Chronic myeloid leukemia: diagnosis and treatment

Physical exercise recommendations for patients with chronic myeloid leukemia based on individual preferences identified in a large international patient survey study of the East German Study Group for Hematology and Oncology (OSHO #97)

Background

Tyrosine kinase inhibitors (TKIs) have significantly lowered mortality of chronic myeloid leukemia (CML) patients adjusting life expectancy to that of the standard population. However, CML and its treatment with TKIs causes a high disease burden. Physical exercise (PE) could be a non-pharmacological approach to reducing these and improving quality of life.

Purpose

The aim of this study was to determine the individual disease burden as well as PE preferences of CML patients and to deduce thereof specific PE recommendations.

Methods

This multicenter survey was conducted in cooperation with the LeukaNET/Leukemia-patient network including CML patients aged ≥18 years (German Registry of Clinical Trials, DRKS00023698). The severity of selected symptoms was assessed using the adapted Myeloproliferative Neoplasms Symptom Assessment Form: 0 (absent), 1-30 (mild), 31-70 (moderate), or 71-100 (severe). Information about patients' PE needs and preferences depending on their motivation was recorded.

Results

A total of 212 questionnaires were analyzed (52% female, median age 54 years). The prevalence of moderate-to-severe symptoms was 49% for fatigue, 40% for musculoskeletal pain, and 37% for concentration problems. Other commonly reported symptoms included skin reactions (42%) and weight gain (24%). The proportion of overweight/obese patients was 52%. Half of all respondents requested more information regarding PE. Patients with CML preferred individual training (82%), located outdoors (71%), at home (47%), or in an indoor swimming pool (31%). Regarding the training frequency, sports-inactive patients preferred a frequency of 1-2 training sessions per week, whereas sports-active patients preferred 3-4 sessions per week (p <0.001). Sports-inactive patients preferred a training time of 15-45 minutes, while sports-active patients preferred 30-60 minutes (p = 0.002). Subsequently, PE recommendations were developed for patients with CML. Combined resistance and endurance training (moderate intensity twice per week for 30 minutes) was recommended for beginners. Obese patients should prioritize joint-relieving sports. To reduce the risk of skin reactions, direct sunlight and possibly water sports should be avoided, and UV protection should be used.

Conclusion

Counseling and motivation of CML patients to be physically active should be part of the standard of care as well as support for implementation.

Bullous Pemphigoid Occurring after Stopping Imatinib Therapy of CML: Is a Continuation of Post-Treatment Follow-Up Needed?

Advancements and the use of tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of Chronic Myeloid Leukemia (CML), achieving unprecedented success rates and expanding their applications to various neoplasms. However, the use of TKIs is not without its drawbacks. Skin, gastrointestinal, and central nervous systems are particularly susceptible to adverse effects, including a higher incidence of autoimmune responses in treated individuals. In this report, we present a unique case of bullous pemphigoid, a rare autoimmune disease, which has not been previously associated with TKI therapy as an adverse effect, particularly appearing after discontinuing Imatinib® treatment.

CD4 T cells in chronic myeloid leukemia present MHC class II-dependent and IFN-γ-dependent cytotoxic capacity

At present, many therapeutic schemes have been used to improve the prognosis of patients with chronic myeloid leukemia (CML), but response remains poor in a small group of patients. CD4 T cell-mediated cytotoxicity has been found in various autoimmune diseases. This study analyzed the characteristics of CD4 T cell mediated cytotoxicity in CML patients and healthy people. The cytotoxicity of CD4 T cells was tested in using two CML cell lines, including the MHC class II-deficient K562 cells and the MHC class II-expressing KU812 cells. CD4 T cell-mediated lysis was minimal in K562 cells but was much higher in KU812 cells. In CML patients, the level of CD4 T cell-mediated lysis was limited to a certain level. Interestingly, pre-treating KU812 cells with IFN-γ could significantly elevate the expression of MHC class II and elevate the level of CD4 T cell-mediated lysis. Overall, these data indicated CD4 T cells could become a potential candidate for cytotoxic elimination of CML cells.

Detection of Hybrid Fusion Transcripts, Aberrant Transcript Expression, and Specific Single Nucleotide Variants in Acute Leukemia and Myeloid Disorders with Recurrent Gene Rearrangements

INTRODUCTION

A variety of gene rearrangements and molecular alterations are key drivers in the pathobiology of acute leukemia and myeloid disorders; current classification systems increasingly incorporate these findings in diagnostic algorithms. Therefore, clinical laboratories require versatile tools, which can detect an increasing number and variety of molecular and cytogenetic alterations of clinical significance.

METHODS

We validated an RNA-based next-generation sequencing (NGS) assay that enables the detection of: (i) numerous hybrid fusion transcripts (including rare/novel gene partners), (ii) aberrantly expressed EVI1 (MECOM) and IKZF1 (Del exons 4-7) transcripts, and (iii) hotspot variants in KIT, ABL1, NPM1 (relevant in the context of gene rearrangement status).

RESULTS

For hybrid fusion transcripts, the assay showed 98-100% concordance for known positive and negative samples, with an analytical sensitivity (i.e., limit of detection) of approximately 0.8% cells. Samples with underlying EVI1 (MECOM) translocations demonstrated increased EVI1 (MECOM) expression. Aberrant IKZF1 (Del exons 4-7) transcripts detectable with the assay were also present on orthogonal reverse transcription PCR. Specific hotspot mutations in KIT, ABL1, and NPM1 detected with the assay showed 100% concordance with orthogonal testing. Lastly, several illustrative samples are included to highlight the assay's clinically relevant contributions to patient workup.

CONCLUSION

Through its ability to simultaneously detect various gene rearrangements, aberrantly expressed transcripts, and hotspot mutations, this RNA-based NGS assay is a valuable tool for clinical laboratories to supplement other molecular and cytogenetic methods used in the diagnostic workup and in clinical research for patients with acute leukemia and myeloid disorders.

Correlates of common concerns in older cancer survivors of leukemia and lymphoma: results from the WHI LILAC study

PURPOSE

Older survivors of leukemia and lymphoma often experience long-term effects of chemotherapy. We described common concerns related to their cancer and treatment in older survivors of leukemia and non-Hodgkin lymphoma (NHL) and assessed correlates of these concerns.

METHODS

We utilized data from the Women's Health Initiative (WHI) Life and Longevity After Cancer (LILAC) study that recruited post-menopausal women aged 50-79. Participants diagnosed with leukemia and NHL were included (n = 420). They were asked about 14 areas of current concerns related to their cancer and treatment and to rate each from 0 (no concern) to 2 (major concern), with total scores ranging from 0 to 28. Linear regression was used to assess factors correlated with the concern score, and logistic regression for factors correlated with the three most common concerns.

RESULTS

Mean age at assessment was 81 years (range 69-99); 72% reported at least one concern, and median concern score among these survivors was 3.5 (Q1-Q3 2-5). Factors significantly correlated with concern scores were sadness, pain, distress, higher prior symptom count, and loneliness (all p < 0.05). Significant factors correlated with common concerns were (1) fatigue/sleep: sadness/depression, distress, higher prior symptom count, greater loneliness, and worse physical functioning; (2) physical functioning/activity: older age, public insurance, higher body mass index, pain, worse QoL, and higher treatment-related comorbidities; (3) memory/concentration: prior chemotherapy or radiation, worse QoL, higher prior symptom count, and greater loneliness (all p < 0.05).

CONCLUSIONS AND IMPLICATIONS FOR CANCER SURVIVORS

Almost three-quarters of older survivors of leukemia and lymphoma reported at least one concern; a multifaceted intervention may be needed to address these concerns.

Applications of Machine Learning in Chronic Myeloid Leukemia

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by dysregulated growth and the proliferation of myeloid cells in the bone marrow caused by the BCR-ABL1 fusion gene. Clinically, CML demonstrates an increased production of mature and maturing granulocytes, mainly neutrophils. When a patient is suspected to have CML, peripheral blood smears and bone marrow biopsies may be manually examined by a hematologist. However, confirmatory testing for the BCR-ABL1 gene is still needed to confirm the diagnosis. Despite tyrosine kinase inhibitors (TKIs) being the mainstay of treatment for patients with CML, different agents should be used in different patients given their stage of disease and comorbidities. Moreover, some patients do not respond well to certain agents and some need more aggressive courses of therapy. Given the innovations and development that machine learning (ML) and artificial intelligence (AI) have undergone over the years, multiple models and algorithms have been put forward to help in the assessment and treatment of CML. In this review, we summarize the recent studies utilizing ML algorithms in patients with CML. The search was conducted on the PubMed/Medline and Embase databases and yielded 66 full-text articles and abstracts, out of which 11 studies were included after screening against the inclusion criteria. The studies included show potential for the clinical implementation of ML models in the diagnosis, risk assessment, and treatment processes of patients with CML.

