Blood 129, 424447 (2017). It's the most common genetic change in acute myeloid leukemia (AML), a type of leukemia that starts in the bone marrow and. Blood 97, 24342439 (2001). You are using a browser version with limited support for CSS. Clonal selection with RAS pathway activation mediates secondary clinical resistance to selective FLT3 inhibition in acute myeloid leukemia. FLT3-ITD fragment length analysis was performed in seven centralized PETHEMA laboratories. has received research funding from Astellas, and Novartis and has served as a member of advisory board in Astellas and Novartis. Among the FLT3mut patients, response rates were numerically higher (33%) and remission duration was longer (31 versus 16 weeks, P=0.09) in those who were naive to treatment with FLT3 inhibitors compared with those who had been exposed to prior FLT3 inhibitors. Only four out of 106 patients had ITD IS in the TKD1 domain. Prognostication refinement in NPM1-mutated acute myeloid leukemia stratified by FLT3-ITD status with different induction doses of cytarabine. Blood 132, 598607 (2018). Regardless of the regimen intensity, all clinical trial participants were grouped in a separate treatment category (n=15). Pulmonary infiltration and acute pneumonitis-like picture are rare (<1%) but noted side effects of midostaurin that treating physicians should be aware of. This result is similar to the RATIFY study, in which 44% of patients lost FLT3 ITD under treatment with midostaurin 36. Oncol. Additionally, different subdomains have been highlighted, such as those conferring an adverse outcome9,10. All samples investigated in this study were obtained at the time of diagnosis. (D) OS according to the FLT3-ITD length and 2010 ELN genetic risk. We prefer a second-generation FLT3i (ideally gilteritinib) in the newly diagnosed setting, and administer the FLT3i D1-D14 during induction, and continuously starting Cycle 2 Day 1 through consolidation. Leukemia 10, 19111918 (1996). Despite the encouraging development of FLT3i, resistance to FLT3i is not uncommon and it can be either primary or secondary. Google Scholar. Although poor prognosis in AML is only associated with FLT3-ITD, all activating FLT3 mutations can contribute to leukemogenesis and are thus potential targets for therapeutic interventions. 1). Perl, A. E. et al. Haematologica 106, 1034 (2020). Thank you for visiting nature.com. (5) No data regarding minimal residual disease (MRD) were available in our cohort, and MRD data could be interesting to analyze in future studies. If C1 D28 marrow confirms remission and ANC<0.5 and/or platelet<50K consider interrupting FLT3i and using neupogen to enhance count recovery. Characteristics and outcome of patients with core binding factor acute myeloid leukemia and FLT3-ITD: results from an international collaborative study. The point mutations that lead to resistance include N676, F691, and D835, together with FLT3-ITD. Yamamoto, Y. et al. https://doi.org/10.1038/s41598-021-00050-x. Two classes of activating FLT3 mutations occur in AML: (1) internal tandem duplication ( FLT3 -ITD) which occur in 20-25% of patients and (2) tyrosine kinase domain mutations ( FLT3 -TKD) which are seen in 5-10% of patients [48]. Lancet Oncol. Hematol. We stop the venetoclax and the FLT3i after Day 14 in patients who achieve marrow remission (<5% blasts) and/or marrow aplasia/hypoplasia/insufficiency (<5% cellularity). Schlenk, R. F. et al. In particular, high (>0.5) mutant-to-wild-type (WT) allelic ratios (AR) in the FLT3-ITD gene are associated with inferior prognosis ( 6, 7 ). 13, 139 (2020). An analysis of OS censoring at the time of allo-HSCT did not yield significant results (data not shown). 15, 17 In our cohort, the prevalence of FLT3-ITD mutation of de novo AML patients was 21.5%. 5 96 102, C Sargas 2020 Networking for advanced molecular diagnosis in acute myeloid leukemia patients is possible: The PETHEMA NGS-AML project Haematologica https://doi.org/10.3324/haematol.2020.263806, Article Quizartinib, a second-generation, type I FLT3i is active against FLT3, KIT, CSF1R, PDGFR, and RET kinase34. Scientific Reports (Sci Rep) @Repeat a C1 D28 bone marrow on all patients to confirm remission. The authors declare no competing interests. 2A). The NPM1/FLT3-ITD patients had normal karyotypes. While both FLT3-ITD and FLT3-TKD mutations are common in AML with a normal karyotype, these mutations are also identified in AML with various karyotypic abnormalities. AR, allelic ratio. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Blood 136, 3233 (2020). To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. 