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Abstract: Despite the use of midostaurin (MIDO) with intensive chemotherapy (ICT) as frontline treatment for Fms-like tyrosine kinase 3 (FLT3)-mutated acute myeloid leukemia (AML), complete remission rates are close to 60% to 70%, and relapses occur in >40% of cases. Here, we studied the molecular mechanisms underlying refractory/relapsed (R/R) disease in patients with FLT3-mutated AML. We conducted a retrospective and multicenter study involving 150 patients with R/R AML harboring FLT3-internal tandem duplication (ITD) (n = 130) and/or FLT3-tyrosine kinase domain mutation (n = 26) at diagnosis assessed by standard methods. Patients were treated with ICT + MIDO (n = 54) or ICT alone (n = 96) according to the diagnosis date and label of MIDO. The evolution of FLT3 clones and comutations was analyzed in paired diagnosis-R/R samples by targeted high-throughput sequencing. Using a dedicated algorithm for FLT3-ITD detection, 189 FLT3-ITD microclones (allelic ratio [AR] of <0.05) and 225 macroclones (AR ≥ 0.05) were detected at both time points. At R/R disease, the rate of FLT3-ITD persistence was lower in patients treated with ICT + MIDO than in patients not receiving MIDO (68% vs 87.5%; P = .011). In patients receiving ICT + MIDO, detection of multiple FLT3-ITD clones was associated with a higher FLT3-ITD persistence rate at R/R disease (multiple clones: 88% vs single clones: 57%; P = .049). If only 24% of FLT3-ITD microclones detected at diagnosis were retained at relapse, 43% became macroclones. Together, these results identify parameters influencing the fitness of FLT3-ITD clones., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

According to current recommendations, older AML patients in first complete remission (CR) after induction chemotherapy should receive consolidation with intermediate-dose cytarabine (IDAC). However, no study has demonstrated the superiority of IDAC over other regimen. In this retrospective study, we compared the efficacy of mini-consolidations (idarubicin 8 mg/m 2 day 1, cytarabine 50 mg/m 2 /12 h, day 1-5) and IDAC. Inclusion criteria were newly diagnosed AML, age > 60 years, first CR after induction and at least 1 cycle of consolidation. Of the 796 included patients, 322 patients received mini-consolidations and 474 patients received IDAC. Mini-consolidation patients were older, and more often, they had de novo AML and unfavorable risk. The rate of allogeneic transplantation was higher in the IDAC group. The median number of cycles was higher in the mini-consolidation group (4 vs. 2; p < .0001). Median relapse-free survival was 18 months with mini-consolidations and 12 months with IDAC (p = .0064). In multivariate analysis, the risk of relapse or death was significantly higher in the IDAC group (p = .004). Median OS was 36 versus 31 months with mini-consolidations or IDAC, respectively (p = .46). In multivariate analysis, the consolidation regimen had no significant influence on OS (p = .43). In older AML patients, post-remission therapy with mini-consolidations represents an alternative to IDAC., (© 2024 The Author(s). American Journal of Hematology published by Wiley Periodicals LLC.)

