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Acute myeloid leukemia (AML) refers to one of the most lethal blood malignancies worldwide. FLT3-ITD mutation is recognized as the most common one that predicted a poorer prognosis. There have been many prominent FLT3-ITD inhibitors approved by the FDA for clinical therapies. However, as impacted by undesirable off-target effects, differentiated metabolic issues, and clinical drug resistance problems, it remains challenging to discover alternative and promising solutions for treating FLT3-ITD+ AML. In this study, dovitinib was chemically modified and converted into CRBN-recruiting PROTACs. Two active compounds were identified, which showed enhanced antiproliferative effects against FLT3-ITD+ AML cells, both in vitro and in vivo. As demonstrated from further biological evaluation, the compounds could induce the degradation of the FLT3-ITD and KIT proteins in a ubiquitin-proteasome-dependent manner and completely block their downstream signaling pathway. The findings of this study would provide another promising strategy to develop novel therapies for FLT3-ITD+ AML.

Background FMS-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) is a molecular genetic alteration significantly affecting the clinical outcome in patients with acute myeloid leukemia (AML). FLT3-ITD mutations are characterized by variable mutant-to-wild allelic ratios (ARs) and sizes of the duplicated sequences. The size of the inserted sequence may vary from a few to hundreds of nucleotides. The aim of this work was to determine the impact of FLT3-ITD ARs, FLT3-ITD allelic frequency (AF), and allele size in de novo AML. Patients and Methods We studied 117 patients with FLT3-ITD gene mutation–positive AML, dividing them into those with low ARs and those with high ARs (>0.64) and examined their prognostic impact. Results High FLT3-ITD AR ≥ 0.64 and AF ≥ 0.5 were significantly associated with a lower overall survival compared with lower AR (median 0.625 vs. 1.020 months, respectively; P = .041) and AF (median 0.493 vs. 0.954 months, respectively; P = .009). NPM1 mutation had no favorable impact on the low-level FLT3-ITD group. Conclusion Initial high total leukocyte count, FLT3-ITD AF, and splenomegaly are independent prognostic factors for poor outcome in FLT3-ITD–positive AML.

Background: The FLT3 gene, a receptor tyrosine kinase encodes a transmembrane protein that plays a fundamental role in normal hematopoiesis. The two types of mutations identified in FLT gene are an internal tandem duplication (FLT3-ITD) in exon 14 and 15, and a missense point mutation in codon 835 in exon 20 (FLT3-D835). These mutations activate a ligand independent constitutive tyrosine-kinase receptor and are mostly found in acute myeloid leukemia and are associated with bad prognosis. We first time from the Indian subcontinent evaluated the frequency of FLT3 mutations in a cohort of Acute lymphoid leukemia (ALL). Methods: FLT3-ITD mutations and FLT3-D835 were investigated in a cohort of 74 confirmed ALL patients at diagnosis, by polymerase chain reaction (PCR) and restriction fragment length-PCR (PCR-RFLP) respectively. Results: Overall 03 mutations were detected from 74 ALL patients (4.05%) in FLT-ITD but no mutation was found in FLT3-D835. All the three patients with FLT mutations were negative for the known translocation in ALL. Among these patients one died in the first year of treatment (33.4%) while the rest of two FLT3 mutant patients are fairly doing well. Conclusions: This report implies that FLT3 gene mutations are present in ALL patients from Kashmir (North India) although not as common as found in AML (20-30%) but do impact the clinical outcome.

The most frequent mutations in acute myeloid leukemia (AML) – FLT3-ITD and NPM1 – are associated with a specific immunophenotype. We evaluated the levels of surface antigens in an uninvestigated AM...

FMS-like tyrosine kinase 3 gene internal tandem (FLT3-ITD) mutations represent one of the most frequent genetic lesions in acute myeloid leukemia (AML) and imparts a negative prognostic. For an optimal patient management, current clinical guidelines recommend the evaluation of the allelic ratio (AR), expressed as the DNA FLT3-ITD/WT mutational burden. We sought to evaluate the differences between the AR and FLT3-ITD/WT mRNA ratio (RR) and their respective impact on the biological characteristics of AML patients. A total of 32 DNA and mRNA samples from AML patients with FLT3-ITD were evaluated. There was a good correlation between the AR and RR (Spearman’s rho= 0.652, P

