scholarly journals Novel missense mutations in the tyrosine kinase domain of the platelet-derived growth factor receptor α(PDGFRA) gene in childhood acute myeloid leukemia with t(8;21)(q22;q22) or inv(16)(p13q22)

Leukemia ◽  
2005 ◽  
Vol 19 (3) ◽  
pp. 476-477 ◽  
Author(s):  
M Hiwatari ◽  
T Taki ◽  
M Tsuchida ◽  
R Hanada ◽  
T Hongo ◽  
...  
2018 ◽  
Vol 19 (10) ◽  
pp. 3198 ◽  
Author(s):  
Dilana Staudt ◽  
Heather Murray ◽  
Tabitha McLachlan ◽  
Frank Alvaro ◽  
Anoop Enjeti ◽  
...  

The identification of recurrent driver mutations in genes encoding tyrosine kinases has resulted in the development of molecularly-targeted treatment strategies designed to improve outcomes for patients diagnosed with acute myeloid leukemia (AML). The receptor tyrosine kinase FLT3 is the most commonly mutated gene in AML, with internal tandem duplications within the juxtamembrane domain (FLT3-ITD) or missense mutations in the tyrosine kinase domain (FLT3-TKD) present in 30–35% of AML patients at diagnosis. An established driver mutation and marker of poor prognosis, the FLT3 tyrosine kinase has emerged as an attractive therapeutic target, and thus, encouraged the development of FLT3 tyrosine kinase inhibitors (TKIs). However, the therapeutic benefit of FLT3 inhibition, particularly as a monotherapy, frequently results in the development of treatment resistance and disease relapse. Commonly, FLT3 inhibitor resistance occurs by the emergence of secondary lesions in the FLT3 gene, particularly in the second tyrosine kinase domain (TKD) at residue Asp835 (D835) to form a ‘dual mutation’ (ITD-D835). Individual FLT3-ITD and FLT3-TKD mutations influence independent signaling cascades; however, little is known about which divergent signaling pathways are controlled by each of the FLT3 specific mutations, particularly in the context of patients harboring dual ITD-D835 mutations. This review provides a comprehensive analysis of the known discrete and cooperative signaling pathways deregulated by each of the FLT3 specific mutations, as well as the therapeutic approaches that hold the most promise of more durable and personalized therapeutic approaches to improve treatments of FLT3 mutant AML.


Author(s):  
Dilana Staudt ◽  
Heather Murray ◽  
Frank Alvaro ◽  
Anoop Enjeti ◽  
Nicole Verrills ◽  
...  

Identification of recurrent driver mutations in genes encoding tyrosine kinases has resulted in the development of molecularly targeted strategies designed to improve the outcomes for patients diagnosed with acute myeloid leukemia (AML). The receptor tyrosine kinase FLT3, is the most commonly mutated gene in AML, with internal tandem duplications within the juxtamembrane domain (FLT3-ITD) or missense mutations in the tyrosine kinase domain (FLT3-TKD), present in 30%-35% of AML patients at diagnosis. An established driver mutation and marker of poor prognosis, the FLT3 tyrosine kinase has emerged as an attractive therapeutic target, and thus has encouraged the development of FLT3 tyrosine kinase inhibitors (TKIs). However, the therapeutic benefit of FLT3 inhibition, particularly as monotherapy, frequently results in the development of treatment resistance and disease relapse. Commonly, FLT3 inhibitor resistance is induced by the emergence of secondary lesions in the FLT3 gene, particularly in the second tyrosine kinase domain at residue Asp835 (D835) to form a ‘dual mutation’ (ITD-D835). Individual FLT3-ITD and FLT3-TKD mutations influence independent signaling cascades however, currently little is known which divergent signaling pathways are controlled by each of these FLT3 specific mutations, particularly in the context of patients harboring dual ITD-D835 mutations. This review provides a comprehensive analysis of the known discrete and cooperative signaling pathways regulated by each of the FLT3 specific mutations, as well as the therapeutic approaches that hold the most promise for development of more durable and personalized therapeutic approaches targeting mutant FLT3, to improve the treatment of AML.


2019 ◽  
Vol 15 (34) ◽  
pp. 3885-3894 ◽  
Author(s):  
Shilpa Paul ◽  
Adam J DiPippo ◽  
Farhad Ravandi ◽  
Tapan M Kadia

FLT3 mutations, characterized by an internal-tandem duplication or missense mutations in the tyrosine kinase domain, are observed in a third of patients with newly diagnosed acute myeloid leukemia. FLT3-ITD mutations are associated with high relapse rates and short overall survival with conventional chemotherapy. Several tyrosine kinase inhibitors targeting FLT3 have been developed in an effort to improve survival and therapeutic options. This review focuses on quizartinib, a second-generation FLT3 inhibitor that has demonstrated efficacy and safety as a single agent and in combination with chemotherapy. We discuss its clinical development as well as its place in the treatment of FLT3-mutated acute myeloid leukemia among the other FLT3 inhibtors currently available and its mechanisms of resistance.


Cancer ◽  
2014 ◽  
Vol 120 (14) ◽  
pp. 2142-2149 ◽  
Author(s):  
Yesid Alvarado ◽  
Hagop M. Kantarjian ◽  
Rajyalakshmi Luthra ◽  
Farhad Ravandi ◽  
Gautam Borthakur ◽  
...  

