BACKGROUND: The genetic and epigenetic alterations observed in acute myeloid leukemia (AML) contribute to its heterogeneity, influencing disease progression response to therapy, and patient outcomes. The use of antisense oligonucleotides (ASOs) technology allows for the design of oligonucleotide inhibitors based on gene sequence information alone, enabling precise targeting of key molecular pathways or specific genes implicated in AML. METHODS AND RESULTS: Midostaurin, a FLT3 specific inhibitor and ASOs targeting particular genes, exons, or mutations was conducted using AML models. This ASOs treatment was designed to bind to exon 7 of the MBNL1 (muscleblind-like) gene. Another target was the FLT3 gene, focusing on two aspects: (a) FLT3-ITD (internal tandem duplication), to inhibit the expression of this aberrant gene form, and (b) the FLT3 in general. Treated and untreated cells were analyzed using quantitative PCR (qPCR), dot blot, and Raman spectroscopy. This study contrasts midostaurin with ASOs that inhibit FLT3 protein production or its isoforms via mRNA degradation. A trend of increased FLT3 expression was observed in midostaurin-treated cells, while ASO-treated cells showed decreased expression, though these changes were not statistically significant. CONCLUSIONS: In AML, exon 7 of MBNL1 is involved in several cellular processes and in this study, exon 7 of MBNL1 was targeted for method optimization, with the highest block of the exon 7 gene variant observed 48 h post-transfection. Midostaurin, a multitargeted kinase inhibitor, acts against the receptor tyrosine kinase FLT3, a critical molecule in AML pathogenesis. While midostaurin blocks FLT3 signaling pathways, it paradoxically increases FLT3 expression.

• MeSH
• akutní myeloidní leukemie * genetika   farmakoterapie   MeSH
• antisense oligonukleotidy * farmakologie   genetika   MeSH
• exony genetika   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• proteiny vázající RNA genetika   metabolismus   MeSH
• regulace genové exprese u leukemie účinky léků   MeSH
• staurosporin * analogy a deriváty   farmakologie   MeSH
• tyrosinkinasa 3 podobná fms * genetika   antagonisté a inhibitory   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Acute myeloid leukaemia (AML) is a complex haematological malignancy characterised by diverse genetic alterations leading to abnormal proliferation of myeloid precursor cells. One of the most significant genetic alterations in AML involves mutations in the FLT3 gene, which plays a critical role in haematopoiesis and haematopoietic homeostasis. This review explores the current understanding of FLT3 gene mutations and isoforms and the importance of the FLT3 protein in AML. FLT3 mutations, including internal tandem duplications (FLT3-ITD) and point mutations in the tyrosine kinase domain (FLT3-TKD), occur in 25-30% in AML and are associated with poor prognosis. FLT3-ITD mutations lead to constitutive activation of the FLT3 signalling pathway, promoting cell survival and proliferation. FLT3-TKD mutations affect the tyrosine kinase domain and affect AML prognosis in various ways. Furthermore, FLT3 isoforms, including shorter variants, contribute to the complexity of FLT3 biology. Additionally, nonpathological polymorphisms in FLT3 are being explored for their potential impact on AML prognosis and treatment response. This review also discusses the development of molecular treatments targeting FLT3, including first-generation and next-generation tyrosine kinase inhibitors, highlighting the challenges of resistance that often arise during therapy. The final chapter describes FLT3 protein domain rearrangements and their relevance to AML pathogenesis.

• MeSH
• akutní myeloidní leukemie * genetika   MeSH
• lidé MeSH
• mutace genetika   MeSH
• protein - isoformy genetika   MeSH
• tyrosinkinasa 3 podobná fms genetika   MeSH
• tyrosinkinasy MeSH
• viabilita buněk MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Mutation of FLT3 protein kinase is often associated with deregulated cell proliferation in acute myeloid leukemia and the inhibition of this kinase is a potential therapeutic strategy. We report a novel series of 3,5,7-trisubstituted pyrazolo[1,5-a]pyrimidines prepared in an effort to study their biological activity particularly toward FLT3-ITD and its downstream regulators as well as toward CDK2 and CDK9. Derivative 10b was capable to strongly inhibit all kinases and its selectivity in FLT3-ITD expressing cell lines MOLM13 and MV4-11 was in line with FLT3-ITD inhibition. Further biochemical analyses and molecular docking confirmed FLT3 as a cellular target of 10b.

