Therapeutic Choices in Patients with Ph-Positive Chronic Myelogenous Leukemia In Mexico in the Era of Tyrosine Kinase Inhibitors: Stem Cell Transplantation or Tyrosine Kinase Inhibitors? Fifteen Years Later

ABSTRACT Background: Chronic myelogenous leukemia is a neoplastic proliferation of the granulocytic series. In Mexico, chronic myelogenous leukemia accounts for approximately 10% of all leukemias. Tyrosine-kinase inhibitors are considered front-line therapy in high-income countries, whereas allogeneic hematopoietic stem cell transplantation is a recognized therapeutic approach, mainly in low- and middle-income countries. Objective: To analyze the overall survival of persons with chronic myelogenous leukemia who have received tyrosine-kinase inhibitors or allogeneic hematopoietic stem cell transplantation in a medical center, since 1994, and briefly discuss the current indications of these treatments in the tyrosine-kinase inhibitors era. Methods: We retrospectively analyzed all patients with a diagnosis of chronic myelogenous leukemia treated in a medical center between 1994 and 2023; subsets of individuals who received an allogeneic hematopoietic stem cell transplantation or tyrosine-kinase inhibitors therapy as first-line treatment were analyzed. Results: 60 persons with chronic myelogenous leukemia were treated with allogeneic hematopoietic stem cell transplantation or tyrosine-kinase inhibitors: 35 received an allogeneic hematopoietic stem cell transplantation, whereas 25 were given tyrosine-kinase inhibitors. All patients who underwent an allogeneic hematopoietic stem cell transplantation engrafted successfully, and the procedure was completed on an outpatient basis in most cases (29/35). The median survival in allogeneic hematopoietic stem cell transplantation was 78.3 months (CI 95%: 0-205.6) and in persons given tyrosine-kinase inhibitors the median was not reached. Conclusion: Tyrosine-kinase inhibitors were significantly superior to allogeneic hematopoietic stem cell transplantation in prolonging the overall survival of persons with chronic myelogenous leukemia in our single institution experience. (Rev Invest Clin. 2024;76(2):91-6)

Analysis of mutation characteristics in TKI-resistant chronic myeloid leukemia patients based on next-generation sequencing technology / 白血病·淋巴瘤

Objective:To explore the characteristics and patterns of gene mutations in tyrosine kinase inhibitor (TKI)-resistant chronic myeloid leukemia (CML) patients and their relationship with TKI-resistant CML.Methods:A retrospective case series study was performed. Clinical data and next-generation sequencing results from TKI-resistant CML patients in Nanfang Hospital of Southern Medical University and Yuebei People's Hospital of Shantou University Medical College from August 2018 to November 2022 were retrospectively analyzed, and the gene mutations of the patients in general and at different disease stages were analyzed.Results:Sixty patients were enrolled, with the age [ M ( Q1, Q3)] of 41.5 years old (32 years old, 53 years old); 38 cases (63.33%) were male and 22 cases (36.67%) were female; 43 cases were in the chronic stage, and 17 cases were in the progression stage (3 cases were in the accelerated stage and 14 cases were in the blast stage). non-ABL1 mutations were detected in 30 patients (50.00%) including 45 times of 15 non-ABL1 genes. The number of non-ABL1 mutation gene was 1 (0, 2) in 60 patients. Of the 60 patients, 21 (35.00%) had ASXL1 mutations, 5 (8.33%) had DNMT3A mutations, 5 (8.33%) had RUNX1 mutations, and 3 (5.00%) had SETBP1 mutations; the proportions of patients with 1 and ≥2 non-ABL1 mutations were 33.33% (20/60) and 16.67% (10/60), respectively. The total detection rates of non-ABL1 mutations were 52.94% (9/17) and 48.84% (21/43), and the detection rates of ≥2 non-ABL1 mutations were 23.53% (4/17) and 13.95% (6/43) in patients with progression and patients with chronic disease, and the differences were not statistically significant ( χ2 = 0.08, P = 0.774; χ2 = 0.80, P = 0.370). Seventeen of 60 patients (28.33%) had mutations in the ABL1 kinase region, of which 14 (82.35%) had non-ABL1 mutations; of these 17 cases, 6 patients with progressive disease all had non-ABL1 mutations, in 11 patients with chronic disease, 8 patients had non-ABL1 mutations, and the difference was not statistically significant ( P = 0.452). Conclusions:Patients with TKI-resistant CML have high frequencies of non-ABL1 mutations, and there is a trend for higher mutation rates in patients with progressive disease than in patients with chronic disease, and these may be related to the abnormal activation of ABL1 kinase by BCR-ABL1 fusion gene in patients with drug-resistant CML, which leads to the genome-level and epigenome-level mutations, and driving disease progression from chronic phase to accelerated or blast phase.

