title: Next-generation sequencing for sensitive detection of BCR-ABL1 mutations relevant to tyrosine kinase inhibitor choice in imatinib-resistant patients.
abstract: In chronic myeloid leukemia (CML) and Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL) patients who fail imatinib treatment, BCR-ABL1 mutation profiling by Sanger sequencing (SS) is recommended before changing therapy since detection of specific mutations influences second-generation tyrosine kinase inhibitor (2GTKI) choice. We aimed to assess i) in how many patients who relapse on second-line 2GTKI therapy next generation sequencing (NGS) may track resistant mutations back to the sample collected at the time of imatinib resistance, before 2GTKI start (switchover sample) and ii) whether low level mutations identified by NGS always undergo clonal expansion. To this purpose, we used NGS to retrospectively analyze 60 imatinib-resistant patients (CML, n = 45; Ph+ ALL,n = 15) who had failed second-line 2GTKI therapy and had acquired BCR-ABL1 mutations (Group 1) and 25 imatinib-resistant patients (CML, n = 21; Ph+ ALL, n = 4) who had responded to second-line 2GTKI therapy, for comparison (Group 2). NGS uncovered that in 26 (43%) patients in Group 1, the 2GTKI-resistant mutations that triggered relapse were already detectable at low levels in the switchover sample (median mutation burden, 5%; range 1.1%-18.4%). Importantly, none of the low level mutations detected by NGS in switchover samples failed to expand whenever the patient received the 2GTKI to whom they were insensitive. In contrast, no low level mutation that was resistant to the 2GTKI the patients subsequently received was detected in the switchover samples from Group 2. NGS at the time of imatinib failure reliably identifies clinically relevant mutations, thus enabling a more effective therapeutic tailoring.
authors.affiliation: Institute of Hematology "L. e A. Seràgnoli", Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Soverini
authors.affiliation: Institute of Hematology "L. e A. Seràgnoli", Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: De Benedittis
authors.affiliation: Institute of Hematology and Blood Transfusion, Prague, Czech Republic.
authors.forename: Katerina Machova
authors.initials: KM
authors.lastname: Polakova
authors.affiliation: Institute of Hematology and Blood Transfusion, Prague, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Linhartova
authors.affiliation: Institute of Hematology "L. e A. Seràgnoli", Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
authors.forename: Fausto
authors.initials: F
authors.lastname: Castagnetti
authors.affiliation: Institute of Hematology "L. e A. Seràgnoli", Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Gugliotta
authors.affiliation: Institute of Hematology "L. e A. Seràgnoli", Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Papayannidis
authors.affiliation: Institute of Hematology "L. e A. Seràgnoli", Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Mancini
authors.affiliation: Institute of Hematology and Blood Transfusion, Prague, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Klamova
authors.affiliation: Oncology-Hematology Department, "S. Maria delle Croci" Hospital, Ravenna, Italy.
authors.forename: Marzia
authors.initials: M
authors.lastname: Salvucci
authors.affiliation: Hematology, Parma University Hospital, Parma, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Crugnola
authors.affiliation: Division of Haematology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Iurlo
authors.affiliation: Hematology Section, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Albano
authors.affiliation: Unit of Blood Disease and Stem Cell Transplantation, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Russo
authors.affiliation: Institute of Hematology "L. e A. Seràgnoli", Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
authors.forename: Gianantonio
authors.initials: G
authors.lastname: Rosti
authors.affiliation: Institute of Hematology "L. e A. Seràgnoli", Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Cavo
authors.affiliation: Institute of Hematology "L. e A. Seràgnoli", Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Baccarani
authors.affiliation: Institute of Hematology "L. e A. Seràgnoli", Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Martinelli
mesh_terms: D000328:Adult; D000368:Aged; D004252:DNA Mutational Analysis / Q000379:methods; D000069439:Dasatinib / Q000627:therapeutic use; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D000068877:Imatinib Mesylate / Q000627:therapeutic use; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000235:genetics*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D012189:Retrospective Studies
chemical_list: C581634:BCR-ABL1 fusion protein, human; D047428:Protein Kinase Inhibitors; D000068877:Imatinib Mesylate; D016044:Fusion Proteins, bcr-abl; D000069439:Dasatinib
keywords: BCR-ABL1; Next-generation sequencing; acute lymphoblastic leukemia; chronic myeloid leukemia; tyrosine kinase inhibitors