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BACKGROUND: IDH2 mutations occur in 8-19% of patients (pts) with AML. ENA is an oral, selective IDH2 inhibitor and AZA is a hypomethylating agent. In a phase 1b/2 trial, combination therapy with ENA + SC AZA significantly improved overall response rate (ORR) and complete remission (CR) rate vs AZA monotherapy (AZA-only) (P = 0.0064 and P = 0.0001, respectively) in pts with newly diagnosed (ND), mutant-IDH2 (m IDH2) AML not eligible for IC (DiNardo, 2020). Injectable AZA has shown to maintain pt-reported health-related quality of life (HRQoL) in ND-AML (Dombret, 2014); the effect of ENA on HRQoL has not been reported. While morphologic responses are associated with improved HRQoL, combining active agents could increase toxicity, which could diminish HRQoL. OBJECTIVE: Assess pt-reported HRQoL outcomes during treatment (Tx) with ENA + AZA and AZA-only in the phase 1b/2 AG-221-AML-005 trial (NCT02677922). METHODS: Adult pts with ECOG PS ≤ 2 and intermediate- or poor-risk cytogenetics were enrolled. In the phase 2 portion, pts were randomized 2:1 to ENA 100-mg QD (continuous) + AZA 75 mg/m 2/day (d) SC × 7d, or to AZA-only, in repeated 28d cycles (C). Pt-reported HRQoL was assessed during Tx using the EORTC QLQ-C30 and EQ-5D-5L instruments, each completed at baseline (BL [C1D1]), on d1 of each Tx cycle, and end of Tx (EOT). The primary HRQoL measures were observed mean changes from BL (CFB) in 5 QLQ-C30 domains-Global Health status (GHS)/QoL, Physical Functioning (PF), Role Functioning (RF), Fatigue, and Dyspnea-each scored from 0-100, with higher scores indicating better QoL or functioning but worse symptomology. Changes in the remaining 10 QLQ-C30 domains, and in the EQ-5D-5L utility index (UI) score (derived via cross-walk to EQ-5D-3L based on UK population weights) and EQ-5D visual analogue scale (VAS) score (0-100) were secondary outcomes. Changes are reported for Tx cycles with ≥ 10 evaluable pts in each Tx arm. Clinically meaningful changes were defined as mean CFB of ≥ 10 points on any QLQ-C30 domain, ≥ 0.08 point on the EQ-5D-5L UI, and ≥ 7 points on the EQ-5D VAS. HRQoL-evaluable pts had an evaluable assessment (≥ 15 items on the QLQ-C30; all 5 EQ-5D-5L items; non-missing EQ-5D VAS) at BL and at ≥ 1 post-BL visit. RESULTS: The HRQoL-evaluable population comprised ~75% of pts randomized to either ENA+AZA (51/68) or AZA-only (25/33); 25 pts were not evaluable due to missing data at BL (n = 16) and/or no post-BL visit (n = 19). QLQ-C30 data were missing for ~20%-30% of eligible pts at almost all post-BL visits through C9D1 (the last visit with ≥ 10 pts in each Tx arm), and for ≥ 50% of pts at the EOT visit; similar rates were observed on the EQ-5D-5L. BL characteristics for HRQoL-evaluable pts were generally comparable between arms and similar to those of the ITT population. At BL, mean QLQ-C30 scores in each Tx arm were meaningfully worse than general population normative scores across the majority of QLQ-C30 domains, including all 5 domains of primary interest, and on the EQ-5D VAS. During early ENA+AZA Tx cycles, observed mean QLQ-C30 scores remained similar to BL in the GHS/QoL and Dyspnea domains, and were worsened from BL in the PF, RF, and Fatigue domains-but reached the threshold for meaningful worsening only in the RF domain and only at C3D1 (Figure). Domain scores then trended toward improvement over time, with clinically meaningful improvements from BL from C4-C9 in the Dyspnea domain, C5-C9 in the GHS/QoL and Fatigue domains (except at C7 for Fatigue), and from C8-C9 in the RF domain; mean scores also improved from BL in the PF domain but were not clinically meaningful at any visit. Similar trends were observed in the AZA-only arm but without the early worsening seen with ENA+AZA (Figure). There were no clinically meaningful or statistically significant differences between Tx arms in mean CFB for any of the primary QLQ-C30 domains through C9. In both Tx arms, mean score CFB in the secondary QLQ-C30 domains, EQ-5D-5L UI, and EQ-5D VAS followed similar trends of improvement over time among pts who remained on Tx. CONCLUSIONS: At BL, these pts with AML reported meaningfully worse HRQoL scores across the majority of the QLQ-C30 domains and the EQ-5D VAS compared with the general population, indicating substantial impairment in HRQoL, functioning, and symptoms. HRQoL scores generally worsened during early ENA+AZA Tx cycles, but then improved with continued Tx, with meaningful improvement across multiple measures during later Tx cycles. Figure 1 Figure 1. Disclosures DiNardo: Agios/Servier: Consultancy, Honoraria, Research Funding; Foghorn: Honoraria, Research Funding; AbbVie: Consultancy, Research Funding; Forma: Honoraria, Research Funding; GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Celgene, a Bristol Myers Squibb company: Honoraria, Research Funding; Novartis: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding; Takeda: Honoraria; Notable Labs: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees; ImmuneOnc: Honoraria, Research Funding. Dohner: Pfizer: Research Funding; Roche: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; GEMoaB: Honoraria; Janssen: Honoraria; Helsinn: Honoraria; Gilead: Honoraria; Berlin-Chemie: Honoraria; Astex Pharmaceuticals: Honoraria; Astellas: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Agios: Honoraria, Research Funding; AstraZeneca: Honoraria; Jazz Pharmaceuticals: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Oxford Biomedica: Honoraria; Abbvie: Honoraria, Research Funding. Zeidan: Agios: Consultancy; AstraZeneca: Consultancy; BioCryst: Other: Clinical Trial Committees; Daiichi Sankyo: Consultancy; Genentech: Consultancy; Cardiff Oncology: Consultancy, Other: Travel support, Research Funding; Incyte: Consultancy, Research Funding; Janssen: Consultancy; Novartis: Consultancy, Other: Clinical Trial Committees, Travel support, Research Funding; Pfizer: Other: Travel support, Research Funding; Amgen: Consultancy, Research Funding; Ionis: Consultancy; Gilead: Consultancy, Other: Clinical Trial Committees; Astellas: Consultancy; BMS: Consultancy, Other: Clinical Trial Committees, Research Funding; Geron: Other: Clinical Trial Committees; Acceleron: Consultancy, Research Funding; Loxo Oncology: Consultancy, Other: Clinical Trial Committees; Kura: Consultancy, Other: Clinical Trial Committees; Boehringer Ingelheim: Consultancy, Research Funding; Aprea: Consultancy, Research Funding; Jasper: Consultancy; Epizyme: Consultancy; Jazz: Consultancy; ADC Therapeutics: Research Funding; BeyondSpring: Consultancy; Astex: Research Funding; AbbVie: Consultancy, Other: Clinical Trial Committees, Research Funding. Schuh: Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GlycoMimetics: Research Funding; Kite/Gilead: Research Funding; Jazz: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Teva: Honoraria, Membership on an entity's Board of Directors or advisory committees. Vyas: Gilead: Honoraria; Jazz: Honoraria; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Novartis: Honoraria; Takeda: Honoraria; Astellas: Consultancy, Honoraria; Pfizer: Honoraria; Daiichi Sankyo: Honoraria; Janssen: Honoraria; AbbVie: Consultancy, Honoraria. Stein: Janssen Pharmaceuticals: Consultancy; Abbvie: Consultancy; Gilead Sciences, Inc.: Consultancy; Blueprint Medicines: Consultancy; Foghorn Therapeutics: Consultancy; Jazz Pharmaceuticals: Consultancy; Bristol Myers Squibb: Consultancy; Celgene: Consultancy; PinotBio: Consultancy; Daiichi Sankyo: Consultancy; Syros Pharmaceuticals, Inc.: Consultancy; Genentech: Consultancy; Syndax Pharmaceuticals: Consultancy; Agios Pharmaceuticals, Inc: Consultancy; Astellas: Consultancy; Novartis: Consultancy. Wei: Novartis, Abbvie, Celgene/BMS: Speakers Bureau; Abbvie, Amgen, Astellas, AstraZeneca, Celgene/BMS, Genentech, Janssen, MacroGenics, Novartis, Pfizer, and Servier: Membership on an entity's Board of Directors or advisory committees; Former employee of Walter and Eliza Hall Institute: Patents & Royalties: Prof. Andrew Wei is a former employee of the Walter and Eliza Hall Institute and is eligible for a fraction of the royalty stream related to Venetoclax; Abbvie, Amgen, AstraZeneca, Celgene/BMS, Novartis, Servier and F. Hoffmann-La Roche: Research Funding; Abbvie, Amgen, Astellas, AstraZeneca, Celgene/BMS, Genentech, Janssen, MacroGenics, Novartis, Pfizer, and Servier: Honoraria; Servier: Consultancy. de Botton: Celgene: Consultancy; Agios: Consultancy, Honoraria; Forma: Consultancy, Honoraria; Astellas: Consultancy; Abbvie: Consultancy; Daiichi: Consultancy; Novartis: Consultancy; Jazz: Consultancy; Pfizer: Consultancy. Chen: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Lord-Bessen: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Martin-Regueira: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months. Lersch: Celgene, a Bristol-Myers Squibb Company: Current Employment. Gong: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months. Guo: Bristol Myers Squibb: Consultancy; Daiichi Sankyo: Consultancy; UCB: Consultancy; Janssen: Consultancy; Gilead: Consultancy; EMD Serono: Consultancy; Evidera: Current Employment. Shi: Bristol Myers Squibb: Consultancy. Montesinos: Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Stemline/Menarini: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Forma Therapeutics: Consultancy; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Glycomimetics: Consultancy; Tolero Pharmaceutical: Consultancy; Agios: Consultancy; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas Pharma, Inc.: Consultancy, Honoraria, Other: Advisory board, Research Funding, Speakers Bureau.

The impact of adverse risk genetic profiles on outcomes in acute myeloid leukemia (AML) patients following allogeneic hematopoietic stem cell transplantation (HCT) has not been fully elucidated. Accordingly, we have profiled somatic mutations at diagnosis using next-generation sequencing (NGS) in 178 AML patients who received allogeneic HCT. NGS revealed 598 somatic mutations in 165/178 patients (92.7%). Frequently mutated genes include DNMT3A, TET2, NPM1, RUNX1, IDH2, and FLT3. Commonly detected cytogenetic profiles include normal karyotype, trisomy 8, monosomal karyotype (MK), deletion 5, complex karyotype (CK), and monosomy 7. In univariate analyses, TP53 mutation, MK, CK, and monosomy 7 were associated with decreased overall survival (OS), relapse-free survival (RFS), and a higher relapse incidence (RI). We defined adverse molecular-genetic profile as harboring at least one of the molecular/genetic abnormalities of TP53 mutation, MK, CK, monosomy 7, and deletion 5. The patients harboring adverse molecular-genetic profile (n = 30) showed a lower 2-year OS (24.9% vs. 57.9%; p = 0.003), RFS (23.7% vs. 57.9%; p = 0.002), and higher RI (47.2% and 17.2%; p = 0.001) after HCT when compared to patients without those lesions. Multivariate analysis confirmed adverse molecular-genetic profile as an independent prognostic factor, associated with decreased OS (HR 2.19), RFS (HR 2.23), and higher RI (HR 2.94).

Background: venous thromboembolism (VTE) is a well-known complication in adults with acute lymphoblastic leukemia (ALL), especially in patients treated with asparaginase (ASNase)-including regiments. However, VTE risk in adult Philadelphia-positive ALL (Ph+ve ALL) patients treated with non-hyperCVAD chemotherapy is unclear. In this study, we examined VTE incidence in adult Ph+ve ALL patients treated with imatinib plus a pediatric-inspired asparaginase (ASNase)-free regimen modified from the Dana Farber Cancer Institute (DFCI) ALL protocol. Methods: a single centre retrospective review of Ph+ve ALL patients treated at Princess Margaret Cancer Center (PMCC) from 2008&ndash, 2019 with imatinib plus modified DFCI protocol was conducted. Results: of the 123 patients included, 30 (24.3%) had at least 1 radiology confirmed VTE event from diagnosis to the end of maintenance therapy. 86.7% (26/30) of the VTE events occurred during active treatment. Of all VTE events, the majority (53.3%) were DVT and/or PE while another significant portion were catheter-related (40.0%). Major bleeding was observed in 1 patient on VTE treatment with low molecular weight heparin (LMWH). Conclusion: a high VTE incidence (24.3%) was observed in adults Ph+ve ALL patients treated with imatinib plus an ASNase-free modified DFCI pediatric ALL protocol, suggesting prophylactic anticoagulation should be considered for all adult Ph+ve ALL patients including those treated with ASNase-free regimens.

PURPOSE Ivosidenib is an oral inhibitor of the mutant isocitrate dehydrogenase 1 (IDH1) enzyme, approved for treatment of IDH1-mutant (m IDH1) acute myeloid leukemia (AML). Preclinical work suggested that addition of azacitidine to ivosidenib enhances mIDH1 inhibition–related differentiation and apoptosis. PATIENTS AND METHODS This was an open-label, multicenter, phase Ib trial comprising dose-finding and expansion stages to evaluate safety and efficacy of combining oral ivosidenib 500 mg once daily continuously with subcutaneous azacitidine 75 mg/m2 on days 1-7 in 28-day cycles in patients with newly diagnosed m IDH1 AML ineligible for intensive induction chemotherapy (ClinicalTrials.gov identifier: NCT02677922 ). RESULTS Twenty-three patients received ivosidenib plus azacitidine (median age, 76 years; range, 61-88 years). Treatment-related grade ≥ 3 adverse events occurring in > 10% of patients were neutropenia (22%), anemia (13%), thrombocytopenia (13%), and electrocardiogram QT prolongation (13%). Adverse events of special interest included all-grade IDH differentiation syndrome (17%), all-grade electrocardiogram QT prolongation (26%), and grade ≥ 3 leukocytosis (9%). Median treatment duration was 15.1 months (range, 0.3-32.2 months); 10 patients remained on treatment as of February 19, 2019. The overall response rate was 78.3% (18/23 patients; 95% CI, 56.3% to 92.5%), and the complete remission rate was 60.9% (14/23 patients; 95% CI, 38.5% to 80.3%). With median follow-up of 16 months, median duration of response in responders had not been reached. The 12-month survival estimate was 82.0% (95% CI, 58.8% to 92.8%). m IDH1 clearance in bone marrow mononuclear cells by BEAMing (beads, emulsion, amplification, magnetics) digital polymerase chain reaction was seen in 10/14 patients (71.4%) achieving complete remission. CONCLUSION Ivosidenib plus azacitidine was well tolerated, with an expected safety profile consistent with monotherapy with each agent. Responses were deep and durable, with most complete responders achieving m IDH1 mutation clearance.

The ultimate goal of treatment for acute myeloid leukemia (AML) is to improve survival, and the best means of doing so is through the induction of morphologic remission, which is historically most reliably achieved with intensive chemotherapy regimens. Older patients with AML are less likely to be candidates for or to benefit from intensive chemotherapy. Patients deemed ineligible for intensive therapy may nevertheless benefit from lower-intensity therapies and from newly available targeted AML treatments. Recently approved lower-intensity treatments for AML include enasidenib, ivosidenib, glasdegib, venetoclax, midostaurin, and gilteritinib, and additional promising agents are in later stages of clinical development. Noncytotoxic agents may result in slower kinetics of therapeutic activity compared to intensive regimens, and although they are generally better tolerated than intensive chemotherapy, bone marrow responses are less frequent and may take longer to achieve. Notably, newer therapies might have been considered ineffective had they been judged solely by 2003 International Working Group response criteria for AML, which were based on experience with intensive regimens in predominantly younger patients. Lower-intensity therapies may require several treatment cycles to induce responses, and failure to achieve rapid morphologic remission may not signal the need for treatment cessation or transition to alternative therapies. Additionally, even in the absence of a conventional complete remission, lower-intensity therapies may provide meaningful clinical benefit, including improved survival and quality of life, by inducing hematologic improvement and transfusion independence. Reviewed here are the mechanisms of activity and response kinetics of lower-intensity AML therapies, as well as the clinical benefits resulting from nontraditional AML responses.

Background: Enasidenib is an oral inhibitor of mutant isocitrate dehydrogenase-2 (IDH2) proteins. We evaluated the safety and activity of enasidenib plus azacitidine versus azacitidine alone in patients with newly diagnosed, mutant-IDH2 acute myeloid leukaemia ineligible for intensive chemotherapy. Methods: This open-label, phase 1b/2 trial was done at 43 clinical sites in 12 countries (the USA, Germany, Canada, the UK, France, Spain, Australia, Italy, the Netherlands, Portugal, Switzerland, and South Korea). Eligible patients were aged 18 years or older and had newly diagnosed, mutant-IDH2 acute myeloid leukaemia, and an Eastern Cooperative Oncology Group performance status of 0–2. In the phase 1b dose-finding portion, patients received oral enasidenib 100 mg/day or 200 mg/day in continuous 28-day cycles, plus subcutaneous azacitidine 75 mg/m2 per day for 7 days of each cycle. In phase 2, patients were randomly assigned (2:1) via an interactive web response system to enasidenib plus azacitidine or azacitidine-only, stratified by acute myeloid leukaemia subtype (de novo or secondary). The primary endpoint in the phase 2 portion was the overall response rate in the intention-to-treat population at a prespecified interim analysis (Aug 20, 2019) when all patients had at least 1 year of follow-up. Safety was assessed in all patients who received at least one dose of study drug. The trial is registered with ClinicalTrials.gov, NCT02677922, and is ongoing. Findings: Between June 3, 2016, and Aug 2, 2018, 322 patients were screened and 107 patients with mutant-IDH2 acute myeloid leukaemia were enrolled. At data cutoff for the interim analysis, 24 patients (including two from the phase 1 portion) were still receiving their assigned treatment. Six patients were enrolled in the phase 1b dose-finding portion of the trial and received enasidenib 100 mg (n=3) or 200 mg (n=3) in combination with azacitidine. No dose-limiting toxicities occurred and the enasidenib 100 mg dose was selected for phase 2. In phase 2, 101 patients were randomly assigned to enasidenib plus azacitidine (n=68) or azacitidine only (n=33). Median age was 75 years (IQR 71–78). 50 (74%; 95% CI 61–84) patients in the enasidenib plus azacitidine combination group and 12 (36%; 20–55) patients in the azacitidine monotherapy group achieved an overall response (odds ratio 4·9 [95% CI 2·0–11·9]; p=0·0003). Common treatment-related grade 3 or 4 adverse events with enasidenib plus azacitidine were thrombocytopenia (25 [37%] of 68 vs six [19%] of 32 in the azacitidine-only group), neutropenia (25 [37%] vs eight [25%]), anaemia (13 [19%] vs seven [22%]), and febrile neutropenia (11 [16%] vs five [16%]). Serious treatment-related adverse events were reported in 29 (43%) patients in the combination group and 14 (44%) patients in the azacitidine-only group; serious treatment-related adverse events occurring in more than 5% of patients in either group were febrile neutropenia (nine [13%] in the combination group vs five [16%] in the azacitidine-only group), differentiation syndrome (seven [10%] vs none), and pneumonia (three [4%] vs two [6%]). No treatment-related deaths were reported. Interpretation: Combination enasidenib plus azacitidine was well tolerated and significantly improved overall response rates compared with azacitidine monotherapy, suggesting that this regimen can improve outcomes for patients with newly diagnosed, mutant-IDH2 acute myeloid leukaemia.