Effect of selinexor combined with imatinib on proliferation and apoptosis of K562/G01 cells / 西安交通大学学报(医学版)

【Objective】 To observe the effect of Selinexor (SEL) combined with Imatinib (IM) on the proliferation and apoptosis of Imatinib-resistant chronic myeloid leukemia K562/G01(KG) cells and explore the possible mechanisms. 【Methods】 K562 cells and KG cells were treated with SEL or IM respectively or in combination. Cells viability was examined by MTT assay. Apoptosis was assessed by flow cytometry. BCR-ABL mRNA was detected by RT-PCR. XPO1 was detected by Western blotting. 【Results】 IM and SEL both inhibited the proliferation of K562 cells and KG cells; half maximal inhibitory concentration (IC50) for 48 h was 0.16 μmol/L vs. 6.48 μmol/L for IM and 132.0 nmol/L vs. 275.9 nmol/L for SEL. Compared with SEL or IM alone, SEL combined with IM significantly inhibited the proliferation of KG cells (P<0.05), induced KG cells apoptosis (P<0.05), downregulated the levels of BCR-ABL mRNA (P<0.05), and inhibited the expressions of XPO1 in KG cells (P<0.05). 【Conclusion】 SEL combined with IM can synergistically inhibit the proliferation and induce apoptosis of KG cells, and then inhibit the expressions of BCR-ABL mRNA and XPO1 to exert an anti-leukemia effect.

Regulatory mechanism and clinical significance of CXC chemokine ligand 8 in bone marrow microenvironment mediating occurrence and development of acute myeloid leukemia / 中国免疫学杂志

Objective:By detecting the level changes of CXC chemokine ligand 8(CXCL8)in acute myelogenous leukemia(AML)patients at different disease stages,to analyze its correlation with the clinical condition and prognosis of AML patients,and to explore the effect of CXCL8 in the bone marrow microenvironment on the occurrence and development of AML and the regulatory mech-anism of malignant biological behavior of AML cell lines,to provide novel reference for the basic research and clinical diagnosis and treatment of AML.Methods:Bone marrow specimens from AML patients at different disease stages were collected,and ELISA was used to detect the content of CXCL8;quantitative real-time PCR(qRT-PCR)was used to detect the expression of CXCL8-specific receptor CXCR1/2 in different AML cell lines.U937 cells were selected as the AML disease model,and different concentrations of exogenous rCXCL8 were intervened in U937 cells,and the morphological changes of the cells were observed under the microscope.BM-MSCs from newly diagnosed AML patients were co-cultured with U937 cells,and ELISA was used to detect the difference in the content of CXCL8 in the co-culture system;Annexin V/PI double staining flow cytometry was used to detect the effects of rCXCL8 and anti-CXCL8 on the apoptosis of U937 cells respectively,and Western blot was used to reveal the accompanying molecular protein mechanism.Results:The level of CXCL8 in newly diagnosed and relapsed AML patients was significantly higher than that in healthy people(P<0.05),the level of CXCL8 in relapsed stage of AML was significantly higher than that in other disease stages of AML(P<0.01),and the level of CXCL8 in AML patients with CR stage and no infection was significantly higher than that in healthy people(P>0.05).The content of CXCL8 in the co-culture system of BM-MSC and U937 cells and the level of CXCL8 mRNA in U937 cells in the co-culture system were significantly higher than those in the monoculture group without BM-MSC(P<0.05).Intervention of rCXCL8 in U937 cells could promote cell proliferation by up-regulating Bcl-2 expression and down-regulating Bax expression,and up-regulate the expression of CXCL8-specific receptors CXCR1/2.After antagonizing CXCL8(anti-CXCL8),it will induce U937 cell apoptosis by up-regulating of Bax expression and down-regulating of Bcl-2 expression while inhibiting the activation level of ERK1/2 signaling pathway.Conclusion:CXCL8 is closely related to the disease and prognosis of AML,and is an effective monitoring indicator for disease pro-gression and prognosis evaluation of AML patients.CXCL8 in the bone marrow microenvironment is an important chemokine for malig-nant proliferation and immune escape of leukemia cells.By antagonizing CXCL8,U937 cells can be induced to undergo apoptosis,whose mechanism may be related to the expression changes of Bcl-2 family proteins and the inhibition of ERK1/2 signaling pathway activation.

