Pediatric chronic myeloid leukemia (CML) is more aggressive than adult CML, with unique molecular characteristics and a higher propensity for lymphoid blast crisis. The application of tyrosine kinase inhibitors (TKIs) has significantly improved the prognosis of pediatric CML. Based on international consensus and clinical experience, this article proposes standardized diagnosis and treatment recommendations for pediatric CML, covering initial therapy selection, efficacy evaluation, drug switching, and management of adverse effects. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is recommended only for patients with disease progression or failure of multiple lines of TKI therapy. For children newly diagnosed with CML in accelerated phase, high-dose imatinib or second-generation TKIs are recommended as first-line therapy. Those achieving optimal responses should continue maintenance therapy, while non-responders require switching to alternative TKIs and consider allo-HSCT. For blast-phase CML, induction therapy requires a combination of TKIs and chemotherapy, with allo-HSCT serving as the core curative intervention. This article highlights common but challenging problems (poor response, drug intolerance, and disease progression) in pediatric CML treatment using three typical cases, aiming to optimize treatment strategies. Furthermore, the goal of achieving treatment-free remission needs to be further addressed through multi-center clinical studies.
Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Child ; Hematopoietic Stem Cell Transplantation ; Protein Kinase Inhibitors/therapeutic use* ; Male ; Female ; Adolescent

Tyrosine kinase inhibitors (TKIs) have significantly improved the prognosis of patients with chronic myeloid leukemia (CML), and achieving treatment-free remission (TFR) has become a new goal for these patients. Various methods of discontinuing medication are continuously being explored, with successful cessation linked to factors such as the duration of TKI treatment, the sustainability of deep molecular response (DMR), transcript type, and immunological factors. Early switching of TKI, combining other therapies, and targeting leukemia stem cells may help increase the TFR rate. This article reviews the latest research developments on the exploration of TKI cessation, factors affecting TFR, selection of patients for discontinuation, strategies to enhance TFR, and monitoring after cessation, expecting to provide reference and guidance for achieving TFR in CML patients.
Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Protein Kinase Inhibitors/therapeutic use* ; Remission Induction ; Tyrosine Kinase Inhibitors

OBJECTIVE: To investigate the effect of different previous treatments on the efficacy of flumatinib in patients with chronic myeloid leukemia (CML). METHODS: The clinical data of 69 patients with CML treated with flumatinib in the Affiliated Hospital of Xuzhou Medical University from 2019 to 2024 were retrospectively analyzed. The patients were divided into a first-line flumatinib group and a first-line non-flumatinib group according to whether flumatinib was used as first-line treatment. The molecular response (MR) at 3, 6 and 12 months of treatment was compared between the two groups to evaluate the early efficacy. The first-line non-flumatinib group was further divided into imatinib group, nilotinib group, and dasatinib group according to the previous first-line drugs used. The efficacy data of these three groups at 3, 6 and 12 months after switching to flumatinib were collected, and the MR was evaluated to compare efficacy differences. RESULTS: The rate of early molecular response (EMR) in the first-line flumatinib group was significantly higher than that in the first-line non-flumatinib group (P < 0.05). At 6 months and 12 months of treatment, the proportion of patients achieving MR 4.5 in the first-line flumatinib group was significantly higher than that in the first-line non-flumatinib group (P < 0.05). Compared with the imatinib and nilotinib groups, the previous dasatinib group showed a significantly higher proportion of patients achieving MR 5.0 at 3, 6, and 12 months after switching to flumatinib (P < 0.05). CONCLUSION Compared with the previous treatment with other tyrosine kinase inhibitors (TKIs), initial use of flumatinib at diagnosis enable patients to achieve deeper molecular remission more rapidly. Compared with previous use of imatinib or nilotinib, previous use of dasatinib is associated with deeper molecular remission after switching to flumatinib.
Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Retrospective Studies ; Imatinib Mesylate/therapeutic use* ; Dasatinib/therapeutic use* ; Treatment Outcome ; Pyrimidines/therapeutic use* ; Female ; Male ; Protein Kinase Inhibitors/therapeutic use* ; Middle Aged ; Antineoplastic Agents/therapeutic use*