368, 20592074 (2013). The on-target mechanism of resistance includes emergence of secondary TKD mutations in patients treated with type II inhibitors like quizartinib or sorafenib69,70. In 40 patients (87%), the prognosis based on the ELN 2017 risk stratification algorithm did not change due to AR, whereas, in 6 patients (13%), the FLT3-ITD mutation burden was <0.5 in DNA and 0.5 in cDNA, which changed their risk stratification. Oncol. Although poor prognosis in AML is only associated with FLT3-ITD, all activating FLT3 mutations can contribute to leukemogenesis and are thus potential targets for therapeutic interventions. The prognostic value of a FLT3 mutation in the tyrosine kinase domain (FLT3-TKD), which has a lower incidence in AML (approximately 7-10% of all cases), is uncertain. We retrospectively reviewed 3555 acute myeloid leukemia patients, who have been assessed for FLT3 mutation at our institution . Mutations of the fms-tyrosine kinase ( FLT3) were first described in 1997 4 and account for the most frequent molecular mutations in AML. Presented in part at the 42nd Annual Meeting of the American Society of Hematology, December 15, 2000, San Francisco, CA (abstract 2334). Authors At a median follow-up of 42 months, sorafenib demonstrated a 2-year estimated RFS of 85% and OS of 90.5% compared with 53.3% (P=0.002), and 66.2% with placebo, respectively (P=0.007). Mali, R. S. et al. Fms-like tyrosine kinase 3 (FLT3) is a recurrent genetic abnormality in AML (~30%)1,2,3. Interestingly, FLT3-ITD mutation, which has an adverse prognosis is found in up to one-third of younger patients but only 15-18% in >65 years. Green indicates non-mutated genes, red indicates mutated genes and white indicates non-mutated genes. Yilmaz et al. Genetic biomarkers of sensitivity and resistance to venetoclax monotherapy in patients with relapsed acute myeloid leukemia. Slider with three articles shown per slide. Blood 130, 723 (2017). Recurrent somatic internal tandem duplications (ITD) in the FMS-like tyrosine kinase 3 (FLT3) gene characterise approximately one third of patients with acute myeloid leukaemia (AML), and FLT3-ITD mutation status guides risk-adapted treatment strategies.The aim of this work was to characterise FLT3-ITD variant distribution in relation to molecular and clinical features, and overall survival in . Addition of venetoclax to this backbone may be associated with prolonged and potentially prohibitive myelosuppression; we have not routinely added and do not at this time recommend adding venetoclax to the backbone of CLIA/FIA with FLT3i63. Burchert, A. et al. All eligible intermediate or high-risk patients (defined as patients with FLT3-ITDmut AR>0.50 irrespective of NPM1mut status, or FLT3-ITDmut AR<0.50 without NPM1mut) are equivocally recommended to proceed to ASCT in CR1 followed by post-ASCT FLT3i maintenance for at least 2 years (although we often continue indefinite FLT3i maintenance until long-term maintenance data becomes available). Despite the current availability of the FLT3 inhibitor midostaurin, there is an unmet need for improved treatment options. evaluated the impact of AR in 323 patients with newly diagnosed FLT3-ITDmut AML. Secondary resistance to FLT3i could be either on-target (changes in the FLT3) or off-target (constitutive activation of non-FLT3-dependent oncogenic pathways). volume11, Articlenumber:20745 (2021) Information regarding the ITD insertion site and mutational status of another 38 genes recurrently mutated in myeloid neoplasms was available in 106 and 118 patients, respectively. The images or other third party material in this article are included in the articles Creative Commons license, unless indicated otherwise in a credit line to the material. Therefore, only 3.8% of the patients showed an FLT3-ITD insertion in the TKD1 domain. Ravandi, F. et al. FLT3-ITD is a constitutively activated variant of the FLT3 tyrosine kinase receptor. 18, 10611075 (2017). The median RFS was 1.2years (CI 0.22.2) and 0.77years (CI 0.51.1), respectively (P=0.06). Of note, we tested 3 different ITD length thresholds, and to be considered significant, the P value should be<0.025. ISSN 2045-2322 (online). Swaminathan, M. et al. 1A). 