Efficacy and safety of flumatinib in treatment of imatinib-resistant or imatinib-intolerant patients with chronic myeloid leukemia / 白血病·淋巴瘤

Objective:To investigate the efficacy and safety of flumatinib in the treatment of imatinib-resistant or imatinib-intolerant patients with chronic phase chronic myelogenous leukemia (CML-CP).Methods:The clinical data of 9 CML-CP patients who received flumatinib after imatinib resistance or intolerance in Jining No. 1 People's Hospital from April 2020 to May 2021 were retrospectively analyzed. Patients were evaluated for the hematologic, cytogenetic and molecular responses, progression-free survival (PFS), event-free survival (EFS), and adverse reactions.Results:Among 9 CML-CP patients, there were 4 imatinib-resistant patients and 5 imatinib-intolerant patients. The median duration of flumatinib exposure was 17 months (1-25 months). Except for 1 case who discontinued flumatinib early due to grade 4 thrombocytopenia and other adverse reactions, 7 of the remaining 8 cases achieved the best response at 3, 6 and 12 months of flumatinib therapy. By the end of follow-up in April 2022, 7, 7 and 6 patients achieved complete cytogenetic response (CCyR), major molecular response (MMR) and molecular response 4.5 (MR4.5), respectively. The median time to achieving CCyR, MMR and MR4.5 was 4.5 months (3-6 months), 12 months (3-12 months) and 15 months (3-21 months), respectively. Within 17 months (11-25 months) of follow-up, 7 of the 9 patients had EFS and 8 patients with continuous flumatinib had PFS. Among 9 patients treated with flumatinib, hematologic adverse reactions were observed in 6 cases, and grade 3-4 hematologic adverse reactions occurred in 2 cases. Non-hematologic reactions events mainly included diarrhea (4 cases), muscle ache (2 cases), fatigue (2 cases) and liver damage (2 cases), which were all grade 1-2.Conclusions:Flumatinib is effective and well tolerated in the treatment of imatinib-resistant or imatinib-intolerant CML-CP patients.

Construction of human TCRP1 gene knockout chronic myeloid leukemia K562 cell line using CRISPR/Cas9 technology and its biological function detection / 中国医师杂志

Objective:To select human chronic myeloid leukemia (CML) cell line K562 as the experimental object, and use lentivirus mediated CRISPR/Cas9 gene editing technology to construct a stable CML cell line K562/TCRP1-KO that knocks out the tongue cancer resistance related protein 1 (TCRP1) gene; and through functional tests such as cell proliferation, apoptosis, and drug sensitivity, compare the phenotypic differences between K562/TCRP1-KO and control cells (K562/cas9-CTL), and preliminarily explore the possible mechanism of TCRP1 gene involvement in the pathogenesis of CML.Methods:The small guide RNA (sgRNA) targeting TCRP1 was designed at a specific location. After annealing, the oligonucleotide fragments were recombined with the linearized Cas9 expression vector, and the lentivirus packaging system was transfected into 293T cells. The purified virus was collected and infected with K562 cells. Positive polyclons were screened for puromycin pressure, and monoclonal K562/TCRP1-KO was further screened by limited dilution method. Stable cell lines were successfully knocked out by sanger sequencing and Western blot detection; Simultaneously, K562 cells transfected with lentiCRISPR vector were constructed as control cell lines (K562/cas9-CTL); Using cell counting method, cell counting kit 8 (CCK8) method, imatinib (IM) gradient dilution method, and flow cytometry cell proliferation, drug sensitivity, and apoptosis analysis were performed on K562/TCRP1-KO and K562/cas9-CTL, respectively.Results:The sgRNA-Cas9 recombinant plasmid vector for TCRP1 knockout was successfully constructed, and after transfection into 293T cells, TCRP1 knockout monoclonal cell lines were successfully screened using limited dilution method. Compared with K562/cas9-CTL cells, the proliferation ability of K562/TCRP1-KO cells was significantly reduced, IM drug sensitivity was significantly enhanced, and the process of cell apoptosis was significantly accelerated (all P<0.05). Conclusions:A CML cell line with TCRP1 knockout was successfully constructed using CRISPR/Cas9. TCRP1 may act as a cancer related gene to affect the proliferation, IM resistance, and apoptosis process of CML cells.

Study on the mechanism of luteolin reversing multidrug resistance in leukemia K562/ADR cells / 天津医药

