Response to Tyrosine Kinase Inhibitors in Patients with BCR-ABL1 Positive Chronic Myeloid Leukemia; 13.5 Years’ Experience at Patan Hospital, Nepal

Background:Since the advent of Tyrosine Kinase Inhibitor (TKI), well controlled studies in developed world have shown that the life expectancy of patients with CML is comparable to normal people without the disease. But long-term follow up studies are lacking in resource poor setting. Methods:This is a retrospective follow up study looking at the molecular response and resistance to Tyrosine Kinase Inhibitors (TKI) in patients enrolled in the Max Access Program since February 2003 till March 2017. Patients with twoor more BCR-ABL1 levels by Karyotyping/ fluorescent in situ hybridization (FISH) / reverse transcriptase polymerase chain reaction (RT-PCR) were included. At baseline, complete blood count (CBC), renal function test (RFT), and liver function test (LFT) were evaluated. Bone marrow aspiration and biopsy for morphology, cytogenetic analysis by Karyotyping/FISH and/or molecular analysis by RT-PCR were also done if these tests were not performed earlier. FISH or RT-PCR was done on peripheral blood every 3–12 months as necessary if the patient could afford. Patients with warning response/failure underwent BCR-ABL1 Resistance Mutation Analysis (IRMA).Results:Three hundred and forty six (346) patients had two or more BCR-ABL1 monitoring tests done. Optimal response was seen in 49.42%. Similarly, suboptimal response and failure were seen in 16.5% and 34% respectively. Overall Survival is 89.6% (at 1.8 -165 months, mean 62 months) . If only CML related events is considered survival is 95.9%. Seventy seven (77) patients with a total of 80 BCR-ABL1 domain Imatinib Resistance Mutation Analyses (IRMA) showed 19 different types of mutations with the most common being T315I mutation (8 and 19.5%). About 22.25% of the total patients showed resistance to Glivec out of which 10.98% showed mutations. Nine patients underwent trial for treatment free response (TFR) and 5 of them relapsed between 2-8 months.Conclusions:Despite all the odds of having financial problem, accessibility problem due to distances, transportation, etc. and difficulty monitoring with routine BCR-ABL1 and IRMA, our findings show that the outcome of TKI therapy in our CML patients is comparable to well controlled studies done elsewhere. Overall survival, molecular and cytogenetic responses and mutations in our patients who developed resistance as well as TFR are also similar to other studies. The resistance rate of 22.25% is slightly higher compared to other studies in developed world. This is mainly because of poor monitoring due to unavailability of the test including IRMA in our country and affordability until 2012. It proves that TKI is very effective in CML even in a resource-poor, developing country

Microarray analysis reveals distinct immune signatures in BCR?ABL positive and negative myeloproliferative neoplasms

Background: BCR?ABL mutation on the Philadelphia chromosome is the key driver of chronic myeloid leukemia (CML) pathogenesis. However, there are certain cases of myeloproliferative neoplasms (MPN) wherein no inherent driver mutation is detected resulting in clinical phenotype. It is important to identify key genes and pathways in driving the disease. The aim of the study was to use a gene-based omics approach to molecularly characterize these mutation-positive and negative cases to further strengthen diagnostics and precision medicine. Methods: A microarray profiling was done on CD34 positive cells isolated from two BCR?ABL positive and five BCR?ABL negative samples. JAK2V617F mutation testing was also done to rule out the presence of any other mutation in the latter group. The fold change cut-off was taken as �5 with p?0.5 for significant genes. The gene network and pathway analysis were done using DAVID and STRING software. Results: The genes upregulated in BCR?ABL negative samples were shown to be involved in immune regulation, signal transduction and T- and B-cell signalling. The protein-protein interaction network of upregulated genes in these samples were enriched for various immunomodulatory genes such as HLADP, HLADQ , IL7R, CCR7, CD3 subtypes. These genes further formed a network with signal transduction genes such as LCK, FYN, RAG1, DOCK1, AKT3, SMAD3, LEF1. Conclusion: The results suggested a modulation of immune response genes and its subsequent effect on oncogenic signalling in BCR?ABL negative samples as compared to BCR?ABL positive samples. The protein network analysis was enriched for genes involved in Src, TGF-beta and PI3K-AKT pathway contributing to the proliferation of neoplastic clone.

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.

Advances in the study of new BCR-ABL kinase inhibitors / 药学学报

The oncogenic product of BCR-ABL is an abnormal tyrosine kinase that causes chronic myeloid leukemia (CML). With further research into the pathogenesis of CML, the discovery of compounds that selectively inhibit abnormal BCR-ABL tyrosine kinases is a research focus worthy of attention. The first three generations of BCR-ABL inhibitors are orthosteric inhibitors, which competitively block the binding of ABL protein tyrosine kinase to ATP and prevent it from activating downstream signals. The fourth-generation BCR-ABL inhibitors allosterically inhibit ABL protein tyrosine kinase by binding to the myristoyl pocket, providing greater selectivity and maintaining activity against drug-resistant mutations proteins. Novel drug design strategies such as proteolytic targeting chimera (PROTAC), covalent inhibitors and dual targeting inhibitors also provide new directions for the development of BCR-ABL kinase inhibitors. This paper reviews recent research advances on BCR-ABL kinase inhibitors and discusses drug design strategies for various novel BCR-ABL inhibitors.