Acute myeloid leukaemia (AML) arising from a myeloproliferative neoplasm (MPN) is more aggressive and less responsive to therapies compared to de novo AML. Olutasidenib, an oral small-molecule inhibitor of mutated IDH1 (mIDH1), showed encouraging and durable responses in a phase 1/2 study of adults with post-MPN mIDH1 AML. Patients received olutasidenib 150 mg BID monotherapy or in combination with azacitidine. Primary end-points: safety and best response defined as complete remission (CR), CR with partial haematological recovery or morphological leukaemia-free state (MLFS). Analysis included 15 patients with post-MPN mIDH1 AML; 10 had relapsed or refractory AML and five had newly diagnosed AML. Six were treated with olutasidenib monotherapy and nine in combination with azacitidine. Treatment emergent adverse events occurred in 15 patients, three of whom discontinued therapy. CR: 40% (n = 6/15); median duration of response: 15.6 months (range: 1.7-44.3); CR with incomplete haematological recovery: 13% (n = 2/15); MLFS: 7% (n = 1/15); composite complete remission (CRc): 53% (n = 8/15); and overall response rate (ORR): 60% (9/18). Median duration of CRc and ORR: 13.15 (range: 2.4-48.7) and 14.3 months (range: 2.4-48.7), respectively, and median overall survival: 13.8 months (95% confidence interval: 3.70-23.7). Olutasidenib demonstrated encouraging response rates with a manageable safety profile for patients with post-MPN mIDH1 AML., (© 2024 The Author(s). British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Abstract: The European LeukemiaNet (ELN) acute myeloid leukemia (AML) genetic risk classification systems are based on response to intensive chemotherapy; their ability to discriminate outcomes in older patients treated with venetoclax-azacitidine may be suboptimal. This pooled analysis of the phase 3 VIALE-A trial (NCT02993523) and phase 1b study (NCT02203773) examined prognostic stratification according to the 2017 and 2022 ELN risk classifications and derived new molecular signatures differentiating venetoclax-azacitidine-treated patients based on overall survival (OS). Overall, 279 patients treated with venetoclax-azacitidine and 113 patients treated with placebo-azacitidine were analyzed. The ELN 2017 or 2022 prognostic criteria classified most patients as adverse-risk AML (60.2% and 72.8% for venetoclax-azacitidine and 65.5% and 75.2% for placebo-azacitidine, respectively). Although outcomes with venetoclax-azacitidine improved across all ELN risk groups compared with placebo-azacitidine, ELN classification systems poorly discriminated venetoclax-azacitidine outcomes. By applying a bioinformatic algorithm, new molecular signatures were derived differentiating OS outcomes with venetoclax-azacitidine. The mutational status of TP53, FLT3 internal tandem duplication (FLT3-ITD), NRAS, and KRAS categorized patients into higher-, intermediate-, and lower-benefit groups (52%, 25%, and 23% of patients, respectively), each associated with a distinct median OS (26.5 months [95% confidence interval (CI), 20.2-32.7]; 12.1 months [95% CI, 7.3-15.2]; and 5.5 months [95% CI, 2.8-7.6], respectively). ELN prognostic classifiers did not provide clinically meaningful risk stratification of OS outcomes in patients treated with venetoclax-azacitidine. TP53, FLT3-ITD, NRAS, and KRAS mutation status allows the classification of these patients into 3 risk groups with distinct differences in median OS. These trials were registered at www.clinicaltrials.gov as #NCT02993523 and #NCT02203773., (© 2024 American Society of Hematology. Published by Elsevier Inc. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

CPX-351 has been approved for patients with therapy-related acute myeloid leukemia (t-AML) or AML with myelodysplasia-related changes (MRC-AML). No extensive data are available on MRD and long-term clinical outcome using CPX-351 in AML in real-life. We retrospectively collected data from 168 patients in 36 centers in France and Italy who had received one or two cycles of induction with CPX-351. All patients were older than 18 years and had newly diagnosed, untreated t-AML or MRC-AML. With a median follow-up of 3 years, median OS was 13.3 months. Median OS was 20.4 months vs. 12.9 months for patients with MRD below or above 10-3, respectively (p=0.006). In a multivariate analysis, only MRD >10-3 was associated with a poorer OS (hazard ratio [HR]=2.6, 95% CI 1.2-5.5, p=0.013). We also observed a trend towards a better median OS in patients who underwent HSCT with MRD <10-3 (not reached vs. 26.0 months, p=0.06). Achievement of MRD negativity contributed to the improvement of OS in the overall population and, maybe, in transplanted patients. These data provide the rationale for the two ongoing studies evaluating CPX-351 vs. 7+3 in non-MRC-AML and non-t-AML using MRD as the primary endpoint for ALFA-2101 phase II clinical trial and event-free survival for AMLSG 30-18 phase III clinical trial., (Copyright © 2024 American Society of Hematology.)