Cytogenetical and hematological analysis of chronic myelogenous leukemia patients with a novel case 52XX, t (1;9;22) (q23.3; q34; q11.2), +6, +8, i(9) (q10;q10), +18,+19,+21+der22 t(9;22)(q34;q11)

(9;22) (q34; q11) translocation is appear in above ninety percent of chronic myelogenous leukemia patients while variant/complex translocations were observed in almost 5% to 8% chronic myelogenous leukemia (CML) positive cases. Gleevec (Imatinib Mesylate) is the first choice breakpoint cluster region (BCR)/ABL targeted oral therapy that produced a complete response almost in 71% to 80% of patients affected with CML. A complete blood count (CBC) of 37 patients was done during diagnosis, however only 21 showed abnormal CBC values which were selected for the study. Karyotyping study using bone marrow samples was performed on 21 CML patients for the conformation of 9;22, however, fluorescence in situ hybridisation was performed for the detection of the BCR-ABL fusion gene of 15 patients. Out of 21, 17 patients showed Ph-positive (9;22) (q34; q11) translocation. Sixteen CML patients showed standard translocation however only CML patients showed a three-way variant/complex translocation with six additional chromosomes, 52XX, t(1;9;22) (q23.3;q34;q11),+6,+8, i(9)(q10;q10), +18,+19,+21 + der22 t(9;22)(q34;q11)). Here we report we report a novel case of six additional chromosomes with the three-way translocation of 52XX, t(1;9;22) (q23.3;q34;q11),+6,+8, i(9)(q10;q10), +18,+19,+21 + der22 t(9;22)(q34;q11) in blast phase.

Reengineering Ponatinib to Minimize Cardiovascular Toxicity

Small molecule tyrosine kinase inhibitors (TKI) have revolutionized cancer treatment and greatly improved patient survival. However, life-threatening cardiotoxicity of many TKIs has become a major concern. Ponatinib (ICLUSIG) was developed as an inhibitor of the BCR-ABL oncogene and is among the most cardiotoxic of TKIs. Consequently, use of ponatinib is restricted to the treatment of tumors carrying T315I-mutated BCR-ABL, which occurs in chronic myeloid leukemia (CML) and confers resistance to first- and second-generation inhibitors such as imatinib and nilotinib. Through parallel screening of cardiovascular toxicity and antitumor efficacy assays, we engineered safer analogs of ponatinib that retained potency against T315I BCR-ABL kinase activity and suppressed T315I mutant CML tumor growth. The new compounds were substantially less toxic in human cardiac vasculogenesis and cardiomyocyte contractility assays in vitro. The compounds showed a larger therapeutic window in vivo, leading to regression of human T315I mutant CML xenografts without cardiotoxicity. Comparison of the kinase inhibition profiles of ponatinib and the new compounds suggested that ponatinib cardiotoxicity is mediated by a few kinases, some of which were previously unassociated with cardiovascular disease. Overall, the study develops an approach using complex phenotypic assays to reduce the high risk of cardiovascular toxicity that is prevalent among small molecule oncology therapeutics.

SIGNIFICANCE

Newly developed ponatinib analogs retain antitumor efficacy but elicit significantly decreased cardiotoxicity, representing a therapeutic opportunity for safer CML treatment.

Association Between the Individual and Combined Effects of the GSTM1 and GSTT1 Polymorphisms and Risk of Leukemia: A Meta-Analysis

Background: Fourteen meta-analyses reported the individual effects of the GSTM1 and GSTT1 polymorphisms on leukemia risk. However, over 40 studies were not included in previously published meta-analyses. Moreover, one key aspect was that previous meta-analyses did not conduct the false-positive test on the aforementioned issues. Furthermore, previous meta-analyses did not observe the combined effects of GSTM1 present/null and GSTT1 present/null polymorphism with leukemia risk. Therefore, we conducted the current study to further analyze these associations.

Objectives: This study aimed to investigate the association between the individual and combined effects of the GSTM1 present/null and GSTT1 present/null polymorphisms and the risk of leukemia.

Methods: A meta-analysis was performed applying Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines. Moreover, false-positive report probability (FPRP) and Bayesian false discovery probability (BFDP) were applied to investigate the false-positive results.

Results: The individual GSTM1 and GSTT1 null genotypes and combined effects of the two genes were associated with a significantly increased leukemia risk in overall and several subgroup analyses, such as Asians, Caucasians, and so on. Then, further analysis was conducted using FPRP and BFDP. Significant associations were considered as “positive” results on the GSTM1 null genotype with leukemia risk in overall populations (FPRP < 0.001 and BFDP = 0.006), Asians (FPRP < 0.001 and BFDP < 0.001), and East Asian population (FPRP < 0.001 and BFDP = 0.002). For the GSTT1 null genotype, significant associations were regarded “positive” results in overall populations, acute myeloid leukemia (AML), Asians, and East Asian population. For the combined effects of the GSTM1 and GSTT1 polymorphisms, significant associations were also considered “positive” results in the overall analysis of Asians, Indians, and East Asian population.

Conclusion: This study strongly indicates that the individual GSTM1 and GSTT1 null genotypes and combined effects of the two genes are associated with increased leukemia risk in Asians, especially in the East Asian population; the GSTT1 null genotype is associated with increased AML risk; the combined effects of the two genes are associated with increased leukemia risk in Indians.

Management of Myeloproliferative Neoplasms in the Molecular Era: From Research to Practice

The 1960 discovery of the Philadelphia chromosome in chronic myeloid leukemia (CML) marked the beginning of the modern genomic era of oncology. In the following years, the molecular underpinnings of CML were unraveled, culminating in the development of the first molecularly targeted therapy: imatinib. Imatinib revolutionized CML management, inducing deep molecular responses for most patients and aligning survival curves with those of age-matched control participants. Five additional tyrosine kinase inhibitors are now approved for CML: dasatinib, nilotinib, bosutinib, ponatinib, and asciminib (approved October 2021). The 2005 discovery of JAK2 mutations in myelofibrosis (MF) sparked enthusiasm that molecularly targeted therapies could have a similar impact in that disease. Three JAK inhibitors are now available for MF: ruxolitinib, fedratinib, and pacritinib (approved February 2022). JAK inhibitors are helpful for improving symptoms and splenomegaly but still only scratch the surface of MF pathophysiology. Clinical research testing novel agents, next-generation JAK inhibitors, and combinations of JAK inhibitors plus novel agents is moving at a tremendous pace in the hope that outcomes for patients with MF may mirror those with CML one day. This review provides an update on the status of clinical care and research for MF and addresses ongoing issues related to CML management.

Bilateral vision loss as initial presentation of chronic myeloid leukemia in a young adult: A case report and review of the literature

Purpose

To report a case of bilateral vision loss as the primary presenting symptom of chronic myeloid leukemia in a young adult.

Observations

The 28-year-old male patient presented to clinic with visual acuity of 20/200 in both eyes after several months of episodic bilateral vision loss. Intraretinal and pre-retinal hemorrhages were appreciated, as well as Roth spots and peripheral neovascularization. Initial lab findings were consistent with a diagnosis of acute myeloid leukemia, later, upon bone marrow examination, the diagnosis was edited to chronic myeloid leukemia. Dasatinib therapy resulted in a complete hematologic resolution after six weeks. After intravitreal injections of bevacizumab in both eyes, visual acuity improved to 20/25 in the right eye and 20/20 in the left eye.

Conclusion and importance

After review, this is one of only a few reported cases of bilateral blurry vision as the primary presenting symptom of chronic myeloid leukemia in a young adult. Because visual disturbances occur more frequently in acute myeloid leukemia, and lab results may be inconclusive, careful consideration should be given to differentiate myelogenous leukemias, as the acute and chronic subtypes may present similarly.

Pro-adherence complementary audiovisual educational intervention model for chronic myeloid leukemia patients treated with imatinib mesylate

BACKGROUND

Imatinib mesylate (IM) treatment adherence is a challenge, especially in an economic-social population neglected from developing countries.