93, E202E205 (2018). The mutation rate of FLT3/ITD in DEK/CAN-positive AML patients is as high as 70% (8,9). PubMed J. Hematol. The median OS was 1.3years (CI 0.71.9) and 1.4years (CI 1.01.8), respectively (P=0.8). volume11, Articlenumber:104 (2021) We found that patients with FLT3-ITD had a poor prognosis at any age, while patients with CEBPA biallelic mutation were younger and had a better prognosis. Multivariate analysis showed that age < 65 years, FLT3-ITD and CEBPA bZIP in-frame mutation were independent prognostic factors. QuANTUM-R, a phase 3 randomized controlled trial, evaluated quizartinib monotherapy vs investigator choice salvage chemotherapy in R/R FLT3-ITDmut AML. DiNardo, C. D. et al. 5, 6 The FLT3 gene is a member of the class III receptor tyrosine kinase family, including c-kit, c-fms, and the platelet-derived growth factor receptors. Azacitidine and venetoclax in previously untreated acute myeloid leukemia. Password. Cancer 125, 37553766 (2019). FLT3 -ITD and FLT3 point mutations show a gain-of-function phenotype with distinct signalling properties in vitro. PubMed Central However, in addition to QTcF prolongation, quizartinib is also more myelosuppressive than many other FLT3 inhibitors likely due to the inhibition of KIT. Netw. Blood 127, 360362 (2016). 61, 72337239 (2001). Larger studies of ITD size, although they did not employ these cutoffs, did not find prognostic power of this measure, which corroborates our results. We have no explanation regarding the reduced number of patients with an FLT3-ITD inserted in TKD1 found in our cohort. The two leading types of FLT3 mutations found in AML include internal tandem duplications in the juxtamembrane domain (ITD, 17-34%) and mutations in the tyrosine kinase domain (TKD) activation loop (~7%) ( 1 ). Brinton, L. T. et al. Rydapt Prescribing Information. In a study that identified molecular mechanisms of resistance to gilteritinib, 32% of patients had emergent mutations in the RAS/MAPK pathway (K/NRAS), and 5% had emergent BCR/ABL1 fusions71. FLT3 plays a role in cell survival, proliferation and differentiation of hematopoietic progenitor cells. The favorable prognostic molecular mutations, such as NPM-1 and CEBPA, are uncommon in elderly AML . However, other studies did not find significantly worse clinical outcomes in patients with non-JMD ITD mutations24,25. In patients 55 years, this regimen appeared to overcome the negative impact of FLT3-ITDmut in NPM1 co-mutated patients, regardless of the FLT3 AR, with comparable 3-year OS rates of 64% and 68% in FLT3-ITDmut NPM1mut and FLT3-ITDWT NPM1mut patients, respectively (P>0.05). Jain, P. et al. Rollig, C. et al. The insertion site of FLT3-ITD was available in 106 of 118 patients (Fig. FLT3 -ITD is located within exon 14, corresponding to JMD,. recently presented the first triplet combination of venetoclax, FLT3i (mainly gilteritinib or sorafenib), and decitabine from the FLT3mut subset of the prospective decitabine 10 days with venetoclax study (NCT03404193)54. J. Hematol. The median OS was 1.0years [CI not calculable (NC)], 2.3years (CI: 1.23.5), 1.6years (CI: 0.62.6) and 1.0years (CI: 0.81.2), respectively (P=0.9). Soc. G Nagel 2017 Epidemiological, genetic, and clinical characterization by age of newly diagnosed acute myeloid leukemia based on an academic population-based registry study (AMLSG BiO) Ann. The AR was determined by fragment length analysis and calculated as previously described32. These observations have made FLT3 an attractive drug target. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. Konopleva, M. et al. In the R/R setting, the CRc rate was 64% (n=18/28) with a median OS of 12.0 months, with responses observed even in prior FLT3i exposed patients48. Among 362 patients, NGS was performed in 118 patients using a panel of 39 genes. Am. Our median ITD length was 48bp (range=3bp to 231bp), similar to previous studies12,14,17. Google Scholar, MR ODonnell 2017 Acute myeloid leukemia, version 3.2017, NCCN clinical practice guidelines in oncology J. Natl. FMS-like tyrosine kinase-3 internal tandem duplication (FLT3-ITD) is one of the most frequent mutations found in AML patients. CAS Among 38 patients with FLT3mut AML who received gilteritinib 120mg daily, the CRc rate was 81.6% (n=31) including 39.5% CR and median OS was not reached at a median follow-up of 35.8 months. In general, AML patients with intermediate-risk cytogenetics and with a FLT3-ITD mutation have a significantly poorer prognosis with an increased relapse risk and decreased . The impact of FLT3 internal tandem duplication mutant level, number, size, and interaction with NPM1 mutations in a large cohort of young adult patients with acute myeloid leukemia. Retrospectively, we investigated the prognostic and predictive. This value highlights the scarce prognostic value of the measure. Clinical outcome stratified according to the FLT3-ITD length (cutoff 39bp) for all patients treated with intensive chemotherapy. Patterns of resistance differ in patients with acute myeloid leukemia treated with type