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.

Role of ancillary techniques in diagnosis, therapy and prognosis of a case of precursor B-cell acute lymphoblastic leukemia in an elderly patient

The chromosomal abnormality of Philadelphia chromosome is mostly seen in Chronic Myeloid Leukemia (CML). But it is observed that the Philadelphia chromosome (Ph), t(9,22), is the most common cytogenetic abnormality in adult patients with acute lymphoblastic leukemia (ALL), occurring in about 20% to 30 % of all cases. Patients with Ph-positive ALL have breaks in the minor breakpoint region, m?BCR (exons 1?2) lead to a short fusion proteins (p190) and is most frequently associated with Ph chromosome- positive ALL. They have an increased risk for central nervous system (CNS) involvement, an aggressive clinical course and poor prognosis. Historically, they had an inferior outcome when compared with their Ph-negative counterparts. Adult Ph+ patients achieve Complete Remission rates comparable to Ph? ALL patients with standard chemotherapy, but the remissions are short and survival poor. The addition of tyrosine kinase inhibitors (TKIs) including imatinib has dramatically improved outcomes. We are presenting this case report of t(9;22), p190 BCR-ABL1 positive ALL in an elderly female patient of south Gujarat.

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.

¿Es importante conocer el tipo de transcripto BCR-ABL en la leucemia mieloide crónica? / Is it important to know the type of BCR-ABL transcript in chronic myeloid leukemia?

La leucemia mieloide crónica se caracteriza por la ocurrencia de una translocación recíproca entre los cromosomas 9 y 22; que da origen a un cromosoma 22 derivativo conocido como Filadelfia. En el sitio de unión se forma el gen de fusión BCR-ABL que conlleva a la síntesis de una proteína híbridacon propiedades oncogénicas. El sitio de unión entre los cromosomas 9 y 22 es variable y da lugar a transcritos diferentes; los conocidos como e13a2 y e14a2 son los más frecuentes y estudiados. El análisis de las características clínico-hematológicas de presentación y la respuesta al tratamiento entre los pacientes portadores de e13a2 o e14a2 ha revelado diferencias que pueden ser útiles para la predicción del pronóstico. Se realizó una revisión de la literatura científica a través de PUBMED. Se analizó y resumió la información. Se evidencian diferentes características de presentación, pero no existe coincidencia entre todos los autores. Respecto al comportamiento de la respuesta al tratamiento con inhibidores de tirosina quinasa, algunos autores encuentran diferencias y algunos sugieren que puede tratarse de dos enfermedades diferentes. Puede ser importante conocer el tipo de transcripto BCR-ABL en la LMC ya que, al menos entre los dos más frecuentes, existen diferencias que pueden ser útiles en la predicción del pronóstico para el paciente, así como para el manejo del tratamiento(AU)

Chronic myeloid leukemia is characterized by the occurrence of a reciprocal translocation between chromosomes 9 and 22; which gives rise to a derivative chromosome 22 known as Philadelphia. At the binding site, the BCR-ABL fusion gene is formed, which leads to the synthesis of a hybrid protein with oncogenic properties. The binding site between chromosomes 9 and 22 is variable and gives rise to different transcripts; those known as e13a2 and e14a2 are the most frequent and studied. The analysis of the clinical-hematological characteristics of presentation and the response to treatment among patients with e13a2 or e14a2 has revealed differences that may be useful for the prediction of prognosis. To describe the different characteristics reported for one or another transcript and to know if it is important to know the type of transcript in the CML. A review of the scientific literature was carried out through PUBMED. The information was analyzed and summarized. Different presentation characteristics are evident but there is no coincidence between all the authors. Regarding the behavior of the response to treatment with tyrosine kinase inhibitors, some authors find differences and some suggest that it may be two different entities. It may be important to know the type of BCR-ABL transcript in CML cause, at least between the two most frequent, there are differences that may be useful in predicting the prognosis for the patient as well as for the management of treatment(AU)

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.

Leucemia mieloide crónica atípica BCR-ABL1 negativa: reporte de 2 casos

BCR-ABL1 negative atypical chronic myeloid leukemia (aCML) is a rare type of myeloproliferative / myelodysplastic syndrome characterized by leukocytosis and proliferation of dysplastic neutrophilic precursors in the absence of positivity for the BCR-ABL1 fusion gene. We report a 66-year-old woman and a 57-year-old man with aCML, who initially presented with general malaise and weight loss, associated with anemia, thrombocytopenia, and leukocytosis with left shift and dysplasia in the neutrophil series. Both evolved unfavorably after admission and died a few days later due to multiple organ failure.