OBJECTIVE

To create a new complementary audiovisual educational intervention model to improve IM treatment adherence of CML patients.

METHODS

Two adherence verification methods were applied before and after intervention: modified Morisky-Green test and molecular responses (BCR-ABL transcripts quantification). Adherence estimates were calculated using univariate and multivariate component analysis (MCA) for the socio-demographic and clinical characteristics of patients.

RESULTS

Modified Morisky-Green test results demonstrated a substantial increase of CML patient adherence from 23% (pre-film) to 65% (post-film). Greater improvement was obtained for patients presenting major molecular response (MMR) from 38% (pre-film) to 60% (post-film). Although slight gain for complete molecular response (CMR) from 23% (pre-film) to 26% (post-film) was achieved, it represents a total tumour regression. MCA identified that females <50 years-old, using less than two medications (no disease associated) and CMR condition were the most benefited with intervention.

CONCLUSION

Audiovisual educational intervention was an effective complementary pro-adherence model, activating patient memory and improving IM treatment adherence. Although this intervention shows effective, not all patients responded as expected, being necessary a combination of educational and clinical interventions to improve IM adherence.

Genetic Biomarkers in Chronic Myeloid Leukemia: What Have We Learned So Far?

Chronic Myeloid Leukemia (CML) is a rare malignant proliferative disease of the hematopoietic system, whose molecular hallmark is the Philadelphia chromosome (Ph). The Ph chromosome originates an aberrant fusion gene with abnormal kinase activity, leading to the buildup of reactive oxygen species and genetic instability of relevance in disease progression. Several genetic abnormalities have been correlated with CML in the blast phase, including chromosomal aberrations and common altered genes. Some of these genes are involved in the regulation of cell apoptosis and proliferation, such as the epidermal growth factor receptor (EGFR), tumor protein p53 (TP53), or Schmidt-Ruppin A-2 proto-oncogene (SRC); cell adhesion, e.g., catenin beta 1 (CTNNB1); or genes associated to TGF-β, such as SKI like proto-oncogene (SKIL), transforming growth factor beta 1 (TGFB1) or transforming growth factor beta 2 (TGFB2); and TNF-α pathways, such as Tumor necrosis factor (TNFA) or Nuclear factor kappa B subunit 1 (NFKB1). The involvement of miRNAs in CML is also gaining momentum, where dysregulation of some critical miRNAs, such as miRNA-451 and miRNA-21, which have been associated to the molecular modulation of pathogenesis, progression of disease states, and response to therapeutics. In this review, the most relevant genomic alterations found in CML will be addressed.

Magnitude and Temporal Trend of the Chronic Myeloid Leukemia: On the Basis of the Global Burden of Disease Study 2019

To map the magnitudes and temporal trends of chronic myeloid leukemia (CML) along with its attributable risk factors, providing the essential foundation for targeted public policies at the national, regional, and global levels.

Temporal trend of CML burden and its attributable factors was mapped to guide public health resource allocation.

Molecular, Cytogenetic, and Hematological Analysis of Chronic Myeloid Leukemia Patients and Discovery of Two Novel Translocations

Chronic myeloid leukemia (CML) is a disease of hematopoietic stem cells and is caused by the balanced translocations among the long arms of chromosomes 9 and 22, which are called the Philadelphia (Ph) chromosome. In this study, 131 CML patients were enrolled. Complete blood cell count was performed at the time of diagnosis for all the patients. Cytogenetic (karyotyping) examination using bone marrow samples was conducted on 76 CML patients for the confirmation of Ph-positive (9;22)(q34;q11) standard translocation, complex variant translocation, and additional chromosome abnormalities. FISH was performed on 38 patients for diagnostic purposes and on 39 patients for monitoring purposes. Twenty-two samples of CML patients were evaluated by reverse transcriptase PCR and real-time PCR for the patients who failed to respond against imatinib mesylate. In this study, 72 (54.96%) were males and 59 (45.03%) were females with a median age of 38.5 years. CBC values in the diagnosis process showed that 75 patients had high values of WBC being >100 × 103/μl, while 71 (58.01) patients exhibited reduced values of hemoglobin, i.e., <10.00 mg/dl, and high values of PLTs > 100 were observed in 40 (30.53%) patients. Cytogenetic results show that standard translocation was developed in 63 (82.89%), development of complex variant translocations in 4 (5.32%), additional chromosomal abnormalities (ACAs) in 3 (3.94%), and ACAs together with complex variant translocations in 1 (1.31%) patient. At the time of diagnosis, 61 (92.95%) patients were in the chronic phase, 4 (5.63%) were in the accelerated phase, and only 1 (1.40%) was in the blast crisis. Out of twenty-two patients, only 6 CML patients who were shifted from imatinib mesylate to nilotinib showed BCR-ABL-positive amplification. However, only 7 out of twenty-one patients exhibit BCR-ABL gene values ≥ 1 after three months of follow-up when analyzed by the quantitative real-time PCR. In conclusion, we found a novel five-way translocation 46XX,t(1;2;2;17;9;22)(p36.3,q21;q11.2,q21,q34,q11.2) and a novel four-way complex variant translocation 48XY,+8(8;17)(9;22),+der(22)(q11.2;q23)(q34;q11.2) in the accelerated phase.

Association of DNA repair gene XPC Ala499Val (rs2228000 C>T) and Lys939Gln (rs2228001 A>C) polymorphisms with the risk of chronic myeloid leukemia: A case-control study in a South Indian population

BACKGROUND

Xeroderma pigmentosum complementation group C (XPC), a DNA repair protein, plays an important role in the maintenance of genomic integrity and is essential for the nucleotide excision repair pathway. Polymorphisms in the XPC gene may alter DNA repair leading to genetic instability and oncogenesis. The present study aimed to assess the relationship between the XPC Ala499Val (rs2228000 C>T) and Lys939Gln (rs2228001 A>C) non-synonymous polymorphisms and susceptibility to chronic myeloid leukemia (CML) pathogenesis, disease progression and the response to targeted therapeutic regimen, imatinib mesylate.

METHODS

This case-control study included 212 cases and 212 controls, and the genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism assays.

RESULTS

Our results showed significant association of variant CT (odds ratio = 1.92, 95% confidence interval = 1.21-3.06, p = 0.003) and TT (odds ratio = 2.84, 95% confidence interval = 1.22-6.71, p = 0.007) genotypes in patients with the XPC Ala499Val polymorphism and CML risk. In addition, these genotypes were associated with CML progression to advanced phases (p = 0.006), splenomegaly (p = 0.017) and abnormal lactate dehydrogenase levels (p = 0.03). XPC Lys939Gln was found to correlate with a poor response to therapy, showing borderline significant association with minor cytogenetic response (p = 0.08) and a poor molecular response (p = 0.06). Significant association of the Ala499Val and Lys939Gln polymorphisms with prognosis was observed (Hasford high risk, p = 0.031 and p = 0.019, respectively). Haplotype analysis showed a strong correlation of variant TC haplotype with poor therapy responses (minor cytogenetic response, p = 0.019; poor molecular response, p < 0.0001).

CONCLUSIONS

In conclusion, our results suggest that XPC Ala499Val is a high-penetrance CML susceptibility polymorphism. Both polymorphisms studied are considered as genetic markers with respect to assessing disease progression, therapy response and prognosis in CML patients.

Chronic myeloid leukemia-from the Philadelphia chromosome to specific target drugs: A literature review

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm and was the first neoplastic disease associated with a well-defined genotypic anomaly - the presence of the Philadelphia chromosome. The advances in cytogenetic and molecular assays are of great importance to the diagnosis, prognosis, treatment, and monitoring of CML. The discovery of the breakpoint cluster region (BCR)-Abelson murine leukemia (ABL) 1 fusion oncogene has revolutionized the treatment of CML patients by allowing the development of targeted drugs that inhibit the tyrosine kinase activity of the BCR-ABL oncoprotein. Tyrosine kinase inhibitors (known as TKIs) are the standard therapy for CML and greatly increase the survival rates, despite adverse effects and the odds of residual disease after discontinuation of treatment. As therapeutic alternatives, the subsequent TKIs lead to faster and deeper molecular remissions; however, with the emergence of resistance to these drugs, immunotherapy appears as an alternative, which may have a cure potential in these patients. Against this background, this article aims at providing an overview on CML clinical management and a summary on the main targeted drugs available in that context.

Inhibition of cystathionine β-synthase promotes apoptosis and reduces cell proliferation in chronic myeloid leukemia

Increased endogenous hydrogen sulfide (H₂S) level by cystathionine β-synthase (CBS) has been shown to closely relate tumorigenesis. H₂S promotes angiogenesis, stimulates bioenergy metabolism and inhibits selective phosphatases. However, the role of CBS and H₂S in chronic myeloid leukemia (CML) remains elusive. In this study, we found that CBS and H₂S levels were increased in the bone marrow mononuclear cells of pediatric CML patients, as well as in the CML-derived K562 cells and CBS expression levels were correlated with different disease phases. Inhibition of CBS reduced the proliferation of the CML primary bone marrow mononuclear cells and induced growth inhibition, apoptosis, cell cycle arrest, and migration suppression in K562 cells and tumor xenografts. The knockdown of CBS expression by shRNA and inhibiting CBS activity by AOAA decreased the endogenous H₂S levels, promoted mitochondrial-related apoptosis and inhibited the NF-κB-mediated gene expression. Our study suggests that inhibition of CBS induces cell apoptosis, as well as limits cell proliferation and migration, a potential target for the treatment of chronic myeloid leukemia.

Future Approaches for Treating Chronic Myeloid Leukemia: CRISPR Therapy

Simple Summary

In the last two decades, the therapeutic landscape of several tumors have changed profoundly with the introduction of drugs against proteins encoded by oncogenes. Oncogenes play an essential role in human cancer and when their encoded proteins are inhibited by specific drugs, the tumoral process can be reverted or stopped. An example of this is the case of the chronic myeloid leukemia, in which all the pathological features can be attributed by a single oncogene. Most patients with this disease now have a normal life expectancy thanks to a rationality designed inhibitor. However, the drug only blocks the protein, the oncogene continues unaffected and treatment discontinuation is only an option for a small subset of patients. With the advent of genome-editing nucleases and, especially, the CRISPR/Cas9 system, the possibilities to destroy oncogenes now is feasible. A novel therapeutic tool has been developed with unimaginable limits in cancer treatment. Recent studies support that CRISPR/Cas9 system could be a definitive therapeutic option in chronic myeloid leukemia. This work reviews the biology of chronic myeloid leukemia, the emergence of the CRISPR system, and its ability as a specific tool for this disease.

Abstract

The constitutively active tyrosine-kinase BCR/ABL1 oncogene plays a key role in human chronic myeloid leukemia development and disease maintenance, and determines most of the features of this leukemia. For this reason, tyrosine-kinase inhibitors are the first-line treatment, offering most patients a life expectancy like that of an equivalent healthy person. However, since the oncogene stays intact, lifelong oral medication is essential, even though this triggers adverse effects in many patients. Furthermore, leukemic stem cells remain quiescent and resistance is observed in approximately 25% of patients. Thus, new therapeutic alternatives are still needed. In this scenario, the interruption/deletion of the oncogenic sequence might be an effective therapeutic option. The emergence of CRISPR (clustered regularly interspaced short palindromic repeats) technology can offer a definitive treatment based on its capacity to induce a specific DNA double strand break. Besides, it has the advantage of providing complete and permanent oncogene knockout, while tyrosine kinase inhibitors (TKIs) only ensure that BCR-ABL1 oncoprotein is inactivated during treatment. CRISPR/Cas9 cuts DNA in a sequence-specific manner making it possible to turn oncogenes off in a way that was not previously feasible in humans. This review describes chronic myeloid leukemia (CML) disease and the main advances in the genome-editing field by which it may be treated in the future.

Association of the Trough, Peak/Trough Ratio of Imatinib, Pyridine-N-Oxide Imatinib and ABCG2 SNPs 34 G>A and SLCO1B3 334 T>G With Imatinib Response in Egyptian Chronic Myeloid Leukemia Patients

Imatinib mesylate (IM) is highly efficacious in the treatment of chronic myeloid leukemia (CML). Therapeutic drug monitoring and pharmacogenetic screening are affirmed for better management of IM therapy. The goal of this study was to gain a greater mechanistic understanding of the factors controlling variability in IM level and its relation to the response. One hundred and two patients with CML at chronic phase were recruited in this study. Blood samples were withdrawn at least 30 days after drug administration, and trough and peak concentrations of imatinib, N-des-methyl imatinib, and pyridine-N-oxide imatinib were determined by HPLC/MS/MS. Genetic polymorphism of the genes ABCG2 SNPs 34 G>A and 421C >A; ABCB1 SNPs 2677 G>A/T, 1236 C>T, 3435 C>T; SLCO1B3 SNPs 334 T>G and CYP3A5 were studied using PCR-RFLP technique. Our study presented significant higher trough IM (1,281 ± 578 ng/ml), lower Peak/Trough ratio, clearance (Cl), and elimination rate constant, k_e, among patients who achieved favorable responses (N = 64) than those for patients who suffered unfavorable response (N = 37). The P/T ratio was the only significant independent factor affecting response, as the P/T ratio increased by one, the risk of unfavorable response increased by more than double as compared to favorable response with 95% CI (1.28-3.92, P = 00.005). Moreover, like the results of IM, the trough concentration of Pyridine-N-oxide imatinib was significantly higher (P = 0.01) and its P/T ratio was significantly lower (P = 0.008) in patients achieved favorable response than those without. The wild GG genotype of the ABCG2.34 G>A gene was associated with favorable response (P = 0.01), lower Cl, K_e and high plasma IM trough level than both (AA+GA) genotypes. ABCG2.421C >A (CC) genotype had a significantly higher plasma peak of IM, N-des-methyl imatinib and higher C_ss. The GG and TG alleles of the SLCO1B3.334 T>G gene were significantly correlated to favorable response, while the wild allele TT was linked to unfavorable response (P = 0.03). In conclusion, the trough and P/ T ratio for both IM and Pyridine-N-oxide imatinib, in addition to Polymorphism of ABCG2 SNPs 34 G>A and SLCO1B3.334 T>G gene, is a good predictor for response of IM in CML Egyptian patients.

Molecular testing of chronic myeloid leukaemia in low resource areas

Most cancer cases occur in areas of low resources. The diagnosis, treatment and monitoring of cancers is especially challenging in these locations. Unique partnerships exist between non-profit organisations and pharmaceutical companies to provide free drugs to CML patients throughout the world if the diagnosis can be rigorously and unambiguously established. But there lies the rub: How do you perform molecular diagnostics in areas where even electricity is unreliable? Here we describe the evolution of testing patients from low resource areas, which, when merged with a remarkable effort to bring tyrosine kinase inhibitors to patients across the globe, have led to survival outcomes similar to cases in industrialised countries.

New approaches to molecular monitoring in CML (and other diseases)

Chronic myeloid leukemia (CML) is the model cancer, demonstrating the clinical benefits of targeted therapy and the power of molecular diagnostics and monitoring. In CML, the BCR-ABL1 fusion gene and its companion messenger RNA offers a unique target differentiating cancer from the normal cell, affording the potential for very sensitive and specific assays. Because CML is such an ideal model, new methods are arising that should make testing in CML faster, more reliable, and reach a greater sensitivity. New ultrasensitive sequencing approaches, coupled with single-cell genomic approaches, further the study of measurable residual disease, clonal heterogeneity, and promise to make clinical trials more innovative and informative. These methods should be able to be transferred to other hematological and solid malignancies.

Evaluation and characterisation of Chronic myeloid leukemia and various treatments in Saudi Arabia: A retrospective study

BACKGROUND

Chronic myeloid leukemia (CML) is a clonal BCR-ABL1-positive myelo-proliferative disorder resulting from an acquired genetic mutation, characterized by the presence of the Philadelphia (Ph) chromosome. CML is associated with significantly high granulocyte numbers in the bone marrow and peripheral blood.

MATERIALS AND METHODS

This retrospective study conducted at the Hematology Unit of King Saud University Medical City aimed to evaluate the incidence and characteristics of CML and the various treatments in Saudi Arabia. We have evaluated the demographic, clinical, and hematological data of 56 consecutive patients who visited the hospital from Jan 2012 to Jan 2018.

RESULTS

The diagnosis and stage of CML were determined based on the World Health Organization criteria, following polymerase chain reaction analysis of bone marrow aspirates. Our study group had equal numbers of genders with a age mean of 43.3+18.1 years. The predominance of younger patients and equal incidence in males and females could be due to the racial and socioeconomic disparities among our patients compared to those in previous studies. While the most predominant symptom was fatigue and bone pain, the most common clinical sign was hepato-splenomegaly, followed by remarkable weight loss, and epistaxis.

CONCLUSION

A patient with an increased WBC count, abdominal pain, left side distension, and hepato-splenomegaly should clearly be evaluated for CML.

Complexity of chronic-phase CML management after failing a second-generation TKI

The treatment landscape of chronic myeloid leukemia (CML) was radically changed with the introduction of imatinib in 2001. With the emergence of treatment failure with imatinib, more specific and potent second- and third-generation tyrosine kinase inhibitors (TKIs) were developed. Currently, 6 TKIs and one protein synthesis inhibitor are available on the market for CML treatment. Despite the availability of these agents, it is not uncommon for some patients to experience treatment failure across several lines of therapy. Sequencing the available treatment options is a challenging task that becomes more complex after patients fail the more potent second- and third-generation TKIs. The ability to successfully salvage such patients is limited. In this paper, we will briefly review the mechanisms of treatment failure in chronic-phase CML (CP-CML) and focus on the complexity of managing patients who fail a second-generation TKI.

Treatment patterns and deep molecular response in chronic phase - chronic myeloid leukemia patients treated with second-line nilotinib or dasatinib: a multi-country retrospective chart review study

Achievement of MR4.5 (BCR-ABL1 ≤ 0.0032% on international scale) is an important goal of tyrosine kinase inhibitor (TKI) treatment for patients with chronic myeloid leukemia (CML). This study describes treatment patterns by region and assesses time to achieve MR4.5 in patients with CML - chronic phase (CP) treated with second-line nilotinib or dasatinib in 10 countries. A multivariate Cox proportional hazards model was used to assess time to MR4.5 for nilotinib versus dasatinib. The model accounted for the competing-risk event of TKI resistance, included random effects for country clustering, and was adjusted for baseline covariates. The study included 280 patients treated with either nilotinib (N = 135 [48%]) or dasatinib (N = 145 [52%]) as second-line TKI with median treatment durations of 19.1 and 18.7 months, respectively. Nilotinib was observed to be better in achieving MR4.5 than dasatinib (adjusted hazard ratio = 1.37, 95% CI [1.11, 1.69]) suggesting second-line nilotinib may perform better in achieving MR4.5 than dasatinib.

Determination of the Apoptotic Effect and Molecular Docking of Benzamide Derivative XT5 in K562 Cells

Background:

The tyrosine kinase inhibitor, imatinib, used as a first line treatment in Chronic Myeloid Leukemia (CML) patients, may lead to resistance and failure to therapy. Novel combinations of imatinib with other drugs is a strategy to improve treatment efficiency.

Objective:

In this study, the antileukemic and apoptotic effects of a benzamide derivative XT5 and benzoxazole derivative XT2B and their combination with imatinib were investigated in imatinib-sensitive (K562S) and imatinib-resistant (K562R) CML cells.

Methods:

In vitro cytotoxicity was determined by MTT assay. Then, apoptotic effect of XT5 on CML cell lines was tested by Annexin V flow cytometry, caspase activation and RT-PCR. Docking calculation was performed using AutoDock Vina in PyMOL environment using AutoDock/Vina plugin for PyMOL.

Results:

According to our MTT assay data, XT5 indicated significant antiproliferative effect on cell lines, therefore we investigated apoptotic effects of XT5. Treatment of K562 cell lines with a combination of XT5 and imatinib-XT5 increased cytotoxicity, the Annexin V binding and caspase 3/7 activation. In addition to apoptosis assays, we observed an increase in the expression levels of the pro-apoptotic (BAX, BAD and BIM) genes in XT5 treated K562R and K562S cells. Molecular modelling experiments showed that XT5 showed hydrogenbonding interactions with important amino acids of BCR-ABL kinase receptor; however XT2B did not show any hydrogen bond interaction.

Conclusion:

Our results indicate that XT5 could be a potential candidate to be used as a new anticancer drug and XT5 combination with imatinib as an alternate treatment strategy for overcoming imatinib resistance.

A Pharmacological Strategy Using Stemofoline for more Efficacious Chemotherapeutic Treatments Against Human Multidrug Resistant Leukemic Cells

Our previous study reported that stemofoline (STF) exhibited a synergistic effect with chemotherapeutic drugs in human multidrug-resistant (MDR) leukemic cells (K526/Adr) by inhibiting the function of P-glycoprotein, which is a membrane transporter that is overexpressed in several types of MDR cancers. This study further investigated the effects of a combination treatment of STF and doxorubicin (DOX) in vitro and in vivo. The combination treatment of 50 mg/kg of STF strongly enhanced the anti-tumor activity of DOX in SCID-beige mice bearing K562/Adr xenografts without additional toxicity when compared to the single treatment groups. Additionally, an examination of the proliferation markers (Ki67) and the apoptotic marker (TUNEL) in tumor tissues in each group revealed that the combination therapy significantly reduced Ki67 positive cells and increased apoptotic cells. From the in vitro experiments we also found that this combination treatment dramatically induced G1 and G2M arrest in K562/Adr when compared to a single treatment of DOX. STF treatment alone did not show any cytotoxic effect to the cells. These results suggest that the accumulation of DOX enhanced by STF was sufficient to induce cell cycle arrest in K562/Adr. These findings support our previous in vitro data and indicate the possibility of developing STF as an adjuvant therapy in cancer treatments.

Pattern of Use and Long-Term Safety of Tyrosine Kinase Inhibitors: A Decade of Real-World Management of Chronic Myeloid Leukemia

BACKGROUND AND OBJECTIVES

First-line treatment of chronic phase (CP) chronic myeloid leukemia (CML) is based on the first-generation tyrosine kinase inhibitor (TKI) imatinib or the second-generation TKIs dasatinib or nilotinib. Thanks to the efficacy of TKIs, CML has switched from a fatal to a 'chronic' pathology, and data from clinical trials have become insufficient to drive physicians' prescription choices and address long-term treatment outcomes. On the brink of commercialization of generic imatinib, this study aims to evaluate the therapeutic pattern of CP-CML and the occurrence of adverse events (AEs) over a decade of local real clinical practice.

METHODS

A retrospective cohort study was performed on CP-CML patients followed up in the Local Health Unit of Treviso (Veneto Region, Italy) during the period 2005-2015. Data were captured from both administrative databases and physicians' patient diaries.

RESULTS

Of 81 CP-CML patients, 73 were treated with first-line imatinib; among the second-generation TKIs, only nilotinib was used (n = 8). Overall, 38% of imatinib-treated subjects needed to switch, mainly due to intolerance, whereas no switches occurred in the nilotinib cohort. Osteoarticular pain was the most common AE and was significantly more frequent in the imatinib cohort (68.49 vs. 25.00%, p = 0.022). Other common AEs were dermatologic manifestations, asthenia, and diarrhea.

CONCLUSION

Although based on a small population, this study represents an unbiased reference on the long-term management of CML in an Italian clinical setting. Our results indicate a better profile of first-line nilotinib, both in terms of persistency and tolerability. AEs remain a major concern, highlighting the importance of close monitoring.

A rare case of three-way complex variant translocation in chronic myeloid leukemia t(6;9;22)(p21;q34;q11): A case report

Philadelphia (Ph)-positive chromosome or Ph translocation has been recognized in 90-95 chronic myeloid leukemia (CML) cases worldwide. However, only 5-8% CML patients show complex variant translocations. In the present study, hematological tests for a 47-year-old female CML patient were performed to determine the hemoglobin, platelets and total leukocyte values. A FISH test was carried out to recognize the BCR/ABL gene fusion, and a cytogenetic analysis was performed. The hematological results showed an increase in WBC (414000/mm³) and a decrease in hemoglobin (8.9 mg/dl), indicating the anemic condition in the CML patient. Furthermore, cytogenetic karyotyping results showed 46,XX,t(6;9;22)(p21;q34;q11) and positive for Ph chromosome. In conclusion, in the present study, we report a rare three-way complex variant translocation in a CML patient.

