ALBERT

Description: Background. Cytogenetically normal acute myeloid leukaemia (CN-AML) occurs in 50% adult AML and is a group of diseases with diverse mutations and distinct clinical outcome. CEBPα, NPM1 and FLT3 mutations that are commonly seen in CN-AML have been incorporated into risk stratification. However, prognostic impacts of other gene mutations and their combinations in this AML subtype have remained unclear. In this study, we examined a cohort of young adults with de novo CN-AML who have received uniform treatment protocol in Hong Kong and identified a mutation pentad that might define their clinical outcome. Methodology. Young adults (18-60 years old) with de novo CN-AML, diagnosed from 1st August 2003 to 7th August 2018 in 8 regional hospitals in Hong Kong, were included. They received standard "7+3" induction (Daunorubicin 60-90 mg/m2 and Cytarabine 100 mg/m2) followed by up to 4 courses of high dose cytarabine consolidation (Cytarabine 3 gram/m2 for 4-6 doses). Decision on allogeneic haematopoietic stem cell transplantation (HSCT) was based on clinical grounds and gene mutations according to ELN recommendations. Next generation sequencing (NGS) was performed in diagnostic bone marrow (BM) in 362 patients for 36 recurrent mutated genes and analyzed by in-house bioinformatics pipelines. Relapse-free survival (RFS) was defined by the time from first complete remission (CR) to relapse or death and overall survival (OS) by the time from diagnosis to death. Patients were censored at last follow up. Survivals were evaluated by Kaplan-Meier analysis and compared by log-rank test. Multivariate analyses of clinical and genetic parameters were analyzed by Cox-regression. P-values of

Description: Background. Acute myeloid leukaemia (AML) is a group of heterogeneous diseases with distinct clinicopathologic, cytogenetic and genetic features, sharing in common an abnormal increase in myeloblasts in blood or bone marrow (BM). Induction and consolidation chemotherapy as well as allogeneic haematopoietic stem cell transplantation (HSCT) are the mainstays of treatment. However, treatment outcome is unsatisfactory and only 30-40% patients achieve durable remission. Disease heterogeneity in AML may account for different treatment responses. In this study, we examined the mutation spectrum of cytogenetically normal AML (CN-AML) patients in Hong Kong, where AML treatment and indications for allogeneic HSCT are uniform, and evaluated their clinical outcome with respect to the specific gene mutations. Patients. Young adult patients (18-60 years old) with AML diagnosed between August 2003 to September 2017 in 8 regional hospitals in Hong Kong were included. Their clinicopathologic and cytogenetic features as well as treatment outcome were examined. Treatment and endpoints. Treatment comprised induction (daunorubicin 60-90 mg/m2 for 3 days; cytarabine 100 mg/m2 for 7 days) and consolidation (cytarabine 3 gram/m2 for 4-6 doses) for 3-4 courses. BM examination was performed on day 28 or until white cell and platelet counts recovered. Non-remission or relapsed cases were treated with salvage chemotherapy comprising combinations of cytarabine with idarubicin/etoposide, fludarabine, mitoxantrone or clofarabine. Complete remission (CR) was defined as circulating and BM blasts of ≤5% with neutrophil (≥1x109/L) and platelet count (≥100x109/L) recovery. CR with incomplete haematological recovery (CRi) was defined as circulating and BM blasts of ≤5% without complete neutrophil or platelet recovery. Mutation profiling. Next generation sequencing (NGS) for 36 recurrently mutated genes in AML was performed in diagnostic BM samples. Sequencing data were analyzed by in-house bioinformatics pipeline. Statistical evaluation. Patient survivals were calculated by Kaplan-Meier analysis and compared by log-rank test. P-values of

Description: Objectives: Acute myeloid leukemia (AML) carrying internal tandem duplication (ITD) of Fms-Like Tyrosine Kinase 3 (FLT3) is associated with high relapse risk and adverse outcome. This single-arm, phase 2 study evaluated efficacy and safety of combination treatment with FLT3 inhibitor quizartinib and protein translation inhibitor omacetaxine mepesuccinate (OME), referred herein QUIZOM - in elderly patients with newly diagnosed FLT3-ITD AML or young patients with relapsed/refractory (R/R) diseases, whose outcome is hitherto dismal. Methods: R/R FLT3-ITD AML patients ≥ 18 years old or newly diagnosed patients ≥ 65 years old were recruited. Treatment comprised quizartinib 30 mg daily and OME [2 mg daily for 7 (first course) or 5 days (second course onwards) every 21-28 days] until disease progression or allogeneic hematopoietic stem cell transplantation (HSCT). Quizartinib was given as post HSCT maintenance after engraftment at doses ranging from 30 mg twice weekly to 30 mg daily, depending on blood counts. Primary endpoint was composite complete remission (CRc) defined by CR+CRi (CR with incomplete haematological recovery). Secondary endpoints were leukaemia-free (LFS) and overall survival (OS). Molecular responses were evaluated by FLT3-ITD based on PCR and NPM1 variant allele frequency (VAF) based on digital PCR (ddPCR). Mutation profiling was performed by MiSeq Next Generation Sequencing (NGS) based on IDT xGen Lockdown probes custom panel of 67 genes or TruSight myeloid panel of 54 genes. Results: Twenty-nine patients (R/R case=22; newly diagnosed case=7) were recruited