• MeSH
• akutní myeloidní leukemie * farmakoterapie   MeSH
• apoptóza MeSH
• inhibitory proteinkinas chemie   MeSH
• lidé MeSH
• mutace MeSH
• nádorové buněčné linie MeSH
• proliferace buněk MeSH
• pyrimidiny * chemie   MeSH
• simulace molekulového dockingu MeSH
• tyrosinkinasa 3 podobná fms genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Genetic lesions of IKZF1 are frequent events and well-established markers of adverse risk in acute lymphoblastic leukemia. However, their function in the pathophysiology and impact on patient outcome in acute myeloid leukemia (AML) remains elusive. In a multicenter cohort of 1606 newly diagnosed and intensively treated adult AML patients, we found IKZF1 alterations in 45 cases with a mutational hotspot at N159S. AML with mutated IKZF1 was associated with alterations in RUNX1, GATA2, KRAS, KIT, SF3B1, and ETV6, while alterations of NPM1, TET2, FLT3-ITD, and normal karyotypes were less frequent. The clinical phenotype of IKZF1-mutated AML was dominated by anemia and thrombocytopenia. In both univariable and multivariable analyses adjusting for age, de novo and secondary AML, and ELN2022 risk categories, we found mutated IKZF1 to be an independent marker of adverse risk regarding complete remission rate, event-free, relapse-free, and overall survival. The deleterious effects of mutated IKZF1 also prevailed in patients who underwent allogeneic hematopoietic stem cell transplantation (n = 519) in both univariable and multivariable models. These dismal outcomes are only partially explained by the hotspot mutation N159S. Our findings suggest a role for IKZF1 mutation status in AML risk modeling.

• MeSH
• akutní myeloidní leukemie * patologie   MeSH
• dospělí MeSH
• lidé MeSH
• mutace MeSH
• nukleofosmin MeSH
• prognóza MeSH
• transkripční faktor Ikaros genetika   MeSH
• transkripční faktory genetika   MeSH
• transplantace hematopoetických kmenových buněk * MeSH
• tyrosinkinasa 3 podobná fms genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH

• MeSH
• akutní myeloidní leukemie * farmakoterapie   genetika   MeSH
• gemtuzumab MeSH
• lidé MeSH
• staurosporin terapeutické užití   MeSH
• tyrosinkinasa 3 podobná fms genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• dopisy MeSH
• Geografické názvy
• Česká republika MeSH

FLT3 kinase is a potential drug target in acute myeloid leukemia (AML). Patients with FLT3 mutations typically have higher relapse rates and worse outcomes than patients without FLT3 mutations. In this study, we investigated the suitability of various heterocycles as central cores of FLT3 inhibitors, including thieno[3,2-d]pyrimidine, pyrazolo[1,5-a]pyrimidine, imidazo[4,5-b]pyridine, pyrido[4,3-d]pyrimidine, and imidazo[1,2-b]pyridazine. Our assays revealed a series of imidazo[1,2-b]pyridazines with high potency against FLT3. Compound 34f showed nanomolar inhibitory activity against recombinant FLT3-ITD and FLT3-D835Y (IC50 values 4 and 1 nM, respectively) as well as in the FLT3-ITD-positive AML cell lines MV4-11, MOLM-13, and MOLM-13 expressing the FLT3-ITD-D835Y mutant (GI50 values of 7, 9, and 4 nM, respectively). In contrast, FLT3-independent cell lines were much less sensitive. In vitro experiments confirmed suppression of FLT3 downstream signaling pathways. Finally, the treatment of MV4-11 xenograft-bearing mice with 34f at doses of 5 and 10 mg/kg markedly blocked tumor growth without any adverse effects.