Background Acute myeloid leukemia (AML) with internal tandem duplication in FMS-like tyrosine kinase 3 (FLT3-ITD) is associated with poor outcomes. This study aimed to analyze the outcomes of pediatric AML patients with FLT3-ITD mutations in the pre-FLT3 inhibitor era. Methods We retrospectively reviewed and identified 18 patients diagnosed with non-M3 AML with FLT3-ITD mutations at Seoul National University Children's Hospital between May 2008 and August 2019. Results The median age was 13 years (range, 6?19 yr). The median follow-up time was 43 months (range, 6?157 mo). Fourteen patients received BH-AC-based (N4-Behenoy1-1-b-D-arabinofuranosy1cytosine) and 4 received cytarabine-based induction chemotherapy. Complete remission (CR) was achieved in 72.2% of the patients after the first induction chemotherapy and 80% of the patients achieved CR after salvage therapy. The overall CR rate was 94% (17/18 patients). These 17 patients underwent hematopoietic stem cell transplantation (9 matched unrelated donors, 5 matched related donors, and 3 haploidentical donors). Relapse occurred in 22% of the patients. Event free survival and overall survival rates were 53.8±12.1% and 53.6±12.1%, respectively, and they were not significantly different according to the type of induction chemotherapy (P=0.690) or the type of donor (P=0.102). Conclusion This study outlines the outcomes of pediatric AML patients with FLT3-ITD-mutations in one institution over a decade. Outcomes were significantly improved in this study compared to our previous report in 2004, where RFS and EFS were 0%. This study can provide baseline data for pediatric patients in the pre-FLT3 inhibitor era.

The prognosis of patients with acute myeloid leukemia (AML) caused by the FLT3-ITD mutation is poor. Arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) can down-regulate FLT3-ITD level and selectively kill leukemia cells carrying the FLT3-ITD mutation. However, the mechanisms of action of these two compounds are unknown. Here, we found that ATO could bind FLT3-ITD at Lys91 and Asp225, whereas ATRA could bind FLT3-ITD at Lys5 and Gln6. Both compounds could not bind wild-type FLT3. Further studies revealed that ATO/ATRA may suppress the Expression of FLT3-ITD by promoting the UBE2L6-mediated ubiquitination pathway and decreasing the expression of C-MYC. However, further studies are needed to define the mechanisms of these compounds on AML. Our research provides an experimental basis for the use of ATO/ATRA in FLT3-ITD AML in clinical practice.

In acute myeloid leukemia (AML) FLT3 internal tandem duplication (ITD) and nucleophosmin 1 (NPM1) mutations provide prognostic information with clinical relevance through choice of treatment, but the effect of age and sex on these molecular markers has not been evaluated. The Swedish AML Registry contains data on FLT3-ITD and NPM1 mutations dating to 2007, and 1570 adult patients younger than 75 years, excluding acute promyelocytic leukemia, had molecular results reported. Females more often had FLT3ITD and/or NPM1mut (FLT3ITD: female, 29%; male, 22% [P = .0015]; NPM1mut: female, 36%; male, 27% [P = .0001]), and more males were double negative (female, 53%; male, 64%; P < .0001). Patients with FLT3ITD were younger than those without (59 vs 62 years; P = .023), in contrast to patients with NPM1mut (62 vs 60 years; P = .059). Interestingly, their prognostic effect had a strong dependence on age: FLT3ITD indicated poor survival in younger patients (

This review discusses the current standard of care for incorporation of FLT3 TKIs and HCT into the treatment of FLT3-ITD AML. Additionally, this review provides an approach to the patient with relapsed/refractory disease. Over the last decade, the routine use of HCT as consolidative therapy and the development of FLT3 TKIs have significantly improved remission rates and overall survival. The value and challenges of MRD assessment in FLT3 disease are discussed and current mechanisms of relapse are explored, as are the ongoing questions in the field that current clinical trials are seeking to answer. FLT3-ITD mutations are common in acute myeloid leukemia and historically have been associated with a poor prognosis, but with the incorporation of FLT3 TKIs and routine use of allogeneic stem cell transplant as consolidative therapy, outcomes have improved dramatically. Ongoing research seeks to answer how and when to best use current therapies, and how to overcome resistance to FLT3 inhibition.

A series of 4-arylamido 5-methylisoxazole derivatives with quinazoline core was designed and synthesised based on conformational rigidification of a previous type II FMS inhibitor. Most of quinazoline analogues displayed activity against FLT3 and FLT3-ITD. Compound 7d, 5-methyl-N-(2-(3-(4-methylpiperazin-1-yl)-5-(trifluoromethyl)phenyl)quinazolin-7-yl)isoxazole-4-carboxamide, exhibited the most potent inhibitory activity against FLT3 (IC50= 106 nM) with excellent selectivity profiles over 36 other protein kinases including cKit and FMS kinase. Compound 7d was also active in FLT-ITD, with an IC50 value of 301 nM, and other FLT3 mutants showing potential as an AML therapeutics.