Background: Acute myeloid leukemia (AML), a hematologic malignancy characterized by clonal expansion of abnormal myeloid progenitors, is a disease exhibiting a dynamic mutational landscape over time. Somatic mutations in isocitrate dehydrogenase 1 (IDH1) are reported in 6-10% of patients (pts) with AML. Ivosidenib (IVO) is an oral, potent, targeted inhibitor of mutant IDH1 (mIDH1) and is FDA-approved for the treatment of mIDH1 relapsed/refractory (R/R) AML and newly diagnosed (ND) AML in adults ≥ 75 years (yrs) of age or with comorbidities precluding intensive induction chemotherapy (IC). In an ongoing phase 1b study (NCT02677922), 23 pts (11 male; median age 76 yrs [range 61-88]) with mIDH1 ND AML received IVO 500 mg daily and subcutaneous azacitidine (AZA) 75 mg/m2 on Days 1-7 in 28-day cycles. As of 19Feb2019, median number of treatment cycles was 15 (range 1-30); 10 pts remained on treatment. Overall response rate (complete remission [CR] + CRi [incomplete neutrophil recovery] + CRp [incomplete platelet recovery] + morphologic leukemia-free state [MLFS]) was 78% (18/23): including CR in 61% (14/23) and CR with partial hematologic recovery (CRh) in 9% (2/23). mIDH1 clearance assessed in bone marrow mononuclear cells (BMMCs) by BEAMing digital PCR (detection limit 0.02-0.04%) was observed in 11/16 pts (69%) with CR/CRh, including 10/14 (71%) with CR. Aim: Characterize clonal evolution and resistance in pts with mIDH1 ND AML treated on study with IVO + AZA. Methods: The secondary efficacy endpoint of CRh was sponsor derived and defined as CR with absolute neutrophil count > 0.5 X 109/L and platelets > 50 X 109/L. Bulk DNA sequencing (DNA-seq, 1400-gene ACE Extended Cancer Panel, 2% variant allele detection limit) was performed on BMMCs and/or peripheral blood mononuclear cells (PBMCs). Single-cell (sc) targeted DNA-seq was performed on PBMCs using a microfluidic platform (Tapestri®) with a 20-gene AML panel capable of detecting rare subclones down to 0.1%. Results: To identify mechanisms of acquired resistance, longitudinal bulk DNA-seq was analyzed for 22/23 pts, including 5 pts with available samples at relapse or disease progression (3 CR and 1 MLFS with morphological relapse; 1 CRh with disease progression). Mutations not detected at baseline but emerging during therapy were categorized into canonical biological pathways (Table). Emerging mutations were observed in 9/22 (41%) pts, including 4 with multiple mutations. 3/22 (14%) pts had emerging IDH2 mutations, with concurrent rise in plasma 2-hydroxyglutarate (2-HG) levels. Within the relapse/progression cases, emerging mutations were observed in 4/5 pts, including 3 where the emerging mutation appeared to be the predominant mutation at relapse/progression (2 CR pts with IDH2 mutations, and 1 CRh pt with a TET2 mutation). To date, from the bulk DNA-seq analysis, no emergence of an IDH1 second-site or receptor tyrosine kinase pathway (FLT3, KRAS, NRAS, PTPN11) mutation has been observed. To further evaluate clonal evolution of clinical response and disease progression, scDNA-seq was performed, with data available for 15 pts (10 CR, 2 CRh, 1 MLFS, and 2 stable disease), including end-of-study time points for 5 relapse/progression pts. In the 2 relapsed pts with an emerging IDH2 mutation observed by bulk DNA-seq, 1 had a minor IDH2 clone present at baseline that expanded independently from IDH1 during therapy (Fig). In a separate case, a subclonal baseline PTPN11 clone evolved to gain both RUNX1 and IDH2 mutations, becoming the predominant clone at relapse. In 2 other cases, scDNA-seq data showed that non-IDH1 clones were selected from baseline clones ancestral (TP53 n = 1) to or emerged separate from mIDH1 (TET2 n = 1). Clonal architecture and evolution from additional pts will be presented. Conclusion: IVO + AZA combination treatment in IC-ineligible ND AML led to deep and durable molecular remissions. Although the dataset is small, IDH2 clones appeared to expand or emerge separate from the IDH1 clone, with no observation of an IDH1 second-site mutation to date. Understanding patterns of emerging mutations/pathways at relapse will allow for comparison with mIDH1 R/R AML and ND AML pts treated with IVO monotherapy. These results underline the importance of mutational testing, particularly at progression to determine optimal salvage therapy. Potential combination or sequential therapies should be evaluated prospectively in future clinical trials. Disclosures Daigle: Agios: Current Employment, Current equity holder in private company. Choe:Agios Pharmaceuticals: Current Employment, Current equity holder in private company. DiNardo:Syros: Honoraria; MedImmune: Honoraria; Notable Labs: Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria; Jazz: Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Agios: Consultancy, Honoraria, Research Funding; Novartis: Consultancy; Daiichi Sankyo: Consultancy, Honoraria, Research Funding; ImmuneOnc: Honoraria; AbbVie: Consultancy, Honoraria, Research Funding; Calithera: Research Funding. Stein:Stemline: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau. Stein:Astellas Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Syros: Membership on an entity's Board of Directors or advisory committees; PTC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Biotheryx: Consultancy; Bayer: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Syndax: Consultancy, Research Funding; Seattle Genetics: Consultancy; Abbvie: Consultancy; Amgen: Consultancy; Celgene Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Fathi:Amphivena: Consultancy, Honoraria; Agios: Consultancy, Research Funding; Forty Seven: Consultancy; Daiichi Sankyo: Consultancy; Celgene: Consultancy, Research Funding; Astellas: Consultancy; Takeda: Consultancy; PTC Therapeutics: Consultancy; Novartis: Consultancy; NewLink Genetics: Consultancy, Honoraria; Kite: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; TrovaGene: Consultancy; Amgen: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Blue Print Oncology: Consultancy; Boston Biomedical: Consultancy; Kura: Consultancy; Pfizer: Consultancy; Seattle Genetics: Consultancy, Research Funding; Trillium: Consultancy; AbbVie: Consultancy. Döhner:Pfizer: Research Funding; Sunesis: Other, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Astex: Consultancy, Honoraria; Jazz: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria; Arog: Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Oxford Biomedicals: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Helsinn: Consultancy, Honoraria; Bristol-Myers Squibb: Research Funding. Martinelli:Celgene: Consultancy, Speakers Bureau; Jazz: Consultancy; Incyte: Consultancy; Pfizer: Consultancy, Research Funding, Speakers Bureau; Daichii Sankyo: Consultancy, Research Funding; Janssen: Consultancy; Amgen: Consultancy; AbbVie: Consultancy, Research Funding; Roche: Consultancy. Patel:France Foundation: Honoraria; DAVA Pharmaceuticals: Honoraria; Celgene: Consultancy, Speakers Bureau; Agios: Consultancy. Tan:AbbVie: Other: Investigator on an AbbVie funded clinical trial; Agios: Research Funding; Janssen: Research Funding; NOHLA Therapeutics: Research Funding; Novartis: Other, Research Funding. Zeidan:Astellas: Consultancy, Honoraria; Taiho: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; BeyondSpring: Consultancy, Honoraria; Epizyme: Consultancy, Honoraria; Ionis: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Trovagene: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Acceleron: Consultancy, Honoraria; Celgene / BMS: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Consultancy, Honoraria; Cardinal Health: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Aprea: Research Funding; MedImmune/Astrazeneca: Research Funding; ADC Therapeutics: Research Funding; Cardiff Oncology: Consultancy, Honoraria, Other; Takeda: Consultancy, Honoraria, Research Funding; Astex: Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Research Funding; Incyte: Consultancy, Honoraria, Research Funding; Leukemia and Lymphoma Society: Other; CCITLA: Other; Otsuka: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Research Funding. De Botton:Forma Therapeutics: Honoraria, Research Funding; Astellas: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Syros: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Agios: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy; Novartis: Consultancy; Pierre Fabre: Consultancy; Janssen: Consultancy, Honoraria; Seattle Genetics: Honoraria; Bayer: Consultancy, Honoraria; Servier: Consultancy. Stone:Syntrix: Consultancy; Macrogenics: Consultancy; Hoffman LaRoche: Consultancy; Stemline: Consultancy; AbbVie: Consultancy, Research Funding; Takeda: Consultancy; Pfizer: Consultancy; Trovagene: Consultancy; Jazz: Consultancy; Otsuka: Consultancy; Novartis: Consultancy, Research Funding; Argenx: Consultancy, Other: Data and safety monitoring board; Biolinerx: Consultancy; AstraZeneca: Consultancy; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; Arog: Research Funding; Daiichi-Sankyo: Consultancy; Agios: Consultancy, Research Funding; Actinium: Consultancy; Celgene: Consultancy, Other: Data and safety monitoring board; Syros: Consultancy; Syndax: Consultancy; Elevate: Consultancy; Gemoab: Consultancy; Janssen: Consultancy. Frattini:BMS: Current Employment, Current equity holder in private company. Franovic:BMS: Current Employment, Current equity holder in private company. Xu:Agios Pharmaceuticals: Current Employment, Current equity holder in private company. Winkler:Agios Pharmaceuticals: Current Employment, Current equity holder in private company. Wu:Agios Pharmaceuticals: Current Employment, Current equity holder in private company. Vyas:Forty Seven: Research Funding; Celgene: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; AbbVie: Speakers Bureau; Astellas: Speakers Bureau; Daiichi Sankyo: Speakers Bureau; Pfizer: Speakers Bureau.

Background : For patients (pts) with acute myeloid leukemia (AML), preserving and measuring perceptions of health-related quality of life (HRQoL) is important, particularly for those ineligible for intensive chemotherapy and with a poor prognosis, especially when evaluating new treatment regimens. This analysis from 2 Phase 3 trials, Viale-A (NCT02993523) and Viale-C (NCT03069352), evaluated HRQoL, including key symptoms and aspects of functioning, in pts with AML receiving venetoclax (VEN) co-administered with azacitidine (AZA) (Viale-A) or low-dose cytarabine (LDAC) (Viale-C). Methods: Viale-A and Viale-C included treatment-naïve pts with AML, ≥18 years of age, and ineligible to receive intensive chemotherapy. Pts were randomized 2:1 to receive VEN +AZA or placebo (PBO)+AZA in Viale-A, and VEN+ LDAC or PBO+LDAC in Viale-C. Pt-reported outcome (PRO) measures included the PROMIS Cancer Fatigue Short Form 7a, the EORTC QLQ-C30 global health status (GHS)/QoL and physical functioning [PF] subscales, and the EQ-5D-5L health status visual analog scale (VAS). PRO data were collected on Day 1 of every 28-day cycle throughout both trials. Time to deterioration (TTD) was assessed to quantify differences between treatment groups. TTD was defined as worsening from baseline in PRO-specific meaningful change thresholds of ≥10, 7, or 5 points for the EORTC-QLQ-C30, EQ-5D-5L VAS, and PROMIS Fatigue, respectively. TTD differences between treatment arms were analyzed using Kaplan-Meier curves, unadjusted log-rank tests, and Cox PH models adjusted for key covariates (age, baseline ECOG and PRO scores, AML type, and cytogenetic risk category). TTD analyses were conducted for all pts in the full dataset who survived up to a given assessment with available data on ≥1 PRO measures from baseline. Results: Viale-A included 431 pts (VEN+AZA: 286, PBO+AZA: 145), of whom 60% were male; median age was 76 years. Compared with PBO+AZA pts, VEN+AZA pts had a non-statistically significant trend to longer TTD in GHS/QoL (median in months [95% CI]: 16.5 [95% CI: 9.8, NE] vs. 9.3 [95% CI: 4.7, 16.6], P=0.066) and fatigue (9.3 [7.2, 16.6] vs. 8.6 [4.2, 16.6], P=0.189) (Figure 1A, B). VEN+AZA pts had significantly longer TTD in PF (9.7 [6.7, 16.0] vs. 6.2 [4.7, 9.5], P=0.028) and health status VAS (10.7 [7.5, 18.6] vs. 3.9 [2.4, 7.4], P Conclusions: Results showed a longer TTD in PRO measures of global health status, VAS, fatigue, and PF for pts receiving VEN combinations vs AZA or LDAC monotherapy, with significantly longer TTD observed for all PRO measures from the unadjusted and adjusted analyses in Viale-C, and for PF and health VAS in Viale-A. These results suggest that VEN conveys meaningful benefit in terms of HRQoL. Limitations included the small sample size beyond early cycles in these studies; however, the early separation of the TTD curves with the initial larger sample size, suggests that these results are not due to chance variability and are statistically valid. Overall the improvements in PROs with VEN are consistent with previous efficacy reports. In summary, VEN appears to have a positive impact on the HRQoL of pts with AML who are ineligible for intensive chemotherapy, leading to a longer preservation of functioning and overall health status. Disclosures Pratz: Millennium: Research Funding; Daiichi Sankyo: Research Funding; Agios: Other: Scientific Advisory Board, Research Funding; Celgene: Other: Scientific Advisory Board; Boston BioMedical: Consultancy; AbbVie: Other: Scientific Advisory Board, Research Funding; Astellas: Other: Scientific Advisory Board, Research Funding; Jazz Pharmaceutical: Consultancy. Panayiotidis:AbbVie: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Roche: Honoraria, Research Funding; Genesis: Honoraria, Research Funding; Takeda: Honoraria; Phizer: Honoraria; ASH: Honoraria; Janssen: Honoraria; Gilead: Honoraria. Jonas:AbbVie: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Tolero: Consultancy; Treadwell: Consultancy; Forty Seven: Research Funding; Daiichi Sankyo: Research Funding; Genentech/Roche: Research Funding; Amgen: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; GlycoMimetics: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Accelerated Medical Diagnostics: Research Funding; AROG: Research Funding; LP Therapeutics: Research Funding; Forma: Research Funding; Pharmacyclics: Research Funding; Pfizer: Research Funding; Jazz: Consultancy, Research Funding; Sigma Tau: Research Funding; Celgene: Consultancy, Research Funding; F. Hoffmann-La Roche: Research Funding; Incyte: Research Funding; Hanmi: Research Funding; Takeda: Consultancy. Dinardo:Takeda: Honoraria; Celgene: Research Funding; Agios: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Notable Labs: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; Daiichi Sankyo: Consultancy, Research Funding; Calithera: Research Funding; ImmuneOnc: Honoraria. Novak:Janssen: Other: Travel expenses; Novartis: Consultancy; Roche: Consultancy; Pfizer: Consultancy; Amgen: Consultancy, Other: Travel expenses; Takeda: Consultancy. Pejsa:Oktal Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sandoz: Honoraria, Membership on an entity's Board of Directors or advisory committees; Alvogen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pliva: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: 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; Takeda: 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; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees. Stevens:Amgen, MorphoSys: Consultancy. Yeh:Amgen: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Astex: Membership on an entity's Board of Directors or advisory committees. Kim:AbbVie: Other: Clinical trials investigator. Fracchiolla:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Yamamoto:Takeda: Consultancy, Honoraria, Research Funding; Yakult: Research Funding; Zenyaku: Research Funding; SymBio: Research Funding; Solasia Pharma: Research Funding; Aichi Cancer Center: Current Employment; AbbVie: Consultancy, Honoraria, Research Funding; Astra-Zeneca: Consultancy, Research Funding; Bayer: Research Funding; Bristol-Myers Squibb: Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Chugai: Consultancy, Honoraria, Research Funding; Eisai: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Consultancy; IQIVA/HUYA: Honoraria; HUYA: Consultancy; IQIVA/Incyte: Research Funding; Gilead Sciences: Research Funding; Janssen: Honoraria; Kyowa Kirin: Honoraria; Meiji Seika Pharma: Consultancy, Honoraria; Mochida: Honoraria; MSD: Consultancy, Honoraria, Research Funding; Mundipharma: Consultancy, Honoraria, Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Ono: Consultancy, Honoraria, Research Funding; Otsuka: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria; Sanofi: Honoraria; Sumitomo Dainippon: Honoraria; Stemline Therapeutics: Consultancy. Ofran:AbbVie: Membership on an entity's Board of Directors or advisory committees. Wei:Astra Zeneca: Honoraria, Research Funding; Walter and Eliza Hall Institute of Medical Research: Patents & Royalties: AW is eligible for royalty payments related to venetoclax; Novartis: Honoraria, Research Funding, Speakers Bureau; Amgen: Honoraria, Research Funding; Macrogenics: Honoraria; Roche: Honoraria; Servier: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria; Janssen: Honoraria; Abbvie: Honoraria, Research Funding, Speakers Bureau; Bristol Myers Squibb: Honoraria, Research Funding, Speakers Bureau. Bui:AbbVie: Current Employment, Current equity holder in publicly-traded company. Benjamin:AbbVie: Current Employment, Current equity holder in publicly-traded company. Kamalakar:AbbVie: Current Employment, Other: may hold stock or other options. Potluri:AbbVie: Current Employment, Other: may hold stock or stock options. Mendes:AbbVie: Current Employment, Current equity holder in publicly-traded company. Devine:Genentech: Current Employment, Current equity holder in publicly-traded company. Fiedler:Daiichi Sankyo: Other: support for meeting attendance; Gilead: Other: support for meeting attendance; Jazz Pharmaceuticals: Honoraria, Other: support for meeting attendance; Abbvie: Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Honoraria; Celgene: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria; ARIAD/Incyte: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Other: support for meeting attendance, Patents & Royalties, Research Funding.

