{"doi":"10.1038/s41409-024-02444-7","title":"Measurable residual FLT3 tyrosine kinase domain mutations before allogeneic transplant for acute myeloid leukemia","abstract":"High relapse rates for patients despite potentially curative allogeneic hematopoietic cell transplant (alloHCT) remain a critical issue in acute myeloid leukemia (AML). Next-generation sequencing (NGS) represents a promising modality for measurable residual disease (MRD) testing in patients with AML, but the appropriate targets for monitoring must be defined [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. We recently reported that detection of persistent NPM1 or FLT3 internal tandem duplication (ITD) mutations in adults with AML in first complete remission (CR1) prior to alloHCT is associated with increased relapse and death compared with those testing negative [ 8 ]. Variants in the FLT3 tyrosine kinase domain (TKD) are present in 7-10% of adult patients with AML at diagnosis [ 9 ], but the utility of this target for AML MRD testing prior to alloHCT is unknown To investigate FLT3 -TKD as an AML MRD target, we performed single-amplicon, ultra-deep, error-corrected next-generation sequencing (SA-NGS) on blood from adults in CR1 before alloHCT who were reported to have FLT3 -TKD detected at AML diagnosis. We hypothesized that measurable residual FLT3 -TKD variants would be associated with increased relapse and death. Patients aged 18 or older who underwent first alloHCT for FLT3 -TKD mutated AML in CR1 at a Center for International Blood and Marrow Transplant Research (CIBMTR) reporting site between the years of 2013 and 2019, with at least three years clinical follow-up with a suitable remission blood sample collected within 100 days prior to transplant, were eligible for this study. Nine of 351 otherwise eligible patients were excluded due to insufficient ( \\( < \\) 10 ng/μL or 1 μg) genomic DNA (gDNA) available. All patients gave written informed consent in accordance with the Declaration of Helsinki for participation in the CIBMTR research database (NCT01166009) and the sample repository database (NCT04920474). SA-NGS utilizing unique molecular identifiers targeting the D835 and I836 codons of the FLT3 gene was performed on 400 ng gDNA [ 10 ]. Libraries were sequenced (paired-end 150 bp) on a NovaSeq 6000 (Illumina) utilizing unique dual indices. Error-corrected variant calling was performed with LoFreq and the Integrative Genomics Viewer [ 11 ] and a patient was considered positive for FLT3 -TKD MRD if the detected variant allele fraction (VAF) was above the limit of detection (LOD) threshold and greater than 0.01%. A subset of samples was orthogonally validated by droplet digital PCR (ddPCR). See also Supplemental Methods. The primary outcomes of this analysis were cumulative incidence of relapse (CIR) and overall survival (OS) from day of transplant. Non-relapse mortality (NRM) was treated as a competing risk for CIR. Relapse-free survival (RFS) was a secondary outcome. OS and RFS were estimated with Kaplan-Meier survival analysis, and curves were compared with log-rank test. We modeled CIR using the method of Fine & Gray and compared curves with Gray’s test. Univariable analyses and multivariable analyses with stepwise selection by likelihood ratio test for OS and CIR were examined with Cox proportional hazards models for hazard ratio estimates. Statistical analysis was performed using R version 4.3.2. Serial dilution and orthogonal validation data were plotted with GraphPad Prism Version 9.5.1. Patient, disease, and transplant characteristics for the 342 patients examined in this study are shown in Supplementary Table 1 . Median age at diagnosis was 56 years (range 18–77 years) and 181 (53%) patients were female. The most common graft source was peripheral blood ( n = 268, 78%) and the most common donor type was HLA-matched, unrelated donor ( n = 214, 63%). Median follow-up time was 37 months (range 6–101 months) and median time to relapse was 5 months (range 1–48 months). Using the current ELN recommended VAF threshold of 0.1% for NGS-based AML MRD detection [ 4 ], 14 patients (4.1%) tested positive for FLT3 -TKD variants (Supplementary","journal":"Bone Marrow Transplantation","year":2024,"id":463378,"datarank":0.3058459328232867,"base_score":1.9459101490553132,"endowment":1.9459101490553132,"self_citation_contribution":0.29188652235829704,"citation_network_contribution":0.013959410464989644,"self_endowment_contribution":0.29188652235829704,"citer_contribution":0.013959410464989644,"corpus_percentile":null,"corpus_rank":null,"citation_count":6,"citer_count":2,"citers_with_citation_signal":1,"citers_with_endowment":1,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9572,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":985202,"name":"Georgia Andrew","orcid":"0000-0001-5871-2885","position":1,"is_corresponding":false},{"id":351427,"name":"Gege Gui","orcid":"0000-0002-4141-183X","position":2,"is_corresponding":false},{"id":985201,"name":"Niveditha Ravindra","orcid":"0000-0002-2550-493X","position":3,"is_corresponding":false},{"id":985203,"name":"Devdeep Mukherjee","orcid":"0000-0003-3727-7882","position":4,"is_corresponding":false},{"id":337298,"name":"Zoë C. Wong","orcid":"0000-0001-6006-1233","position":5,"is_corresponding":false},{"id":313710,"name":"Jeffery J. Auletta","orcid":"0000-0002-1515-2141","position":6,"is_corresponding":false},{"id":764611,"name":"Firas El Chaer","orcid":"0000-0001-9596-0714","position":7,"is_corresponding":false},{"id":1172993,"name":"Adam Corner","orcid":null,"position":8,"is_corresponding":false},{"id":122963,"name":"Steven M. Devine","orcid":"0000-0001-7731-759X","position":9,"is_corresponding":false},{"id":705035,"name":"Antonio Jiménez","orcid":"0000-0003-2817-6836","position":10,"is_corresponding":false},{"id":339781,"name":"Marcos de Lima","orcid":"0000-0002-8568-4522","position":11,"is_corresponding":false},{"id":284142,"name":"Mark R. Litzow","orcid":"0000-0002-9816-6302","position":12,"is_corresponding":false},{"id":104772,"name":"Partow Kebriaei","orcid":"0000-0002-8607-9404","position":13,"is_corresponding":false},{"id":122972,"name":"Wael Saber","orcid":"0000-0002-6544-5815","position":14,"is_corresponding":false},{"id":122974,"name":"Stephen R. Spellman","orcid":"0000-0002-7271-8252","position":15,"is_corresponding":false},{"id":6679,"name":"Scott L. Zeger","orcid":"0000-0001-8907-1603","position":16,"is_corresponding":false},{"id":348728,"name":"Kristin Page","orcid":"0000-0001-9670-8828","position":17,"is_corresponding":false},{"id":218235,"name":"Laura W. Dillon","orcid":"0000-0002-4877-9354","position":18,"is_corresponding":false},{"id":218236,"name":"Christopher S. Hourigan","orcid":"0000-0002-6189-8067","position":19,"is_corresponding":false},{"id":1172602,"name":"Pranay S. Hegde","orcid":"0000-0002-4996-5247","position":0,"is_corresponding":true}],"reference_count":13,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T02:04:28.838123Z","pmid":"39424958","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}