In acute myeloid leukemia (AML) internal tandem duplications of the FLT3 gene (FLT3-ITD) are associated with poor prognosis. Retrospectively, we investigated the prognostic and predictive impact of FLT3-ITD insertion site (IS) in 452 patients randomized within the RATIFY trial, which evaluated midostaurin additionally to intensive chemotherapy. Next-generation sequencing identified 908 ITDs, with 643 IS in the juxtamembrane domain (JMD) and 265 IS in the tyrosine kinase domain-1 (TKD1). According to IS, patients were categorized as JMDsole (n = 251, 55%), JMD and TKD1 (JMD/TKD1; n = 117, 26%), and TKD1sole (n = 84, 19%). While clinical variables did not differ among the 3 groups, NPM1 mutation was correlated with JMDsole (P = 0.028). Overall survival (OS) differed significantly, with estimated 4-year OS probabilities of 0.44, 0.50, and 0.30 for JMDsole, JMD/TKD1, and TKD1sole, respectively (P = 0.032). Multivariate (cause-specific) Cox models for OS and cumulative incidence of relapse using allogeneic hematopoietic cell transplantation (HCT) in first complete remission as a time-dependent variable identified TKD1sole as unfavorable and HCT as favorable factors. In addition, Midostaurin exerted a significant benefit only for JMDsole. Our results confirm the distinct molecular heterogeneity of FLT3-ITD and the negative prognostic impact of TKD1 IS in AML that was not overcome by midostaurin.

Purpose: Previous studies have shown that patients with NPM1+/FLT3-ITD+ acute myeloid leukaemia (AML) have a poor prognosis, especially those with a high FLT3-ITD allelic ratio. However, no studies have confirmed a clear prognostic impact of DNMT3A on NPM1+/FLT3-ITD+ AML patients. Methods: Our study included a total of 165 patients with newly diagnosed non-acute promyelocytic leukaemia (non-APL) AML at The First Hospital of Lanzhou University between January 2018 and June 2021. Further bioinformatics analysis was performed using the Gene Expression Omnibus (GEO) database. Results: We retrospectively studied 165 patients newly diagnosed non-APL AML and identified 11 (6.7%) patients with NPM1/FLT3-ITD/DNMT3A triple mutations. The patients with triple-mutated AML had advanced age, higher white blood cell (WBC) counts, de novo AML, normal karyotypes, and poor survival, and all were in the M4/M5 French-American-British (FAB) category. Notably, half of the patients with triple-mutated AML had mature monocyte characteristics that were difficult to distinguish from chronic myelomonocytic leukaemia (CMML). We validated the prognosis of patients with triple-mutated AML by further bioinformatics analysis and found that the GNG4 gene, one of the hub genes, was related to triple-mutated AML patients' survival. Conclusion: Our data demonstrate that DNMT3A gene mutation has adverse prognostic significance in NPM1+FLT3-ITD+comutation AML patients.

FLT3-ITD mutations are detected in approximately 25% of newly diagnosed adult acute myeloid leukemia (AML) patients and confer an adverse prognosis. The FLT3-ITD allelic ratio has clear prognostic value. Nevertheless, there are numerous manuscripts with contradictory results regarding the prognostic relevance of the length and insertion site (IS) of the FLT3-ITD fragment. We aimed to assess the prognostic impact of these variables on the complete remission (CR) rates, overall survival (OS) and relapse-free survival (RFS) of AML patients with FLT3-ITDmutations. We studied the FLT3-ITD length of 362 adult AML patients included in the PETHEMA AML registry. We tried to validate the thresholds of ITD length previously published (i.e., 39 bp and 70 bp) in intensively treated AML patients (n = 161). We also analyzed the mutational profile of 118 FLT3-ITD AML patients with an NGS panel of 39 genes and correlated mutational status with the length and IS of ITD. The AUC of the ROC curve of the ITD length for OS prediction was 0.504, and no differences were found when applying any of the thresholds for OS, RFS or CR rate. Only four out of 106 patients had ITD IS in the TKD1 domain. Our results, alongside previous publications, confirm that FLT3-ITD length lacks prognostic value and clinical applicability.