Background: Approximately 40-60% of older patients (pts) with AML achieve complete remission (CR) with IC. Factors influencing the use of consolidation after induction include disease-related considerations, extent of hematopoietic recovery, pt fitness, and physician and pt preference. Most older pts who achieve AML remission will experience disease relapse despite consolidation therapy (Schlenk, Haematologica, 2018). In the phase III, randomized, double-blind QUAZAR AML-001 Maintenance Trial, CC-486, an oral hypomethylating agent, was shown to significantly prolong OS and RFS vs. placebo (PBO) in pts with AML in first remission following induction ± consolidation. Prior to study entry, the use of consolidation chemotherapy and number of consolidation cycles was at the discretion of the treating physician, with study eligibility not contingent on the use of consolidation. Objective: Assess survival outcomes in the QUAZAR AML-001 trial in pt subgroups defined by number of consolidation courses received before study entry. Methods: Eligible pts were aged ≥55 years with newly diagnosed AML, intermediate- or poor-risk cytogenetics, and ECOG PS ≤3. Within 4 months (mo) of attaining first CR or CR with incomplete blood count recovery (CRi), pts were randomized 1:1 to CC-486 300 mg or PBO QD for 14 days per 28-day treatment (Tx) cycle. OS and RFS were compared among pts who received no consolidation ("No Consolidation"), 1 cycle of consolidation ("1 Consolidation"), or ≥2 cycles of consolidation ("≥2 Consolidations"). For these analyses, "induction" and "consolidation" defined regimens received before and after, respectively, the reported date of first CR/CRi. OS was defined as the time from randomization to death, and RFS as time from randomization to relapse or death. Kaplan-Meier OS/RFS estimates were compared for CC-486 vs. PBO using log-rank test. Hazard ratios (HRs) and 95% CIs were generated using a stratified Cox proportional hazards model. These analyses were not powered sufficiently to determine statistical significance. Results: 472 pts were randomized to CC-486 (N=238) or PBO (N=234). Most pts (80%) received consolidation before study entry. The No Consolidation cohort comprised 94 pts (20%; CC-486 52, PBO 42), the 1 Consolidation cohort comprised 212 pts (45%; CC-486 110, PBO 102), and the ≥2 Consolidations cohort comprised 166 pts (35%; CC-486 76, PBO 90), including 19 pts (CC-486 6, PBO 13) who received 3 consolidation cycles. Common agents used for consolidation were cytarabine (377/378 pts), idarubicin (95/378), and daunorubicin (37/378). While most pts received 1 induction, 97 pts received ≥2 induction courses; of them, 21 (CC-486 14, PBO 7) did not receive consolidation and 76 (CC-486 43, PBO 33) received ≥1 consolidation cycle. Baseline characteristics (eg, CR / CRi after IC, ECOG PS, cytogenetic risk at diagnosis) were generally similar among Tx arms and cohorts. Median (range) ages of pts in the 0 / 1 / ≥2 Consolidation cohorts were 71 (58-84), 68 (55-86), and 67 (55-82) years, respectively. In the No Consolidation cohort, median OS from the time of randomization with CC-486 vs. PBO was 23.3 vs. 10.9 mo, respectively (HR 0.55 [95%CI 0.34, 0.89]), and median RFS was 8.4 vs. 3.9 mo (0.55 [0.34, 0.88]) (Figure A). In the 1 Consolidation cohort, median OS was 21.0 vs. 14.3 mo with CC-486 vs. PBO, respectively (HR 0.75 [95%CI 0.55, 1.02]), and median RFS was 10.0 vs. 4.7 mo (0.72 [0.53, 0.99]) (Figure B). In the ≥2 Consolidations cohort, median OS was 28.6 mo with CC-486 vs. 17.6 mo with PBO (HR 0.75 [95%CI 0.50, 1.11]), and median RFS was 13.0 vs. 6.1 mo (0.59 [0.41, 0.87]) (Figure C). Conclusions: CC-486 was associated with consistent survival benefits vs. PBO regardless of number of prior consolidation cycles. Use of consolidation was generally associated with nominal improvements in OS and RFS within each Tx arm; however, in the CC-486 arm, median OS for pts who did not receive consolidation was similar to those who received 1 consolidation cycle (23.3 and 21.0 mo, respectively). Results should be interpreted with caution, as these cohorts were not prospectively defined and the study was not powered to detect significant differences between subgroups. Nevertheless, these data clearly suggest that older pts with AML in first remission after induction can benefit from CC-486, regardless of their fitness to receive consolidation or the number of consolidation cycles received before starting CC-486. Disclosures Wei: AMGEN: Honoraria, Other: Advisory committee, Research Funding; Walter and Eliza Hall Institute: Patents & Royalties; Novartis: Honoraria, Research Funding, Speakers Bureau; Abbvie: Honoraria, Other: Advisory committee, Research Funding, Speakers Bureau; Genentech: Honoraria, Other: Advisory committee; Servier: Consultancy, Honoraria, Other: Advisory committee; Astellas: Honoraria, Other: Advisory committee; Pfizer: Honoraria, Other: Advisory committee; Macrogenics: Honoraria, Other: Advisory committee; Celgene: Honoraria, Other: Advisory committee, Speakers Bureau; Astra-Zeneca: Honoraria, Other: Advisory committee, Research Funding; Janssen: Honoraria, Other. Roboz:Orsenix: Consultancy; Actinium: Consultancy; Argenx: Consultancy; Jazz: Consultancy; Astex: Consultancy; Celgene: Consultancy; Janssen: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Bayer: Consultancy; Array BioPharma: Consultancy; Abbvie: Consultancy; Agios: Consultancy; Astellas: Consultancy; Daiichi Sankyo: Consultancy; AstraZeneca: Consultancy; Jasper Therapeutics: Consultancy; Cellectis: Research Funding; Otsuka: Consultancy; Takeda: Consultancy; Trovagene: Consultancy; Eisai: Consultancy; Celltrion: Consultancy; Epizyme: Consultancy; Helsinn: Consultancy; MEI Pharma: Consultancy; Sandoz: Consultancy; Roche/Genentech: Consultancy; Amphivena: Consultancy. Dombret:Sunesis: Consultancy; Abbvie: Consultancy; Shire-Baxalta: Consultancy; Immunogen: Consultancy; Otsuka: Consultancy; Janssen: Consultancy; Menarini: Consultancy; Pfizer: Consultancy, Research Funding; Jazz Pharma: Consultancy, Research Funding; Celgene: Consultancy; Nova: Consultancy, Research Funding; Incyte: Consultancy, Research Funding; Astellas: Consultancy; Servier: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Daiichi Sankyo: Consultancy; Cellectis: Consultancy. Döhner:Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Astex: Consultancy, Honoraria; Astellas: Consultancy, Honoraria, Research Funding; AROG: Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Agios: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; Sunesis: Research Funding; Oxford Biomedicals: Consultancy, Honoraria; Pfizer: Research Funding; Roche: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Helsinn: Consultancy, Honoraria; Jazz: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria; GEMoaB: Consultancy, Honoraria. Selleslag:Amgen: Consultancy, Honoraria, Speakers Bureau; MSD: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau; Incyte: Consultancy, Honoraria; GSK: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Alexion: Consultancy, Honoraria; Astellas: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Janssen Cilag: Consultancy, Honoraria, Speakers Bureau; AbbVie: Consultancy, Honoraria, Speakers Bureau; Belgian College: Membership on an entity's Board of Directors or advisory committees; Teva: Consultancy, Honoraria, Speakers Bureau; Takeda: Consultancy, Honoraria, Speakers Bureau. La Torre:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Skikne:Bristol Myers Squibb: Current Employment. Kumar:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Dong:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Beach:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Ravandi:Macrogenics: Research Funding; Astellas: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Research Funding; Orsenix: Consultancy, Honoraria, Research Funding; Xencor: Consultancy, Honoraria, Research Funding; Jazz Pharmaceuticals: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria.

Key Points DNMT3A R882, TET2, ASXL1, and SRSF2 mutations identified at the time of diagnosis are associated with delayed count recovery. Persistence of preleukemic mutations in remission at high variant allele frequency is associated with delayed count recovery.

With the recent approval of multiple new drugs for the treatment of acute myeloid leukemia (AML), the relevance of conventional treatment approaches, such as daunorubicin and cytarabine (“3+7”) induction chemotherapy, has been challenged. We review the AML risk stratification, the efficacy of the newly approved drugs, and the role of “3+7”. Treatment of AML is becoming more niched with specific subtypes more appropriately treated with gemtuzumab, midostaurin, and CPX-351. Although lower intensity therapies can yield high response rates, they are less efficient at preventing relapses. The only curative potential for poor-risk AML is still an allogeneic stem cell transplant. The number of AML subtypes where 3+7 alone is an appropriate therapeutic option is shrinking. However, it remains the backbone for combination therapy with newer agents in patients suitable for intensive chemotherapy.

Measurable (minimal) residual disease (MRD) is an established, key prognostic factor in adult B-cell acute lymphoblastic leukemia (B-ALL), and testing for MRD is known to be an important tool to help guide treatment decisions. The clinical value of MRD testing depends on the accuracy and reliability of results. Currently, there are no Canadian provincial or national guidelines for MRD testing in adult B-ALL, and consistent with the absence of such guidelines, there is no uniform Ontario MRD testing consensus. Moreover, there is great variability in Ontario in MRD testing with respect to where, when, and by which technique, MRD testing is performed, as well as in how the results are interpreted. To address these deficiencies, an expert multidisciplinary working group was convened to define consensus recommendations for improving the provision of such testing. The expert panel recommends that MRD testing should be implemented in a centralized manner to ensure expertise and accuracy in testing for this low volume indication, thereby to provide accurate, reliable results to clinicians and patients. All adult patients with B-ALL should receive MRD testing after induction chemotherapy. Philadelphia chromosome (Ph)-positive patients should have ongoing monitoring of MRD during treatment and thereafter, while samples from Ph-negative B-ALL patients should be tested at least once later during treatment, ideally at 12 to 16 weeks after treatment initiation. In Ph-negative adult B-ALL patients, standardized, ideally centralized, protocols must be used for MRD testing, including both flow cytometry and immunoglobulin (Ig) heavy chain and T-cell receptor (TCR) gene rearrangement analysis. For Ph-positive B-ALL patients, MRD testing using a standardized protocol for reverse transcription real-time quantitative PCR (RT-qPCR) for the BCR-ABL1 gene fusion transcript is recommended, with Ig/TCR gene rearrangement analysis done in parallel likely providing additional clinical information.

Summary The ongoing COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 is a global public health crisis. Multiple observations indicate poorer post-infection outcomes for patients with cancer than for the general population. Herein, we highlight the challenges in caring for patients with acute leukaemias and myeloid neoplasms amid the COVID-19 pandemic. We summarise key changes related to service allocation, clinical and supportive care, clinical trial participation, and ethical considerations regarding the use of lifesaving measures for these patients. We recognise that these recommendations might be more applicable to high-income countries and might not be generalisable because of regional differences in health-care infrastructure, individual circumstances, and a complex and highly fluid health-care environment. Despite these limitations, we aim to provide a general framework for the care of patients with acute leukaemias and myeloid neoplasms during the COVID-19 pandemic on the basis of recommendations from international experts.

Introduction Patients (pts) with acute myeloid leukemia (AML) with poor-risk cytogenetics at diagnosis have inadequate responses to standard treatment. Pre-clinical and clinical data show that TP53mutation (mut) is associated with poor outcomes with venetoclax (Ven). However, the clinical impact of AML with poor-risk cytogenetics with and without a TP53 mut treated with a hypomethylating agent (HMA) and Ven is unknown. Herein, we evaluated the efficacy and safety of the Ven + azacitidine (Aza) or HMA combination in pts with treatment-naïve AML with poor-risk cytogenetics with TP53wt or TP53mut. Methods Treatment-naïve pts with AML unfit for intensive chemotherapy either due to age ≥75 years or co-morbidities were enrolled. Data were pooled from an ongoing phase 3 study (NCT02993523) comparing pts treated with Ven+Aza or placebo (Pbo)+Aza, and a phase 1b study (NCT02203773), in which pts were treated with Ven and an HMA, either Aza or decitabine (Dec). Ven 400 mg daily, Aza 75 mg/m 2 (days 1-7), or Dec 20 mg/m 2 (days 1-5), were administered over 28-day cycles. Cytogenetic risk was determined locally pre-treatment per NCCN (2016) criteria with the following abnormalities associated with poor outcomes: complex (≥3 clonal chromosomal abnormalities), monosomal karyotype, -5,5q, -7,7q, 11q23-non t(9;11) inv(3), t(3;3), t(6;9), and t(9;22). TP53mut status was assessed from pre-treatment BM aspirates at screening and analyzed centrally using MyAML panel assays (covering all coding and non-coding exons, limit of detection 1%; Invivoscribe). Pts without a result either due to an inconclusive test or missing specimen were excluded from the analysis. Response assessments were performed per modified International Working Group response criteria for AML. Results The pooled analysis included 546 pts; 353 and 145 pts in the Ven+Aza and Aza groups, respectively, with poor-risk cytogenetics observed in 127 (36%; TP53wt, 50; TP53mut, 54) and 56 (39%; TP53wt, 22; TP53mut, 18) pts. There were 401 pts in the Ven+HMA group with poor-risk cytogenetics observed in 152 (38%, TP53wt, 61; TP53mut, 68). The median variant allele frequency for TP53 was 42.9% (range 6.5 ─ 93.4) for Ven+Aza and 42.9% (3.5 ─ 93.7) for Aza. Key pt demographics are shown in the Table. In pts with poor-risk cytogenetics +TP53wt who received Ven+Aza vs. Aza, the composite remission rates (CRc: complete remission [CR] + CR with incomplete hematologic remission [CRi]) were 70% vs. 23%, median duration of remission (DoR) was 18.37 (95% CI 9.63 ─ not evaluable [NE]) vs. 8.51 (1.05 ─ NE) months (mos), and median overall survival (OS) was 23.43 (95% CI 11.93 ─ NE) vs. 11.29 (4.90 ─ 12.78) mos (Figure A). Similar results were observed in pts treated with Ven+HMA: CRc rate was 74%, median DoR 16.72 (95% CI 8.08 ─ 20.99) mos, and median OS was 21.13 (95% CI 11.93 ─ 29.01) mos (Figure B).These poor-risk cytogenetics + TP53wt results were comparable to those of pts with intermediate-risk cytogenetics + TP53wt (Ven+Aza [n=166]: CRc 72%, DoR 21.91 mos, OS 19.15 mos; Ven+HMA [n=187]: CRc 72%, DoR 21.19 mos, OS 19.81 mos). In pts with poor-risk cytogenetics + TP53mut who received Ven+Aza or Aza, CRc rates were 41% vs. 17%, median DoR was 6.54 (95% CI 2.79 ─ 10.61) vs. 6.7 (6.7 ─ NE) mos, and median OS was 5.17 (95% CI 2.17 ─ 6.83) vs. 4.9 (2.14 ─ 9.3) mos. In pts treated with Ven+HMA, the CRc rate was 47%, median DoR was 6.54 (95% CI 3.58 ─ 12.09) mos, and median OS was 5.42 (95% CI 3.71 ─ 7.39) mos. In pts with poor-risk cytogenetics + TP53 wt, the common ≥ grade 3 (G3) adverse events (AEs) on Ven+Aza or Aza were thrombocytopenia (36%/36%), febrile neutropenia (32%/14%), anemia (26%/6%), neutropenia (24%/27%), and pneumonia (18%/23%). In pts with poor-risk cytogenetics + TP53 mut, the common ≥G3 AEs on Ven+Aza or Aza were also febrile neutropenia (43%/22%), thrombocytopenia (28%/28%), neutropenia (26%/17%), anemia (13%/32%), and pneumonia (26%/33%). In pts treated with Ven+HMA, the most common ≥G3 AEs in pts with poor-risk cytogenetics + TP53 wt or TP53 mut were similar. Conclusion Among pts with poor-risk cytogenetics +TP53wt, treatment with Ven+Aza or Ven+HMA was associated with higher remission rates and prolonged DoR and OS compared to pts treated with Aza alone. Outcomes were similar to intermediate-risk TP53wt Ven+Aza pts. In contrast, for similarly treated pts with poor-risk cytogenetics + TP53mut, improved response rates did not translate into improved DoR or OS.No new toxicities were noted. Figure 1 Figure 1. Disclosures Pollyea: Syndax: Honoraria; Takeda: Honoraria; Novartis: Consultancy, Honoraria; Foghorn: Honoraria; Genentech: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Jazz: Honoraria; Karyopharm: Consultancy, Honoraria; Kiadis: Honoraria; Amgen: Honoraria; Teva: Research Funding; Celgene: Honoraria; Syros: Consultancy, Honoraria; Bristol Myers Squibb: Honoraria; Astellas: Honoraria; Aprea: Honoraria; AbbVie: Consultancy, Honoraria, Research Funding. Pratz: Millenium: Research Funding; Novartis: Consultancy; Astellas: Consultancy, Honoraria, Research Funding; Agios: Consultancy; BMS: Consultancy, Honoraria; Cellgene: Consultancy, Honoraria; University of Pennsylvania: Current Employment; Abbvie: Consultancy, Honoraria, Research Funding. Wei: Novartis, Celgene, AbbVie, Servier, AstraZeneca, and Amgen: Research Funding; Novartis, Janssen, Amgen, Roche, Pfizer, Abbvie, Servier, BMS, Macrogenics, Agios, Gilead: Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria. Pullarkat: Amgen, Dova, and Novartis: Consultancy, Honoraria; AbbVie, Amgen, Genentech, Jazz Pharmaceuticals, Novartis, Pfizer, and Servier: Membership on an entity's Board of Directors or advisory committees. Jonas: 47, AbbVie, Accelerated Medical Diagnostics, Amgen, AROG, Celgene, Daiichi Sankyo, F. Hoffmann-La Roche, Forma, Genentech/Roche, Gilead, GlycoMimetics, Hanmi, Immune-Onc, Incyte, Jazz, Loxo Oncology, Pfizer, Pharmacyclics, Sigma Tau, Treadwell: Research Funding; AbbVie, BMS, Genentech, GlycoMimetics, Jazz, Pfizer, Takeda, Treadwell: Consultancy; AbbVie: Other: Travel reimbursement. Recher: BMS/Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Honoraria; Janssen: Honoraria; Jazz: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; MaatPharma: Research Funding; Macrogenics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Babu: BMS: Consultancy, Honoraria, Other: Travel accommodations, expenses, Research Funding, Speakers Bureau; Novartis: Research Funding; Alexion: Consultancy, Honoraria, Other: Travel, accommodations, expenses, Speakers Bureau; Genentech/Roche: Other: Travel, accommodations, expenses, Research Funding; Janssen Oncology: Other: Travel, accommodations, expenses, Research Funding; Amgen, TG Therapeutics, AbbVie, Nektar, Sanofi, Argenx: Research Funding; Lily: Honoraria, Other: Travel, accommodations, expenses, Research Funding; Astra-Zeneca: Consultancy, Honoraria, Research Funding; Bayer, Castle Biosciences: Honoraria. Schuh: Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GlycoMimetics: Research Funding; Kite/Gilead: Research Funding; Jazz: Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Teva: Honoraria, Membership on an entity's Board of Directors or advisory committees. Dail: Genentech/Roche: Current Employment, Current equity holder in publicly-traded company. Sun: AbbVie: Current Employment. Potluri: AbbVie: Current Employment. Chyla: AbbVie: Current Employment, Current equity holder in publicly-traded company. DiNardo: GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Research Funding; ImmuneOnc: Honoraria, Research Funding; Forma: Honoraria, Research Funding; Agios/Servier: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Honoraria, Research Funding; Notable Labs: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria; Novartis: Honoraria; Foghorn: Honoraria, Research Funding; Celgene, a Bristol Myers Squibb company: Honoraria, Research Funding.

BACKGROUND: Isocitrate dehydrogenase 2 (IDH2) mutations are found in about 10-15% of acute myeloid leukemia (AML) cases. Enasidenib (ENA) is a first-in-class mutant IDH2 inhibitor that induces differentiation of IDH2-mutated leukemic cells. However, the clinical efficacy of single agent ENA therapy in relapsed or refractory (R/R) AML is limited, underscoring the need for combination therapy. Preclinical studies have shown that IDH-mutated leukemic cells are particularly sensitive to BCL2 inhibition with venetoclax (VEN), a finding supported by clinical studies of VEN combination therapies. We previously demonstrated that the combination of ENA and VEN can be more effective than each drug alone, in reducing leukemic burden in patient-derived xenograft models of IDH2-mutated AML. Here, we report preliminary safety and efficacy results of an ongoing open-label, single-arm, phase Ib/II trial (NCT04092179) of ENA in combination with VEN in patients with IDH2-mutated myeloid malignancies. METHODS: Patients 18 years of age or above with IDH2-mutated R/R AML or high-risk MDS/MPN and an ECOG performance status of 0-2 were eligible. Patients previously treated with an IDH2 or BCL2 inhibitor were excluded. Participants received VEN continuously starting on cycle 1 day 1 with a 3-day ramp-up to a target dose of 400 mg daily (dose level 0) in cohorts 1 and 2. ENA was administered at 100 mg daily continuously starting on cycle 1 day 15. Each cycle was 28 days. Concurrent use of a moderate or strong CYP3A4 inhibitor was allowed with 50% dose reduction of VEN after completion of the first 2 cycles at 100% target dose. Interruptions of VEN and/or ENA were permitted for management of adverse events (AEs). Primary endpoints were 1) safety and tolerability and 2) overall response rate (ORR) defined as complete remission (CR) + CR with incomplete blood count recovery (CRi) + morphologic leukemia-free state (MLFS) + partial remission (PR) by revised IWG criteria. Secondary endpoints include pharmacokinetic (PK) profiles of VEN, duration of response, overall survival (OS), and IDH2 mutant allele burden in bone marrow by ddPCR. RESULTS: The study opened to recruitment in November of 2020. As of July 28, 2021 (data cutoff), 11 patients were enrolled on study; 10 with R/R AML and 1 with very-high risk MDS by IPSS-R. Six patients had a R140Q mutation, and 5 had a R172K mutation. Median age was 72 years (range: 32 - 80); 6 patients were male. Participants had received a median of 2 prior lines of therapies (range: 1 - 4). Six of 10 AML patients had primary refractory disease. The MDS patient experienced secondary azacitidine failure. Key treatment emergent grade ≥ 3 AEs regardless of attribution were: febrile neutropenia (n=3), intracranial hemorrhage (n=3), lung infection (n=2), other infection (n=2), elevated AST/ALT (n=2), sepsis (n=1), leukocytosis (n=1), TRALI (n=1), and small bowel obstruction (n=1). No cases of differentiation or tumor lysis syndrome were observed. No patients discontinued the study due to AEs. The addition of ENA, a known inhibitor of CYP3A4, did not significantly affect the PK profiles of VEN. Nine of the AML patients completed at least 1 cycle of treatment and are considered evaluable for efficacy. One AML patient died from intracranial hemorrhage prior to completion of cycle 1. Median duration of observation is 3.5 months. Of the evaluable patients, CR was achieved in 2 patients (22%) and CRi in 3 patients (33%) for an ORR of 55% (Fig. 1). Median number of cycles to response was 3. All responders remain in remission and on study with a median of 6 cycles received to date (range: 3 - 8). Of the remaining 4 patients, 2 patients (22%) remain on study with stable disease, and 2 patients (22%) experienced progressive disease and died (one after 7 cycles and the other after 1 cycle). Median OS for the entire cohort has not been reached. A sustained reduction in mutant IDH2 allele frequency in bone marrow correlated with response (Fig. 2). For the MDS patient, no response was observed after 1 cycle of treatment. CONCLUSIONS: VEN in combination with ENA is a well-tolerated regimen with no dose-limiting toxicities observed at the current dose level. The preliminary efficacy of this combination is encouraging with an ORR of 55% in evaluable R/R AML patients, with some responders achieving deep molecular remissions. Patient enrollment in dose-escalation cohorts is ongoing. Figure 1 Figure 1. Disclosures Chan: AbbVie: Research Funding; BMS: Research Funding. Gupta: Sierra Oncology: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Constellation Pharma: Consultancy, Honoraria; Incyte: Honoraria, Research Funding; AbbVie: Consultancy, Honoraria; Roche: Consultancy; BMS-Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy. Maze: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene-BMS: Honoraria; Takeda: Research Funding; PharmaEssentia: Research Funding; Kronos Bio: Research Funding. Minden: Astellas: Consultancy. Schimmer: Takeda Pharmaceuticals: Consultancy, Research Funding; Medivir AB: Research Funding; Novartis: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Otsuka Pharmaceuticals: Consultancy, Honoraria; UHN: Patents & Royalties. Schuh: AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GlycoMimetics: Research Funding; Kite/Gilead: Research Funding; Jazz: Membership on an entity's Board of Directors or advisory committees; Teva: Honoraria, Membership on an entity's Board of Directors or advisory committees. Yee: Pfizer: Membership on an entity's Board of Directors or advisory committees; Forma Therapeutics: Research Funding; F. Hoffmann La Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolero: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Shattuck Labs: Membership on an entity's Board of Directors or advisory committees; Onconova: Research Funding; Bristol-Myers Squibb/Celgene: Membership on an entity's Board of Directors or advisory committees; Otsuka: Membership on an entity's Board of Directors or advisory committees; Paladin: Membership on an entity's Board of Directors or advisory committees; Geron: Research Funding; MedImmune: Research Funding; Jazz: Research Funding; TaiHo: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria; Astex: Membership on an entity's Board of Directors or advisory committees, Research Funding. DiNardo: Agios/Servier: Consultancy, Honoraria, Research Funding; Notable Labs: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria; AbbVie: Consultancy, Research Funding; Novartis: Honoraria; Foghorn: Honoraria, Research Funding; Forma: Honoraria, Research Funding; GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Honoraria, Research Funding; ImmuneOnc: Honoraria, Research Funding; Celgene, a Bristol Myers Squibb company: Honoraria, Research Funding. OffLabel Disclosure: Enasidenib is approved for the treatment of relapsed or refractory AML as single agent. Venetoclax, in combination with azacitidine or low-dose cytarabine, is approved for the treatment of newly diagnosed AML patients who are 75 years or older, or who have comorbidities that preclude use of intensive induction chemotherapy.

Background: Somatic mutations in isocitrate dehydrogenase 1 (IDH1) occur in 6-10% of patients with acute myeloid leukemia (AML). Ivosidenib - an oral, potent inhibitor of the mutant IDH1 (mIDH1) enzyme - is FDA-approved for adults with relapsed/refractory m IDH1 AML and adults with newly diagnosed m IDH1 AML who are ≥ 75 years or have comorbidities that preclude use of intensive induction chemotherapy (IC). Data from a phase 1b study of 23 patients with newly diagnosed m IDH1 AML showed a favorable safety profile and encouraging clinical activity of ivosidenib + azacitidine (IVO+AZA; NCT02677922). Methods: In this global, double-blind, randomized, placebo-controlled, phase 3 study, patients were randomized 1:1 to IVO 500 mg once daily + AZA 75 mg/m 2 subcutaneously or intravenously for 7 days in 28-day cycles, or placebo + AZA (PBO+AZA), and stratified by region and de novo vs secondary AML. Key eligibility: untreated AML (WHO criteria), centrally confirmed m IDH1 status, not eligible for IC, ECOG 0-2. Primary endpoint: event-free survival (EFS; time from randomization until treatment failure, i.e. failure to achieve complete remission [CR] by week 24, relapse from remission, or death from any cause). Key secondary endpoints: CR rate, overall survival (OS), CR + CR with partial hematologic recovery (CRh) rate, and objective response rate (ORR). Results: From 19-Mar-2018 to 18-Mar-2021, 146 patients were randomized: 72 to IVO+AZA (median [interquartile range] age, 76.0 [70.5-79.5] years) and 74 to PBO+AZA (median [interquartile range] age, 75.5 [70.0-80.0] years). Fifty-four (75.0%) patients had de novo AML vs 18 (25.0%) with secondary AML in the IVO+AZA arm. Sixteen (22.2%) patients receiving IVO+AZA had poor-risk genetics per ELN guidelines vs 20 (27.0%) patients receiving PBO+AZA. Thirty-nine (26.7%) patients remain on treatment (27/72 patients in the IVO+AZA arm vs 12/74 patients in the PBO+AZA arm). EFS was statistically significant (HR = 0.33 [95% CI 0.16, 0.69]; P = 0.0011) in favor of the IVO+AZA arm. Median OS with IVO+AZA was 24.0 months vs 7.9 months with PBO+AZA (HR = 0.44 [95% CI 0.27, 0.73]; P = 0.0005). CR rate with IVO+AZA was 47.2% (34/72 patients; 95% CI 35.3%, 59.3%) vs 14.9% (11/74 patients; 95% CI 7.7%, 25.0%) with PBO+AZA (P < 0.0001). Median time to CR was 4.3 months with IVO+AZA vs 3.8 months with PBO+AZA. CR+CRh rate with IVO+AZA was 52.8% (38/72 patients; 95% CI 40.7%, 64.7%) vs 17.6% (13/74 patients; 95% CI 9.7%, 28.2%) with PBO+AZA (P < 0.0001). The CR rate by 24 weeks for IVO+AZA vs PBO+AZA was 37.5% and 10.8%, respectively. ORR with IVO+AZA was 62.5% (45/72 patients; 95% CI 50.3%, 73.6%) vs 18.9% (14/74 patients; 95% CI 10.7%, 29.7%) with PBO+AZA (P < 0.0001). All reported P-values are 1-sided. Common all-grade adverse events (AEs) occurring in > 20% of patients receiving IVO+AZA vs PBO+AZA were nausea (42.3% vs 38.4%), vomiting (40.8% vs 26.0%), diarrhea (35.2% vs 35.6%), pyrexia (33.8% vs 39.7%), anemia (31.0% vs 28.8%), febrile neutropenia (28.2% vs 34.2%), thrombocytopenia (28.2% vs 20.5%), constipation (26.8% vs 52.1%), and pneumonia (23.9% vs 31.5%). Sixty-six (93.0%) patients receiving IVO+AZA vs 69 (94.5%) patients receiving PBO+AZA experienced a grade ≥ 3 AE. Common grade ≥ 3 AEs occurring in > 20% of patients receiving IVO+AZA vs PBO+AZA included febrile neutropenia (28.2% vs 34.2%), anemia (25.4% vs 26.0%), thrombocytopenia (23.9% vs 20.5%), and pneumonia (22.5% vs 28.8%). Frequency of all-grade differentiation syndrome (DS) as assessed by investigators was 14.1% with IVO+AZA vs 8.2% with PBO+AZA, and that of grade ≥ 3 DS was 4.2% with IVO+AZA vs 4.1% with PBO+AZA. Based on the recommendation of the Independent Data Monitoring Committee, further enrollment into the study was prematurely discontinued due to evidence of benefit. Conclusions: IVO+AZA significantly improved EFS, OS, and clinical response (CR, CR+CRh, ORR) compared with PBO+AZA in patients with IC-ineligible, newly diagnosed m IDH1 AML. The safety profile of IVO+AZA was favorable and consistent with previous studies. These data demonstrate the clinical benefit of IVO+AZA in this difficult-to-treat AML population. Disclosures Montesinos: Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Stemline/Menarini: Consultancy; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Forma Therapeutics: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Glycomimetics: Consultancy; Tolero Pharmaceutical: Consultancy; Agios: Consultancy; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas Pharma, Inc.: Consultancy, Honoraria, Other: Advisory board, Research Funding, Speakers Bureau. Recher: Incyte: Honoraria; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria; Macrogenics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS/Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; MaatPharma: Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Wang: AbbVie: Consultancy; Astellas Pharma, Inc.: Research Funding. Heuser: Tolremo: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS/Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer Pharma AG: Research Funding; Astellas: Research Funding; BergenBio: Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria; Jazz: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Calado: AA&MDS International Foundation: Research Funding; Agios: Membership on an entity's Board of Directors or advisory committees; Team Telomere, Inc.: Membership on an entity's Board of Directors or advisory committees; Novartis Brasil: Honoraria; Instituto Butantan: Consultancy; Alexion Brasil: Consultancy. Schuh: Kite/Gilead: Research Funding; GlycoMimetics: Research Funding; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz: Membership on an entity's Board of Directors or advisory committees; Teva: Honoraria, Membership on an entity's Board of Directors or advisory committees. Daigle: Agios: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Servier: Current Employment. Hui: Servier: Current Employment; Agios: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Boehringer Ingelheim: Ended employment in the past 24 months. Zhang: Servier: Current Employment; Agios: Current equity holder in publicly-traded company, Ended employment in the past 24 months. Pandya: Agios: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Servier: Current Employment. Gianolio: Servier: Current Employment; Agios: Current equity holder in publicly-traded company, Ended employment in the past 24 months. de Botton: Pierre Fabre: Other; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria; Bayer: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Syros: Honoraria, Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees; Forma Therapeutics: Honoraria, Research Funding; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees. Döhner: Oxford Biomedicals: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; GEMoaB: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Pfizer: Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Berlin-Chemie: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Jazz: Consultancy, Honoraria, Research Funding; Helsinn: Consultancy, Honoraria; Astex: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria, Research Funding; Agios: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Ulm University Hospital: Current Employment. OffLabel Disclosure: 1) Ivosidenib (AG-120) is an isocitrate dehydrogenase-1 (IDH1) inhibitor indicated for the treatment of acute myeloid leukemia (AML) with a susceptible IDH1 mutation as detected by an FDA-approved test in: i) Adult patients with newly diagnosed AML who are 75 years of age or older or who have comorbidities that preclude use of intensive induction chemotherapy ii) Adult patients with relapsed or refractory AML. 2) It is being evaluated in a clinical trial in combination with azacitidine in adults 18 years of age or older with previously untreated acute myeloid leukemia with an IDH1 mutation.

Background: Prognosis is dismal for older patients (pts) with R/R AML, especially if multiple lines of AML treatment (Tx) have failed. Attaining response is more difficult after each Tx failure, and many pts cannot tolerate high-intensity salvage chemotherapy regimens. IDH2 mutations occur in ~8-19% of pts with AML. ENA is an oral IDH2 inhibitor approved for Tx of adult pts with m IDH2 R/R AML. The phase 3, randomized IDHentify trial compared ENA monotherapy vs. conventional care regimens (CCR)-intermediate-dose cytarabine (IDAC), low-dose cytarabine (LDAC), azacitidine (AZA), or best supportive care (BSC) only-in older pts with late-stage m IDH2 R/R AML who had received multiple prior AML Tx. Reported here are clinical outcomes for pts in IDHentify who were preselected to one of the lower-intensity CCR options (LDAC, AZA, or BSC only) before randomization to ENA or CCR. Methods: This international, multicenter, open-label trial enrolled pts aged ≥60 yrs with ECOG PS ≤2 and m IDH2 AML R/R to 2-3 prior AML Tx. Before randomization, pts were preselected to AZA 75 mg/m 2/day (d) ×7d, IDAC 0.5-1.5 g/m 2 ×3-6d, LDAC 20 mg BID ×10d, or BSC only. Pts were then randomized 1:1 to receive ENA (100 mg QD) or CCR in repeated 28d Tx cycles; pts randomized to CCR received their preselected Tx. All pts could receive BSC. These post hoc analyses include pts preselected to lower-intensity AZA, LDAC, or BSC only. Endpoints included overall response rate (ORR: complete remission [CR], CR with incomplete recovery [CRi/CRp], partial response [PR], or morphologic leukemia-free state [MLFS], per IWG 2003 AML response criteria), rates of hematologic improvement (HI) and transfusion independence (TI) (IWG 2006 MDS criteria), overall survival (OS), event-free survival (EFS), and time to Tx failure (TTF). OS was assessed in the intent-to-treat (ITT) population and among efficacy-evaluable (E-E) pts who received ≥1 study drug dose and had ≥1 response evaluation on-Tx. Results: In all, 267 (84%) of 319 enrolled pts were preselected to a lower-intensity Tx regimen and then randomized 1:1 to receive ENA (n = 139) or their preselected CCR (n = 128: AZA 69, LDAC 37, BSC 22). At data cutoff (17-Mar 2020), 10 ENA pts and 4 CCR pts continued to receive their assigned Tx. Median Tx durations were 143d (range 3-1270) in the ENA arm and 49d (1-1166) in the CCR arm; 15 CCR pts (12%) and 1 ENA pt discontinued before receiving assigned Tx. After discontinuing Tx, 43 ENA pts (31%) and 52 CCR pts (41%) received subsequent AML Tx, including 12 CCR pts (9%) who received commercially available ENA. Baseline (BL) characteristics were generally similar between Tx arms. Median age overall was 72 yrs (range 60-86), 80% of pts had received 2 prior AML Tx, 61% had ELN adverse-risk AML, 41% had primary refractory AML (ie, never attained CR/CRi/CRp), and 63% and 51% of pts were RBC and platelet transfusion-dependent (TD), respectively. Among all pts preselected to a lower-intensity Tx (ITT), ORR was substantially greater with ENA vs CCR (41% vs 11%, respectively), as were rates of CR (26% vs 3%) and HI (41% vs 13%) (P < 0.001, all comparisons) (Table), and proportionally more pts in the ENA arm achieved or sustained RBC and platelet TI (Table). OS was prolonged with ENA vs CCR (HR 0.74 [95% CI 0.56, 0.97]; P = 0.029), with a late separation of the curves after median OS had been reached (median OS 6.8 vs 6.2 mo, respectively), and 1-yr survival rates were 41% vs 26% (∆15.0% [3.4%, 26.6%]). Among E-E pts (ENA, n = 133; CCR, n = 110), OS was improved with ENA (HR 0.70 [0.53, 0.93]; P = 0.013): median OS was 6.9 mo, vs 5.7 mo with CCR. EFS and TTF in the ITT population were also prolonged with ENA vs CCR (Table). The safety of ENA in this pt subgroup was similar to that for all ENA-randomized pts and consistent with previous findings (Stein 2019). ENA-related differentiation syndrome occurred in 13% of pts and hyperbilirubinemia in 26% of pts. Conclusions: In pts with late-stage m IDH2 R/R AML, ENA was associated with clinically meaningful improvements in morphologic response, HI, RBC and platelet TI, and survival compared with conventional lower-intensity Tx options. OS outcomes were potentially confounded by the substantial number of pts randomized to CCR who did not receive Tx or discontinued Tx early, and by extensive use of subsequent Tx (including ENA) during follow-up. These clinical benefits support use of ENA as an appropriate oral outpatient Tx for pts with m IDH2 R/R AML who are not candidates for intensive therapies. Figure 1 Figure 1. Disclosures DiNardo: Forma: Honoraria, Research Funding; ImmuneOnc: Honoraria, Research Funding; Notable Labs: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Foghorn: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria, Research Funding; GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria; Novartis: Honoraria; AbbVie: Consultancy, Research Funding; Agios/Servier: Consultancy, Honoraria, Research Funding; Celgene, a Bristol Myers Squibb company: Honoraria, Research Funding. Montesinos: Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Agios: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolero Pharmaceutical: Consultancy; Stemline/Menarini: Consultancy; Forma Therapeutics: Consultancy; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Glycomimetics: Consultancy; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas Pharma, Inc.: Consultancy, Honoraria, Other: Advisory board, Research Funding, Speakers Bureau. Schuh: Kite/Gilead: Research Funding; GlycoMimetics: Research Funding; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz: Membership on an entity's Board of Directors or advisory committees; Teva: Honoraria, Membership on an entity's Board of Directors or advisory committees. Papayannidis: AbbVie: Honoraria; Astellas: Honoraria; Janssen: Honoraria; Amgen: Honoraria; Pfizer: Honoraria; Novartis: Honoraria. Vyas: AbbVie: Consultancy, Honoraria; Novartis: Honoraria; Daiichi Sankyo: Honoraria; Jazz: Honoraria; Pfizer: Honoraria; Takeda: Honoraria; Astellas: Consultancy, Honoraria; Gilead: Honoraria; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Janssen: Honoraria. Wei: Novartis, Celgene, AbbVie, Servier, AstraZeneca, and Amgen: Research Funding; Novartis, Janssen, Amgen, Roche, Pfizer, Abbvie, Servier, BMS, Macrogenics, Agios, Gilead: Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria. Zeidan: Daiichi Sankyo: Consultancy; Epizyme: Consultancy; Genentech: Consultancy; Gilead: Consultancy, Other: Clinical Trial Committees; Kura: Consultancy, Other: Clinical Trial Committees; AbbVie: Consultancy, Other: Clinical Trial Committees, Research Funding; BMS: Consultancy, Other: Clinical Trial Committees, Research Funding; Geron: Other: Clinical Trial Committees; ADC Therapeutics: Research Funding; Acceleron: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Boehringer Ingelheim: Consultancy, Research Funding; BioCryst: Other: Clinical Trial Committees; Novartis: Consultancy, Other: Clinical Trial Committees, Travel support, Research Funding; Cardiff Oncology: Consultancy, Other: Travel support, Research Funding; BeyondSpring: Consultancy; Pfizer: Other: Travel support, Research Funding; Agios: Consultancy; Jazz: Consultancy; Janssen: Consultancy; AstraZeneca: Consultancy; Ionis: Consultancy; Aprea: Consultancy, Research Funding; Astellas: Consultancy; Loxo Oncology: Consultancy, Other: Clinical Trial Committees; Jasper: Consultancy; Astex: Research Funding; Incyte: Consultancy, Research Funding. Bluemmert: Bristol Myers Squibb: Current Employment. Yu: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Hasan: Bristol Myers Squibb: Current Employment. Martin-Regueira: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months. de Botton: Pfizer: Consultancy; Jazz: Consultancy; Novartis: Consultancy; Daiichi: Consultancy; Abbvie: Consultancy; Astellas: Consultancy; Forma: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Celgene: Consultancy.

In myelofibrosis (MF), driver mutations in JAK2, MPL, or CALR impact survival and progression to blast phase, with the greatest risk conferred by triple-negative status. Subclonal mutations, including mutations in high–molecular risk (HMR) genes, such as ASXL1, EZH2, IDH1/2, and SRSF2 have also been associated with inferior prognosis. However, data evaluating the impact of next-generation sequencing in MF patients treated with JAK1/2 inhibitors are lacking. Using a 54-gene myeloid panel, we performed targeted sequencing on 100 MF patients treated with ruxolitinib (n = 77) or momelotinib (n = 23) and correlated mutational profiles with treatment outcomes. Ninety-nine patients had at least 1 mutation identified, 46 (46%) had 2 mutations, and 34 (34%) patients had ≥3 mutations. Seventy-nine patients carried a mutation in JAK2V617F, 14 patients had mutations in CALR, 6 patients had an MPL mutation, and 2 patients were triple negative. No mutation was significantly associated with spleen or anemia response. A high Dynamic International Prognostic Scoring System score and pretreatment transfusion dependence were associated with a shorter time to treatment failure (TTF), and this association retained significance on multivariable analysis. Patients with ASXL1 (hazard ratio [HR], 1.86; P = .03) and EZH2 mutations (HR, 2.94; P = .009) and an HMR profile (HR, 2.06; P = .01) had shorter TTF. On multivariate analysis, ASXL1 or EZH2 mutations were independently associated with shorter TTF and overall survival. These findings help identify patients unlikely to have a durable response with current JAK1/2 inhibitors and provide a framework for future studies.

Azacitidine is recommended front-line treatment for older patients with acute myeloid leukemia (AML) who are not candidates for intensive treatment regimens, and was recently granted approval in the European Union for treatment of adult AML. Reviewed here is azacitidine experience in AML, including: mechanistic and pharmacokinetic data; safety and efficacy in controlled trials; treatment effects in AML subpopulations defined by disease characteristics; experience in unselected patients treated in the community setting; clinical outcomes relative to other approved AML therapies; and experience with azacitidine-based combination treatment regimens. Collectively, these data suggest that (a) azacitidine may prolong overall survival to a similar or greater extent than do other approved AML treatments, but with less toxicity, (b) azacitidine may be the preferred treatment option for older patients with unfavorable cytogenetics, and (c) experience and outcomes with azacitidine in the clinic are similar to those seen in clinical trials. Continued investigation of combination regimens on an azacitidine backbone is warranted.

BACKGROUND Blinatumomab, a bispecific monoclonal antibody construct that enables CD3-positive T cells to recognize and eliminate CD19-positive acute lymphoblastic leukemia (ALL) blasts, was approved for use in patients with relapsed or refractory B-cell precursor ALL on the basis of single-group trials that showed efficacy and manageable toxic effects. METHODS In this multi-institutional phase 3 trial, we randomly assigned adults with heavily pre-treated B-cell precursor ALL, in a 2: 1 ratio, to receive either blinatumomab or standardof- care chemotherapy. The primary end point was overall survival. RESULTS Of the 405 patients who were randomly assigned to receive blinatumomab (271 patients) or chemotherapy (134 patients), 376 patients received at least one dose. Overall survival was significantly longer in the blinatumomab group than in the chemotherapy group. The median overall survival was 7.7 months in the blinatumomab group and 4.0 months in the chemotherapy group (hazard ratio for death with blinatumomab vs. chemotherapy, 0.71; 95% confidence interval [CI], 0.55 to 0.93; P = 0.01). Remission rates within 12 weeks after treatment initiation were significantly higher in the blinatumomab group than in the chemotherapy group, both with respect to complete remission with full hematologic recovery (34% vs. 16%, P

Introduction: CFI-400945 is a first-in-class, potent, selective, orally active inhibitor of Polo-like kinase 4 (PLK4) (Ki=0.26nM), a master regulator of centriole duplication, necessary for genomic integrity (Mason et al. Cancer Cell 2014; 26:163-76). CFI-400945 has activity in leukemia cell lines and primary leukemia samples including those with complex karyotype, inversion 3 and monosomy 7 (Minden. personal communications). This suggests that CFI-400945 may provide an effective treatment of patients with AML. The objectives of this phase 1 trial was to establish the safety, tolerability, and recommend phase II dose (RP2D) of CFI-400945 in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Methods: Patients with relapsed/refractory AML or MDS and patients with untreated AML who refused induction chemotherapy or who are not candidates for intensive chemotherapy were eligible. Dose escalation followed a standard 3+3 design with a starting dose of 64 mg orally once daily. Plasma levels of CFI-400945 free base were measured on Days 1, 2, & 29 of Cycle 1 and Day 15 on all subsequent cycles. Peripheral blood and/or bone marrow were obtained at baseline, Day 8 of Cycle 1 and Day 1 of each subsequent cycle prior to dosing for pharmacodynamic monitoring. Safety assessments using the NCI CTCAE version 4.03 were performed. Results: From May 2018 to June 2019, nine patients have been enrolled on study across three pre-defined dose levels (64 mg [n=3], 96 mg [n=4], and 128 mg [n=2]). Three patients had untreated AML, five patients had relapsed/refractory AML and one patient had myelodysplastic syndrome/myeloproliferative disorder (MDS/MPN). Patient characteristics at diagnosis are outlined in Table 1. Six (67%) patients had baseline high throughput sequencing; the most frequent mutations were TP53 (33%), TET2 (33%), KRAS (33%) and DNMT3A (33%). A total of 20 cycles were administered with a median of 1 cycle (range, 0 to 7 cycles). The most common non-hematological drug related toxicities of any grade, which occurred in over 20%, were diarrhea (44%), headache (44%), colitis (33%), vomiting (33%), bilirubin increase (22%), dizziness (22%), fatigue (22%), and nausea (22%). One patient on the 96 mg dose level was not evaluable for DLT and hence, replaced. Both patients treated at the 128 mg/day dose level developed DLTs, consisting of grade 3 colitis and grade 5 sepsis and colitis. Pharmacokinetic profile indicated low interpatient variability between patients. Maximum exposure did not correlate with toxicity Six patients were evaluable for disease response. Two (33%) achieved complete remission (CR), 3 pts (50%) had stable disease (with one patient having a 78% reduction in marrow blast count). The patient with MDS/MPN who did not complete 1 cycle of therapy progressed to AML (Figure 1). Both patients who obtained a CR had an early response within 2 cycles. One CR has been durable for 218 days with no measurable residual disease (MRD) by flow cytometry. The additional patient, who obtained a CR with incomplete platelets recovery, with subsequent best response of CR, had a sustained response for 91 days before relapse was confirmed by bone marrow examination (Figure 1). Conclusion: Single agent CFI-400945 has activity in patients with poor risk AML. The RP2D in this population is 96 mg once daily. Dose expansion is occurring at the RP2D level. A phase 2 study with CFI-400945 single agent or in combination study with azacitidine or decitabine is planned. Disclosures Leber: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Alexion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Lundbeck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda/Palladin: Honoraria, Membership on an entity's Board of Directors or advisory committees; Treadwell: 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, Speakers Bureau; BMS/Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Otsuka Pharmaceutical: 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. Bray:Treadwell Therapeutics: Current Employment; TIO Discovery: Current Employment. Gupta:Pfizer: Consultancy; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sierra Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol MyersSquibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Research Funding. Maze:Novartis: Honoraria; Pfizer: Consultancy; Takeda: Research Funding. McNamara:Novartis: Honoraria. Schimmer:Jazz: Honoraria; Otsuka: Honoraria; Medivir AB: Research Funding; AbbVie Pharmaceuticals: Other: owns stock ; Takeda: Honoraria, Research Funding; Novartis: Honoraria.

Background: Therapy options for pts with HR-MDS or AML who are not candidates for intensive chemotherapy (IC) or hematopoietic stem cell transplantation (HSCT) are limited, and clinical outcomes are poor. Novel, effective and tolerable therapies are urgently needed. TIM-3 is an inhibitory receptor that regulates both adaptive and innate immune responses. It is expressed on immune cells and on leukemic stem cells (LSCs) and blasts, but not on normal hematopoietic stem cells, making it a promising target in MDS and AML. Sabatolimab is a high-affinity, humanized, anti-TIM-3 IgG4 (S228P) antibody that simultaneously targets TIM-3 on immune and myeloid cells; this may restore immune function while also directly targeting LSCs and blasts. In preclinical studies, sabatolimab enhanced immune cell-mediated killing of AML cells in vitro. In early results from a ph 1b study (NCT03066648), sabatolimab + hypomethylating agents (HMAs; decitabine [Dec] or azacitidine [Aza]) demonstrated encouraging overall response rates in pts with high-/very high-risk MDS (+ Dec, 61%; + Aza, 57%) and newly diagnosed AML (+ Dec, 47%; + Aza, 29%), and a favorable safety profile. Study Design and Methods: The STIMULUS clinical trial program currently includes 3 trials evaluating the efficacy and safety of sabatolimab combination therapy in pts with HR-MDS or AML who are ineligible for IC or HSCT: STIMULUS-MDS1 (NCT03946670; ph 2) in pts with HR-MDS, STIMULUS-MDS2 (NCT04266301; ph 3) in pts with HR-MDS or chronic myelomonocytic leukemia-2 (CMML-2), and STIMULUS-AML1 (NCT04150029; ph 2) in pts with AML. STIMULUS-MDS1 is a randomized, double-blind, placebo-controlled ph 2 study evaluating the addition of sabatolimab to HMA in pts with HR-MDS. The 2 primary endpoints are complete remission (CR) rate and/or progression-free survival. Secondary endpoints include overall survival (OS), event-free survival (EFS), leukemia-free survival, duration of CR, transfusion independence, safety, pharmacokinetics (PK), and immunogenicity. Approximately 120 pts will be randomized 1:1 to receive sabatolimab 400 mg or placebo IV Q2W (D8 and D22 of each 28-d cycle), + Dec 20 mg/m2 IV on D1-D5 or Aza 75 mg/m2 IV/SC on D1-D7, or D1-D5 + D8 and D9, of each 28-d cycle. STIMULUS-MDS2 is a randomized, double-blind, placebo-controlled ph 3 study of sabatolimab in combination with Aza in pts with HR-MDS or CMML-2; the primary endpoint is OS. Secondary endpoints include measures related to pt quality of life, such as time to definitive deterioration of fatigue, improvement of fatigue, transfusion-free intervals, and physical/emotional functioning, as well as additional efficacy and safety parameters. Approximately 500 pts will be randomized 1:1 to sabatolimab 800 mg or placebo IV Q4W at D8 of each 28-d cycle + Aza using the same Aza dosing schedule as in STIMULUS-MDS1. Eligible pts for STIMULUS-MDS1 or -MDS2 are treatment-naïve adults with HR-MDS (Revised International Prognostic Scoring System [IPSS-R] intermediate-/high-/very high-risk MDS). Pts with intermediate-risk MDS enrolling in STIMULUS-MDS1 are also required to have ≥5% bone marrow blasts at baseline. Pts with CMML-2 are eligible for STIMULUS-MDS2 only. STIMULUS-AML1 is a single-arm ph 2 study evaluating the safety and efficacy of sabatolimab in combination with Aza and venetoclax in pts with AML who are not candidates for IC or HSCT. Primary endpoints are incidence of dose-limiting toxicities (safety run-in) and CR rate. Secondary endpoints include safety and tolerability, CR/CRi rate, measurable residual disease-negative rate, durability of CR, relapse-free survival, EFS, OS, PK, transfusion independence, and immunogenicity. Eligible pts for STIMULUS-AML1 are adults with newly diagnosed AML who are not candidates for IC or HSCT, based on comorbidities (including renal and hepatic impairments, cardiac and pulmonary comorbidities), age (≥75 years old), or Eastern Cooperative Oncology Group performance status of 2 or 3. STIMULUS-AML1 will enroll approximately 86 pts. Part 1 consists of a safety run-in (≈18 pts) across 2 escalating sabatolimab dose levels (400/800 mg IV Q4W on D8 of each 28-d cycle) in combination with Aza (75 mg/m2 IV/SC on D1-D7, or D1-D5 + D8 and D9) and venetoclax 400 mg PO QD. If this triple combination is assessed to be safe, part 2 (expansion) will open and enroll approximately 68 additional pts who will receive sabatolimab 800 mg Q4W in combination with Aza and venetoclax. Disclosures Zeidan: Incyte: Consultancy, Honoraria, Research Funding; Trovagene: Consultancy, Honoraria, Research Funding; Astex: Research Funding; Celgene / BMS: Consultancy, Honoraria, Research Funding; Otsuka: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; CCITLA: Other; Taiho: Consultancy, Honoraria; Cardinal Health: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Acceleron: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Research Funding; Agios: Consultancy, Honoraria; MedImmune/Astrazeneca: Research Funding; Leukemia and Lymphoma Society: Other; Epizyme: Consultancy, Honoraria; Ionis: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Research Funding; Cardiff Oncology: Consultancy, Honoraria, Other; BeyondSpring: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Aprea: Research Funding; ADC Therapeutics: Research Funding. Giagounidis:AMGEN: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Kim:SL VaxiGen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AML Global Portal: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Hanmi: Consultancy, Honoraria; Astellas: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Yuhan: Consultancy, Honoraria; Chugai: Consultancy, Honoraria; BL&H: Research Funding; Sanofi Genzyme: Honoraria; Abbvie: Honoraria. Miyazaki:Novartis Pharma KK: Honoraria; NIPPON SHINYAKU CO.,LTD.: Honoraria; Astellas Pharma Inc.: Honoraria; Otsuka Pharmaceutical: Honoraria; Chugai Pharmaceutical Co., Ltd.: Honoraria; Kyowa Kirin Co., Ltd.: Honoraria; Celgene: Honoraria; Sumitomo Dainippon Pharma Co., Ltd.: Honoraria. Platzbecker:Amgen: Honoraria, Research Funding; Takeda: Consultancy, Honoraria; Geron: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding. Sekeres:BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda/Millenium: 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. Malek:Novartis: Current Employment. Scott:Novartis: Current Employment. Niolat:Novartis: Current Employment. Peyrard:Novartis: Current Employment. Ma:Novartis: Current Employment. Kiertsman:Novartis: Current Employment. Stegert:Novartis AG: Current Employment, Current equity holder in publicly-traded company. Hertle:Novartis Pharma AG: Current Employment, Current equity holder in publicly-traded company. Fenaux:BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Jazz: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding. Santini:Takeda: Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Honoraria; Novartis: Consultancy, Honoraria; Acceleron: Consultancy; Takeda: Consultancy, Honoraria; Menarini: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria.