Objective To investigate the mechanism of luteolin's(Lut)reversal effect on multidrug resistance of chronic myeloid leukemia K562/ADR cells.Methods CCK-8 assay was used to detect drug resistance in K562 and K562/ADR cells 24 hours after treatment with different doses of adriamycin(ADR).CCK-8 assay was used to assess the cytotoxicity and sensitizing effect of Lut on ADR after K562/ADR cells were treated with Lut alone or in combination with ADR for 24 hours.K562/ADR cells in logarithmic growth phase were separated into three group:0μmol/L Lut,2μmol/L and 4μmol/L Lut groups.ADR accumulation in cells was measured using flow cytometry.Nuclear factor erythroid-2-related factor 2(Nrf2),multidrug resistance associated protein 1(MRP1),P-glycoprotein(P-gp)and glutathione-S-transferase-PI(GST-pi)mRNA and protein expressions were identified using RT-PCR and Western blot assay.Glutathione(GSH)kit was used to detect intracellular GSH content.Results Compared with K562 cells,K562/ADR cell line was significantly resistant to ADR,and the drug resistance was 53.69 times.K562/ADR cell proliferation was decreased to variable degrees by different doses of Lut when compared to the 0μmol/L Lut group(P＜0.05).The proliferation inhibition rates of K562/ADR cells treated with 2 and 4μmol/L Lut were less than 10%,indicating that the concentration of Lut was non-toxic.Compared with the 0 μmol/L Lut group,the 2 μmol/L Lut group and the 4 μmol/L Lut group showed significantly increased ADR growth inhibition rate on K562/ADR and increased accumulation of ADR in cells,improved the reversal resistance fold,and decreased GSH content in cells.MRP1,P-gp,GST-pi and Nrf2 mRNA and protein expression were reduced in cells(P＜0.05).The effect of 4 mol/L Lut was greater than that of 2 mol/L Lut.Conclusion Lut may decrease K562/ADR cell proliferation and reverse ADR medication resistance.The mechanism could be connected to the downregulation of Nrf2,MRP1,P-gp and GST-pi expression,which leads to an increase in ADR accumulation in K562/ADR cells.

Research Progress of Next Generation Sequencing in Acute Leukemia --Review / 中国实验血液学杂志

With the advent of precision medicine, next-generation sequencing (NGS) is playing an increasingly important role in clinical oncology diagnosis and treatment with its advantages of high sensitivity, high accuracy, high efficiency and operability. NGS reveals the genetic characteristics of acute leukemia(AL) patients by screening for specific disease-causing genes to identify occult as well as complex genetic mutations in patients with AL, leading to early diagnosis and targeted drug therapy for AL patients, as well as to predict disease recurrence by detecting mnimal residual disease (MRD) and analyzing mutated genes to determine patient prognosis. NGS plays an increasingly important role in the diagnosis, treatment and prognosis assessment in AL, providing a direction for the pursuit of precision medicine. This paper reviews the research progress of NGS in AL.

Pediatric chronic myeloid leukemia in myeloid blast crisis

ABSTRACT Chronic myeloid leukemia (CML) accounts for 2-3% of childhood leukemias. About 5% of cases present in a blastic phase of CML which clinically and morphologically mimics more common acute leukemias of childhood. We report a case of a 3-year-old male who presented with gradual onset swelling of the abdomen and extremities along with generalized weakness. Examination revealed massive splenomegaly, pallor, and pedal edema. Initial workup showed anemia, thrombocytopenia, and leukocytosis (120,000/uL) with a blast percentage of 35%. Blasts were positive for CD13, CD33, CD117, CD34 and HLA-DR, and stained negative for Myeloperoxidase and Periodic Acid Schiff. Fluorescence in situ hybridization was positive for b3a2/e14a2 junction BCR-ABL1 transcript and negative for RUNX1-RUNX1T1/t(8;21), clinching the diagnosis of CML in myeloid blast crisis. The patient expired within 17 days of diagnosis and initiation of therapy.

Brazilian chronic myeloid leukemia working group recommendations for discontinuation of tyrosine kinase inhibitors in chronic myeloid leukemia in clinical practice

ABSTRACT Introduction: Treatment-free remission (TFR) is a new goal of chronic myeloid leukemia (CML) therapy. TFR is feasible when the patient has achieved a deep and stable molecular response and met the criteria required to ensure its success. Treatment discontinuation should not be proposed to the CML patient if minimum conditions are not met. In Brazil, for example, molecular tests (BCR::ABL1) are not broadly available, making it difficult to monitor the patients adequately. Objective: In this sense, providing TFR recommendations for Brazilian physicians are therefore necessary. These recommendations include the main criteria checklist to start the TKIs treatment discontinuing process in patients diagnosed with CML and the population-eligible characteristics for treatment discontinuation. Method: Age, risk score at diagnosis, TKI treatment duration, BCR::ABL1 transcripts type, depth of the molecular response for treatment discontinuation, treatment adherence, patient monitoring and withdrawal syndrome are essential factors to consider in TFR. After TKI discontinuation, BCR::ABL1 transcripts monitoring should be more frequent. When a major molecular response loss is observed during the monitoring of a patient in TFR, the TKI treatment should be resumed. Conclusion: These recommendations should serve as a basis for medical professionals interested in proposing TKI discontinuation for CML patients in clinical practice. It is important to highlight that, despite the benefits of TFR for the patients and the health system, it should only be feasible following the minimum standards proposed in this recommendation.