Objective: To analyze and compare therapy responses, outcomes, and incidence of severe hematologic adverse events of flumatinib and imatinib in patients newly diagnosed with chronic phase chronic myeloid leukemia (CML) . Methods: Data of patients with chronic phase CML diagnosed between January 2006 and November 2022 from 76 centers, aged ≥18 years, and received initial flumatinib or imatinib therapy within 6 months after diagnosis in China were retrospectively interrogated. Propensity score matching (PSM) analysis was performed to reduce the bias of the initial TKI selection, and the therapy responses and outcomes of patients receiving initial flumatinib or imatinib therapy were compared. Results: A total of 4 833 adult patients with CML receiving initial imatinib (n=4 380) or flumatinib (n=453) therapy were included in the study. In the imatinib cohort, the median follow-up time was 54 [interquartile range (IQR), 31-85] months, and the 7-year cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) were 95.2%, 88.4%, 78.3%, and 63.0%, respectively. The 7-year FFS, PFS, and OS rates were 71.8%, 93.0%, and 96.9%, respectively. With the median follow-up of 18 (IQR, 13-25) months in the flumatinib cohort, the 2-year cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) were 95.4%, 86.5%, 58.4%, and 46.6%, respectively. The 2-year FFS, PFS, and OS rates were 80.1%, 95.0%, and 99.5%, respectively. The PSM analysis indicated that patients receiving initial flumatinib therapy had significantly higher cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) and higher probabilities of FFS than those receiving the initial imatinib therapy (all P<0.001), whereas the PFS (P=0.230) and OS (P=0.268) were comparable between the two cohorts. The incidence of severe hematologic adverse events (grade≥Ⅲ) was comparable in the two cohorts. Conclusion: Patients receiving initial flumatinib therapy had higher cumulative incidences of therapy responses and higher probability of FFS than those receiving initial imatinib therapy, whereas the incidence of severe hematologic adverse events was comparable between the two cohorts.
Adult ; Humans ; Adolescent ; Imatinib Mesylate/adverse effects* ; Incidence ; Antineoplastic Agents/adverse effects* ; Retrospective Studies ; Pyrimidines/adverse effects* ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Treatment Outcome ; Benzamides/adverse effects* ; Leukemia, Myeloid, Chronic-Phase/drug therapy* ; Aminopyridines/therapeutic use* ; Protein Kinase Inhibitors/therapeutic use*

OBJECTIVE: To explore the expression pattern and clinical significance of Integral membrane protein 2A（ITM2A） in drug resistant patients with chronic myeloid leukemia (CML). METHODS: The expression of ITM2A in CML was evaluated by qRT-PCR, Western blot and immunocytochemistry. In order to understand the possible biological effects of ITM2A, apoptosis, cell cycle and myeloid differentiation antigen expression of CML cells were detected by flow cytometry after over-expression of ITM2A. The nuderlying molecular mechanism of its biological effect was explored. RESULTS: The expression of ITM2A in bone marrow of CML resistant patients was significantly lower than that of sensitive patients and healthy donors（P<0.05）. The CML resistant strain cell K562R was successfully constructed in vitro. The expression of ITM2A in the resistant strain was significantly lower than that in the sensitive strain(P<0.05). Overexpression of ITM2A in K562R cells increased the sensitivity of K562R cells to imatinib and blocked the cell cycle in G₂ phase(P<0.05), but did not affect myeloid differentiation. Mechanistically, up-regulation of ITM2A reduced phosphorylation in ERK signaling (P<0.05). CONCLUSION The expression of ITM2A was low in patients with drug resistance of CML, and the low expression of ITM2A may be the key factor of imatinib resistance in CML.
Humans ; Antineoplastic Agents/pharmacology* ; Apoptosis ; Drug Resistance, Neoplasm ; Imatinib Mesylate/therapeutic use* ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Signal Transduction