I versus type II FLT3-inhibitors. While the adverse prognostic impact of FLT3-ITDmut in AML has been clearly proven, the prognostic significance of FLT3-TKDmut remains speculative. We administer a second-generation FLT3i (ideally gilteritinib) continuously with HMA from cycle 1 Day 1. Publishers note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. A Conventional approach. Rosnet, O. et al. In the frontline setting (n=4), the CRc rate with the triplet was 100% with FLT3-PCR negativity in all four patients56. and JavaScript. Conceptualization, T.C., J.M.A., E.B. FLT3-ITD has been strongly associated with a bad prognosis, leukocytosis, high blast counts, increased risk of relapse and shorter overall survival. Yilmaz et al. In patients with FLT3mut AML who relapsed after first ASCT, sorafenib was found to be tolerable with long-lasting remissions in 7 of 29 patients treated, suggesting a potential synergy with post-ASCT alloimmune effects41. Cortes, J. et al. Although the label indication for gilteritinib is as a single agent we have never used it as a single agent but always in combination with either HMA alone, venetoclax alone or as a triplet with HMA and venetoclax. Therefore, these patients were not included in the analysis stratified by 2010 ELN genetic risk21. 135, 397402 (1986). https://doi.org/10.1038/s41408-021-00495-3, DOI: https://doi.org/10.1038/s41408-021-00495-3. N.D. has received research funding from Daiichi-Sankyo, Bristol-Myers Squibb, Pfizer, Gilead, Sevier, Genentech, Astellas, Daiichi-Sankyo, Abbvie, Hanmi, Trovagene, FATE, Amgen, Novimmune, Glycomimetics, and ImmunoGen and has served in a consulting or advisory role for Daiichi-Sankyo, Bristol-Myers Squibb, Pfizer, Novartis, Celgene, AbbVie, Astellas, Genentech, Immunogen, Servier, Syndax, Trillium, Gilead, Amgen, and Agios. To mitigate prolonged myelosuppression with the triplet and avoid over-treatment, we perform an early bone marrow assessment on Cycle 1 Day 14 (Fig. 15 926 957, H Dhner DJ Weisdorf CD Bloomfield 2015 Acute myeloid leukemia N. Engl. Biol. This study shows that the size of FLT3-ITD mutations has no prognostic impact in terms of survival, relapse or CR rate among newly diagnosed AML patients treated with first-line intensive regimens. Astellas Reports XOSPATA (gilteritinib) in combination with azacitidine did not meet endpoint of overall survival in newly diagnosed flt3 mutation-positive acute myeloid leukemia patients ineligible for intensive induction chemotherapy (2020). Results of a Phase 2, Randomized, Double-Blind Study of Sorafenib Versus Placebo in Combination with Intensive Chemotherapy in Previously Untreated Patients with FLT3-ITD Acute Myeloid Leukemia (ALLG AMLM16) (ASH, 2020). Elderly patients with AML have a distinct genetic landscape compared with the younger population. In patients with FLT3mut AML unsuitable for intensive chemotherapy, azacitidine with venetoclax demonstrated encouraging CR/CRi rates (5570%) and a median OS of 13.3 months64 which prompted the inclusion of this combination approach as part of NCCN AML guidelines (Fig. Unlike midostaurin, quizartinib monotherapy, even at lower doses demonstrated significant marrow remissions in R/R FLT3mut AML35,36,37. The choice of treatment backbone depends on the patients ability to successfully tolerate intensive chemotherapy. Souki Cancer Research Fund and generous philanthropic contributions to the MD Anderson Moon Shots Program. Request PDF | Prognostic impact of FLT3-ITD, NPM1 mutation and CEBPA bZIP domain mutation in cytogenetically normal acute myeloid leukemia: a Hokkaido Leukemia Net study | Mutation status of FLT3 . PubMedGoogle Scholar. Blood 111, 27762784 (2008). We have no information on the treatment received by the remaining patients. These combinations appear to improve the efficacy over single agent gilteritinib and could be considered if there is expertise in using such an approach, For patients relapsing while on gilteritinib or soon after gilteritinib based therapy a combination of azacitidine with sorafenib or azacitinde with venetoclax or gemtuzumab based approaches may be considered as salvage options (with clinical trials being clearly the best option if available). contracts here. FLT3-ITD mutations occur in the form of a replicated sequence in the juxtamembrane domain (JMD) and/or TKD1 of the FLT3 gene. Clinical outcomes in patients with relapsed/refractory acute myeloid leukemia treated with gilteritinib who received prior midostaurin or sorafenib. Fishers exact test was employed to correlate the ITD insertion site and mutational status. Blood 100, 43724380 (2002). Welch John, S. et