Respuesta molecular profunda con ponatinib en leucemia mieloide crónica en fase crónica con resistencia a imatinib y dasatinib: Reporte de caso y revisión de la literatura / Profound molecular response with ponatinib in chronic phase of chronic myeloid leukemia with resistance to imatinib and dasatinib: Case report and review of the literature

RESUMEN Se reporta el caso de una mujer quien a la edad de 54 años fue diagnosticada de leucemia mieloide crónica en fase crónica; inició tratamiento con inhibidor de tirosina cinasa de primera generación, y evidenció falla por ausencia de respuesta hematológica y citogenética. A pesar del cambio de tratamiento a un inhibidor de tirosina cinasa de segunda generación (dasatinib), no fue posible alcanzar niveles óptimos de respuesta, documentándose la positividad para la mutación T315I en dominio ABL de la tirosina cinasa desregulada BCR/ABL, frente a la cual el único medicamento que muestra actividad es ponatinib. Luego de iniciar tratamiento con ponatinib, se evidenciaron niveles óptimos de respuesta citogenética y molecular, así como una adecuada calidad de vida de la paciente.

SUMMARY We report the case of a woman who at the age of 54 years was diagnosed with chronic myeloid leukemia in chronic phase; she began treatment with a first-generation tyrosine kinase inhibitor, and evidenced failure due to the absence of a hematological and cytogenetic response. Despite changing treatment to a second-generation tyrosine kinase inhibitor (dasatinib), it was not possible to achieve optimal levels of response, documenting positivity for the T315I mutation in the ABL domain of the deregulated BCR/ABL tyrosine kinase, compared to ponatinib, the only drug that shows activity. After starting treatment with ponatinib, optimal levels of cytogenetic and molecular response were evidenced, as well as an adequate quality of life for the patient.

Analysis of the Curative Effect and Influencing Factors of Nilotinib Second-line and Dasatinib Third-line on Chronic Myelogenous Leukemia Failed First-line and Second-line Treatment / 中国实验血液学杂志

OBJECTIVE@#To evaluate the efficacy of the second-line nilotinib and third-line dasatinib on chronic myelogenous leukemia (CML) with failed first- and second-line treatments, and analyze the influencing factors of the efficacy.@*METHODS@#Selected 83 patients in The Third People's Hospital of Kunshan City, Jiangsu Province with CML who were treated with nilotinib as the second-line treatment after the failure of the first-line treatment with imatinib as the second-line treatment group (referred to as the second-line group) from January 2014 to December 2018, and 61 CML patients who were treated by dasatinib as the third-line treatment group (referred to as the third-line group) after the failure of the second-line treatment with nilotinib; the first-line treatment with imatinib failed, but due to various reasons, the patients were fully after being informed of the possible serious consequences of not changing the drug treatment, 37 CML patients who were still required to continue imatinib treatment served as the control group. The hematological, genetic and molecular responses of each group were compared for 3, 6, and 24 months of treatment. LogistiC regression was used to analyze the factors affecting the second and third line curative effects.@*RESULTS@#The three groups had statistically significant differences in the rates of achieving CHR, MCyR, and MMR at 3, 6, and 12 months of treatment (P<0.05). Compared the two groups, the CHR rates of the second-line group at 3, 6, and 12 months of treatment were 100.00%, 97.59%, and 95.18%, respectively; higher than the third-line group's 90.16%, 86.89%, 83.61% and the control group's 83.78%, 75.68% and 72.97%; the CHR rate of the third-line group was higher than that of the control group at 6 and 12 months of treatment. The rates of reaching MCyR at 3, 6, and 12 months after treatment in the second-line group were 87.95%, 93.98% and 93.98%, respectively, while those in the third-line group were 80.33%, 88.52% and 86.89%, which were higher than those of the control group of 67.57%, 64.86% and 48.65%. The rates of achieving MMR at 3, 6, and 12 months of treatment in the second-line group were 19.28%, 33.72% and 60.24%, respectively, and those in the third-line group were 11.48%, 26.23% and 49.18%, which were higher than those of the control group of 0.00%, 2.70% and 0.00%; The rate of reaching MMR within 12 months of treatment in the second-line group was higher than that of the third-line group, and the differences was statistically significant (P<0.05). There was no significant difference in the rate of reaching MCyR between the second-line group and the third-line group at 3, 6, and 12 months, and the rate of reaching MMR at 3 and 6 months (P>0.05). The incidence of nausea and vomiting among the three main non-hematological adverse reactions, and the incidence of grade 1~2 anemia among the hematological adverse reactions were statistically significant (P<0.05). There was no significant difference in the incidence of rash, eyelid edema, diarrhea, thrombocytopenia, leukopenia and neutropenia in the three groups (P>0.05). The incidence of nausea and vomiting and grade 1~2 anemia in the second-line group and the third-line group were higher than that of the control group, and the difference was statistically significant (P<0.05). There were statistically significant differences in Sokal score, medication compliance, and hematological adverse reactions between the MMR group and the non-MMR group (P<0.05). Logistic regression analysis showed that dose reduction or withdrawal during the treatment period, and grade 3~4 hematological adverse reactions were the main factors affecting the second and third line curative effects (OR=22.160, 2.715, 95% CI=2.795-93.027, 1.882-48.834).@*CONCLUSION@#The second-line nilotinib and the third-line dasatinib have a better effect on CML patients who have failed the first and second-line treatments. Grade 3~4 hematological adverse reactions, dose reduction or withdrawal are risk factors that affect the efficacy of second and third-line treatments.