Internal tandem duplications of FLT3 (FLT3-ITD) occur in approximately 25% of all acute myeloid leukemia (AML) cases and confer a poor prognosis. Optimization of the screening hit 1 from our in-house compound library led to the discovery of a series of pyrazolo[1,5-a]pyrimidine derivatives as potent and selective FLT3-ITD inhibitors. Compounds 17 and 19 displayed potent FLT3-ITD activities both with IC50 values of 0.4 nM and excellent antiproliferative activities against AML cell lines. Especially, compounds 17 and 19 inhibited the quizartinib resistance- conferring mutations, FLT3D835Y, both with IC50 values of 0.3 nM. Moreover, western blot analysis indicated that compounds 17 and 19 potently inhibited the phosphorylation of FLT3 and attenuated downstream signaling in AML cells. These results indicated that pyrazolo[1,5-a]pyrimidine derivatives could be promising FLT3-ITD inhibitors for the treatment AML.

Internal tandem duplication within FLT3 (FLT3-ITD) is one of the most frequent mutations in acute myeloid leukemia (AML) and correlates with a poor prognosis. Whereas the FLT3 receptor tyrosine kinase is activated at the plasma membrane to transduce PI3K/AKT and RAS/MAPK signaling, FLT3-ITD resides in the endoplasmic reticulum and triggers constitutive STAT5 phosphorylation. Mechanisms underlying this aberrant FLT3-ITD subcellular localization or its impact on leukemogenesis remain poorly established. In this study, we discovered that FLT3-ITD is S-palmitoylated by the palmitoyl acyltransferase ZDHHC6. Disruption of palmitoylation redirected FLT3-ITD to the plasma membrane and rewired its downstream signaling by activating AKT and extracellular signal-regulated kinase pathways in addition to STAT5. Consequently, abrogation of palmitoylation increased FLT3-ITD–mediated progression of leukemia in xenotransplant-recipient mouse models. We further demonstrate that FLT3 proteins were palmitoylated in primary human AML cells. ZDHHC6-mediated palmitoylation restrained FLT3-ITD surface expression, signaling, and colonogenic growth of primary FLT3-ITD(+) AML. More important, pharmacological inhibition of FLT3-ITD depalmitoylation synergized with the US Food and Drug Administration–approved FLT3 kinase inhibitor gilteritinib in abrogating the growth of primary FLT3-ITD(+) AML cells. These findings provide novel insights into lipid-dependent compartmentalization of FLT3-ITD signaling in AML and suggest targeting depalmitoylation as a new therapeutic strategy to treat FLT3-ITD(+) leukemias.

Background Recognition of molecular abnormalities in acute myeloid leukaemia (AML) has improved our understanding of its biology. NPM1 and FLT3-ITD mutations are recurrent in AML and clinically significant. NPM1 mutations are associated with a favourable prognosis, while FLT3-ITD mutations are an independent poor prognostic factor in AML. Objective This study described the prevalence and molecular characteristics of the NPM1 and FLT3-ITD mutations in a newly diagnosed AML patient cohort in central South Africa. Methods The study included 40 de novo AML patients. An NPM1 and FLT3-ITD multiplex polymerase chain reaction assay was optimised to screen patients for the respective mutations and were confirmed using Sanger sequencing. The prevalence of the NPM1 and FLT3-ITD mutations were determined, and mutation-specific characteristics were described in relation to patients' demographic information and AML classifications. Results The patients' median age was 38.5 years, with 77.5% (n = 31) of patients being self-proclaimed Black Africans. AML with recurrent genetic abnormalities was most prevalent (57.5%; n = 23), of which acute promyelocytic leukaemia (APL) was most common (40.0%; n = 16). None of the patients had the NPM1 mutation. FLT3-ITD was present in 37.5% (6/16) of APL patients and in one (20.0%) of five AML patients with a t(8;21) translocation. Most patients had an FLT3-ITD allele ratio of ≥ 50% and ITD lengths of > 39 bp. Conclusion FLT3-ITD mutations were mainly found in APL cases at a similar prevalence as reported in the literature. High FLT3-ITD allele ratios and long ITD lengths predominated. No NPM1 mutations were detected.