between November 2017 and July 2019. Their clinicopathologic characteristics were shown in Table 1. Twenty-seven patients completed at least one course of QUIZOM (median= 2 courses, range: 1-20 courses) of whom 22 (R/R=19; newly diagnosed=3) achieved CR/CRi [CR=2 (7%); CRi=20 (74%), CRc=22 (81%)], 3 patients showed partial remission (PR) and 2 patients did not respond. All 6 patients who had prior FLT3 inhibitors (sorafenib or midostaurin) achieved CR/CRi. Median LFS and OS of CR/CRi group were 5.2 and 11.07 months (Figure 1). Seven patients received allogeneic HSCT of whom all have remained in remission post HSCT as of 31 July 2019 (OS 6.43 to 19.8 months) (Figure 1). Deep molecular responses (DMR) as defined by FLT3-ITD VAF ≤0.1% and NPM1 VAF ≤ 0.001% could be accomplished in 78% and 27% patients. Adverse effects associated with QUIZOM were primarily haematological and non-haematologic adverse effects were scarce. Two patients succumbed before commencement and on day 1 of QUIZOM due to pneumonia and intracranial haemorrhage. None of recurrently mutated genes was significantly associated with treatment responses in this cohort. Conclusion: QUIZOM is effective and safe for newly diagnosed and R/R FLT3-ITD AML. Acknowledgements: Li Shu Fan Medical Foundation, S.K. Yee Medical Foundation, Croucher Foundation, LKS Faculty of Medicine, University of Hong Kong, Daiichi Sankyo Inc. Disclosures No relevant conflicts of interest to declare.

Description: Abstract 2414 Donor cell leukemia (DCL) is a rare occurrence and refers to leukemia of donor origin in patients who have received allogeneic hematopoietic stem cell transplantation (HSCT). We have previously described a male patient with IgG-κ myeloma who received non-myeloablative allogeneic HSCT from a HLA-matched brother and developed complex karyotype acute myeloid leukemia (AML) of donor origin 10 years after transplantation. He achieved complete remission (CR) with standard induction and consolidation chemotherapy but relapsed one year afterwards. We hypothesized that a comparison of the donor HSC before transplantation (pre-leukemic) and the subsequent AML at whole genome level will provide a unique dataset that may shed light on the pathogenesis of leukemia. DNA was extracted from an aliquot of donor mobilized peripheral blood mononuclear cells (mPBMNC) frozen before transplantation as well as unfractionated and CD34+ myeloblasts of the patient's bone marrow at diagnosis and subsequent relapse of AML. The complete donor origin of the AML was confirmed by PCR based on polymorphic STRs. Whole-genome sequencing (WGS) was performed to sequence paired-end reads generated by Illumina HiSeq 2000. Reads were aligned to the human referecne genome (hg19, NCBI37) by SOAP3 and analysed to detect single nucleotide variants (SNVs), small insertion and deletion (indels) and copy number variations (CNVs). Selected genes after filtering were independently validated by Sanger sequencing. There were 835M and 810M 100bp paried-end reads with insert distance of 500bp generated from donor mPBMNC and CD34+ myeloblasts of the relapsed DCL with respective mean depths of 43.2X and 42.6X after alignment. The digital karytoyping based on the read depth was consistent with that by conventional cytogenetic study. 3,979,582 and 1,020,717 SNVs and indels were detectable from both samples. Based on the Catalog of Somatic Mutations in Cancer (COSMIC) and excluding those asian specific wildtypes annotated in 1000 genome project, 11 SNVs and 15 indels within coding sequence with potential roles as tumor suppressors or oncogenes were identified. On the other hand, there were 128,752 and 56,330 SNVs and indels detected exclusively in DCL. Those putative non-pathogenic SNP and those changes locating outside the gene regions were filtered. Within the gene region, SNVs in introns and synonymous mutations were also filtered. 142 non-synonymous SNVs (139 missense and 3 nonsense mutations) were identified of which 25 were considered as statistically highly confident and 17 of them could be confirmed by Sanger Sequencing. Twelve of these were also identified from the whole BM sample of DCL at diagnosis. These candidates include transcription factor (SALL1), metabolic enzymes (UGT1A5, SPEG), membrane protein (TMC6, SCN3A), cytoskeleton protein (MYH10), ribonucleoprotein (RAVER1), secreted protein (WNT7A), protein involved in DNA damage repair (APLF) and others (PRPF8, ZNF518B and MKRN3). 26 indels were indentified in the coding region of which 5 were considered as statistically highly confident, however, only one indel could be confirmed by Sanger Sequencing in the relapse sample and was not present in the diagnostic sample. The WGS performed in paired pre-leukemic (donor HSC) and leukemic (DCL) human samples has provided us with unique opportunities to dissect the genetic changes in HSC that may contribute to the initiation of AML with complex karyotype. The potential impacts of bone marrow microenvironment in this patient with myeloma in inducing DCL are also being evaluated. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction Sickle cell disease (SCD) is an inherited disorder in which pathology is driven by hemoglobin polymerization and red blood cell sickling, leading to chronic anemia, hemolysis, and episodic vaso-occlusion. Anemia affects the brain, kidneys and cardiovascular system, and is associated with neurocognitive dysfunction, silent cerebral infarction, stroke, renal dysfunction, pulmonary hypertension, and mortality. Limited research has been conducted to quantify the economic burden of end organ damage among patients with sickle cell disease in the US. Methods Patients with ≥3 nondiagnostic SCD ICD-9/ICD-10 codes within 5 years (Jan 1, 2013-Dec 31, 2017) were identified in the MarketScan® Medicaid claims databases. The first date of SCD diagnosis was the index date. At least three months of continuous enrollment with medical and pharmacy benefits prior to the index date, and at least 1 month of continuous enrollment following the index date were required to be included. Each patient's post-index period was divided into a series of 3-month intervals. For each 3-month interval, patients' entire available claims history (as early as 1/1/2008) was checked to identify four types of end organ damage experienced by SCD patients including stroke (within 1st year and 〉1 year after an acute stroke event), chronic kidney disease (CKD), end-stage renal disease (ESRD), and pulmonary hypertension (PH). Total healthcare costs (plan paid and patient out-of-pocket payment) and healthcare resource utilization (HRU) information were determined for each 3-month interval. Patient characteristics, HRU, and costs were summarized descriptively by type of end organ damage. Three multivariate generalized linear models with loglink function and gamma error distribution (assuming the cost follows an exponential relationship to the weighted average of covariates) were employed to estimate the relative cost ratios of patients with vs. without end organ damage, controlling for patients' demographic and clinical characteristics. Annualized costs for adult patients with each type of end organ damage were estimated based on the regression results. Results A total of 10,784 patients with SCD on Medicaid were identified. Patients were followed for 3.35 years on average, contributing 152,455 intervals (age ≥18: 42.7%; female: 54.6%; urban: 84.4%). Approximately 20% of the intervals had end organ damage. Patients with end organ damage had more days in hospital, ER visits, outpatient visits, lab tests, and outpatient pharmacy claims per month than patients without organ damage (Figure). The mean (SD) cost per hospitalization for acute stroke was $55,314 ($76, 847). In multivariate regression model 1 (accounting for end organ damage only), patients with any end organ damage had significantly higher costs than those without these conditions. After controlling for patient demographic characteristics (model 2) and additional clinical characteristics (model 3), the results were similar. The costs of SCD patients in the first year after stroke are 4.68 times as high as the costs of patients without any organ damage (2.08 times if 〉1 yr after stroke; 2.32 times for PH; 2.19 times for CKD; and 3.40 times for ESRD) (Table). The transitional age group (18-30 years) had significantly higher costs than other age groups. Having other SCD complications such as avascular necrosis, gallstones, cholelithiasis, cholecystitis, leg ulcers, osteomyelitis, or priapism also significantly increased the total costs. Based on model 3, after controlling for patient demographics and clinical characteristics, the predicted mean annual costs for adult patients with SCD in the first year after a stroke is $285,816; $127,393 if more than one year after a stroke; $148,174, $135,492, or $209,172 if the patient had PH, CKD or ESRD, respectively. Patients with multiple SCD complications had even higher costs. For example, the predicted mean annual cost for adult patients with CKD and avascular necrosis is $270,513. Conclusions Sickle cell disease is associated with substantial economic burden. When patients experience end organ damage such as stroke, renal dysfunction, or cardiopulmonary conditions, this economic burden is significantly elevated. SCD management strategies that can potentially reduce the risks of end organ damage offer both clinical and economic values to patients and society. Disclosures Song: Global Blood Therapeutics: Other: Xue Song is an employee of IBM Watson Health, which receives funding from Global Blood Therapeutics to conduct research. Campbell:Cyclerion: Consultancy, Research Funding; Novartis: Research Funding; Global Blood Therapeutics: Consultancy, Research Funding. Cong:Global Blood Therapeutics: Employment, Equity Ownership. Agodoa:Global Blood Therapeutics: Employment, Equity Ownership. Martinez:Global Blood Therapeutics: Other: Diane Martinez is an employee of IBM Watson Health, which receives funding from Global Blood Therapeutics to conduct research. Lew:Global Blood Therapeutics: Other: Carolyn Lew is an employee of IBM Watson Health, which receives funding from Global Blood Therapeutics to conduct research. Black:Global Blood Therapeutics: Other: Danae Black is an employee of IBM Watson Health, which receives funding from Global Blood Therapeutics to conduct research. Varker:Global Blood Therapeutics: Other: Helen Varker is an employee of IBM Watson Health, which receives funding from Global Blood Therapeutics to conduct research. Chan:Global Blood Therapeutics: Other: Chris Chan is an employee of IBM Watson Health, which receives funding from Global Blood Therapeutics to conduct research. Lanzkron:Pfizer: Research Funding; Ironwood: Research Funding; Global Blood Therapeutics: Research Funding; HRSA: Research Funding; NIH: Research Funding; PCORI: Research Funding.