Status and significance of BCR-ABL1 kinase domain mutations in imatinib-resistant chronic myelogenous leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia patients from Northeast China / 白血病·淋巴瘤

Objective:To explore the characteristics of BCR-ABL1 kinase domain mutations in imatinib-resistant chronic myelogenous leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL) patients from Northeast China and their impact on prognosis. Methods:The clinical data of 252 CML patients and 49 Ph + ALL patients who were admitted to the First Hospital of Jilin University from January 2013 to October 2018 were retrospectively analyzed. The samples of bone marrow or peripheral blood were collected from patients when imatinib treatment was not effective. Nested polymerase chain reaction (PCR) was used to amplify the BCR-ABL1 kinase domain, and Sequencing Analysis v5.4 software was used to analyze the mutation of BCR-ABL1 kinase domain. Patients were followed up for 6-48 months, and the survival analysis was performed. Results:Among 252 CML patients, the mutations in ABL1 kinase domain were found in 57 patients (22.6%), including 25 patients in the chronic phase, 21 patients in the accelerated phase and 11 patients in the blast crisis; 50 patients had 20 types of single point mutation, and the most common mutation types were E255K (16.0%, 8/50), T315I (14.0%, 7/50), M244V (8.0%, 4/50) and G250E (8.0%, 4/50), which were all concentrated in the P-loop and C-helix domains; 7 patients had double mutations; patients with multiple mutations had the worst prognosis, with a median overall survival (OS) time of 3.2 months. Among 49 Ph + ALL patients, 17 cases (34.7%) were positive for mutations in the BCR-ABL1 kinase domain, 14 patients had 12 types of single point mutation, and 3 patients had multiple mutations; the median OS time of patients with multiple mutations, mutations located in the P-loop and C-helix domains and mutations located in the other domains was 2.0, 8.0 and 18.0 months, and the difference in OS among the three groups was statistically significant ( P < 0.01). Conclusions:Among the imatinib-resistant CML and Ph + ALL patients from Northeast China, point mutations in the P-loop and C-helix domains are most commonly found. Multiple mutations, mutations in the P-loop and C-helix domains are related to the poor prognosis of the patients.

Progress in molecular resistance mechanisms of targeted therapy for chronic myeloid leukemia / 白血病·淋巴瘤

Resistance or drug-resistant recurrence of targeted tumor therapy is a complex and multi-factorial process, with the final result of tumor clones that can evade treatment or have relative proliferation advantages under treatment pressure being selectively retained. The BCR::ABL1 fusion gene is the primary molecular abnormality of chronic myeloid leukemia (CML), and the development and application of tyrosine kinase inhibitors (TKI) targeting the BCR::ABL1 fusion protein pioneered the era of small molecule targeted therapeutics. Several TKI have been approved for clinical application or in development. Although most CML patients manifest an excellent response to TKI treatment, there are still some patients with poor primary response or relapse with drug resistance. With the increase in the number of patients with long-term maintenance therapy and the sequential use of multiple TKI, the resistance of TKI has become more complicated. This article introduces the research progress of CML molecular resistance mechanisms in recent years and shares the relevant cutting-edge reports at the 63rd American Society of Hematology Annual Meeting in 2021.

Progress of treatment-free remission in chronic myeloid leukemia / 白血病·淋巴瘤

The application of tyrosine kinase inhibitor (TKI), a target therapy of chronic myeloid leukemia (CML), has greatly improved the prognosis of patients with CML. However, uninterrupted treatment with TKI affects the quality of life and aggravates the economic burden of patients. Achieving treatment-free remission (TFR) has become the current research direction of CML treatment. This paper reviews the relevant foreign literature on the discontinuation of TKI in recent years.