Introduction Midostaurin is the only approved FLT3 inhibitor for combination with intensive induction and consolidation chemotherapy in newly diagnosed patients with FLT3 mutant AML. The FLT3 inhibitor, sorafenib, was investigated in the randomized SORAML trial (Röllig, Lancet Onc 2015), in combination with intensive chemotherapy (IC) for newly diagnosed adults with AML Methods The Australasian Leukaemia and Lymphoma Group (ALLG) conducted a randomized phase 2 study [ACTRN12611001112954] in 99 adults aged 18-65 years with newly diagnosed FLT3-ITD positive (allelic ratio (AR) ≥0.05) AML to determine whether addition of SOR to IC would improve event-free survival (EFS). The study was powered to identify a 25% increase in 2-year EFS with SOR. Patients 18-55 yrs received induction with IDAC-3 (idarubicin [IDA] 12 mg/m2 D1-3 and ara-C 1.5 g/m2 BD D1,3,5,7); patients 56-65 received 7+3 (IDA 12 mg/m2 D1-3 and ara-C 100 mg/m2 D1-7 IVI). Patients were randomized 2:1 to SOR or PBO 400 mg BD on days 4-10 of induction and each consolidation cycle. Due to the pharmacokinetic interaction between SOR and azoles, antifungal prophylaxis during induction was with AmBisome 5 mg/kg IV twice weekly. For consolidation, patients 18-55 yrs received 2 cycles of IcE (IDA 9 mg/m2 D1-2, ara-C 100 mg/m2 D1-5 IVI and etoposide 75 mg/m2 D1-5), those 56-65 yrs received 2 cycles of IDAC-2 (IDA 12 mg/m2 D1-2 and ara-C 1g/m2 BD D1,3,5). Maintenance was with SOR/PBO 400 mg bd days 1-28 for 12 cycles. Allogeneic HCT (allo-HCT) was at investigator discretion. SOR/PBO was not continued post allo-HCT. The primary endpoint was EFS without censoring for allo-HCT with events defined as failure to achieve complete remission (CR) or CR with incomplete hematologic recovery (CRi), relapse or death. Pre-specified secondary endpoints included overall response rate (ORR) defined as CR and CRi, tolerability, EFS according to FLT3-ITD AR < or ≥ 0.7 and impact of randomization on allograft outcome. Results Between Jan 2013-May 2018, 18 centers randomized 99 patients to induction with either SOR (n=65) or PBO (n=33); one patient later found to be FLT3-ITD negative was excluded. Patient characteristics are shown in Table 1. Treatment arms were balanced apart from fewer patients in the SOR arm with NPM1 mutant AML. Deliverability of therapy was comparable, with commencement of consolidation in 78% and 79% and maintenance therapy in 32% and 27% in the SOR and PBO arms, respectively. The overall response rate (ORR) was high in both arms; 91% in the SOR (CR 80%, CRi 11%) and 94% in the PBO (CR 70%, CRi 24%) arm. In the SOR arm, 5% achieved partial remission, went off study and were deemed treatment failures. With a median overall follow-up of 25 mo, there was no significant difference in EFS (HR 0.87 95% CI 0.50-1.49; P=0.61)(Fig A) or OS (HR 0.70 95% CI 0.38-1.29; P=0.26)(Fig. B), nor in a sensitivity analysis with censoring at HCT. 2 yr EFS was 47.9% (SOR) vs 45.4% (PBO) and 2-year OS 66.8% (SOR) vs 56.4% (PBO). Hematopoietic cell transplant (HCT) in CR1 was performed in 62% and 58% in the SOR and PBO arms, respectively. For patients in CR1, 2 yr OS post-HCT was 78.5% (SOR) vs 54.2% (PBO)(Fig C). Suggestive of an on-target effect against FLT3-ITD, the impact of SOR on OS appeared greater for patients with higher FLT3-ITD AR ≥0.7 (Fig. D) (Table 2). Only one early death (within 30 days) was recorded in each treatment arm. The frequency of grade 3-4 adverse events (AEs) were similar between the two arms, apart from palmar-plantar rash, reported as drug-related in 15.4% and 6.1% pts in the SOR and PBO arms, respectively. Correlative studies will be reported in a companion abstract. Conclusions SOR did not improve EFS when combined with intensive chemotherapy in adults with newly diagnosed FLT3-ITD AML. Although not powered for significance, SOR showed a trend for improved OS among patients with higher FLT3-ITD AR or receiving HCT in CR1. Further exploration of more potent FLT3 inhibitors in the pre- and post-allograft setting are warranted for patients with newly diagnosed FLT3 mutant AML. Acknowledgements: The ALLG AMLM16 trial was funded through an Australian Government NHMRC grant and a research grant from the Leukaemia Foundation of Australia. Bayer supplied sorafenib and Gilead AmBisome. Disclosures Wei: Roche: Honoraria; Servier: Consultancy, Honoraria, Research Funding; Novartis: Honoraria, Research Funding, Speakers Bureau; Amgen: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding, Speakers Bureau; Pfizer: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding, Speakers Bureau; Walter and Eliza Hall Institute of Medical Research: Patents & Royalties: AW is eligible for royalty payments related to venetoclax; Astra Zeneca: Honoraria, Research Funding; Janssen: Honoraria; Macrogenics: Honoraria. Enjeti:Novartis: Membership on an entity's Board of Directors or advisory committees; Alexion: Speakers Bureau; Bayer: Speakers Bureau; Sanofi: Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees. D'Rozario:Abbvie: Membership on an entity's Board of Directors or advisory committees; BMS/ Celgene: Membership on an entity's Board of Directors or advisory committees. Marlton:Celgene: 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; AbbVie: Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche Ltd: Membership on an entity's Board of Directors or advisory committees; Astra-Zeneca: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Verner:Janssen Cilag Pty Ltd.: Research Funding. Hahn:Roche: Honoraria; Astra Zeneca: Honoraria. Hiwase:Novartis Australia: Research Funding. Anstee:Walter and Eliza Hall Institute: Patents & Royalties: milestone and royalty payments related to venetoclax.. Levis:FujiFilm: Honoraria, Research Funding; Amgen: Honoraria; Daiichi-Sankyo: Honoraria; Menarini: Honoraria; Astellas: Honoraria, Research Funding. Bajel:Abbvie: Honoraria; Astellas: Honoraria; Pfizer: Honoraria; Amgen: Honoraria, Speakers Bureau; Novartis: Honoraria. Roberts:Genentech: Patents & Royalties: for venetoclax to one of my employers (Walter & Eliza Hall Institute); I receive a share of these royalties; Janssen: Research Funding; Servier: Research Funding; AbbVie: Research Funding. OffLabel Disclosure: Sorafenib for FLT3-ITD AML

Patients with internal tandem duplication in fms-related tyrosine kinase receptor gene 3 (FLT3-ITD)-mutated acute myeloid leukemia (AML) have a dismal prognosis and the only curative option seems to be allogeneic stem cell transplantation (alloSCT). However, its timing is still matter of debate.We retrospectively analyzed 73 consecutive AML patients with FLT3-ITD (median age 53, range 20-68 years) allografted with consistent policy to try to refer them all for upfront alloSCT in first complete remission (CR1).With a median follow-up of 44 (range, 5-135) months the 5-year overall survival (OS)/disease-free survival (DFS) probabilities were 49%/47%. The cumulative incidence of relapse and nonrelapse mortality (NRM) were 37% and 14%, respectively. The estimated 5-year OS for patients who received transplantation in CR1 was 62% versus 0% for patients who received transplantation beyond CR1. Multivariable analysis identified stem cell transplantation beyond CR1 as the key factor for poor OS (hazard ratio [HR], 5.41; P .0001), DFS (HR, 4.41; P = .0002), and high relapse incidence (HR, 8.08; P .0001). Acute graft versus host disease Grade ≥3 predicted higher NRM (HR, 3.80; P = .059) as well as inferior OS (HR, 2.04; P = .0079). No association of patient age, nucleophosmin status, donor type, conditioning, and other variables on the survival was detected.AlloSCT should be regarded with urgency as soon as CR1 is achieved in this subset of AML patients.

Background: Acute myeloid leukaemia (AML) is a malignancy that is heterogeneous in nature characterized by genetic abnormalities some of which are established in the diagnosis and prognosis of the disease. An additional role for alterations in epigenetic mechanisms has been also highlighted in the pathogenesis of the disease. This may have a role in determining the disease outcome, impact the treatment decision and provide options for targeted therapies especially in patients who lack genetic aberrations. One of the modes of epigenetic dysregulation is mutation in genes encoding isocitrate dehydrogenase 1 and 2 that has been observed in AML with a higher incidence in patients with normal karyotype (NK). Aim of the work: The aim of this work was to study the frequency of IDH1 (R132) and IDH2 (R140Q, R172K) mutations in adult Egyptian patients with de novo acute myeloblastic leukemia (AML), their relation with clinical characteristics, other molecular markers (the internal tandem duplication (ITD)) mutation of FLT3 gene and NPM1 gene mutation) and impact on treatment outcome. Methods: Peripheral blood samples from 50 adult patients with denovo acute myeloid leukemia, admitted to the haematology unit at Alexandria Main University Hospital from February 2015 to February 2017, were used. The polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) was used for detection of IDH1 codon R132 and IDH2 codons (R140, R172) mutations on genomic DNA. PCR was used for detection of FLT3-ITD mutation on genomic DNA. PCR was used for detection of NPM1 mutation on RNA. Results: IDH 1and 2 mutations occurred in 30% of newly diagnosed AML patients and 47.6% of NK patients. Both mutations did not co-occur except in one case. IDH positive patients were significantly older than IDH negative patients (p=0.003). There was no statistically significant correlation between any of the clinical parameters and the IDH mutations. FAB-M2 was the most common FAB subtype among IDH positive patients. No correlation between IDH mutations and NPM1 or FLT3 could be demonstrated. IDH positive patients had significantly lower CR rates after induction chemotherapy than IDH negative patients (p=0.021). Conclusion: IDH1, 2 mutations are recurring genetic alterations in AML with a higher incidence in patients with normal karyotype and they may have an unfavorable impact on clinical outcome in adult AML patients.