• MeSH
• akutní myeloidní leukemie * patologie   MeSH
• antitumorózní látky * farmakologie   terapeutické užití   MeSH
• apoptóza MeSH
• inhibitory proteinkinas farmakologie   terapeutické užití   MeSH
• lidé MeSH
• mutace MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• pyridaziny * farmakologie   terapeutické užití   MeSH
• pyrimidiny farmakologie   MeSH
• tyrosinkinasa 3 podobná fms genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Patients with acute myeloid leukaemia (AML) positive for internal tandem duplication (ITD) mutations of FLT3 have poor outcomes. Quizartinib, an oral, highly potent, selective, type 2 FLT3 inhibitor, plus chemotherapy showed antitumour activity with an acceptable safety profile in patients with FLT3-ITD-positive newly diagnosed AML. The aim of the study was to compare the effect of quizartinib versus placebo on overall survival in patients with FLT3-ITD-positive newly diagnosed AML aged 18-75 years. METHODS: We conducted a randomised, double-blind, placebo-controlled, phase 3 trial comparing quizartinib and placebo in combination with chemotherapy in induction and consolidation, followed by quizartinib or placebo single-agent continuation, in patients with FLT3-ITD-positive newly diagnosed AML at 193 hospitals and clinics in 26 countries in Europe; North America; and Asia, Australia, and South America. Patients aged 18-75 years were eligible. Patients were randomly assigned (1:1) to the quizartinib group or the placebo group by an independent biostatistician through an interactive web and voice response system, stratified by region, age, and white blood cell count at diagnosis. Patients, investigators, funders, and contract research organisations were masked to treatments assigned. Induction therapy comprised a standard 7 + 3 induction regimen of cytarabine 100 mg/m2 per day (or 200 mg/m2 per day allowed if institutional or local standard) by continuous intravenous infusion from day 1 to day 7 and anthracycline (daunorubicin 60 mg/m2 per day or idarubicin 12 mg/m2 per day) by intravenous infusion on days 1, 2, and 3, then quizartinib 40 mg orally or placebo once per day, starting on day 8, for 14 days. Patients with complete remission or complete remission with incomplete neutrophil or platelet recovery received standard consolidation with high-dose cytarabine plus quizartinib (40 mg per day orally) or placebo, allogeneic haematopoietic cell transplantation (allo-HCT), or both as consolidation therapy, followed by continuation of single-agent quizartinib or placebo for up to 3 years. The primary outcome was overall survival, defined as time from randomisation until death from any cause and assessed in the intention-to-treat population. Safety was evaluated in all patients who received at least one dose of quizartinib or placebo. This study is registered with ClinicalTrials.gov (NCT02668653). FINDINGS: Between Sept 27, 2016, and Aug 14, 2019, 3468 patients with AML were screened and 539 patients (294 [55%] male patients and 245 [45%] female patients) with FLT3-ITD-positive AML were included and randomly assigned to the quizartinib group (n=268) or placebo group (n=271). 148 (55%) of 268 patients in the quizartinib group and 168 (62%) of 271 patients in the placebo group discontinued the study, primarily because of death (133 [90%] of 148 in the quizartinib group vs 158 [94%] of 168 in the placebo group) or withdrawal of consent (13 [9%] of 148 in the quizartinib group vs 9 [5%] of 168 in the placebo group). Median age was 56 years (range 20-75, IQR 46·0-65·0). At a median follow-up of 39·2 months (IQR 31·9-45·8), median overall survival was 31·9 months (95% CI 21·0-not estimable) for quizartinib versus 15·1 months (13·2-26·2) for placebo (hazard ratio 0·78, 95% CI 0·62-0·98, p=0·032). Similar proportions of patients in the quizartinib and placebo groups had at least one adverse event (264 [100%] of 265 in the quizartinib group and 265 [99%] of 268 in the placebo group) and one grade 3 or higher adverse event (244 [92%] of 265 in the quizartinib group and 240 [90%] of 268 in the placebo group). The most common grade 3 or 4 adverse events were febrile neutropenia, hypokalaemia, and pneumonia in both groups and neutropenia in the quizartinib group. INTERPRETATION: The addition of quizartinib to standard chemotherapy with or without allo-HCT, followed by continuation monotherapy for up to 3 years, resulted in improved overall survival in adults aged 18-75 years with FLT3-ITD-positive newly diagnosed AML. Based on the results from the QuANTUM-First trial, quizartinib provides a new, effective, and generally well tolerated treatment option for adult patients with FLT3-ITD-positive newly diagnosed AML. FUNDING: Daiichi Sankyo.

• MeSH
• akutní myeloidní leukemie * farmakoterapie   genetika   MeSH
• benzothiazoly * terapeutické užití   MeSH
• cytarabin MeSH
• dospělí MeSH
• dvojitá slepá metoda MeSH
• fenylmočovinové sloučeniny * terapeutické užití   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• protokoly antitumorózní kombinované chemoterapie terapeutické užití   MeSH
• senioři MeSH
• tyrosinkinasa 3 podobná fms antagonisté a inhibitory   genetika   MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky, fáze III MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH

OBJECTIVES: Quizartinib is an oral, potent, selective, type II FLT3 inhibitor with prolonged OS as a single-agent in relapsed/refractory FLT3-ITD+ AML. We report results from the global, randomized, double-blind, phase 3 QuANTUM-First trial (NCT02668653), evaluating quizartinib plus standard induction and post-remission consolidation (including allogeneic hematopoietic cell transplant [allo-HCT] in first complete remission [CR1]) followed by single-agent continuation (up to 3 years) vs placebo plus chemotherapy in newly diagnosed FLT3-ITD+ AML. METHODS: Patients 18-75 years with newly diagnosed FLT3-ITD+ AML received induction with cytarabine 100 or 200 mg/m2/day (days 1-7) and daunorubicin 60 mg/m2/day or idarubicin 12 mg/m2/day (days 1-3). Patients were randomized to quizartinib (40 mg/day [days 8-21]) or placebo; stratified by region, age, and white blood cell count at diagnosis. Patients with CR or CR with incomplete hematologic recovery (CRi) received up to 4 cycles of high-dose cytarabine plus quizartinib (40 mg/day) or placebo and/or allo-HCT followed by continuation with quizartinib (30-60 mg/day) or placebo (up to 3 years). The primary endpoint was OS. RESULTS: Between September 2016 and August 2019, 539 patients were randomized (quizartinib [n=268], placebo [n=271]). Median age was 56 years (range, 20-75 years). As of August 2021 (median follow-up, 39.2 months), 58 patients remained on continuation. Median OS was significantly longer with quizartinib vs placebo (31.9 vs 15.1 months; HR, 0.776; 95% CI, 0.615-0.979; 2-sided P=.0324). CR+CRi rates were 71.6% and 64.9%, respectively. Allo-HCT in CR1 was performed in 157 patients (quizartinib, 31%; placebo, 27%). When censored for allo-HCT, OS trended longer with quizartinib vs placebo (HR, 0.752; 95% CI, 0.562-1.008; 2-sided P=.055). Relapse-free survival was longer with quizartinib vs placebo (HR, 0.733; 95% CI, 0.554-0.969). Grade ≥3 adverse events (AEs) were similar across arms. Discontinuations due to AEs occurred in 20.4% (quizartinib) and 8.6% (placebo). Fifty-six patients died from treatment-emergent AEs (quizartinib, 11.3%; placebo, 9.7%); mostly infections. Grade 3/4 electrocardiographic QT prolongation occurred in 3.0% (quizartinib) and 1.1% (placebo). CONCLUSIONS: Quizartinib plus standard therapy, followed by continuation, including after allo-HCT, for up to 3 years was tolerable with statistically significant and clinically meaningful OS improvements in adults ≤75 years with newly diagnosed FLT3-ITD+ AML.

• MeSH
• akutní myeloidní leukemie * farmakoterapie   genetika   MeSH
• benzothiazoly MeSH
• chemoterapie konsolidační MeSH
• cytarabin terapeutické užití   MeSH
• daunomycin terapeutické užití   MeSH
• dospělí MeSH
• fenylmočovinové sloučeniny MeSH
• idarubicin terapeutické užití   MeSH
• lidé středního věku MeSH
• lidé MeSH
• transplantace hematopoetických kmenových buněk * metody   MeSH
• tyrosinkinasa 3 podobná fms genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky, fáze III MeSH
• randomizované kontrolované studie MeSH

Oncogenic mutations in gene encoding FLT3 kinase are often detected in acute myeloid leukaemia (AML) patients, and several potent kinase inhibitors have been developed. However, the FLT3 inhibitor treatment often leads to the resistance development and subsequent relapse. Targeted degradation of oncogenic protein kinases has emerged as a feasible pharmacological strategy, providing more robust effect over traditional competitive inhibitors. Based on previously developed competitive inhibitor of FLT3 and CDK9, we have designed and prepared a novel pomalidomide-based PROTAC. A series of biochemical and cellular experiments showed selectivity towards FLT3-ITD bearing AML cells and confirmed proteasome-dependent mechanism of action. Dual FLT3-ITD and CDK9 protein degradation resulted in the block of FLT3-ITD downstream signalling pathways, apoptosis activation and cell cycle arrest of FLT3-ITD AML cells. Moreover, transcriptional repression caused by CDK9 degradation significantly reduced expression of crucial genes involved in AML pathogenesis. The obtained results indicate the beneficial impact of simultaneous FLT3-ITD/CDK9 degradation for AML therapy.

• MeSH
• akutní myeloidní leukemie * patologie   MeSH
• apoptóza MeSH
• cyklin-dependentní kinasa 9 metabolismus   MeSH
• inhibitory proteinkinas farmakologie   terapeutické užití   MeSH
• lidé MeSH
• mutace MeSH
• proteolýza MeSH
• tyrosinkinasa 3 podobná fms genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• akutní myeloidní leukemie * diagnóza   farmakoterapie   MeSH
• antitumorózní látky terapeutické užití   MeSH
• indukční chemoterapie metody   MeSH
• kombinovaná farmakoterapie metody   MeSH
• lidé MeSH
• míra přežití MeSH
• mutace MeSH
• prognóza MeSH
• rizikové faktory MeSH
• tyrosinkinasa 3 podobná fms genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH