Chronic myeloid leukemia

Zebrafish Models of Human Leukemia: Technological Advances and Mechanistic Insights

Insights concerning leukemic pathophysiology have been acquired in various animal models and further efforts to understand the mechanisms underlying leukemic treatment resistance and disease relapse promise to improve therapeutic strategies. The zebrafish (Danio rerio) is a vertebrate organism with a conserved hematopoietic program and unique experimental strengths suiting it for the investigation of human leukemia. Recent technological advances in zebrafish research including efficient transgenesis, precise genome editing, and straightforward transplantation techniques have led to the generation of a number of leukemia models. The transparency of the zebrafish when coupled with improved lineage-tracing and imaging techniques has revealed exquisite details of leukemic initiation, progression, and regression. With these advantages, the zebrafish represents a unique experimental system for leukemic research and additionally, advances in zebrafish-based high-throughput drug screening promise to hasten the discovery of novel leukemia therapeutics. To date, investigators have accumulated knowledge of the genetic underpinnings critical to leukemic transformation and treatment resistance and without doubt, zebrafish are rapidly expanding our understanding of disease mechanisms and helping to shape therapeutic strategies for improved outcomes in leukemic patients.

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.

Current Trends in the Treatment of Acute and Chronic Myelogenous Leukemia

Acute myelogenous and chronic myelogenous leukemia are uniformly fatal if left untreated. Treatment with conventional chemotherapeutic agents results in a cure for a small percentage of patients and substantial toxicities in all patients that receive treatment. The first of a new generation of “targeted therapies” has recently been introduced. It is hoped that these agents will demonstrate enhanced efficacy and a decreased toxicity profile. Gemtuzumab ozogamicin (Mylotarg™) is the first antibody-targeted therapy approved for use in patients with acute myelogeneous leukemia, arsenic trioxide (Trisenox®) has demonstrated efficacy in patients with acute promyelocytic leukemia, and imatinib mesylate (Gleevec™) has proven efficacy in patients with chronic myelogenous leukemia. Initially, these agents were granted FDA approval for use in those who were refractory to or intolerant of conventional treatment options. Research is ongoing to further define the full therapeutic potential of these agents and to discover additional targeted therapies with increased efficacy.

A review of imatinib mesilate in the treatment of patients with gastrointestinal stromal tumours and chronic myeloid leukaemia

Context. Imatinib mesylate (GlivecÒ, GleevecÒ, Novartis) has made a dramatic impact on the treatment available for both chronic myeloid leukaemia (CML) and gastrointestinal stromal tumours (GISTs). Both are rare diseases that have possibly been unfamiliar to many pharmacists until now.

Objective. To provide readers with a structured overview of CML and GISTs and the trial data available to support the role imatinib is playing in the treatment of these diseases.

Data sources. Published reviews and primary trial results were sourced via Medline to prepare the review. Articles published up to and including August 2002 were considered. Additionally, pertinent books were used to prepare the text and Novartis kindly supplied information currently only available on file at the company. As imatinib has only been available for a short time, all types and sizes of trials were considered for inclusion. The authors made the final decision as to the relevance and therefore subsequent inclusion of data.

Conclusions. Imatinib is a new molecularly targeted therapy for the treatment of CML and GISTs. It has provided an efficacious alternative therapy choice for physicians managing the care of patients suffering from these diseases. In the future there is the possibility that imatinib may demonstrate activity in other disease states characterized by the genetic changes targeted by imatinib. The results of randomized controlled trials in new and existing indications are awaited.

Chronic Myeloid Leukemia in Nigerian Patients: Anemia is an Independent Predictor of Overall Survival

OBJECTIVES

The advent of the tyrosine kinase inhibitors has markedly changed the prognostic outlook for patients with Ph(+) and/or BCR-ABL1 (+) chronic myeloid leukemia (CML). This study was designed to assess the overall survival (OS) of Nigerian patients with CML receiving imatinib therapy and to identify the significant predictors of OS.

METHODS

All patients with CML receiving imatinib from July 2003 to June 2013 were studied. The clinical and hematological parameters were studied. The Kaplan-Meier technique was used to estimate the OS and median survival. P-value of <0.05 was considered as statistically significant.

RESULTS

The median age of all 527 patients (male/female = 320/207) was 37 (range 10-87) years. There were 472, 47, and 7 in chronic phase (CP), accelerated phase, and blastic phase, respectively. As at June 2013, 442 patients are alive. The median survival was 105.7 months (95% confidence interval [CI], 91.5-119.9); while OS at one, two, and five years were 95%, 90%, and 75%, respectively. Multivariate Cox regression analysis revealed that OS was significantly better in patients diagnosed with CP (P = 0.001, odds ratio = 1.576, 95% CI = 1.205-2.061) or not in patients with anemia (P = 0.031, odds ratio = 1.666, 95% CI = 1.047-2.649). Combining these variables yielded three prognostic groups: CP without anemia, CP with anemia, and non-CP, with significantly different median OS of 123.3, 92.0, and 74.7 months, respectively (χ (2) = 22.042, P = 0.000016).

CONCLUSION

This study has clearly shown that for Nigerian patients with CML, the clinical phase of the disease at diagnosis and the hematocrit can be used to stratify patients into low, intermediate, and high risk groups.

A Multi-centric Bioequivalence Trial in Ph+ Chronic Myeloid Leukemia Patients to Assess Bioequivalence and Safety Evaluation of Generic Imatinib Mesylate 400 mg Tablets

PURPOSE

This study was designed to characterize the pharmacokinetic profile and to assess bioequivalence of the sponsor's test formulation (imatinib mesylate 400 mg tablets) with an innovator product (Gleevec 400 mg tablets, Novartis Pharmaceuticals) under fed conditions, in adult patients of Philadelphia chromosome positive chronic myeloid leukemia (Ph+ CML) stabilized on imatinib mesylate 400 mg. In addition, the aim of this study was to monitor the safety profile of investigational medicinal products (IMPs).

MATERIALS AND METHODS

A multicenter, randomized, open label, two-period, crossover, single dose bioequivalence study was designed for conduct under fed conditions in 42 adult Ph+ CML patients already stabilized on imatinib 400 mg tablets. Pharmacokinetic parameters Tmax, Cmax, and AUC0-24 were calculated using a non-compartmental model on validated WinNonlin software. Validated SAS software was used for statistical evaluation of data. The safety profile of investigational products was monitored during the course of study by applying a clinical process for recording observed untoward effects postadministration of investigational products.

RESULTS

The 90% confidence intervals for the test/reference mean ratios of the ln-transformed PK variables Cmax (99.0%) and AUC0-24 (99.2%) were within an acceptable range of 80%-125%, as per bioequivalence assumptions. Both formulations were well tolerated after oral administration of IMPs.

CONCLUSION

The test product was found to be bioequivalent and safe, and thus can be used interchangeably in clinical practice.

Chronic Myeloid Leukemia in Nigerian Patients: Anemia is an Independent Predictor of Overall Survival

OBJECTIVES

The advent of the tyrosine kinase inhibitors has markedly changed the prognostic outlook for patients with Ph⁺ and/or BCR-ABL1⁺ chronic myeloid leukemia (CML). This study was designed to assess the overall survival (OS) of Nigerian patients with CML receiving imatinib therapy and to identify the significant predictors of OS.

METHODS

All patients with CML receiving imatinib from July 2003 to June 2013 were studied. The clinical and hematological parameters were studied. The Kaplan–Meier technique was used to estimate the OS and median survival. P-value of <0.05 was considered as statistically significant.

RESULTS

The median age of all 527 patients (male/female = 320/207) was 37 (range 10–87) years. There were 472, 47, and 7 in chronic phase (CP), accelerated phase, and blastic phase, respectively. As at June 2013, 442 patients are alive. The median survival was 105.7 months (95% confidence interval [CI], 91.5–119.9); while OS at one, two, and five years were 95%, 90%, and 75%, respectively. Multivariate Cox regression analysis revealed that OS was significantly better in patients diagnosed with CP (P = 0.001, odds ratio = 1.576, 95% CI = 1.205–2.061) or not in patients with anemia (P = 0.031, odds ratio = 1.666, 95% CI = 1.047–2.649). Combining these variables yielded three prognostic groups: CP without anemia, CP with anemia, and non-CP, with significantly different median OS of 123.3, 92.0, and 74.7 months, respectively (χ² = 22.042, P = 0.000016).

CONCLUSION

This study has clearly shown that for Nigerian patients with CML, the clinical phase of the disease at diagnosis and the hematocrit can be used to stratify patients into low, intermediate, and high risk groups.

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.

TWIST-1 promotes cell growth, drug resistance and progenitor clonogenic capacities in myeloid leukemia and is a novel poor prognostic factor in acute myeloid leukemia

Alterations of TWIST-1 expression are often seen in solid tumors and contribute to tumorigenesis and cancer progression. However, studies concerning its pathogenic role in leukemia are scarce. Our study shows that TWIST-1 is overexpressed in bone marrow mononuclear cells of patients with acute myeloid leukemia (AML) and chronic myeloid leukemia (CML). Gain-of-function and loss-of-function analyses demonstrate that TWIST-1 promotes cell growth, colony formation and drug resistance of AML and CML cell lines. Furthermore, TWIST-1 is aberrantly highly expressed in CD34⁺CD38⁻ leukemia stem cell candidates and its expression declines with differentiation. Down-modulation of TWIST-1 in myeloid leukemia CD34⁺ cells impairs their colony-forming capacity. Mechanistically, c-MPL, which is highly expressed in myeloid leukemia cells and associated with poor prognosis, is identified as a TWIST-1 coexpressed gene in myeloid leukemia patients and partially contributes to TWIST-1-mediated leukemogenic effects. Moreover, patients with higher TWIST-1 expression have shorter overall and event-free survival (OS and EFS) in AML. Multivariate analysis further demonstrates that TWIST-1 overexpression is a novel independent unfavourable predictor for both OS and EFS in AML. These data highlight TWIST-1 as a new candidate gene contributing to leukemogenesis of myeloid leukemia, and propose possible new avenues for improving risk and treatment stratification in AML.

Mutations in the BCR-ABL1 Kinase Domain and Elsewhere in Chronic Myeloid Leukemia

Chronic myeloid leukemia (CML) has been the first human malignancy to be associated, more than 50 years ago, with a consistent chromosomal abnormality--the t(9;22)(q34;q11) chromosomal translocation. The resulting BCR-ABL1 fusion gene, encoding a tyrosine kinase with deregulated activity, has a central role in the pathogenesis of CML. Ancestral or additional genetic events necessary for CML to develop have long been hypothesized but never really demonstrated. CML can successfully be treated with tyrosine kinase inhibitors (TKIs). Mutations in the BCR-ABL1 kinase domain might arise, however, that confer resistance to 1 or more of the currently available TKIs. Hence, the critical role of BCR-ABL1 mutation screening for optimal therapeutic management, with the current gold standard technique, conventional sequencing, likely to be replaced soon by ultra-deep sequencing. Mutations in genes other than BCR-ABL1 include ASXL1, TET2, RUNX1, DNMT3A, EZH2, and TP53 in chronic phase patients and RUNX1, ASXL1, IKZF1, WT1, TET2, NPM1, IDH1, IDH2, NRAS, KRAS, CBL, TP53, CDKN2A, RB1, and GATA-2 mutations in advanced phase patients. The latter also display additional cytogenetic abnormalities, including submicroscopic regions of gain or loss that only single nucleotide polymorphism arrays or array comparative genomic hybridization can detect. Whether whole genome/exome sequencing studies will uncover novel mutations relevant for pathogenesis, progression, and risk-adapted therapy is still unclear.

Fluorescent In Situ Hybridization Monitoring and Effect of Detected Early Responses in the Outcome of Patients With Chronic Phase Chronic Myeloid Leukemia: A Report From a Latin American Country

INTRODUCTION

The cytogenetic hallmark of chronic myeloid leukemia (CML) is the Philadelphia chromosome. Monitoring the response in patients receiving therapy is a standard of care. The present study was conducted to assess the monitoring adherence and reliableness of fluorescent in situ hybridization (FISH) as a monitoring tool and the effect of a complete cytogenetic response (CCyR) assessed by FISH on the prognosis of patients in a chronic phase (CP)-CML cohort.

MATERIALS AND METHODS

We retrospectively analyzed the data from 63 newly diagnosed CP-CML patients treated with imatinib mesylate at a dose of 400 mg/day as frontline therapy. The clinical data and cytogenetic test results at diagnosis and during monitoring were collected. The cytogenetic monitoring adherence assessment rates were measured. A correlation between chromosome banding analysis (CBA) and FISH was performed. The CCyR assessed by FISH was defined as < 1% BCR-ABL1(+) nuclei. The Kaplan-Meier method was used for overall survival analysis and time-to-event estimates.