OBJECTIVE: To analyze the efficacy and safety of flumatinib in the treatment of patients with chronic myeloid leukemia (CML). METHODS: The clinical data of 56 CML patients treated with flumatinib from January 2020 to December 2021 in the First Affiliated Hospital of Nanchang University were retrospectively analyzed. Patients were divided into three groups: 35 new diagnosed CML patients treated with flumatinib (group A), 10 patients with imatinib/dasatinib intolerance (group B) and 11 patients with imatinib/dasatinib resistance (group C) switched to flumatinib treatment, respectively. The molecular response and adverse effects of flumatinib treatment were evaluated. RESULTS: In group A, the early molecular response (EMR) at 3 months was 40.0%, and the major molecular response (MMR) at 6 and 12 months was 43.7% and 46.2%, respectively. In group B, the EMR was 50.0% at 3 months, and the MMR was 70.0% and 66.2% at 6 and 12 months, respectively. Among evaluable patients, 6 cases in group B achieved molecular response of 4.5 (MR4.5) at 12 months after switching to flumatinib treatment. In group C, 3 cases who switched from imatinib resistance to flumatinib achieved MR4.5 at 12 months, but 2 cases who switched from dasatinib resistance to flumatinib failed. Subgroup analysis showed significant differences in EUTOS long-term survival (ELTS) scores for patients in the medium-risk/high-risk group compared with those in the low-risk group for 3-month EMR (18.8% vs 57.9%), 6-month MMR (15.4% vs 63.2%) and 12-month MR4.5 (15.4% vs 69.2%) (P =0.036, P =0.012,P =0.015). The most common adverse effect in group A was thrombocytopenia, accounting for 54.5%, and 22.8% (8/35) patients discontinued the drug due to haematological adverse effects. Compared with patients who did not discontinue the drug or whose recovery time from discontinuation due to haematological toxicity was <1 month, patients whose recovery time from discontinuation was ≥1 month had a significantly worse 3-month EMR, 6-month MMR and 12-month MR4.5 (P =0.028, P =0.021, P =0.002). CONCLUSIONS Flumatinib has better molecular response and tolerance in patients with primary, imatinib/dasatinib-intolerant or resistant CML. Medium-risk/high-risk in ELTS score and time to recovery from discontinuation due to haematological toxicity ≥1 month are important factors influencing achievement of better molecular response in flumatinib treatment.
Humans ; Imatinib Mesylate/therapeutic use* ; Dasatinib/therapeutic use* ; Protein Kinase Inhibitors/therapeutic use* ; Retrospective Studies ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Benzamides/therapeutic use* ; Chronic Disease ; Treatment Outcome ; Antineoplastic Agents/therapeutic use*

Objective: To develop a scoring system to predict molecular responses in patients with chronic myeloid leukemia in the chronic phase (CML-CP) receiving initial imatinib therapy. Methods: Data from consecutive adults with newly diagnosed CML-CP treated by initial imatinib was interrogated and subjects were distributed randomly into training and validation cohort, in a ratio of 2∶1. Fine-gray models were applied in the training cohort to identify co-variates of predictive value for major molecular response (MMR) and MR4. A predictive system was built using significant co-variates. The predictive system was then tested in the validation cohort and the area under the receiver-operator characteristic curve (AUROC) was used to estimate accuracy of the predictive system. Results: 1 364 CML-CP subjects receiving initial imatinib were included in this study. Subjects were distributed randomly into training cohort (n=909) and validation cohort (n=455) . In the training cohort, the male gender, European Treatment and Outcome Study for CML (EUTOS) Long-Term Survival (ELTS) intermediate-risk, ELTS high-risk, high WBC (≥130×10(9)/L or 120×10(9)/L, MMR or MR4) and low HGB (<110 g/L) at diagnosis were significantly related with poor molecular responses and were given points based on their regression coefficients. For MMR, male gender, ELTS intermediate-risk and low HGB (<110 g/L) were given 1 point; ELTS high-risk and high WBC (≥130×10(9)/L) , 2 points. For MR4, male gender was given 1 point; ELTS intermediate-risk and low HGB (<110 g/L) were given 2 points; high WBC (≥120×10(9)/L) , 3 points; ELTS high-risk, 4 points. We divided all subjects into 3 risk subgroups according to the predictive system above. Cumulative incidence of achieving MMR and MR4 in 3 risk subgroups was significantly different in both training and validation cohort (all P values <0.001) . In the training and validation cohorts, the time-dependent AUROC ranges of MMR and MR4 predictive systems were 0.70-0.84 and 0.64-0.81, respectively. Conclusions: A scoring system combining gender, WBC, HGB level and ELTS risk was built to predict MMR and MR4 in CML-CP patients receiving initial imatinib therapy. This system had good discrimination and accuracy, which could help phsicians optimize the selsction of initial TKI-therapy.
Adult ; Humans ; Male ; Imatinib Mesylate/therapeutic use* ; Antineoplastic Agents/therapeutic use* ; Treatment Outcome ; Protein Kinase Inhibitors/therapeutic use* ; Retrospective Studies ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Chronic Disease

