Whether there is really a distinct accelerated phase (AP) at diagnosis in chronic myeloid leukaemia (CML) in the context of tyrosine kinase-inhibitor (TKI)-therapy is controversial. We studied 2122 consecutive subjects in chronic phase (CP, n = 1837) or AP (n = 285) at diagnosis classified according to the 2020 European LeukemiaNet (ELN) classification. AP subjects with increased basophils only had similar transformation-free survival (TFS) and survival compared with CP subjects classified as ELTS intermediate-risk. Those with increased blasts only had worse TFS but similar survival compared with CP subjects classified as ELTS high-risk. AP subjects with decreased platelets only had similar TFS but worse survival compared with subjects classified as ELTS high-risk. Proportions of CP and AP subjects meeting the 2020 ELN TKI-response milestones were similar. However, worse TFS at 3-month and survival at 6- or 12-month were only in AP subjects failing to meet ELN milestones. Findings were similar using the 2022 International Consensus Classification (ICC) criteria for AP replacing decreased platelets with additional cytogenetic abnormalities. Our data support the 2022 WHO classification of CML eliminating AP. We suggest adding a very high-risk cohort to the ELTS score including people with increased blasts or decreased platelets and dividing CML into 2 phases at diagnosis: CP and acute or blast phases.

在酪氨酸激酶抑制剂 （TKI） 治疗的情况下，慢性髓系白血病 （CML） 在诊断时是否真的存在明显的加速期 （AP） 存在争议。我们研究了 2122 名连续的慢性期 （CP， n = 1837） 或 AP （n = 285） 受试者，诊断时根据 2020 年欧洲白血病网 （ELN） 分类。与被归类为 ELTS 中等风险的 CP 受试者相比，嗜碱性粒细胞增加的 AP 受试者仅具有相似的无转化生存期 （TFS） 和生存率。与被归类为 ELTS 高危的 CP 受试者相比，原始细胞增加的人的 TFS 更差，但生存率相似。血小板减少的 AP 受试者仅具有相似的 TFS，但与被归类为 ELTS 高危的受试者相比，生存率较差。达到 2020 年 ELN TKI 反应里程碑的 CP 和 AP 受试者的比例相似。然而，3 个月时的 TFS 较差，6 个月或 12 个月的生存率仅在未能达到 ELN 里程碑的 AP 受试者中。使用 2022 年国际共识分类 （ICC） 标准，AP 用额外的细胞遗传学异常替代减少的血小板，结果相似。我们的数据支持 2022 年 WHO 对消除 AP 的 CML 分类。我们建议在 ELTS 评分中增加一个极高危队列，包括原始细胞增加或血小板减少的人群，并在诊断时将 CML 分为 2 个阶段：CP 和急性期或急变期。