RESULTS

The cytogenetic monitoring assessment adherence was 50.8% at 3 months, 93.5% at 6 months, 96.7% at 12 months, and 88.6% at 18 months. The Pearson correlation coefficient showed a significantly positive association (r = 0.84; P < .001) between CBA and FISH. The median follow-up duration after imatinib mesylate initiation was 60 months. A CCyR was achieved in 90.4% of patients within the first 18 months of therapy. At 3 months, 31 patients underwent a FISH evaluation, and 13 (41.9%) had achieved a CCyR. The patients who did not achieve a CCyR at 3 months had a significantly inferior probability of 5-year failure-free survival (38% vs. 94%; P = .001) and progression-free survival (80% vs. 100%; P = .043) compared with those with a CCyR.

CONCLUSION

We found improved monitoring adherence compared with the previous reports of Latin American populations. In countries with a high incidence of failure for CBA and a lack of real-time polymerase chain reaction standardization, FISH is a sensitive monitoring tool. In our cohort, patients not achieving an early CCyR, as tested by FISH, were a poor prognosis subgroup with worse rates of failure-free survival and progression-free survival.

DC generation from peripheral blood mononuclear cells in patients with chronic myeloid leukemia: Influence of interferons on DC yield and functional properties

In Chronic Myeloid Leukemia (CML), standard treatment consists of modern tyrosine-kinase inhibitors (TKI). Nevertheless, there is evidence that immune responses against leukemia-associated antigens (LAA) may play an important role in disease control. Dendritic cell (DC)- based immunotherapy is able to induce T cell responses against LAA and might therefore pose an interesting therapeutic option in CML, especially in the setting of minimal residual disease (MRD). GMP production of DC for clinical vaccination remains a time- and cost- intensive procedure and standardized DC generation is warranted. We asked whether maturation-induction with IFN-γ and IFN-α has an influence on functional properties of DC derived from peripheral blood mononuclear cells (PBMC) in CML patients. Monocyte-derived DC from healthy donors and from patients with CML were analyzed after maturation-induction with our TNF-α-containing standard cytokine cocktail with or without addition of IFN-α and/or IFN-γ. Our results confirm that the addition of IFN-γ leads to enhanced IL-12 secretion in healthy donors. In contrast, in CML patients, IFN-γ was not able to increase IL-12 secretion, possibly due to a higher degree of cell adherence and lower cell yield during the cell culture. Our data suggest, that- in contrast to healthy donors-, additional interferons are not beneficial for maturation induction during large-scale DC production in patients with CML.

Precision oncology for patients with advanced cancer: the challenges of malignant snowflakes

Precision oncology implies customizing treatment to the unique molecular and biologic characteristics of each individual and their cancer. Its implementation is being facilitated by remarkable technological advances in genomic sequencing, as well as the increasing availability of targeted and immunotherapeutic drugs. Yet, next generation sequencing may be a disruptive technology in that its results suggest that classic paradigms for clinical research and practice are a poor fit with the complex reality encountered in metastatic malignancies. Indeed, it is evident that advanced tumors have heterogeneous molecular landscapes that mostly differ between patients. Traditional modes of clinical research/practice are drug centered, with a strategy of finding commonalities between patients so that they can be grouped together and treated similarly. However, if each patient with metastatic cancer has a unique molecular portfolio, a new patient-centered, N-of-one approach that utilizes individually tailored treatment is needed.

Omacetaxine Mepesuccinate for Chronic Myeloid Leukemia

Omacetaxine mepesuccinate is approved by the Food and Drug Administration in the United States for the treatment of chronic myeloid leukemia in chronic or accelerated phase resistant to two or more tyrosine kinase inhibitors. This review summarizes the mode of action, pharmacokinetics, efficacy and safety of omacetaxine mepesuccinate. Omacetaxine mepesuccinate has activity in chronic myeloid leukemia, especially in the chronic phase, regardless of the presence of ABL1 kinase domain mutations. Omacetaxine mepesuccinate has distinct but manageable adverse events profile. Omacetaxine mepesuccinate is a treatment option for a subset of patients with refractory chronic myeloid leukemia.