Progress of immunological surveillance in the treatment-free remission of chronic myelogenous leukemia / 白血病·淋巴瘤

With the wide application of tyrosine kinase inhibitor (TKI), to obtain treatment-free remission (TFR) has gradually become the long-term goal for patients with chronic myelogenous leukemia (CML). Self-renewing leukemia stem cells during disease progression are related with the recurrence, and surveillance of residual leukemic cells is hypothesized to be one of the critical factors in successful TFR. On the way to obtain TFR, many breakthroughs have been made in innate and adaptive immunity of CML cells. This paper reviews the immune function of CML patients, the role of the immune markers in maintaining TFR, and the exploration of TKI combined with new immunomodulator therapy to achieve a greater degree of TFR.

Impacto econômico da interrupção do tratamento com inibidor de tirosina quinase em pacientes com leucemia mieloide crônica em um hospital federal referência em oncologia / Economic impact of discontinuing treatment with tyrosine kinase inhibitor in patients with chronic myeloid leukemia at a federal hospital reference in oncology

Objetivo: Avaliar o impacto econômico da descontinuação do tratamento da leucemia mieloide crônica (LMC) com inibidores da tirosina quinase (ITQs) em primeira ou segunda linha. Métodos: O modelo incluiu pacientes com diagnóstico de LMC em tratamento com ITQs que iniciaram o tratamento até 2012, em condições elegíveis no ano de 2015. Foi considerado um horizonte temporal de cinco anos sob a perspectiva do sistema público de saúde. Custos associados ao tratamento, como medicamento, monitoramento e manejo de eventos adversos, foram analisados. A avaliação foi composta por dois cenários: o cenário referência, com uso contínuo do medicamento, e o cenário comparador, com a interrupção do tratamento medicamentoso. Ambos os cenários consideraram as tecnologias disponíveis no período de 2015 a 2019. A análise de sensibilidade propôs variações nos cenários com a finalidade de avaliar a robustez do modelo. Além disso, uma extrapolação para nível nacional foi realizada, utilizando dados epidemiológicos para a obtenção do número de pacientes. Resultados: Foram selecionados 268 pacientes que iniciaram o tratamento até 2012. Desses, 65 foram elegíveis à descontinuação. A análise econômica mostrou uma economia de R$ 670.558,10 no primeiro ano, uma economia acumulada em cinco anos de R$ 3.665.355,98 e de R$ 66.517.232,80 no contexto institucional e nacional, respectivamente. A análise de sensibilidade foi favorável em todos os cenários propostos. Conclusões: A descontinuidade do tratamento da LMC mostrou-se, economicamente, uma importante oportunidade sob a perspectiva do sistema de saúde em flexibilizar novos investimentos tecnológicos e/ou ampliação de cesso, além da melhoria na qualidade de vida do paciente.

Objective: To assess the economic impact of discontinuing treatment of chronic myeloid leukemia (CML) with first or second line tyrosine kinase inhibitors (ITQs). Methods: The model included patients diagnosed with CML undergoing treatment with ITQs who started treatment until 2012, under eligible conditions in the year 2015. A 5-year time horizon was considered from the perspective of the public health system. Costs associated with treatment, such as medication, monitoring and handling adverse events were analyzed. The evaluation consisted of two scenarios, the reference scenario with continuous use of the drug and the comparator scenario with the interruption of drug treatment. Both scenarios considered the technologies available in the period from 2015 to 2019. The sensitivity analysis proposed variations in the scenarios in order to assess the robustness of the model. In addition, an extrapolation to the national level was performed, using epidemiological data to obtain the number of patients. Results: 268 patients who started treatment until 2012 were selected. Of these, 65 were eligible for discontinuation. The economic analysis showed savings of R$ 670,558.10 in the first year, accumulated savings in five years of R$ 3,665,355.98 and R$ 66,517,232.80 in the institutional and national context, respectively. The sensitivity analysis was favorable in all the proposed scenarios. Conclusions: The discontinuity of CML treatment proved to be, economically, an important opportunity from the perspective of the health system in making new technological investments and / or expanding access more flexible, in addition to improving the patient's quality of life

Progress of targeted therapy for chronic myeloid leukemia / 白血病·淋巴瘤

The application of tyrosine kinase inhibitors (TKI) has revolutionarily improved the treatment outcome and survival of patients with chronic myeloid leukemia (CML). The new purpose of the current CML treatment is to achieve a sustained deep molecular biological response to reduce the relapse because of drug resistance and even to achieve treatment-free remission maintenance and cure of the disease. Four kinds of TKI have been approved internationally for the first-line treatment of newly diagnosed chronic-phase CML, and there are constantly new drugs and treatment regimens in development and clinical research. This article introduces the research progress of targeted therapy for CML in combination with the related reports at the 62nd American Society of Hematology Annual Meeting.