BACKGROUND: Multiparameter flow cytometry (MFC) has increasingly been used for measurable residual disease (MRD) assessment in patients with acute myeloid leukemia (AML), while next-generation sequencing (NGS)-based MRD monitoring tool is in clinical development for its application. Clonal hematopoiesis (CH), in which leukemia-associated somatic mutations gene are present in individuals with no apparent hematologic disease, adds a challenge in the detection of MRD. In patients with AML, CH could be potentially pre-leukemic, while persistent mutations in DNMT3A, TET2 orASXL1 (DTA) in remission marrow are usually removed from the analysis of residual leukemic cells. However, reports suggest that persistent DTA mutations in remission may be correlated with an increased relapse risk. In the patients with DTA mutations, the use of NGS for MRD monitoring is limited or modified due to the presence of CH clone in the remission marrow. We evaluated whether MFC-MRD can be adjunctive to predict the risk of AML relapse in this population of 221 patients with DTA mutation (DNMT3A (n=123), ASXL1 (n=56) or TET2 (n=100). METHODS: The present study evaluated long-term outcomes in AML patients who achieved first complete remission (CR1) and compared outcomes according to MFC-based MRD status (was defined as negative if patients achieved 0.1 or less) assessed at the time of CR1. A total of 435 patients diagnosed with AML and treated with induction chemotherapy between 2015 and 2018 were included. MFC-MRD was assessed in 336 patients in CR1 (77%). NGS was performed using samples obtained at the time of initial diagnosis and used for mutational subgroup classification. Overall survival (OS) was calculated as the date of CR1 to the date of death and censored on the date of the last follow-up. Relapse-free survival (RFS) was defined as the time from the date of CR1 to the date of relapse or death from any cause. Cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) were calculated considering competing risk. The Kaplan-Meier method using a log-rank test and a multivariate Cox proportional hazard model was used for analyses of time-to-event endpoints. For CIR and NRM, Gray test was performed for the risk factors and the Fine-Gray model was adopted for the multivariate model. RESULTS: According to the MFC-MRD status, i.e., the group with positive MRD (MRDpos; n=118, 35%) vs. those with negative MRD (MRDneg; n=218, 65%), we evaluated OS, RFS, and CIR. The MFC-MRDneg group showed better OS at 2 years 67.0% than the MFC-MRDpos group 40.7% (p We divided the groups according to the number of induction treatment courses, AML type, cytogenetics risk, and age ( Also, we evaluated MFC-MRD status at CR by mutational profile subgroup. Long-term outcomes such as OS, RFS, CIR or NRM were compared by the mutational subgroup. It consistently showed a trend of superior OS, RFS and lower risk of CIR in patients with MFC-MRDneg compared to MFC-MRDposTab1. Of interest, in the subgroup of patients carrying any DTA mutations (n=221), those with MFC-MRDneg (n=103) showed better OS (HR 1.61 [1.01-2.55%]; p=0.042), RFS (HR 1.66 [1.06-2.61%]; p=0.026) and CIR (HR 1.99[1.03-3.83%]; p=0.04) compared to those MFC-MRDpos (n=64; Fig 1). Multivariate analysis confirmed that the MFC-MRDneg is an independent prognostic factor in patients with DTAmutwith respect to OS: MFC-MRDpos (HR 1.63, p=0.04) and age (≥60; HR 2.04, p=0.008) for OS; for RFS, MFC-MRDpos (HR 1.71, p=0.02) and age (≥60; HR 2.32, p= 0.001); for CIR, MFC-MRDpos (HR 2.31, p=0.01) and HCT (HR 0.14, p= Conclusion: These findings suggest that in AML patients with DTAmut, MFC-MRD status at the time of remission assessment can be a tool for MRD assessment when NGS-based MRD assessment is limited. Further study is strongly warranted to reach a clearer conclusion with multiple cohorts. Disclosures Schimmer: Takeda: Honoraria, Research Funding; Novartis: Honoraria; Jazz: Honoraria; Otsuka: Honoraria; Medivir AB: Research Funding; AbbVie Pharmaceuticals: Other: owns stock . Tierens:Amgen: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Astellas Pharma: Membership on an entity's Board of Directors or advisory committees. McNamara:Novartis: Honoraria. Maze:Pfizer: Consultancy; Novartis: Honoraria; Takeda: Research Funding. Gupta:Pfizer: Consultancy; Bristol MyersSquibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sierra Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Research Funding.

Introduction: Acute myeloid leukemia (AML) is driven by a subpopulation of leukemia stem cells (LSCs), which possess properties such as quiescence and self-renewal that are linked to therapy resistance and relapse. The LSC17 score was derived from genes differentially expressed between functionally validated LSC+ and LSC- fractions from 78 AML patients and is strongly associated with survival and response to standard therapy. A critical advantage of the LSC17 test over cytogenetic and molecular analysis is its rapid turnaround time (24-48h on a NanoString platform), providing clinicians with a rapid and powerful tool for upfront risk stratification. We have developed a clinical assay for the LSC17 score validated in a CAP/CLIA-lab setting. Methods: We conducted a prospective, multicenter validation and feasibility study to test the prognostic value of the LSC17 assay under real-world conditions in AML patients treated with curative intent. Patients with a possible new diagnosis of AML were eligible. Patients with a confirmed diagnosis of acute promyelocytic leukemia were excluded from analysis. Standard prognostic markers including cytogenetics, molecular studies and targeted sequencing using a standard AML panel were performed in parallel to the LSC17 score. Treatment was administered according to physician preference, based on patient history and results of standard prognostic assays, when available. Survival data was censored on June 14th, 2020. Results: 381 patients were recruited to the study between June 2016 and March 2020. 4 patients were excluded for quality control reasons (one sample had insufficient RNA and three samples failed quality control checks). 103 were excluded as they had alternative diagnoses. 84 patients were excluded because they did not receive intensive chemotherapy. LSC17 scores ranged from 0 to 1.25, and were classified as high or low according to the median score of 0.51 from a previously validated reference cohort (Ng et al, Nature 2016). Of the 190 patients included in this analysis, 84 had a low LSC17 score and 106 had a high LSC17 score. The median age was 61 years (range 18-79); 86 (45%) were female. When stratified according to ELN 2017 criteria, 48 (27%), 51 (29%), and 77 (44%) patients had favorable, intermediate, and adverse risk disease, respectively. Low LSC17 score was associated with normal cytogenetics (high vs low, 33% vs 58%; P We first considered response to induction chemotherapy (Table 1). 141 patients had standard induction chemotherapy with 3+7, 40 had Flag-IDA and 9 had CPX-351. High score patients had inferior responses to 3+7 with only 59% achieving complete remission (CR) after 1 cycle of chemotherapy compared to 96% of low score patients; responses for LSC17 high score patients were better in the Flag-IDA group with 80% achieving CR after 1 cycle. When considering overall CR rates after 2 cycles of induction, patients with a high LSC17 score were less likely to achieve CR (high vs low, 87% vs 98%; P=0.02). However, this difference was predominantly observed in patients treated with 3+7 (87% vs 99% CR rate in high vs low score patients, respectively); response rates to Flag-IDA were not significantly different between the 2 groups. Measurable residual disease (MRD) monitoring by flow cytometry was performed at the time of CR in 135 (71%) patients enrolled at Princess Margaret Cancer Centre. Patients with a high LSC17 score were significantly more likely to have MRD compared to low score patients (46% vs 10% respectively, P Conclusion: AML patients with a high LSC17 score have inferior outcomes following 3+7 induction chemotherapy. The LSC17 score should be considered as a tool to identify and stratify high-risk patients to alternative upfront therapies such as Flag-IDA. A risk adapted study is planned to validate these results. Disclosures Gupta: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sierra Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy; Bristol MyersSquibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Research Funding. Maze:Novartis: Honoraria; Takeda: Research Funding; Pfizer: Consultancy. McNamara:Novartis: Honoraria. Schimmer:Medivir AB: Research Funding; AbbVie Pharmaceuticals: Other: owns stock ; Takeda: Honoraria, Research Funding; Novartis: Honoraria; Jazz: Honoraria; Otsuka: Honoraria. Leber:Takeda/Palladin: Honoraria, Membership on an entity's Board of Directors or advisory committees; Treadwell: 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, Speakers Bureau; BMS/Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Otsuka Pharmaceutical: Honoraria, Membership on an entity's Board of Directors or advisory committees; Lundbeck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Alexion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Tierens:Amgen: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Astellas Pharma: Membership on an entity's Board of Directors or advisory committees. Wang:Trilium therapeutics: Patents & Royalties: There is an existing license agreement between TTI and University Health Network and J.C.Y.W. may be entitled to receive financial benefits further to this license and in accordance with UHN's intellectual property policies. .

Background and objectives: CPX-351 is a liposomal formulation of daunorubicin and cytarabine in a fixed synergistic ratio of 5:1. It has been approved by both the FDA and EMA for use in high risk AML including therapy related AML (t-AML) and AML with myelodysplastic related change (AML-MRC). When compared with '3+7', CPX-351 resulted in superior OS (9.56 vs 5.96 months) and overall response rate (47.7% v 33.3%; P = .016; Lancet JCO 2018). However, this is little data of CPX-351 in a real world setting. The primary objective of our multi-centre study was to assess outcomes and associated toxicities of CPX-351 in these high risk AML patients. Methods: Patients aged 18 and over who were treated with CPX-351 and who met the WHO criteria for t-AML and AML-MRC were included in the study. Retrospective data was collected from 6 centres throughout Canada. Targeted sequencing was performed on DNA samples using the TruSight Myeloid Sequencing Panel isolated from peripheral blood or bone marrow samples at diagnosis. Overall survival (OS) and progression free survival (PFS) rates were calculated using the Kaplan-Meier method. Results: Fifty patients treated with CPX-351 were identified from six centres. Baseline characteristics are seen in Table 1. Cytogenetics was available in 45 (90%) patients and an abnormal karyotype was seen in 30 (60%) patients. Monosomal (33%) and complex (28%) karyotype were the most common chromosomal abnormalities seen. Targeted sequencing was performed on 64% patients (32/50) and the average number of mutations was 2(0-7). RUNX1 was the most commonly mutated gene found in 22% (7/32), followed by SRSF2 in 19% (6/32) with ASXL1 and NRAS both at 16% (5/32). Other commonly mutated genes were NPM1, IDH2, DNMT3a and TP53 all occurred at a frequency of 12% (4/32). Of the 10 patients (20%) that were FLT3 mutated (80% ITD and 20% TKD), 5 patients received the FLT3 inhibitor midostaurin in combination with CPX-351. Assessing treatment responses, 50% (25/50) of patients achieved a complete remission (CR) or a complete remission with incomplete recovery (CRi). Median neutrophil recovery (≥500/μl) was 32 days (range 18-68) and median platelet recovery (≥50 000/μl) was 34 days (range 19-70). Proven or probable fungal infection was seen in 10 (20%) patients. 30 day mortality was 4% (2/50) and 60-day mortality was 10% (5/50). The median CR duration was short at 7.17 months. Of the 25 patients who did not achieve a CR, 6 (24%) had prior azacitidine use for MDS suggesting CPX-351 may not have activity in this group of patients. Median follow up was 7.43 months (range 0.2 to 18 months). OS was 44% at 12 months (0.28-0.58 95% CI) and 29% at 18 months (Fig 1; 0.13-0.46 95% CI). PFS was 28% at 12 months (0.15-0.43 95% CI) and 18% at 18 months (0.06-0.39 95% CI). There were no differences in OS when stratified by ELN risk (p=0.25), adverse risk cytogenetics (p=0.1485), or poor risk mutations such as FLT3-ITD (p=0.29), RUNX1 (p=0.123) or ASXL1 (p=0.06). This is consistent with previous studies, which suggest that CPX-351 overcomes the poor prognosis associated with these mutations. 18 (36%) patients received an allogeneic stem cell transplant (ASCT) in CR1. Patients who received a allogeneic transplant had significant improvement of OS of 62% at 18 months compared to those who did not receive a transplant of 14.5% at 18 months (Fig 2; p=0.0008). Conclusion Our study reveals that CPX-351 produces high remission rates in patients with AML with a similar efficacy and toxicity profile seen in the Phase 3 trial data (Lancet JCO 2018). However, response rates are short and therefore CPX-351 is most effective when used as a bridge for allogeneic stem cell transplantation in this high risk population. Disclosures Assouline: AbbVie: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Speakers Bureau; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Speakers Bureau; Takeda: Research Funding; BeiGene: Consultancy, Honoraria, Research Funding. Brandwein:Celgene: Honoraria; Astellas: Honoraria; Taiho: Honoraria; Roche: Honoraria; Jazz Pharmaceuticals: Honoraria; Pfizer: Honoraria; Amgen: Honoraria. Gupta:Sierra Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Honoraria, Research Funding; Bristol MyersSquibb: Honoraria, Membership on an entity's Board of Directors or advisory committees. Maze:Pfizer: Consultancy; Takeda: Research Funding; Novartis: Honoraria. McNamara:Novartis: Honoraria. Sanford:Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees. Schimmer:Medivir AB: Research Funding; AbbVie Pharmaceuticals: Other: owns stock ; Takeda: Honoraria, Research Funding; Novartis: Honoraria; Jazz: Honoraria; Otsuka: Honoraria.