New Methodologies in the Molecular Monitoring of CML

In chronic myeloid leukemia (CML), the BCR-ABL fusion gene is both the therapeutic target of tyrosine kinase inhibitors and the indisputable direct marker of disease burden. Thus, sensitive assays for BCR-ABL now drive therapeutic options and are good surrogates for short- and long-term outcomes. Because CML is such an ideal model, new methods are arising that should make testing in CML faster, more reliable, and reach a greater sensitivity. These methods should be able to be transferred to other hematological malignancies that have mutation markers.

Molecular study of ABCB1 gene and its correlation with imatinib response in chronic myeloid leukemia

PURPOSE

The introduction and success of imatinib mesylate have become a paradigm shift in chronic myeloid leukemia (CML) treatment. However, despite its high efficiency, resistance to imatinib has emerged as a significant problem, which may in part be caused by pharmacogenetic variability. Three single-nucleotide polymorphisms (C1236T, G2677T/A, C3435T) and/or mRNA expression changes of ABCB1 gene were demonstrated to be associated with inter-individual variability of imatinib response in CML patients. In this study, we aimed to examine whether genetic variations and/or altered expression of ABCB1 gene may influence response to imatinib.

METHODS

Sixty nine CML Tunisian patients, undergoing imatinib therapy, were enrolled in this study. These were divided into two groups: responders and non-responders to imatinib. The relative transcript expression levels of ABCB1 gene and the distribution of allele and genotype frequency of ABCB1 SNPs were compared between these two categories of patients. Linkage disequilibrium tests and haplotypes analysis were also studied.

RESULTS

Our results showed that the mRNA expression level of ABCB1 gene did not differ significantly between the two categories of patients. In addition, results obtained from ABCB1 polymorphisms study and their correlation with imatinib response showed that the optimal response rate to imatinib did not differ significantly between C1236T, G2677T/A or C3435T genotypes. However, haplotype analysis showed that the 1236C-2677A-3435C haplotype was observed only in imatinib non-responders' patients suggesting that CAC haplotype was linked to higher risk of imatinib resistance.

CONCLUSION

Furthermore, analyses of ABCB1 haplotypes should be taken into account to study the relationship between ABCB1 genotypes and imatinib efficacy.

Chronic Myeloid Leukemia in the Era of Tyrosine Kinase Inhibitors: An Evolving Paradigm of Molecularly Targeted Therapy

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm, characterized by the unrestrained expansion of pluripotent hematopoietic stem cells. CML was the first malignancy in which a unique chromosomal abnormality was identified and a pathophysiologic association was suggested. The hallmark of CML is a reciprocal chromosomal translocation between the long arms of chromosomes 9 and 22, t(9; 22)(q34; q11), creating a derivative 9q+ and a shortened 22q-. The latter, known as the Philadelphia (Ph) chromosome, harbors the breakpoint cluster region-abelson (BCR-ABL) fusion gene, encoding the constitutively active BCR-ABL tyrosine kinase that is necessary and sufficient for initiating CML. The successful implementation of tyrosine kinase inhibitors (TKIs) for the treatment of CML remains a flagship for molecularly targeted therapy in cancer. TKIs have changed the clinical course of CML; however, some patients nonetheless demonstrate primary or secondary resistance to such therapy and require an alternative therapeutic strategy. Therefore, the assessment of early response to treatment with TKIs has become an important tool in the clinical monitoring of CML patients. Although mutations in the BCR-ABL have proven to be the most prominent mechanism of resistance to TKIs, other mechanisms-either rendering the leukemic cells still dependent on BCR-ABL activity or supporting oncogenic properties of the leukemic cells independent of BCR-ABL signaling-have been identified. This article provides an overview of the current understanding of CML pathogenesis; recommendations for diagnostic tools, treatment strategies, and management guidelines; and highlights the BCR-ABL-dependent and -independent mechanisms that contribute to the development of resistance to TKIs.

Inactivation of Receptor Tyrosine Kinases Reverts Aberrant DNA Methylation in Acute Myeloid Leukemia

Purpose: Receptor tyrosine kinases (RTKs) are frequently deregulated in leukemia, yet the biological consequences of this deregulation remain elusive. The mechanisms underlying aberrant methylation, a hallmark of leukemia, are not fully understood. Here we investigated the role of RTKs in methylation abnormalities and characterized the hypomethylating activities of RTK inhibitors.Experimental Design: Whether and how RTKs regulate expression of DNA methyltransferases (DNMTs), tumor suppressor genes (TSGs) as well as global and gene-specific DNA methylation were examined. The pharmacologic activities and mechanisms of actions of RTK inhibitors in vitro, ex vivo, in mice, and in nilotinib-treated leukemia patients were determined.Results: Upregulation of RTKs paralleled DNMT overexpression in leukemia cell lines and patient blasts. Knockdown of RTKs disrupted, whereas enforced expression increased DNMT expression and DNA methylation. Treatment with the RTK inhibitor, nilotinib, resulted in a reduction of Sp1-dependent DNMT1 expression, the diminution of global DNA methylation, and the upregulation of the p15^INK4B gene through promoter hypomethylation in AML cell lines and patient blasts. This led to disruption of AML cell clonogenicity and promotion of cellular apoptosis without obvious changes in cell cycle. Importantly, nilotinib administration in mice and human patients with AML impaired expression of DNMTs followed by DNA hypomethylation, TSG re-expression, and leukemia regression.Conclusions: Our findings demonstrate RTKs as novel regulators of DNMT-dependent DNA methylation and define DNA methylation status in AML cells as a pharmacodynamic marker for their response to RTK-based therapy, providing new therapeutic avenues for RTK inhibitors in overcoming epigenetic abnormalities in leukemia. Clin Cancer Res; 23(20); 6254-66. ©2017 AACR.

Investigating critical genes and gene interaction networks that mediate cyclophosphamide sensitivity in chronic myelogenous leukemia

Drug resistance is an obstacle in the treatment of chronic myelogenous leukemia (CML), and is a common reason for treatment failure or disease progression. However, the underlying mechanisms of cyclophosphamide resistance remain poorly defined. In the present study, microarray data concerning cyclophosphamide‑sensitive and ‑resistant chronic myelogenous leukemia cell lines were analyzed. A total of 258 differentially‑expressed genes (DEGs) were identified between these two groups, from which 139 DEGs were upregulated and 119 were downregulated. Several candidate genes that were associated with cyclophosphamide resistance were also identified. These DEGs were subsequently classified using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathway analysis. A total of 487 biological processes and 17 KEGG pathways were revealed to be enriched. Furthermore, an interaction network was established to identify the core genes that regulated cyclophosphamide resistance. Signal transducer and activator of transcription 5A (STAT5A), FYN proto‑oncogene, Src family tyrosine kinase and spleen associated tyrosine kinase were revealed to be the hub genes in multiple enriched biological processes and signaling pathways, indicating that these were involved in mediating cyclophosphamide sensitivity in CML cells. The expression levels of 5 DEGs were also confirmed in two human CML cell lines (K‑562 and KU812) by reverse transcription‑quantitative polymerase chain reaction. Furthermore, selective knockdown of STAT5A and S100 calcium binding protein A4 (S100A4) recovered cyclophosphamide sensitivity in K‑562 cells, suggesting their involvement in drug resistance. The present study identified several potential genes and pathways contributing to cyclophosphamide resistance, and confirmed the involvement of STAT5A and S100A4 in drug resistance. These results enable improved understanding of the mechanisms underlying drug resistance in CML cells.

Bcl6 gene-silencing facilitates PMA-induced megakaryocyte differentiation in K562 cells

Targeted therapy via imatinib appears to be a promising approach for chronic myeloid leukemia (CML) therapy. However, refractory and resistance to imatinib therapy has encouraged many investigators to get involved in development of new therapeutic agents such as Phorbol 12-myrestrat 13-acetate (PMA) for patients with CML. In that line, we attempted to investigate the chemosensitizing effect of PMA on the imatinib-resistant cells. Based on our western blot analyses, resistant K562 cells (K562R) showed high levels of FoxO3a and Bcl6 expressions which were not modulated by imatinib treatment. However, upon PMA treatment, the levels of both FoxO3a and Bcl6 were up-regulated among both the sensitive and the resistant cells and this treatment was associated with initiation of megakaryocytic differentiation of the cells. SiRNA-silencing of FoxO3a led to augmentation of megakaryocytic differentiation of the cells. Similarly, siRNA gene silencing of Bcl6 enhanced the differentiation and induced cell apoptosis among both types of cells. Regarding these results, it might be concluded that Bcl6 knockdown combined with PMA therapy could present a new therapeutical strategy for refractory CML patients to imatinib.