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Maria Rogdaki ◽  
Xinhua Xiao

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.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 32-33
Author(s):  
Kotoko Yamatani ◽  
Tomohiko Ai ◽  
Kaori Saito ◽  
Haeun Yang ◽  
Vivian Ruvolo ◽  
...  

Internal tandem duplications in the juxtamembrane domain of FMS-like tyrosine kinase 3 gene (FLT3-ITD) and missense mutations in the gene's tyrosine-kinase domain (FLT3-TKD) play critical roles in the pathophysiology of acute myeloid leukemia (AML). Recent study revealed that AML cells resistant to quizartinib, a type II TKI, consist of heterogeneous clonal populations harboring wild-type FLT3 as well as FLT3-ITD, FLT3-TKD and FLT3-ITD/TKD mutations, and on- and off-target mechanisms may contribute to the resistance to TKIs. To overcome the heterogeneous resistance mechanisms of FLT3-ITD and TKD mutations, various combinatorial therapies have been investigated. For example, BCL-2 inhibition in the presence of TKIs increased survival a murine FLT3-ITD AML model, and a phase Ib/II clinical trial of a combination of quizartinib with venetoclax, a BCL2 inhibitor is ongoing in relapsed/refractory FLT3-mutant AML patients (NCT03735875). To dissect underlying mechanisms of drug-resistance and exploring new targets in refractory AML with FLT3-ITD and TKD mutations, we investigated alterations of transcriptome signatures by analyzing AML samples with FLT3-ITD/D835 dual mutations. Previously, we reported BCL2A1 transcriptomes were upregulated in primary AML cells with FLT3-ITD/D835 dual mutations compared to cells with FLT3-ITD mutations only. This was recapitulated in the MV4-11 cells harboring FLT3-ITD/D835 dual mutations after 6 month-exposure to quizartinib. The MV4-11 cells with the FLT3-ITD/D835 dual mutations became resistant to quizartinib, and the cells also became resistant to venetoclax, a BCL2 inhibitor (Yamatani et al. ASH 2019). In this study, we further investigated BCL2A1 as new target in refractory AML with FLT3-ITD/D835 dual mutations. First, we examined whether overexpression of BCL2A1 induces drug-resistance in MV4-11 and Molm13 cell lines with FLT3-ITD. While parental MV4-11 and Molm13 cells are sensitive to venetoclax and quizartinib, MV4-11 and Molm13 cells transfected with lentivirus carrying BCL2A1 became resistant to venetoclax (IC50: MV4-11 with BCL2A1 over-expression >1000 nM vs. mock vector 0.71 nM; Molm13 with over-expression >1000 nM vs. mock vector 0.38 nM, 72h). In contrast, the sensitivity to quizartinib was retained in the BCL2A1 overexpressing MV4-11 and Molm13 cells. These findings indicate that the overexpression of BCL2A1 could play a role in the acquired resistance to venetoclax, but not to quizartinib. Bromodomain-containing protein 4 (BRD4), a family member of bromodomain and extra-terminal motif (BET) is known to transcriptionally modulate BCL2A1 gene expression. Next, we examined effects of CPI-0610, a BET inhibitor, on MV4-11 cells with FLT3-ITD or the FLT3-ITD/D835 dual mutation. CPI-0610 inhibited cell growth of MV4-11 cells by inducing apoptosis irrespective of co-existing FLT3 mutations (IC50: FLT3-ITD/D835, 255 nM vs. FLT3-ITD, 191 nM, 72h). Immunoblotting analyses confirmed that BET inhibition by CPT-0610 decreased the expression of BCL2A1 in MV4-11 cells FLT3-ITD/D835. WIn conclusion, transcriptome analysis and molecular pharmacological approaches identified alterations in the anti-apoptotic BCL2 family proteins in double-mutant FLT3 leukemias. BCL2A1 upregulation might be involved in drug resistance of FLT3-ITD/D835 dual mutant AML cells, and could be a promising new target in refractory AML with FLT3-ITD/D835 dual mutations. Disclosures Konopleva: Cellectis: Research Funding; Eli Lilly: Research Funding; Calithera: Research Funding; Sanofi: Research Funding; Ascentage: Research Funding; AstraZeneca: Research Funding; Agios: Research Funding; Stemline Therapeutics: Consultancy, Research Funding; Kisoji: Consultancy; Genentech: Consultancy, Research Funding; F. Hoffmann La-Roche: Consultancy, Research Funding; Forty-Seven: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Reata Pharmaceutical Inc.;: Patents & Royalties: patents and royalties with patent US 7,795,305 B2 on CDDO-compounds and combination therapies, licensed to Reata Pharmaceutical; Rafael Pharmaceutical: Research Funding; Ablynx: Research Funding; Amgen: Consultancy. Carter:Syndax: Research Funding; AstraZeneca: Research Funding; Amgen: Research Funding; Ascentage: Research Funding. Andreeff:Daiichi-Sankyo; Breast Cancer Research Foundation; CPRIT; NIH/NCI; Amgen; AstraZeneca: Research Funding; Centre for Drug Research & Development; Cancer UK; NCI-CTEP; German Research Council; Leukemia Lymphoma Foundation (LLS); NCI-RDCRN (Rare Disease Clin Network); CLL Founcdation; BioLineRx; SentiBio; Aptose Biosciences, Inc: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Daiichi-Sankyo; Jazz Pharmaceuticals; Celgene; Amgen; AstraZeneca; 6 Dimensions Capital: Consultancy.


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