Curcumin, a major active compound in the turmeric rhizome, has many biological properties, especially anti-leukemia activity. The overexpression of FMS-like tyrosine kinase 3 protein with internal tandem duplication (FLT3-ITD) mutation protein was related to the poor prognosis and disease progression of leukemia. In this study, the cytotoxicity and inhibitory effect of curcumin on cell cycle of FLT3-ITD overexpressing MV4-11 leukemic cells were evaluated. Moreover, curcumin polymeric micelles conjugated with FLT3-specific peptide (FLT3-Cur-micelles) were prepared using a film hydration method to increase curcumin solubility and the inhibitory effect on MV4-11 cells was evaluated. Cytotoxicity and cell cycle analysis were performed using an MTT assay and flow cytometry, respectively. Physical properties of FLT3-Cur-micelles, including particle size, size distribution, morphology, and entrapment efficiency (EE), were evaluated. Cellular uptake of the micelles on MV4-11 cells was determined by flow cytometry and fluorescence microscopy. FLT3-Cur-micelles were observed with size less than 50 nm and high EE of75%. In addition, FLT3-Cur-micelles demonstrated excellent internalization and increased curcumin accumulation in leukemic cells when compared to free curcumin. Furthermore, FLT3-Cur-micelles exhibited a strong cytotoxic effect on MV4-11 cells with IC

A 69-year-old woman who had been diagnosed with unresectable papillary thyroid cancer was referred to our hospital. We initially treated her with sorafenib, but she subsequently developed erythema multiforme, which was suspected to be a drug rush due to sorafenib; therefore, sorafenib was discontinued. At the time of discontinuation, immature blast cells were detected in her peripheral blood. Approximately two weeks later, her skin rash improved substantially, but the proportion of blasts in the peripheral blood increased. We performed a bone marrow examination, and she was diagnosed with FLT3-ITD-positive acute myeloid leukemia. FLT3-ITD expression is found in 20–25% of AML and is a known independent poor prognostic factor. To overcome the poor prognosis associated with FLT3-ITD, molecular drugs targeting FLT3-ITD are attracting much attention. Sorafenib, a multi-kinase inhibitor, also has an effect on FLT3-ITD. Although primary disease flares after tyrosine kinase inhibitor discontinuation have been reported, this is the first report to describe discontinuation of sorafenib treatment as a potential trigger of FLT3-ITD-positive acute myeloid leukemia in papillary thyroid cancer.

FLT3 mutations are among the most common genetic alterations in acute-myeloid leukemia (AML). They are associated with poor prognosis. Multiple FLT3 inhibitors have been in clinical evaluation at various stages. Resistance to FLT3 inhibitors due to acquired point mutations in the tyrosine-kinase domain (TKD), have limited the effectiveness of treatments. A “gatekeeper” mutation (F691L), is also resistant to most FLT3 inhibitors. New therapies are therefore needed. FLT3 inhibitors are needed to protect against FLT3-TKD mutations and FLT3 internal tandem duplicate (FLT3–ITD). We identified KX2-391, a dual FLT3/tubulin inhibitor, and examined its efficacy and mechanisms for overcoming drug-resistant FLT3ITD-TKD mutations. KX2-391 had potent growth inhibitory effects and apoptosis promoting effects on AML cell lines that harbor FLT3-ITD mutations. KX2-391 orally administered significantly prolonged the survival time of a murine model with leukemia caused by FLT3ITD-F691L. KX2-391 also inhibited growth of primary AML cells that express FLT3ITD-F691L and 2 primary cells that are FLT3ITD-D835Y. Preclinical data suggest that KX2-391 is a promising FLT3 inhibitor. The treatment of AML patients with FLT3 mutations, particularly refractory/relapsed patients suffering from F691L or other FLT3TKD mutations.