Factors Associated With Tyrosine Kinase Inhibitor Initiation and Adherence Among Medicare Beneficiaries With Chronic Myeloid Leukemia

Purpose There is substantial concern surrounding affordability of orally administered anticancer therapies, particularly for Medicare beneficiaries. We examined rates of initiation and adherence to tyrosine kinase inhibitors (TKIs) among Medicare beneficiaries with chronic myeloid leukemia (CML) with and without cost-sharing subsidies. We selected TKIs given their effectiveness and strong indication for use among patients diagnosed with CML. Patients and Methods Using SEER-Medicare data, we identified individuals diagnosed with CML from 2007 to 2011. We used Cox proportional hazards regression to assess time from diagnosis to TKI initiation. We used generalized estimating equations to examine treatment initiation within 180 days and TKI adherence among initiators. We defined adherence as at least 80% of days covered during the 6 months after TKI initiation. Results Among 393 individuals diagnosed with CML from 2007 to 2011, 68% initiated TKI treatment within 180 days after diagnosis. In multivariate analysis, individuals with cost-sharing subsidies, younger age, lower comorbidity, and later year of diagnosis were significantly more likely to initiate TKIs. Among TKI initiators, 61% were adherent; adherence was lower for individuals age 80 years or older versus 66 to 69 years. Conclusion Only 68% of Medicare beneficiaries with CML initiated TKI therapy within 6 months of diagnosis. Delayed initiation among individuals without cost-sharing subsidies suggests that out-of-pocket costs may be a barrier to timely initiation of therapy among individuals diagnosed with CML.

Association of Vascular Endothelial Growth Factor A (VEGFA) and its Receptor (VEGFR2) Gene Polymorphisms with Risk of Chronic Myeloid Leukemia and Influence on Clinical Outcome

INTRODUCTION

Vascular endothelial growth factor A (VEGFA) and its kinase insert domain receptor (VEGFR2/KDR) were reported to be upregulated in chronic myeloid leukemia (CML); however, the influence of polymorphisms in VEGFA and VEGFR2 in CML pathogenesis and therapeutic response, have not yet been elucidated.

METHODS

We aimed to analyze these polymorphisms in 212 CML patients and 212 healthy controls by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach.

RESULTS

The VEGFA+936C>T polymorphism did not differ significantly between the CML patients and controls. The frequency of CT genotype was higher in CML patients than in controls (25 vs. 18%), higher in males than in females (29 vs. 18%), was more prevalent in the patients with splenomegaly (p = 0.03), and was negatively associated with lactate dehydrogenase (LDH) levels (p = 0.01). The frequency of VEGFR2 mutant T-allele was higher in CML patients than controls (p < 0.0001). In the dominant model, patients having the combined AT and TT genotypes were associated with 2.6-fold higher risk of CML [odds ratio (OR) = 2.6, 95% confidence interval (CI) = 1.71–3.97, p < 0.0001]. VEGFR2 AT genotype was significantly associated with high blast count (p = 0.006), minor hematological response (p = 0.03) and poor cytogenetic response (p = 0.003), indicating its role in therapeutic resistance. In contrast, poor molecular response was observed in patients with TT genotype (p = 0.02). VEGFA+936C>T polymorphism was found to have synergistic interaction with VEGFR2+1416A>T in inflating the risk for CML further (P(interaction) = 0.0002).

CONCLUSION

Our results indicate that VEGFR2+1416A>T polymorphism may be a useful marker in assessing the disease progression in CML patients. In addition, VEGFA+936C>T was observed to have additive effect in inflating the risk further.

What Is the Optimal Dose and Schedule for Dasatinib in Chronic Myeloid Leukemia: Two Case Reports and Review of the Literature

Efficacy and safety of dasatinib in chronic phase (CP) chronic myelogenous leukemia (CML) patients has been well established. Initially approved dose and schedule of 70 mg twice daily has been changed to 100 mg once daily after demonstration of the same efficacy with less toxicity. Some patients require significant dose reductions to enable continued treatment with dasatinib. Even at a dose of 80 mg once daily, several patients may require further dose reductions due to substantial toxicity while maintaining good control of their disease. We report two CP-CML patients achieving and maintaining major molecular responses while on very low doses of dasatinib, ultimately achieving undetectable levels of BCR-ABL fusion transcript in their peripheral blood. Observations of several CP-CML cases responding remarkably well to dasatinib despite very low dose and frequent dose interruptions challenge our current understanding and the accuracy of the data regarding the optimum dose and schedule of this drug. In selected intolerant patients, low-dose dasatinib therapy may be a safe and effective alternative treatment option before a treatment discontinuation or change considered.

Programmed cell death 4 and BCR-ABL fusion gene expression are negatively correlated in chronic myeloid leukemia

Programmed cell death 4 (PDCD4) is a tumor suppressor that inhibits carcinogenesis, tumor progression and invasion by preventing gene transcription and translation. Downregulation of PDCD4 expression has been identified in multiple types of human cancer, however, to date, the function of PDCD4 in leukemia has not been investigated. In the present study, PDCD4 mRNA and protein expression was investigated in 50 patients exhibiting various phases of chronic myeloid leukemia (CML) and 20 healthy individuals by reverse transcription-quantitative polymerase chain reaction and western blot analysis. PDCD4 expression and cell proliferation was also investigated following treatment with the tyrosine kinase inhibitor, imatinib, in K562 cells. The results demonstrated that PDCD4 mRNA and protein expression was decreased in all CML samples when compared with healthy controls, who expressed high levels of PDCD4 mRNA and protein. No significant differences in PDCD4 expression were identified between chronic phase, accelerated phase and blast phase CML patients. In addition, PDCD4 expression was negatively correlated with BCR-ABL gene expression (r=-0.6716; P<0.001). Furthermore, K562 cells treated with imatinib exhibited significantly enhanced PDCD4 expression. These results indicate that downregulation of PDCD4 expression may exhibit a critical function in the progression and malignant proliferation of human CML.

A rare case of a three way complex variant positive Philadelphia translocation involving chromosome (9;11;22)(q34;p15;q11) in chronic myeloid leukemia: A case report

The t(9;22)(q34;q11) translocation is present in 90-95% of patients with chronic myeloid leukemia (CML). Variant complex translocations have been observed in 5-8% of CML patients, in which a third chromosome other than (9;22) is involved. Imatinib mesylate is the first line breakpoint cluster region-Abelson gene (BCR/ABL)-targeted oral therapy for CML, and may produce a complete response in 70-80% of CML patients in the chronic phase. In the present study, a bone marrow sample was used for conventional cytogenetic analysis, and the fluorescence in situ hybridization (FISH) test was used for BCR/ABL gene detection. A hematological analysis was also performed to determine the white blood cell (WBC) count, red blood cell count, hemoglobin levels, packed and mean cell volumes, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration and platelet values of the patient. The hematological analysis of the patient indicated the increased WBC of 186.5×10³ cells/µl, and decreased hemoglobin levels of 11.1 g/dl. The FISH test revealed that 67% cells demonstrated BCR/ABL gene translocation. The patient was treated with 400 mg imatinib mesylate daily, and was monitored at various intervals over a 6-month period. The present study reports the rare case of a patient that demonstrates a three-way Philadelphia chromosome-positive translocation involving 46XY,t(9;11;22)(q34;p15;q11)[10], alongside CML in the chronic phase. The translocation was analyzed using cytogenetic and FISH tests.

Molecular monitoring of chronic myeloid leukemia: present and future

INTRODUCTION

Fusion of BCR-ABL1 genes causes chronic myeloid leukemia (CML). As a reliable marker of disease burden, it also serves as the target of tyrosine kinase inhibitors (TKIs). New more sensitive molecular diagnostic tools for BCR-ABL1 can contribute to therapeutic decision-making, especially in considering drug discontinuation for patients enjoying prolonged deep molecular response. Areas covered: Several novel platforms are transforming CML molecular diagnostics to enable faster point-of-care devices, better understanding of clonal diversity and resistance mutations. Here, we review these molecular platforms, knowing implementation in other hematological malignancies will ensue. Expert commentary: Treatment with TKI in CML is the first example of a highly effective targeted therapy. Monitoring of BCR-ABL1 mRNA is standard in assessing disease burden being highly predictive of outcomes recommended by both European LeukemiaNet (ELN) and National Comprehensive Cancer Network (NCCN); however, studies has demonstrated poor adherence to these recommendations. In both clinical practice and assay performance, further optimizing of BCR-ABL1 monitoring can be envisioned including point-of-care methods for increased availability of rapid, standardized testing and increasingly sensitive molecular assays that allow for quantification of MRD and detecting resistance mutations.