Humans ; Child ; Tyrosine Protein Kinase Inhibitors ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Protein Kinase Inhibitors/therapeutic use* ; Chronic Disease

The treatment of chronic myeloid leukemia (CML) was revolutionized with the advent of the first-generation tyrosine kinase inhibitors (TKIs), but drug resistance developed during treatment, leading to the development of the second-generation (dasatinib, nilotinib, and bosutinib) and third-generation (ponatinib) TKI. Compared with previous treatment regimens, specific TKI can significantly improve the response rate, overall survival rate and prognosis of CML. Only a few patients with BCR-ABL mutation are insensitive to the second-generation TKIs, so it is suggested to select the second-generation TKIs for patients with specific mutations. For patients with other mutations and without mutations, the second-generation TKI should be selected according to the patient's medical history, while the third-generation TKIs should be selected for mutations that are insensitive to the second-generation TKIs, such as T315I mutation that is sensitive to ponatinib. Due to different BCR-ABL mutations in patients with different sensitivity to the second and third-generation TKIs, this paper will review the latest research progress of the efficacy of the second and third-generation TKIs in CML patients with BCR-ABL mutations.
Humans ; Antineoplastic Agents/pharmacology* ; Dasatinib/pharmacology* ; Drug Resistance, Neoplasm/genetics* ; Fusion Proteins, bcr-abl/genetics* ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Mutation ; Protein Kinase Inhibitors/therapeutic use*

Objective: To explore the influencing covariates of severe neutrophils and/or thrombocytopenia and their effect on treatment response and outcome in patients with chronic-phase chronic myeloid leukemia (CP-CML) receiving initial second-generation tyrosine kinase inhibitors (2G-TKI) . Methods: Data from consecutive patients aged ≥18 years with newly diagnosed CP-CML who received initial 2G-TKI at Peking University People's Hospital from September 2008 to November 2021 were interrogated. Binary logistic regression models and Fine-Gray and Cox regression models were applied. Results: Data from 267 patients who received initial 2G-TKI, including nilotinib (n=239, 89.5% ) and dasatinib (n=28, 10.5% ) , were interrogated. The median age was 36 (range, 18-73) years, and 156 (58.4% ) patients were male. At a median treatment period of 1.0 (0.1-3.0) month, 43 (16.1% ) patients developed grade ≥3 neutrophils and/or thrombocytopenia and recovered within 1.0 (0.1-24.6) month. Male (OR=2.9, 95% CI 1.2-6.8; P=0.018) , age of ≥36 years (OR=3.2, 95% CI 1.4-7.2, P=0.005) , a spleen below a costal margin of ≥7 cm (OR=2.8, 95% CI 1.2-6.6, P=0.020) , and a hemoglobin (HGB) level of <100 g/L (OR=2.9, 95% CI 1.3-6.8, P=0.012) at diagnosis were significantly associated with grade ≥ 3 neutrophils and/or thrombocytopenia. Based on their regression coefficients, male, age of ≥36 years, a spleen below a costal margin of ≥7 cm, and an HGB level of <100 g/L were given 1 point to form a predictive system. All patients were divided into three risk subgroups, and the incidence of severe cytopenia significantly differed among the three groups (P < 0.001) . Grade ≥3 neutrophils and/or thrombocytopenia for >2 weeks was significantly associated with lower cumulative incidences of complete cytogenetic response (CCyR, HR=0.5, 95% CI 0.3-0.7, P<0.001) and major molecular response (MMR, HR=0.4, 95% CI 0.3-0.8, P=0.004) and was not significantly associated with failure, progression, and survival. Conclusion: Male, advanced age, a large spleen, and a low HGB level were significantly associated with severe cytopenia. The four covariates were used to establish a prediction model, in which the incidence of severe cytopenia among different risk groups was significantly different. Severe cytopenia for >2 weeks was a negative factor for responses but not for outcomes.
Humans ; Male ; Adolescent ; Adult ; Female ; Protein Kinase Inhibitors/therapeutic use* ; Tyrosine Protein Kinase Inhibitors ; Treatment Outcome ; Retrospective Studies ; Dasatinib/therapeutic use* ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Leukemia, Myeloid, Chronic-Phase/drug therapy* ; Thrombocytopenia