Study on the mechanism of circular permuted tumor necrosis factor-related apoptosis-inducing ligand reversing the resistance to imatinib in chronic myeloid leukemia cells / 白血病·淋巴瘤

Objective:To explore the mechanism of circular permuted tumor necrosis factor-related apoptosis-inducing ligand (CPT) reversing the resistance to imatinib in chronic myeloid leukemia (CML) cells.Methods:Five patients with CML in the Affiliated Hospital of Inner Mongolia Medical University from 2016 to 2020 were selected, and heparinized bone marrow blood samples were collected at the first diagnosis and imatinib resistance phase, and mononuclear cells were isolated. The mononuclear cells collected at the first diagnosis were named A1-E1, and the mononuclear cells collected after imatinib resistance were named A2-E2. Human CML wild-type K562 cell line (K562-W) was given gradually increasing small doses of low-concentration imatinib to obtain imatinib-resistant K562 cells (K562-R). K562-R cells were cultured with 20 μg/L CPT and these cells were set as CPT-K562-R group. The CCK-8 method was used to detect the half inhibitory concentration ( IC50) of cells for imatinib. K562-W and K562-R cells were used to establish CML xenografts nude mice models, then the nude mice were divided into K562-W, K562-R and CPT-K562-R xenograft groups. Imatinib was perfused orally in all three groups, and CPT was injected subcutaneously in the CPT-K562-R group at the same time. The tumor volume of the three groups of nude mice before and 4 weeks after treatment with imatinib, and the survival time of the three groups of nude mice were compared. Western blot was used to detect the changes of tyrosine protein kinase receptor B4 (EphB4) and myeloid cell leukemia protein 1 (Mcl-1) protein levels in bone marrow mononuclear cells, K562 cell line and transplanted tumor tissues of CML patients. Results:The expressions of EphB4 protein in A2-E2 cells of 5 patients with CML were higher than those in A1-E1 cells (all P < 0.01). The IC50 of K562-W, K562-R and CPT-K562-R cells for imatinib were (0.160±0.015) mg/L, (5.450±0.460) mg/L, (0.300±0.035) mg/L, and the difference was statistically significant ( F = 390.65, P < 0.01). In cells of K562-W group, EphB4 and Mcl-1 proteins were expressed at low levels (0.54±0.02 and 0.70±0.08); in cells of K562-R group, the expressions of EphB4 and Mcl-1 proteins were enhanced (3.04±0.11 and 2.88±0.04); in cells of CPT-K562-R group, the expressions of EphB4 and Mcl-1 proteins decreased (0.57±0.03 and 0.38±0.04). Before imatinib treatment, there was no statistically significant difference in the tumor volumes of nude mice among the K562-W, K562-R and CPT-K562-R xenograft groups ( F = 0.39, P = 0.68), suggesting the transplanted tumors formed in nude mice were balanced; after imatinib treatment, the difference in the tumor volumes among the three groups were statistically significant ( F = 26.16, P < 0.01). The survival time of nude mice in the K562-W, K562-R and CPT-K562-R xenograft groups was (18.5±3.3) d, (10.0±2.4) d and (17.5±1.6) d, and the difference was statistically significant ( F = 20.45, P < 0.01). In K562-W xenograft group, both EphB4 and Mcl-1 proteins were expressed at low levels (0.55±0.06 and 0.67±0.06); in K562-R xenograft group, the expressions of EphB4 and Mcl-1 proteins were enhanced (1.95±0.08 and 6.21±0.53); the expressions of EphB4 and Mcl-1 in CPT-K562-R xenograft group decreased (0.59±0.04 and 0.37±0.04) and were close to their expressions in K562-W xenograft group. Conclusion:CPT may enhance the sensitivity of CML to imatinib by inhibiting the expressions of EphB4 and Mcl-1, and this may be a targeted pathway for imatinib therapy.

Progress of hematologic malignancy related gene mutations in patients with chronic myelogenous leukemia / 白血病·淋巴瘤

Chronic myelogenous leukemia (CML) is a myeloproliferative disease characterized by heterotopic Ph chromosome. Tyrosine kinase inhibitor (TKI) has significantly improved the prognosis of patients with CML. Cytogenetic and molecular monitoring for assessing the therapeutic efficacy of TKI to guide disease management has become an important component of CML therapy. However, the expanded genomic analysis of the disease diagnosis, transformation and drug resistance has not been fully explored in CML research. The paper reviews the frequency and type of gene mutations at initial diagnosis and the time of treatment failure and transformation, and investigates the relationship between genetic mutations and the prognosis of CML patients in the diagnosis and treatment.