{"title":"KIR3DL1-HLA-Bw status in CML is associated with achievement of TFR: the POKSTIC trial, a multicenter observational study","authors":"Hiroshi Ureshino , Yasunori Ueda , Shin Fujisawa , Kensuke Usuki , Hideo Tanaka , Masaya Okada , Shugo Kowata , Kazunori Murai , Asao Hirose , Motohiro Shindo , Takashi Kumagai , Tomoharu Takeoka , Kazuharu Kamachi , Keisuke Kidoguchi , Takero Shindo , Satoshi Iyama , Junki Inamura , Takafumi Nakao , Tsutomu Kobayashi , Eri Kawata , Shinya Kimura","doi":"10.1016/j.bneo.2024.100001","DOIUrl":null,"url":null,"abstract":"<div><h3>Abstract</h3><p>Achievement of treatment-free remission (TFR) after tyrosine kinase inhibitor (TKI) discontinuation in patients who show a durable deep molecular response (DMR) during TKI treatment of chronic myeloid leukemia in chronic phase (CML-CP) is a therapeutic goal; however, the prognostic factors that predict successful achievement of TFR are unclear. Previously, we reported that killer immunoglobulin-like receptor (<em>KIR)</em> and <em>HLA</em> polymorphisms are associated with achievement of a DMR. Here, we investigated the association between <em>KIR</em> and <em>HLA</em> polymorphisms and TFR. We conducted the POKSTIC (POlymorphisms of Killer immunoglobulin-like receptor, which affect Stop Tyrosine kinase Inhibitor in patients with Chronic myeloid leukemia) trial, a multicenter collaborative observational study that enrolled 76 patients with CML-CP. The median age was 63 years (interquartile range [IQR], 49-70). Of 76 patients, 42 (56.6%; 95% confidence interval [CI], 47.7-66.8 at 6 months) discontinued TKIs without molecular relapse; the median follow-up time for TFR was 24 months (IQR, 16-64). <em>KIR</em> genotyping and allele typing did not identify risk factors for molecular relapse; however, univariate and multivariate analysis identified the combination of <em>KIR3DL1</em>-<em>HLA-Bw4</em> (an <em>HLA-B</em> allele) as an independent factor for a higher risk of molecular relapse (hazard ratio, 2.206; 95% CI, 1.112-4.376; <em>P</em> = .024). Notably, patients at higher risk of relapse had a significantly lower number of natural killer (NK) cells at TKI discontinuation than the other patients (CD16<sup>+</sup>/CD56<sup>+</sup> NK cells: median 499.63 cells per μL vs 629.17 cells per μL, respectively; <em>P</em> = .049). Thus, <em>KIR3DL1-HLA-Bw</em> status reflects NK cell responses and is associated with TFR. The study is registered with the UMIN Clinical Trials Registry as #UMIN000041798.</p></div>","PeriodicalId":100189,"journal":{"name":"Blood Neoplasia","volume":"1 1","pages":"Article 100001"},"PeriodicalIF":0.0000,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2950328024000013/pdfft?md5=4478bc59bb04e478596db505d5a8f1b4&pid=1-s2.0-S2950328024000013-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Blood Neoplasia","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2950328024000013","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Achievement of treatment-free remission (TFR) after tyrosine kinase inhibitor (TKI) discontinuation in patients who show a durable deep molecular response (DMR) during TKI treatment of chronic myeloid leukemia in chronic phase (CML-CP) is a therapeutic goal; however, the prognostic factors that predict successful achievement of TFR are unclear. Previously, we reported that killer immunoglobulin-like receptor (KIR) and HLA polymorphisms are associated with achievement of a DMR. Here, we investigated the association between KIR and HLA polymorphisms and TFR. We conducted the POKSTIC (POlymorphisms of Killer immunoglobulin-like receptor, which affect Stop Tyrosine kinase Inhibitor in patients with Chronic myeloid leukemia) trial, a multicenter collaborative observational study that enrolled 76 patients with CML-CP. The median age was 63 years (interquartile range [IQR], 49-70). Of 76 patients, 42 (56.6%; 95% confidence interval [CI], 47.7-66.8 at 6 months) discontinued TKIs without molecular relapse; the median follow-up time for TFR was 24 months (IQR, 16-64). KIR genotyping and allele typing did not identify risk factors for molecular relapse; however, univariate and multivariate analysis identified the combination of KIR3DL1-HLA-Bw4 (an HLA-B allele) as an independent factor for a higher risk of molecular relapse (hazard ratio, 2.206; 95% CI, 1.112-4.376; P = .024). Notably, patients at higher risk of relapse had a significantly lower number of natural killer (NK) cells at TKI discontinuation than the other patients (CD16+/CD56+ NK cells: median 499.63 cells per μL vs 629.17 cells per μL, respectively; P = .049). Thus, KIR3DL1-HLA-Bw status reflects NK cell responses and is associated with TFR. The study is registered with the UMIN Clinical Trials Registry as #UMIN000041798.