BACKGROUND: In newly diagnosed AML, high remission rates are typically achieved with IC, but the response is often transient, and detectable residual disease in the bone marrow post-chemotherapy is predictive of early relapse. Emerging data show that the identification of ≥ 0.1% MRD by multiparameter flow cytometry (MFC) in patients with AML in remission after IC is an important prognostic marker that may help guide treatment (Tx) decisions. CC-486 is an oral hypomethylating agent that allows for extended dosing schedules to prolong drug exposure over the Tx cycle. In the QUAZAR AML-001 Maintenance Trial, Tx with CC-486 300 mg QD for 14 days/28-day Tx cycle was associated with significantly improved overall (OS) and relapse-free survival (RFS) vs. placebo (PBO) in patients (pts) with AML in first remission after induction chemotherapy ± consolidation. Samples for MFC were obtained prior to randomization and serially throughout the study to assess the impact of MRD on OS and RFS, and to evaluate rates of conversion from MRD positivity (+) to negativity (-) in the CC-486 and PBO arms. METHODS: Eligible pts aged ≥ 55 years with AML were randomized 1:1 to CC-486 300 mg or PBO within 4 months of achieving first complete remission (CR) or CR with incomplete blood count recovery (CRi). MFC assessments of bone marrow aspirates were performed centrally at screening; at cycles 3, 6, 9, 12, 15, 18, 21, 24, 30, and 36; and as clinically indicated. Samples were analyzed with a panel of 22 cell surface markers using an MRD+ cutoff of ≥ 0.1% (per ELN MRD guidelines). For pts MRD+ at baseline (BL; ie, at randomization), an MRD response was defined as achievement of MRD- for ≥ 2 consecutive assessments. MRD- duration was calculated from the time of randomization (for pts MRD- at BL) or from the first of ≥ 2 consecutive MRD- tests (for pts MRD+ at BL), until the last MRD- assessment (for pts who became MRD+) or Tx discontinuation. OS, RFS, and MRD- durations were estimated using Kaplan-Meier methods. Multivariate (MV) Cox regression analyses were performed to evaluate the association of BL MRD status (MRD+ vs. MRD-) and randomized Tx arm (CC-486 vs. PBO) with OS and RFS. RESULTS: The MRD-evaluable cohort comprised 463/472 randomized pts (98.1%; CC-486, n=236; PBO, n=227) who had samples available for evaluation at BL and at ≥ 1 post-BL visit. At BL, 43% of pts (n=103) in the CC-486 arm and 50% (n=116) in the PBO arm were MRD+. Overall, BL characteristics were similar between MRD+ and MRD- pts: median ages were 69 (range 55-84) and 68 (55-86) years, respectively; 84% and 88% had intermediate-risk cytogenetics at diagnosis; 52% and 46% of pts had an ECOG PS of 0; and 79% and 82% received ≥ 1 cycle of consolidation after induction. CC-486 Tx resulted in improved OS from time of randomization compared with PBO in pts who were either MRD+ (median 14.6 vs. 10.4 mo, respectively; HR 0.69 [95%CI 0.51, 0.93]) or MRD- (median 30.1 vs. 24.3 mo; HR 0.81 [0.59, 1.12]) at BL. Median RFS was also extended with CC-486 vs. PBO for both MRD+ (7.1 vs. 2.7 mo, respectively; HR 0.58 [95%CI 0.43, 0.78]) and MRD- pts (13.4 vs. 7.8 mo; HR 0.71 [0.52, 0.98]). In MV analyses, BL MRD status (MRD+ vs. MRD-) was significantly associated with OS (HR 1.85; P < 0.0001) and RFS (HR 2.04; P < 0.0001), and CC-486 showed a significant Tx benefit vs. PBO on both OS (HR 0.74; P = 0.0067) and RFS (HR 0.63; P < 0.0001) independent of MRD status at BL (Figure). The median duration of MRD negativity was extended with CC-486 vs. PBO: 11.0 vs. 5.0 mo, respectively (HR 0.62 [95%CI 0.48, 0.78]). Tx with CC-486 also resulted in a higher rate of MRD response (MRD+ to MRD-) vs. PBO: 37% vs. 19%, respectively. Among MRD responders, 9/38 patients (24%) in the CC-486 arm achieved MRD negativity > 6 mo after randomization, compared with only 1/22 patients (5%) in the PBO arm. CONCLUSIONS: The QUAZAR AML-001 Maintenance Trial was the first prospective, randomized trial to include long-term longitudinal assessment of MRD in older patients with AML in remission. In both treatment arms, MRD+ status (≥ 0.1%) after induction ± consolidation was associated with significantly shorter OS and RFS compared with MRD- status. Approximately one-fourth of MRD responders treated with CC-486 achieved MRD negativity > 6 mo after study entry, suggesting that CC-486 could induce MRD negativity after prolonged MRD+ status. Maintenance Tx with CC-486 substantially improved OS and RFS independent of MRD status at BL. Disclosures Roboz: Otsuka: Consultancy; AstraZeneca: Consultancy; Orsenix: Consultancy; Astellas: Consultancy; Argenx: Consultancy; Actinium: Consultancy; Sandoz: Consultancy; Roche/Genentech: Consultancy; Jazz: Consultancy; Eisai: Consultancy; Celltrion: Consultancy; MEI Pharma: Consultancy; Helsinn: Consultancy; Epizyme: Consultancy; Jasper Therapeutics: Consultancy; Cellectis: Research Funding; Trovagene: Consultancy; Takeda: Consultancy; Astex: Consultancy; Amphivena: Consultancy; Agios: Consultancy; Abbvie: Consultancy; Pfizer: Consultancy; Novartis: Consultancy; Janssen: Consultancy; Celgene: Consultancy; Bayer: Consultancy; Array BioPharma: Consultancy; Daiichi Sankyo: Consultancy. Ravandi:Abbvie: Consultancy, Honoraria, Research Funding; Xencor: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria; Macrogenics: Research Funding; Jazz Pharmaceuticals: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Orsenix: Consultancy, Honoraria, Research Funding. Wei:Pfizer: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding, Speakers Bureau; Janssen: Honoraria; Walter and Eliza Hall Institute of Medical Research: Patents & Royalties: AW is eligible for royalty payments related to venetoclax; Roche: Honoraria; Amgen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding, Speakers Bureau; Abbvie: Honoraria, Research Funding, Speakers Bureau; Servier: Consultancy, Honoraria, Research Funding; Macrogenics: Honoraria; Astra Zeneca: Honoraria, Research Funding. Dombret:Menarini: Consultancy; Janssen: Consultancy; Cellectis: Consultancy; Shire-Baxalta: Consultancy; Immunogen: Consultancy; Otsuka: Consultancy; Abbvie: Consultancy; Astellas: Consultancy; Daiichi Sankyo: Consultancy; Servier: Consultancy, Research Funding; Sunesis: Consultancy; Amgen: Consultancy, Research Funding; Jazz Pharma: Consultancy, Research Funding; Celgene: Consultancy; Nova: Consultancy, Research Funding; Incyte: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding. Döhner:Astex: Consultancy, Honoraria; Astellas: Consultancy, Honoraria, Research Funding; AROG: Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Agios: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria; GEMoaB: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Oxford Biomedicals: Consultancy, Honoraria; Sunesis: Research Funding; Pfizer: Research Funding; Roche: Consultancy, Honoraria; Jazz: Consultancy, Honoraria, Research Funding; Helsinn: Consultancy, Honoraria; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding. Thol:Abbvie: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees. Voso:Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Porkka:Novartis: Consultancy, Honoraria, Research Funding; BMS/Celgene: Honoraria, Research Funding. La Torre:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Skikne:Bristol Myers Squibb: Current Employment. Kumar:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Dong:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Beach:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Risueño:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: Named in BMS (before Celgene) patent filings related to predictive patient response biomarkers in hematological malignancies. Lopes de Menezes:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Ossenkoppele:Novartis: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Roche: Consultancy; J&J: Consultancy, Research Funding; Agios: Consultancy; Jazz: Consultancy; Astellas: Consultancy; Daiichi Sayko: Consultancy; Amgen: Consultancy.

Upfront therapy for newly diagnosed patients with acute myeloid leukemia (AML) includes intensive induction chemotherapy with curative intent, low dose chemotherapy, best supportive care, and clinical trials. The choice between these therapies is influenced by multiple factors including age, cytogenetic and molecular mutations, and performance status. In our single payer provincial health care system, induction chemotherapy and clinical trials are only offered at a small number of specialized quaternary care centers with geographically large catchment areas. As a result, some patients are required to travel long distances for their appointments, which may constitute a barrier to care, especially among elderly patients. We therefore asked whether distance from the quaternary center influences the choice of care for AML. We reviewed the records of patients ≥18 years of age diagnosed with AML from 2015-2017 and assessed at our quaternary care center in Toronto, Canada. We compared upfront therapy choice and survival between patients living close versus distant from the cancer center (empirically defined as 50km) and stratified by age. A total of 675 patients were assessed by our quaternary center for a new diagnosis of AML during the timeframe studied. Of those patients, 477 (71%) patients lived ≤50km, and 198 (29%) patients lived >50km from the quaternary center. The overall median distance from patient residence to the quaternary center was 33.2km (range: 1-1791km), and the median distance of patients in the >50km group was 93km (range: 50.2-1791km). Age, sex, baseline Eastern Cooperative Oncology Group Performance Status (ECOG), and cytogenetic risk were not significantly different between the two groups. There were no differences in the proportion of patients receiving induction chemotherapy or clinical trial as upfront therapy between patients living close versus distant from the quaternary center, even when stratified for age ≥70 years. There was no difference in overall survival between patients living ≤50km versus >50km from the quaternary center either overall, or when stratified by age. In conclusion, geographic distance from treatment center does not appear to impact choice of upfront therapy, access to clinical trials, or clinical outcomes in this study of newly diagnosed patients with AML treated in a single payer environment. Disclosures Gupta: Bristol MyersSquibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Honoraria, Research Funding; Pfizer: Consultancy; Sierra Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees. Maze:Novartis: Honoraria; Pfizer: Consultancy; Takeda: Research Funding. McNamara:Novartis: Honoraria. Schimmer:Takeda: Honoraria, Research Funding; Novartis: Honoraria; Jazz: Honoraria; Otsuka: Honoraria; Medivir AB: Research Funding; AbbVie Pharmaceuticals: Other: owns stock .

Outcomes for adults with relapsed/refractory acute lymphoblastic leukemia (ALL) are poor with chemotherapy, particularly in later salvage. The TOWER study examined survival, remission, bridge to allogeneic hematopoietic stem cell transplantation (HSCT), and safety with blinatumomab versus chemotherapy. This report examined outcomes separately for study treatment as first or later salvage. Adults with Philadelphia chromosome-negative B-cell precursor ALL relapsed/refractory to chemotherapy were randomly assigned 2:1 to receive blinatumomab by continuous infusion for 4 weeks in 6-week cycles, or standard salvage chemotherapy. Overall survival for blinatumomab versus chemotherapy was higher both in first salvage and in later salvage. Safety was similar between patients in first salvage and those in later salvage. Blinatumomab as later salvage was associated with higher complete remission rates and served as a bridge to allogeneic HSCT, supporting the use of blinatumomab in both settings. This study is registered at www.clinicaltrials.gov as #NCT02013167.

7018 Background: In the phase 3 VIALE-A trial, rates of composite complete remission (CRc; complete remission [CR] + CR with incomplete hematologic recovery [CRi]) and measurable residual disease response (MRD-3) were higher in patients (pts) treated with venetoclax (Ven) + azacitidine (Aza) compared to Aza alone (23.4%/7.6%, p-3 in the VIALE-A trial (NCT02993523). Methods: Enrolled pts were ≥18 years and unfit for intensive chemotherapy. Pts received Ven 400 mg orally; days 1–28 and Aza 75 mg/m2; days 1-7/28-day cycle. Bone marrow aspirate samples for multiparametric flow cytometry assessments by integrated leukemia-associated immunophenotypes and different than normal procedures were collected for central analysis (Covance Central Laboratory Services) at baseline, end of cycle 1, and every 3 cycles thereafter. Assessments were performed independent of disease responses. MRD response was defined as -3). CRc, DoR, OS, and EFS were assessed. Disease assessments were per modified International Working Group response criteria for AML. Results: 211/286 (74%) pts treated with Ven+Aza with at least one valid post-baseline MRD assessment were considered MRD evaluable; 78/211 (37%) achieved MRD-3 and 133/211 (63%) had MRD≥10-3. Median age (MRD-3/ MRD≥10-3) was 76 (range: 49-89)/77 (58-91) yrs. Pts (MRD-3/ MRD≥10-3) received median of 14.5 (range: 1-28) /7.0 (1-30) cycles of Ven+Aza. At median follow-up of 22.0 (range: 20.1-23.0)/20.8 (19.8-22.3) months (mos), CRc + MRD-3/ MRD≥10-3 was achieved by 67 (86%)/ 97 (73%); 20/67 (30%) achieved CRc + MRD-3 by end of cycle 1. Median DoR, OS, and EFS were not reached in pts with CRc + MRD-3 response (Table). The 12-mo estimates for DoR, OS, and EFS for pts with CRc + MRD-3response were 81.2%, 94.0%, and 83.2%, respectively. Adverse events ≥grade 3 (MRD-3/ MRD≥10-3) were febrile neutropenia (50%/43%), neutropenia (50%/35%), and thrombocytopenia (44%/44%), similar to the overall population. Conclusions: Pts with best response of CRc who achieved MRD-3 response with Ven+Aza treatment had longer DoR, OS, and EFS than pts who were CRc and MRD positive. Clinical trial information: NCT02993523. [Table: see text]

7011 Background: Patients (pts) with therapy-related myeloid neoplasms (tMN), antecedent myelodysplastic syndrome, or antecedent myelodysplastic/myeloproliferative neoplasms (A-MDS/MPN) may have poor outcomes due to age and adverse genetic/karyotypic features. In the VIALE-A study, pts with tMN and A-MDS/MPN unfit for intensive chemotherapy treated with venetoclax (Ven) and azacitidine (Aza) demonstrated superior response rates and overall survival (OS) than Aza alone. Herein, the efficacy and safety of Ven+Aza among pts with tMN and A-MDS/MPN are described. Methods: Data were pooled from pts enrolled in VIALE-A (NCT02993523) comparing pts who received Ven+Aza or placebo (Pbo)+Aza and a prior phase 1b study (NCT02203773) where pts received Ven+Aza. Enrolled pts were ≥18 years, treatment-naïve with no prior exposure to hypomethylating agents, and ineligible for intensive chemotherapy. Pts on Ven+Aza received Ven 400 mg orally (days 1–28) and Aza (75 mg/m2; days 1-7/28-day cycle). Composite complete remission rate (CRc; complete remission [CR] + CR with incomplete hematologic recovery [CRi]), duration of response (DoR), and OS were assessed. Disease assessments were per modified International Working Group response criteria for AML. Results: In this pooled analysis, tMN was observed in (Ven+Aza/Pbo+Aza) 31/9 and A-MDS/MPN in 59/26 pts. Poor-risk cytogenetics were observed in 18 (58%)/6 (67%) with tMN (5 or 5q deletion [del]: 4/1 ; 7 or 7q del: 6/1 ; complex [≥ 3 clonal abnormalities]: 10/4), and 19 (32%)/13 (50%) with A-MDS/MPN (5 or 5q del: 10/5; 7 or 7q del: 6/1; complex: 14/9). TP53 mutation was observed in 5/3 pts with tMN and 8/0 pts with A-MDS/MPN. Pts with tMN received a median (Ven+Aza/Pbo+Aza) of 5/4 cycles of treatment. CRc was achieved by 19 (61%)/1 (11%). The mDoR was not reached (NR) (95% CI: 17.8, NR)/8.5 (NR, NR) months. The mOS was 16.4 (95% CI: 4.1, NR)/11.3 (0.6, 17.5) months. Pts with A-MDS/MPN received a median (Ven+Aza/Pbo+Aza) of 9/5 cycles of treatment. CRc was achieved by 39 (66%)/7 (27%) pts with mDoR of 17.3 (95% CI: 9.6, NR)/5.8 (1.1, NR) mos. The mOS was 15.9 (95% CI: 11.5, NR)/10.1 (4.7, 14.5) mos. Common grade≥3 adverse events (Ven+Aza/Pbo+Aza) were febrile neutropenia (tMN: 39%/11% and A-MDS/MPN: 36%/12%) neutropenia (tMN: 29%/33%; A-MDS/MPN: 39%31%), and thrombocytopenia (tMN: 32%/33%; A-MDS/MPN: 39%/62%). Conclusions: Ven+Aza compared to Aza monotherapy resulted in higher CRc rates with longer DoR and median OS among treatment-naïve pts with tMN and A-MDS/MPN ineligible for intensive chemotherapy. The safety profile was similar to overall pts with the Ven+Aza combination. Outcomes by cytogenetic and molecular risk-groups will be presented. Clinical trial information: NCT02993523, NCT02203773.

We analyzed the outcome of 80 sequential patients with core binding factor acute myeloid leukemia and evaluated the influence of molecular monitoring by quantitative reverse transcriptase polymerase chain reaction. With a median follow-up of 5 years, the estimated 5-year relapse-free survival and overall survival were 58% and 66%, respectively. Patients who were in molecular remission at the completion of consolidation chemotherapy had a 21% risk of relapse, while the relapse risk for those in molecular remission at the end of 2 years was 5.5%. Our data indicate that postconsolidation molecular remission does not necessarily preclude disease relapse and further monitoring is required. In contrast, molecular negativity by quantitative reverse transcriptase polymerase chain reaction at the end of 2 years is associated with a low risk of relapse.

Few studies describe the comprehensive immunophenotypic pattern of blastic plasmacytoid dendritic cell neoplasm (BPDCN) in the bone marrow and its treatment. This retrospective analysis evaluates the diagnostic flow cytometry (FCM) pattern and outcome of nine patients diagnosed with BPDCN. A four-tube 10-color FCM panel used for diagnosis of acute leukemia (AL), showed cells in the blast gate (CD45dim/low SSC) and were positive for CD4(bright), CD33(dim), CD56(heterogenous), CD123(bright), CD36, CD38, HLA-DR, CD71. Seven patients received front-line induction therapy with HyperCVAD with an overall response rate of 86%. Five of six responders underwent planned allogeneic hematopoietic cell transplantation (allo-HCT). For a median follow up of 13.3 months, the 1-year disease free survival and overall survival were 56 and 67%, respectively. An accurate diagnosis of BPDCN can be made by 10-color FCM using a four-tube AL panel demonstrating a characteristic pattern of antigen expression. Front-line induction chemotherapy with HyperCVAD can yield high remission rates, but allo-HCT is required for long-term durable remissions.

Aims We evaluated efficacy of Azacitidine (AZA)+Venetoclax (VEN) combination vs. AZA+Placebo (PBO) in treatment-naive patients with acute myeloid leukemia (AML) ineligible for intensive therapy. Methods This phase 3, randomized, double-blinded, multicenter, placebo-controlled study included AML patients ineligible for intensive induction therapy due to medical comorbidities and/or age > 75 years. Patients were randomized 2:1 to either AZA+VEN(AZA: 75 mg/m2 subcutaneous or intravenous, days [d] 1-7 per 28-day cycle; VEN: 400 mg orally QD, d1-28 with 3-day ramp up in cycle 1) or AZA+PBO (PBO: orally QD, d1–28). Primary endpoint was overall survival (OS). Secondary endpoints were rates of: composite complete remission [complete remission (CR) + CR with incomplete count recovery (CRi)], CR+CRi by initiation of cycle 2, CR, transfusion independence, CR+CRi and OS by molecular subgroups, and event-free survival (EFS). A sample size of 400 was estimated to detect a hazard ratio (HR) of 0.7 in OS with 2-sided alpha of 4% and power of 87%. OS and EFS were analyzed by the Kaplan-Meier method and compared between arms using the log-rank test stratified by age (18 to Results As of 01/04/2020, 431 patients (median age 76 years, range 49-91) were randomized to AZA+VEN (n=286) or AZA+PBO (n=145). With median follow-up of 20.5 months (mos), median OS was 14.7 mos in AZA+VEN and 9.6 in AZA+PBO (HR: 0.66, 95% CI: 0.52–0.85, p Conclusions Among treatment-naive predominantly elderly patients with AML ineligible for intensive therapy, combination AZA+VEN showed statistically significant and clinically meaningful improvement in response rates and OS vs AZA, with a manageable safety profile. Abstract was previously published at EHA25.