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 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.

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 of BCR-ABL fusion gene and JAK2 V617F mutation double-positive myeloproliferative neoplasms / 白血病·淋巴瘤

Myeloproliferative neoplasms (MPN) are a group of clonal disorders of hematopoietic stem cells, and JAK2 V617F gene mutation is the main basis for the diagnosis of MPN. Previous studies have shown that BCR-ABL fusion gene and JAK2 V617F gene mutation are mutually exclusive in MPN patients, but in recent years, patients with a double mutation of both genes are often reported. The article synthesizes the relevant domestic and foreign literature in recent years, and reviews the BCR-ABL fusion gene and JAK2 V617F mutation double-positive MPN.

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

Inclusion of molecular monitoring (BCR-ABL1) in the treatment of chronic myeloid leukemia in the Brazilian Public Health System (SUS): an urgent need for treatment management

ABSTRACT Introduction: Chronic Myeloid Leukemia (CML) is a myeloproliferative disease that affects mainly adults between 50 and 55 years. In Brazil, information from the Sistema Único de Saúde (SUS) Outpatient Information System indicates that 12,531 patients had the Autorização de Procedimento Ambulatorial (APAC) approved for the CML treatment in 2017. Disease monitoring through molecular response evaluation is critical to the care of CML patients. The quantitative PCR test (real-time polymerase chain reaction) provides adequate evaluation parameters that allow the health professional to intervene at the right moments in order to reduce the chance of progression of the disease, providing the best outcome to the patient, including the possibility of treatment discontinuation for eligible patients. Although the test is included in the Clinical Protocol and Therapeutic Guidelines (PCDT) of CML, it is not possible to monitor the molecular response within SUS since there is no reimbursement for this test. Objective: Obtain expert recommendations on the importance, financing, and reimbursement of molecular monitoring in SUS. Methods: Six CML experts with different perspectives participated in the panel. The discussion was based in the main publications about the quantitative PCR test in CML monitoring. Results: Experts' recommendations: Molecular monitoring should be part of the integral treatment of patients with CML to reduce the chances of disease progression and costs to the health system; The government should put into practice what is provided in the PCDT of Chronic Myeloid Leukemia in Brazil: performing the monitoring of the molecular response via quantitative PCR; The government should create a code with adequate nomenclature and reimbursement value in SIGTAP, so that the test is carried out and covered by the public health network, as it is contained in the PCDT of the disease and the existing APAC does not cover the operational costs for its performance; Patients with chronic phase CML should perform a quantitative PCR every 3 months and, after reaching the MMR, should perform the examination every 6 months, as recommended by international guidelines; Patients should be monitored in reference laboratories that are standardized according to the international scale; The laboratories that are within the reference public centers could absorb all the test demand in Brazil, and other centers could be qualified through an ABHH accreditation; Adequate molecular monitoring may allow some patients to stop taking drugs and selffinancing the molecular test for all SUS patients Conclusion: A solution for the molecular test (BCR-ABL1) funding is urgent to ensure the monitoring of CML patients in SUS. The savings that might be generated with patients that stop taking the medication when adequately monitored may finance the test.

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.

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.

H396P mutation in chronic myeloid leukaemia patient on nilotinib – A case report

@#Introduction: The advent of BCR-ABL1-targeted therapy with the tyrosine kinase inhibitor (TKI), for example, imatinib and nilotinib, marked a turning point in the therapy of chronic myeloid leukaemia (CML). However, a substantial proportion of patients experience primary or secondary disease resistance to TKI. There are multifactorial causes contributing to the treatment failure of which BCR-ABL1 kinase domain mutation being the most common. Here, we describe a case of a CML patient with H396P mutation following treatment with nilotinib. Case: A 60-year-old woman presented with abdominal discomfort and hyperleukocytosis. She was diagnosed as CML in the chronic phase with positive BCR-ABL1 transcripts. Due to the failure to obtain an optimal response with imatinib treatment, it was switched to nilotinib. She responded well to nilotinib initially and achieved complete haematological and cytogenetic responses, with undetectable BCR-ABL1 transcripts. However, in 4 years she developed molecular relapse. Mutation analysis which was done 70 months after commencement of nilotinib showed the presence of BCRABL1 kinase domain mutation with nucleotide substitution at position 1187 from Histidine(H) to Proline(P) (H396P). Currently, she is on nilotinib 400mg twice daily. Her latest molecular analysis showed the presence of residual BCR-ABL1 transcripts at 0.22 %. Discussion/conclusion: This case illustrates the importance of BCR-ABL1 mutation analysis in CML patients with persistent BCR-ABL1 positivity in spite of treatment. Early detection and identification of the type of BCRABL1 mutation are important to guide appropriate treatment options as different mutation will have different sensitivity to TKI.