low-risk category. CBF pts with FLT3-ITD warrants further study and should be included in FLT3-inhibitor trials. Disclosures Brunner: Astra Zeneca: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Forty Seven Inc: Membership on an entity's Board of Directors or advisory committees; Jazz Pharma: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding. Novak:Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel,Accommodations; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Other: Travel,Accommodations; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees. Stoelzel:Neovii: Other: Travel funding; Shire: Consultancy, Other: Travel funding; JAZZ Pharmaceuticals: Consultancy. Thiede:Daiichi Sankyo: Honoraria; AgenDix GmbH: Employment, Equity Ownership; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Diaceutics: Membership on an entity's Board of Directors or advisory committees. Platzbecker:Novartis: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria. Levis:Agios: Consultancy, Honoraria; Astellas: Consultancy, Research Funding; FUJIFILM: Consultancy, Research Funding; Menarini: Consultancy, Honoraria; Novartis: Consultancy, Research Funding; Daiichi Sankyo Inc: Consultancy, Honoraria; Amgen: Consultancy, Honoraria.