Monitoring disease burden in chronic myeloid leukemia: Past, present, and future

Tyrosine kinase inhibitor (TKI) therapy yields sustained cytogenetic remissions in most patients with chronic-phase chronic myeloid leukemia (CML). Peripheral blood quantitative reverse transcription polymerase chain reaction (qRT-PCR) monitoring of the chimeric BCR-ABL1 mRNA transcript levels is a very sensitive method to measure disease burden in patients with cytogenetic remission. qRT-PCR allows identification of patients (1) at high risk of progression early (3-6 months) after treatment initiation, (2) with no response to TKI therapy, (3) with undetectable disease who could be eligible for TKI discontinuation trials. Molecular monitoring is a minimally invasive method to optimize treatment and outcomes in CML. Am. J. Hematol. 91:742-746, 2016. © 2016 Wiley Periodicals, Inc.

A Novel Four-Way Complex Variant Translocation Involving Chromosome 46,XY,t(4;9;19;22)(q25:q34;p13.3;q11.2) in a Chronic Myeloid Leukemia Patient

Philadelphia (Ph) chromosome (9;22)(q34;q11) is well established in more than 90% of chronic myeloid leukemia (CML) patients, and the remaining 5-8% of CML patients show variant and complex translocations, with the involvement of third, fourth, or fifth chromosome other than 9;22. However, in very rare cases, the fourth chromosome is involved. Here, we found a novel case of four-way Ph+ chromosome translocation involving 46,XY,t(4;9;19;22)(q25:q34;p13.3;q11.2) with CML in the chronic phase. Complete blood cell count of the CML patient was carried out to obtain total leukocytes count, hemoglobin, and platelets. Fluorescence in situ hybridization technique was used for the identification of BCR-ABL fusion gene, and cytogenetic test for the confirmation of Ph (9;22)(q34;q11) and the mechanism of variant translocation in the bone marrow. The patient is successfully treated with a dose of 400 mg/day imatinib mesylate (Gleevec). We observed a significant decrease in white blood cell count of 11.7 × 10(9)/L after 48-month follow-up. Patient started feeling better generally. There was a reduction in the swelling of the body, fatigue, and anxiety.

Single nucleotide polymorphisms in apoptosis pathway are associated with response to imatinib therapy in chronic myeloid leukemia

Background

The mechanism of action of imatinib is known to involve the Fas-mediated apoptosis pathway. Consequently inter-individual variations in this apoptosis pathway might be associated with imatinib response or resistance.

Methods

This study attempted to focus on eight genotypes in the apoptosis pathway including FAS (rs1800682, rs2229521, rs2234767 and rs2234978), FASLG (rs763110), CASP10 (rs13006529), and APAF1 (rs1439123, rs2288713) and analyzed their association with treatment outcomes including molecular response with 4.5 log reduction (MR4.5), following imatinib therapy in 187 Korean CML patients.

Results

The GG/GA genotype in FAS (rs2234767) showed a higher rate of MR4.5 than the AA genotype (at 5 years 59.7 vs 37.4 %, p = 0.013). Using a bootstrap procedure for internal validation we confirmed that FAS (rs2234767) correlates with MR4.5 (p = 0.050). Multivariate analysis confirmed that the FAS genotype (rs2234767) is an independent surrogate for MR4.5 (p = 0.019, HR 0.43, 95 % CI [0.22–0.87]).

Conclusions

The Fas/FasL signaling pathway may represent the major pathway that mediates apoptosis in CML treated with imatinib. SNP markers in the apoptosis pathway including FAS genotype (rs2234767) can be potential surrogates for predicting deeper molecular response after imatinib therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0837-5) contains supplementary material, which is available to authorized users.

Three-way complex variant translocation involving short arm chromosome (1;9;22)(p36;q34;q11) in a chronic myeloid leukemia patient

Chronic myeloid leukemia (CML) is a disease of the clonal hematopoietic stem cells caused by a balanced translocation between the long arms of chromosomes 9 and 22. Overall, 90-95% of CML patients present with a Philadelphia (Ph) chromosome t(9;22)(q34;q11) translocation and in addition, variant complex translocations, involving a third chromosome, are observed in 5-8% of CML patients. Cytogenic testing using bone marrow sample was performed and the FISH test was used for the detection of BCR-ABL fusion gene and complete blood analysis of CML patient was also performed. Results of hematological analysis showed the induced values of white blood cells (168,5000/mm³) and platelets (300,000/mm³) and FISH analysis test showed that 98% cells were positive for BCR/ABL gene translocation. The present study describes a three-way (1;9;22)(p36;q34;q11) Ph chromosome translocation in a 24-year-old female with CML. The patient, who was in the chronic phase of the disease, was treated with daily dose of 400 mg/dl with imatinib mesylateand was monitored constantly at various intervals over a 6-month period. Many studies reported that certain CML patents with variant translocation responded poorly to imatinib. In the current case report, the CML patient exhibited a suboptimal response to imatinib, denoting a poor prognosis.

Comparison of the utility and applicability of the Sokal, Hasford, and EUTOS scores in a population of Chinese patients with chronic-phase chronic myeloid leukemia undergoing imatinib therapy

BACKGROUND

Tyrosine kinase inhibitors are increasingly used to treat chronic myeloid leukemia (CML), but loss of complete cytogenetic response (CCyR) indicates treatment failure.

AIM

To compare the efficacy of Sokal, European Treatment Outcome Study (EUTOS), and Hasford prognostic scores with 3-month and 12-month CCyR, event-free survival (EFS) and progression-free survival (PFS) in patients with chronic-phase CML (CP-CML) undergoing imatinib therapy.

METHODS

We retrospectively analyzed the outcome of 210 patients with CP-CML treated at the First Affiliated Hospital of Anhui Medical University treated between January 2006 and December 2013. Sokal, EUTOS, and Hasford scores were compared with 3-month and 12-month CCyR, EFS, and PFS.

RESULTS

Kaplan-Meier analyses revealed that 3-month and 12-month CCyR and PFS were lower in patients with high EUTOS scores, and intermediate or high Sokal and Hasford scores (all P<0.05). Furthermore, EFS was lower in patients with intermediate or high Sokal and Hasford scores (both P<0.05). Hasford score (hazard ratio =2.608, 95% confidence interval: 1.473-4.617, P=0.001) was independently associated with 3-month CCyR.

CONCLUSION

Although all three scoring systems were associated with EFS, PFS, and 3-month and 12-month CCyR in the Kaplan-Meier analyses (except EFS with EUTOS), only the Hasford score was independently associated with 3m-CCyR, while EUTOS score and Sokal score were not independently associated with any of these outcomes.

Detection of BCR/ABL Fusion Gene by Hematological and Cytogenetical Analysis in Chronic Myeloid Leukemia Patients in Quetta, Pakistan

BACKGROUND

Chronic myeloid leukemia (CML) is a myeloproliferative disorder of pluripotent stem cells, caused by reciprocal translocation between the long arms of chromosomes 9 and 22, t(9;22)(q34;q11), known as the Philadelphia chromosome.

MATERIALS AND METHODS

A total of 51 CML patients were recruited in this study. Complete blood counts of all CML patients were performed to find out their total leukocytes, hemoglobin and platelets. FISH was performed for the detection of BCR-ABL fusion and cryptogenic tests using bone marrow samples were performed for the conformation of Ph (9;22)(q34;q11) and variant translocation mechanisms.

RESULTS

In cytogenetic analysis we observed that out of 51 CML patients 40 (88.9%) were Ph positive and 4 (8.88%) had Ph negative chromosomes. Mean values of WBC 134.5 103/μl, hemoglobin 10.44 mg/dl, and platelets 288.6 103/μl were observed in this study.

CONCLUSIONS

In this study, Ph positive translocation between chromosome (9:22)(q34;q11) were observed in 40 (88.9%) CML patients.