7513 Background: A goal of AML maintenance therapy is to decrease the risk of relapse by suppressing growth of residual leukemic cells post-induction. CC-486 is an oral hypomethylating agent that allows for extended dosing schedules ( >7 days [d]/28d cycle) to sustain therapeutic activity. In the QUAZAR AML-001 trial (NCT01757535), CC-486 maintenance treatment (Tx) significantly prolonged overall (OS) and relapse-free survival vs. placebo (PBO) in pts with AML in first remission following induction chemotherapy (IC), who were not candidates for hematopoietic stem cell transplant (HSCT). Pts initially received CC-486 or PBO for 14d/cycle, but pts who relapsed with 5–15% blasts could receive escalated 21d/cycle dosing. We review outcomes of pts who received 21d dosing in QUAZAR AML-001. Methods: Pts were aged ≥ 55 years, with intermediate- or poor-risk cytogenetics and ECOG PS ≤ 3, and had achieved first CR/CRi after IC ± consolidation. Within 4 mo of CR/CRi, pts were randomized 1:1 to CC-486 300 mg or PBO QD on d 1–14 of 28d Tx cycles. CR/CRi status was assessed every 3 cycles. Pts relapsing with 5%–15% blasts in blood or bone marrow could receive study drug for 21d/cycle at the investigator’s discretion. Tx could continue until > 15% blasts, unacceptable toxicity, or HSCT. Results: 91 patients (CC-486, 51/238 [21%]; PBO, 40/234 [17%]) were assigned to ≥ 1 21d/cycle dosing schedule. Median time to dose escalation was 9.2 mo (range 1.0-52.7) for CC-486 and 6.0 mo (0.5-19.3) for PBO. Median number of 21d dosing cycles was 2.0 (range 1-45) in the CC-486 arm and 2.0 (1-16) in the PBO arm; 43% and 18% of pts, respectively, received > 3 cycles of 21d dosing. Among 78 evaluable pts, 10/43 (23%) CC-486 pts and 4/35 (11%) PBO pts regained CR/CRi (central review) during dose escalation. Median OS from randomization was 22.8 mo vs. 14.6 mo with CC-486 vs. PBO, respectively (HR 0.66 [95%CI 0.42, 1.0]; P = 0.073), and 1-year survival rates were 80.4% vs. 59.5% (+20.9% [95%CI 2.1%, 39.7%]). The most common AEs with first onset during 21d dosing were febrile neutropenia (CC-486 24%, PBO 3%), thrombocytopenia (22%, 23%), anemia (22%, 20%), and neutropenia (20%, 10%). Conclusions: Escalated 21d CC-486 dosing was well tolerated and resulted in prolongation of OS and restoration of remission in approximately one-fourth of pts. Hematologic AEs first reported during escalated dosing in both Tx arms may be due in part to disease relapse. A 21d dosing schedule should be considered for pts receiving CC-486 who experience relapse with 5–15% blasts. Clinical trial information: NCT01757535 .

7501 Background: ENA and AZA each induce overall response rates (ORR) of ~30% and complete remission (CR) rates of ~20% in ND-AML. In vitro, combining ENA + AZA enhances cell differentiation. We report results of the phase II portion of an open-label, randomized phase I/II study of ENA + AZA (“E+A”) vs. AZA monotherapy (“A”) in patients (pts) with m IDH2 ND-AML (NCT02677922). Methods: Pts age ≥ 18 years ineligible for intensive chemotherapy, with ECOG PS ≤ 2 and intermediate- or poor-risk cytogenetics, were randomized 2:1 to E+A or A in 28-day (d) cycles. All pts received SC AZA 75 mg/m2/d x 7 d/cycle; pts randomized to E+A also received ENA 100 mg QD. The primary endpoint was ORR (CR, CR with incomplete recovery, partial remission, morphologic leukemia-free state). Other endpoints include duration of response (DOR), overall and event-free survival (OS, EFS), safety, and m IDH2 VAF. Results: 101 pts received E+A (n = 68) or A (n = 33). Median age was 75 years (57–85); most pts (83%) had intermediate-risk cytogenetics. 21 pts in the E+A arm and 1 in the A arm were ongoing at data cutoff (Aug 2019). Most common reason for discontinuation was disease progression (E+A 31%, A 52%). Median number Tx cycles was 10 (1–26) in the E+A arm and 6 (1–28) in the A arm. 7 pts (21%) in the A arm received subsequent Tx with ENA. ORR, CR rate and DOR were significantly improved with E+A vs. A (Table). Median OS was 22 mo in both arms (HR 0.99 [95%CI 0.52, 1.87]; P = 0.97). Median EFS was 17.2 and 10.8 mo in the E+A and A arms, respectively (HR 0.59 [95%CI 0.30, 1.17]; P = 0.13). Maximal m IDH2 VAF change from BL was –83.4% with E+A vs. –17.7% with A ( P < 0.01). No baseline co-mutation predicted primary resistance. Common Tx-related grade 3–4 AEs in the E+A arm were thrombocytopenia (37%), neutropenia (35%), anemia (19%), and febrile neutropenia (15%); these occurred in 19%, 22%, 22%, and 16% in the A arm. Grade 3–4 infections occurred in 18% of E+A pts and 31% of A pts. IDH differentiation syndrome occurred in 12 pts (18%) in the E+A arm. 5 E+A pts (7%) and 1 A pt (3%) died in the first 60 d. Conclusions: Combining ENA + AZA resulted in significantly improved response rates and durations, and was generally well-tolerated in older patients with m IDH2 ND-AML. The impact of subsequent Tx on OS/EFS and new translational data will be presented at the meeting. Clinical trial information: NCT02677922 . [Table: see text]

Clonal hematopoiesis (CH) is a novel shared risk factor for acute myeloid leukemia (AML) and cardiovascular events (CVEs). Our objective was to determine whether: 1) CH-associated mutations in patients with AML are independently associated with CVEs, and 2) CVE and CH-related mutations are

Aplastic anaemia (AA) is infrequently observed in pregnancy. We describe 19 pregnancies in 9 women at a tertiary care centre over a period of 30 years. Spontaneous resolution of AA did not occur postpartum in the five pregnancies where AA was first diagnosed in pregnancy. In the remaining pregnancies, although haematological indices declined and transfusion support was needed in 35% of pregnancies, relapses were not observed. There were no deaths, but complications occurred in 79% of pregnancies. Preterm delivery and postpartum haemorrhage were observed in 21% and 26% of pregnancies, respectively.

In the phase 3 TOWER study, blinatumomab significantly improved overall survival in adults with relapsed or refractory (R/R) Philadelphia chromosome-negative (Ph-) B-cell precursor acute lymphoblastic leukemia (BCP-ALL) relative to standard-of-care chemotherapy. A secondary objective of this study was to assess the impact of blinatumomab on health-related quality of life (HRQL) as measured by the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30). This analysis included the 342 of 405 randomized patients for whom baseline and ≥1 postbaseline result were available in any EORTC multi-item scale or single-item measure. In general, patients receiving blinatumomab (n = 247) reported better posttreatment HRQL across all QLQ-C30 subscales, based on descriptive mean change from baseline, than did those receiving chemotherapy (n = 95). The hazard ratios for time to deterioration (TTD) of ≥10 points from baseline in HRQL or death ranged from 0.42 to 0.81 in favor of blinatumomab, with the upper bounds of the 95% confidence interval

Supplemental Digital Content is available in the text, Although next-generation sequencing (NGS) has helped characterize the complex genomic landscape of myeloid malignancies, its clinical utility remains undefined. This has resulted in variable funding for NGS testing, limiting its accessibility. At our center, targeted sequencing (TAR-SEQ) using a 54-gene NGS myeloid panel is offered to all new patients referred for myeloid malignancies, as part of a prospective observational study. Here, we evaluated the diagnostic, prognostic, and potential therapeutic utility of clinical grade TAR-SEQ in the routine workflow of 179 patients with myeloproliferative neoplasms (MPN). Of 13 patients with triple negative (TN) MPN, who lacked driver mutations in JAK2, CALR, and MPL, TAR-SEQ confirmed clonal hematopoiesis in 8 patients. In patients with intermediate-risk myelofibrosis (MF), TAR-SEQ helped optimize clinical decisions in hematopoietic cell transplant (HCT)-eligible patients through identifying a high molecular risk (HMR) mutation profile. The presence of an HMR profile favored HCT in 9 patients with intermediate-1 risk MF. Absence of an HMR profile resulted in a delayed HCT strategy in 10 patients with intermediate-2 risk MF, 7 of which were stable at the last follow-up. Finally, TAR-SEQ identified patients with various targetable mutations in IDH1/2 (4%), spliceosome genes (28%), and EZH2 (7%). Some of these patients can be potential candidates for future targeted therapy trials. In conclusion, we have demonstrated that TAR-SEQ improves the characterization of TN MPN, can be integrated in clinical practice as an additional tool to refine decision making in HCT, and has the potential to identify candidates for future targeted therapy trials.

There is a paucity of data regarding the impact of mutations on outcomes in accelerated-phase (AP) and blast-phase (BP) myeloproliferative neoplasms (MPNs). Moreover, it is unknown whether mutational status affects survival, as seen in chronic-phase MPNs. Therefore, we performed a retrospective analysis of all patients treated at our institution with AP/BP MPNs (N = 122; AP = 14; BP = 108) to comprehensively describe the mutational profile and correlate with clinical outcomes. Targeted sequencing with a 54-gene panel was performed. Forty-four patients were treated with intensive therapy, 27 with nonintensive therapy, and 51 with best supportive care (BSC). The most common mutation was JAK2V617F, occurring in 55% of subjects; CALR was found in 13% of patients and MPL in 6%. Thirty-two (26%) patients were triple negative. Other frequently mutated genes were ASXL1 (30%), TET2 (25%), SRSF2 (22%), RUNX1 (20%), and TP53 (17%). Mutations in 1, 2, 3, and ≥4 genes were seen in 15%, 13%, 25%, and 46% of patients, respectively. There was no difference in survival between patients treated with intensive vs nonintensive therapy, and the benefit of intensive therapy was limited to patients who were able to undergo transplantation. TP53 was the only individual mutation to correlate with shorter overall survival (hazard ratio, 1.89; P = .03). In the multivariate analysis, mutated TP53, ≥4 mutations, low albumin, increased peripheral blood blasts, ≥3 cytogenetic abnormalities, and BSC were associated with shorter survival. In conclusion, mutational data enhance the understanding of patients with AP/BP MPN who are likely to benefit from current therapeutic options.

Despite the widespread use of 5-HT3 antagonists as anti-emetic prophylaxis in patients with acute myeloid leukemia (AML) receiving induction chemotherapy, nausea and vomiting persist in many cases. We performed a Phase II single-arm study evaluating the use of aprepitant on days 1–5, in combination with a 5-HT antagonist on days 1–3, in AML patients undergoing induction chemotherapy with daunorubicin on days 1–3 plus cytarabine, given as a continuous infusion, on days 1–7. This was compared to a retrospective cohort of AML patients that received the same chemotherapy regimen with a 5-HT antagonist but without aprepitant. The cumulative incidence of vomiting/retching by the end of day 5 was significantly lower in the aprepitant vs. the control group (26.3 vs. 52.8%, p = 0.013). The cumulative incidence of nausea by the end of day 5 was 61% in the aprepitant group vs. 75% in the control group. The total use of supplemental anti-emetics on days 2–5 was also significantly lower in the aprepitant group (p = 0.01). In contrast, the cumulative incidence of vomiting/retching by the end of day 8, the incidence of vomiting/retching on days 6–8, and the use of anti-emetics on days 6–8, were not significantly different between the two groups. The results suggest that the use of aprepitant may be associated with a lower rate of emesis during aprepitant dosing days, but not afterward. However, this requires confirmation in a randomized trial.

We evaluated outcomes of 100 patients with high risk AML treated with Ida-FLAG induction as first-line therapy. 72 achieved remission with one cycle; 19 did not. High risk cytogenetics and TP53 mutations were associated with failure to achieve remission. In those reaching remission, allogeneic bone marrow transplantation was associated with better relapse-free and overall survival. Those not achieving remission with induction therapy were extremely unlikely to reach remission with further therapy and had a dismal prognosis. Exploratory molecular analysis confirmed persistence of the dominant genetic mutations identified at diagnosis. Ex vivo chemosensitivity did not demonstrate significant differences between responders and non-responders. Thus, Ida-FLAG induction has a high chance of inducing remission in patients with high risk AML. Those achieving remission require allogeneic transplantation to achieve cure; those not achieving remission rarely respond to salvage chemotherapy and have a dismal outcome. Alternatives to conventional chemotherapy must be considered in this group.

Background In the phase 3 TOWER study, patients with relapsed or refractory (r/r) Ph– B-cell precursor (BCP) acute lymphoblastic leukemia (ALL) who received blinatumomab had longer overall survival and improved health-related quality of life (HRQoL) versus patients who received standard of care chemotherapy (SOC). Because ALL patients who relapse from previous hematopoietic stem cell transplantation (HSCT) have poorer prognosis, we analyzed the HRQoL of TOWER patients with or without prior allogeneic HSCT (alloHSCT). Methods Adults (n=405) with r/r Ph– BCP ALL were randomized 2:1 to 2 cycles of induction blinatumomab (n=271) or SOC (n=134), followed by up to 3 consolidation cycles; 12 months of maintenance was allowed. AlloHSCT was allowed after cycle 1. HRQoL was assessed in cycle 1 (days 8, 15, and 29) using the EORTC QLQ-C30 Questionnaire. For global health status and functioning scales, a higher score indicates better HRQoL; for symptom scales/items, a lower score indicates better HRQoL. Time to deterioration analyses assessed the treatment effect based on a 10-point deterioration (clinically significant threshold) from baseline. Results Of 342 evaluable patients (blinatumomab, n=247; SOC, n=95); 114 (blinatumomab, n=85; SOC, n=29) and 228 (blinatumomab, n=162; SOC, n=66) did and did not, respectively, have prior alloHSCT. In those with no prior alloHSCT, changes in global health status were minimal for blinatumomab and SOC (Figure 1). In contrast, in patients with prior alloHSCT, global health status modestly improved in the blinatumomab group but worsened by ≥10 points at all time points for SOC, indicating clinically meaningful deterioration. Changes in functioning scales were minimal in the blinatumomab arm, both with or without prior alloHSCT, except for relatively improved emotional scores in patients with prior alloHSCT. In contrast, SOC patients had worsening in most functioning scales, regardless of prior alloHSCT status. This effect was most marked in those with prior alloHSCT, in whom physical, role, and social functioning deteriorated by ≥10 points. Similar patterns were observed for symptom scales/items: while blinatumomab was associated with improved or less worsening in symptom scores versus SOC, most symptom scores worsened in the SOC arm, especially in patients with prior alloHSCT, for whom all symptoms (except dyspnea) deteriorated by ≥10 points. Compared with SOC, blinatumomab was associated with a delayed time to clinically meaningful deterioration, particularly in patents with prior alloHSCT (Figure 2). Conclusions In patients with r/r Ph– BCP ALL, blinatumomab was associated with improved HRQoL compared with SOC, regardless of whether patients had received prior alloHSCT. Notably, however, the HRQoL benefit of blinatumomab was most pronounced among patients with prior alloHSCT.

[Background] Compared with World Health Organization-defined acute myeloid leukaemia (AML) not otherwise specified, patients with AML with myelodysplasia-related changes (AML-MRC) are generally older and more likely to have poor-risk cytogenetics, leading to poor response and prognosis. More than one-half of all older (≥65 years) patients in the phase 3 AZA-AML-001 trial had newly diagnosed AML-MRC., [Methods] We compared clinical outcomes for patients with AML-MRC treated with azacitidine or conventional care regimens (CCR; induction chemotherapy, low-dose cytarabine, or supportive care only) overall and within patient subgroups defined by cytogenetic risk (intermediate or poor) and age (65–74 years or ≥75 years). The same analyses were used to compare azacitidine with low-dose cytarabine in patients who had been preselected to low-dose cytarabine before they were randomized to receive azacitidine or CCR (ie, low-dose cytarabine)., [Results] Median overall survival was significantly prolonged with azacitidine (n = 129) versus CCR (n = 133): 8.9 versus 4.9 months (hazard ratio 0.74, [95%CI 0.57, 0.97]). Among patients with intermediate-risk cytogenetics, median overall survival with azacitidine was 16.4 months, and with CCR was 8.9 months (hazard ratio 0.73 [95%CI 0.48, 1.10]). Median overall survival was significantly improved for patients ages 65–74 years treated with azacitidine compared with those who received CCR (14.2 versus 7.3 months, respectively; hazard ratio 0.64 [95%CI 0.42, 0.97]). Within the subgroup of patients preselected to low-dose cytarabine before randomization, median overall survival with azacitidine was 9.5 months versus 4.6 months with low-dose cytarabine (hazard ratio 0.77 [95%CI 0.55, 1.09]). Within the low-dose cytarabine preselection group, patients with intermediate-risk cytogenetics who received azacitidine had a median overall survival of 14.1 months versus 6.4 months with low-dose cytarabine, and patients aged 65–74 years had median survival of 14.9 months versus 5.2 months, respectively. Overall response rates were similar with azacitidine and CCR (24.8% and 17.3%, respectively), but higher with azacitidine versus low-dose cytarabine (27.2% and 13.9%). Adverse events were generally comparable between the treatment arms., [Conclusions] Azacitidine may be the preferred treatment for patients with AML-MRC who are not candidates for intensive chemotherapy, particularly patients ages 65–74 years and those with intermediate-risk cytogenetics., [Trial registration] This study was registered at clinicalTrials.gov on February 16, 2010 (NCT01074047)., This study was funded by Celgene Corporation.