al. Statistically significant results were not observed for any other gene in this analysis. Haematologica (2021). Kiyoi, H. et al. Prognostic implication of FLT3 and N-RAS gene mutations in acute myeloid leukemia. We tried to validate the thresholds of ITD length previously published (i.e., 39bp and 70bp) in intensivelytreated AML patients (n=161). A comparable decrease in CRc rates (45%21%10%) and OS (7.94.04.1 months) was observed with sequential FLT3i-based therapies in the R/R AML setting73. Sci Rep 11, 20745 (2021). Cortes, J. E. et al. Furthermore, a global query was sent to the different centralized laboratories of PETHEMA to verify the ITD length, insertion site and molecular profile of the patients by NGS when these data were available. Nevertheless, some thresholds have been applied in more than one study [i.e., 39bp and 70bp]11,15,16,17. Minetto, P. et al. Venetoclax Added to Cladribine, Idarubicin, and Cytarabine with or without a FLT3 Inhibitor in Newly Diagnosed Acute Myeloid Leukemia (EHA, 2020). Cortes, J. E. et al. Increase in bilirubin and transaminase can be seen with giltertiinib but are usually self-resolving and transient. The impact of prognostic factors may change as the AML treatment landscape evolves. Libura, M. et al. We observed a low frequency of NPM1 mutation (10.1%), which correlated with the good prognosis of this mutation. Acute myeloid leukemia (AML) patients with FLT3/ITD mutations have a poor prognosis. 21, 12011212 (2020). S2) in PETHEMA centralized diagnostic laboratories as previously described33. Sorafenib plus intensive chemotherapy improves survival in patients with newly diagnosed, FLT3-internal tandem duplication mutation-positive acute myeloid leukemia. The Programa Espaol de Tratamientos en Hematologa (PETHEMA) AML epidemiologic registry (NCT02607059) includes patients diagnosed with AML, regardless of the treatment administered. The phase III RATIFY study (CALGB 10603), for example, looked at the addition of the tyrosine kinase inhibitor midostaurin to intensive chemotherapy in newly-diagnosed AML with FLT3 mutations (either ITD or TKD) and showed an overall survival (OS) benefit with midostaurin compared to placebo (74.7 vs. 25.6 months, respectively) . Nakao, M. et al. The survival rates in patients 60 years of age were also similar across NPM1 mut /FLT3 wt, NPM1 mut /FLT3-ITD low, and NPM1 mut . Daver, N. et al. 94, 984991 (2019). To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Sorafenib maintenance after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia with FLT3internal tandem duplication mutation (SORMAIN). FLT3-ITD allelic ratio and HLF expression predict FLT3 inhibitor efficacy in adult AML, Impact of numerical variation, allele burden, mutation length and co-occurring mutations on the efficacy of tyrosine kinase inhibitors in newly diagnosed FLT3- mutant acute myeloid leukemia, Molecular landscape and prognostic impact of FLT3-ITD insertion site in acute myeloid leukemia: RATIFY study results, Distinct clinico-biological features in AML patients with low allelic ratio FLT3-ITD: role of allogeneic stem cell transplantation in first remission, Poor outcome of pediatric patients with acute myeloid leukemia harboring high FLT3/ITD allelic ratios, Mutational spectrum and prognostic stratification of intermediate-risk acute myeloid leukemia, Genomic landscape of patients with FLT3-mutated acute myeloid leukemia (AML) treated within the CALGB 10603/RATIFY trial, Impact of FLT3-ITD allele ratio and ITD length on therapeutic outcome in cytogenetically normal AML patients without NPM1 mutation, Mutational spectrum and prognosis in NRAS-mutated acute myeloid leukemia, https://doi.org/10.3324/haematol.2020.263806, http://creativecommons.org/licenses/by/4.0/. Off-target resistance includes clonal evolution during FLT3i therapy even when FLT3-ITDmut clone is lost70. FLT3 activating mutations (FLT3mut) may involve either the juxta membrane domain [internal tandem duplication mutations (FLT3-ITD)]4 or the tyrosine kinase domain (FLT3-TKD)5,6. FLT3 mutations are the most common mutations in AML 2 Of patients newly diagnosed with AML and tested for FLT3 mutations: 30 were positive for FLT3-ITD 7 were positive for FLT3-TKD FLT3-ITD mutations negatively impact survival in relapsed or refractory AML 1 Given the increasing importance that massive sequencing techniques are acquiring in the prognosis determination and therapeutic management of AML patients, we decided to study the possible correlation between the length or site of the insertion of the mutated ITD fragment and the mutational profile of these patients.