Acute myeloid leukemia is a malignant disease results from mutation in a multipotent haemopoietic stemcell. The study aimed to investigate NPM1 and FLT3-ITD mutations in Iraqi patients with AML and correlateresults with other clinical and laboratory findings. Fifty-eight AML patients, admitted to Baghdad TeachingHospital from October 2019 till March 2020 in addition to 25 normal controls, were included in the study.A detailed history, laboratory investigations including FLT3-ITD and NPM1 mutations were collected fromand analyzed. FLT3-ITD was detected in 17.24% of patients, NPM1 mutation in 10.34%. Most of thepatients are presented with pallor. FLT3-ITD mutation had a higher blast cell count (74%) while NPM1mutation had higher WBCs count.Conclusion: AML is common in middle age group, patients with NPM1 mutation had significantly higherWBCs count while patients with FLT3-ITD mutation have higher blast percentage compared with nonmutated patients.

Purpose: The significance of vascular endothelial growth factor receptor (VEGFR)-3 in numerous solid tumors and acute myeloid leukemia (AML) has been demonstrated, but Apatinib remains largely unexplored. In this study, we explored whether Apatinib combined with HHT could kill AML cell lines and its possible mechanisms. Methods: All cell lines were treated with Apatinib and HHT in different concentrations with control, Apatinib alone, HHT alone, and Apatinib combined with HHT. The changes of IC50 were measured by CCK8 assay, apoptosis rate, cell cycle, and mitochondrial membrane potential in each group were measured by flow cytometry. Finally, the possible cytotoxicity mechanism was analyzed by Western blotting. Results: Our results noted that Apatinib combined with HHT remarkably inhibited cell proliferation, reduced the capacity of colony-forming, and induced apoptosis and cell cycle arrest in AML cells. Mechanistically, Apatinib and HHT play a role as a suppressor in the expression of VEGFR2 and the downstream signaling cascades, such as the PI3K, MAPK, and Stat3 pathways. Conclusion: Our preclinical data demonstrate that Apatinib combined with HHT exerts a better anti-leukemia effect than Apatinib alone by inhibiting the VEGFR2 signaling pathway, suggesting the potential role for Apatinib and HHT in the treatment of AML.

Objective Diagnosis of AML requires additional procedures, including pathological examination, immunophenotyping, cytogenetic examination, and molecular diagnosis. The determination of the specific cytogenetic abnormality is important for the selection of appropriate treatment and prognostic analysis.The 2 most common mutations of the FLT3 gene are FLT3-ITD and FLT3-D835. Here, we will present FLT3-ITD positive AML cases admitted to our clinic between 2019-2021. Case report We have 5 cases of AML FLT3-ITD heterozygous. In all our cases, Midastaurin was given with 7+3 chemotherapy (CT) in the initial treatment. While 1 of our cases went into remission, the other 4 relapsed. All of the patients who relapsed were given FLAG CT, no remission was achieved and they were switched to ADE CT. Remission was achieved in 2 of 4 patients, 2 of them were refractory. One patient was given gilteritinib. HSCT was performed in 2 patients. While 2 of our patients are dead, 2 of them are in remission and 1 of our patients is still under treatment. Results FLT3 gene mutations are strongly associated with leukocytosis and poor prognosis in patients with AML(1-3). Patients with any of these mutations have a higher risk of recurrence and a lower survival rate3. All of our patients had leukocytosis at the time of diagnosis. Four of our patients relapsed and all of these patients were refractory to chemotherapy. Our patients who were refractory to treatment had a high mortality rate (50%) and a lower survival time (8-12 months). Conclusion FLT3 signaling inhibitors have been used both alone and in combination to improve clinical outcomes in patients with AML with FLT3 mutations. While inhibitor monotherapy provides clinical response, its efficacy is usually temporary and resistance develops rapidly. Various combination therapies are used to enhance efficacy and prevent or overcome resistance. More studies are needed to evaluate its efficacy and explain the development of resistance.

Purpose: To evaluate the outcome and prognostic significance of FLT3/ITD allelic ratios (AR) among pediatric acute myeloid leukemia (AML) from TARGET dataset. Methods: A total of 1,857 pediatric patients who were diagnosed with AML were enrolled in this study by using a retrospective cohort study method from September 1996 to December 2016. Results: The prevalence of FLT3/ITD mutation in the whole cohort was 18.4%. Generalized additive models and threshold effect analysis using piece-wise linear regression were applied to identify the cut-off value of 0.5 on FLT3/ITD AR. High FLT3/ITD AR were significantly associated with higher WBC ( P