Hematopoietic and Leukemic Stem Cells Have Distinct Dependence on Tcf1 and Lef1 Transcription Factors

Hematopoietic and leukemic stem cells (HSCs and LSCs) have self-renewal ability to maintain normal hematopoiesis and leukemia propagation, respectively. Tcf1 and Lef1 transcription factors are expressed in HSCs, and targeting both factors modestly expanded the size of the HSC pool due to diminished HSC quiescence. Functional defects of Tcf1/Lef1-deficient HSCs in multi-lineage blood reconstitution was only evident under competitive conditions or when subjected to repeated regenerative stress. These are mechanistically due to direct positive regulation of Egr and Tcf3 by Tcf1 and Lef1, and significantly, forced expression of Egr1 in Tcf1/Lef1-deficient HSCs restored HSC quiescence. In a preclinical CML model, loss of Tcf1/Lef1 did not show strong impact on leukemia initiation and progression. However, when transplanted into secondary recipients, Tcf1/Lef1-deficient LSCs failed to propagate CML. By induced deletion of Tcf1 and Lef1 in pre-established CML, we further demonstrated an intrinsic requirement for these factors in LSC self-renewal. When combined with imatinib therapy, genetic targeting of Tcf1 and Lef1 potently diminished LSCs and conferred better protection to the CML recipients. LSCs are therefore more sensitive to loss of Tcf1 and Lef1 than HSCs in their self-renewal capacity. The differential requirements in HSCs and LSCs thus identify Tcf1 and Lef1 transcription factors as novel therapeutic targets in treating hematological malignancies, and inhibition of Tcf1/Lef1-regulated transcriptional programs may thus provide a therapeutic window to eliminate LSCs with minimal side effect on normal HSC functions.

Best Practices in Chronic Myeloid Leukemia Monitoring and Management

: Optimal use of current therapeutic opportunities for chronic myeloid leukemia patients requires integration of clinical and laboratory monitoring. Assessment of molecular response (MR) by real-time quantitative polymerase chain reaction is the most sensitive way to monitor tyrosine kinase inhibitor (TKI) treatment efficacy. Besides major molecular response, which has emerged as a safe haven for survival since the initial studies of first-line imatinib treatment, two additional MR milestones have recently been defined: early molecular response and deep molecular response. The achievement of such MR milestones within defined time points during therapy is thought to draw the ideal trajectory toward optimal long-term outcome and, possibly, successful treatment discontinuation. Sensitive and reproducible MR measurement and proper interpretation of MR results are therefore critical to correctly inform therapeutic decisions. In patients who do not achieve an optimal response to TKI therapy, BCR-ABL1 mutation screening should also be performed, because it may deliver useful information for TKI choice. This review aims to help clinicians apply and translate the latest response definitions and clinical recommendations into practice. We provide a critical update on how these recommendations have incorporated MR levels in the clinical decision algorithms and how detection of BCR-ABL1 mutations should be interpreted. We also include a practical guide for pathologists and molecular biologists to best perform molecular testing and for hematologists and oncologists to best integrate it into routine practice.

IMPLICATIONS FOR PRACTICE

Ever-more-potent therapeutic strategies have been developed for chronic myeloid leukemia (CML) in parallel with the evolution of therapeutic goals and the refinement of response definitions and monitoring schemes and procedures. Terminology and methodology continue to evolve rapidly, making it difficult for busy hematology/oncology professionals to keep abreast of the newest developments. Optimal CML patient management results from the timely and rational use of molecular testing, the critical assessment of the power and pitfalls of current technology, and the appropriate interpretation and contextualization of results.

Transient monosomy 7 in a chronic myelogenous leukemia patient during nilotinib therapy: a case report

Tyrosine kinase inhibitor treated chronic myelogenous leukemia patients with monosomy 7 arising in Philadelphia chromosome negative (Ph−) cells tend to evolve into MDS/AML. However, monosomy 7 in Ph− cells can be a transient finding, and it is not an absolute indication of the emergence of a new myeloid malignancy.

MIP-1α/CCL3-expressing basophil-lineage cells drive the leukemic hematopoiesis of chronic myeloid leukemia in mice

Basophilia is a frequently observed hematological abnormality in chronic myeloid leukemia (CML), but its pathophysiological roles are undefined. We previously demonstrated that an inflammatory chemokine, CCL3, preferentially acts on normal hematopoietic stem/progenitor cells and crucially contributes to the maintenance of leukemia initiating cells (LICs) in bone marrow (BM) during the initiation process of CML. However, the major cellular source of CCL3 in BM and the precise mechanism of CCL3-mediated maintenance of LICs remain to be investigated. To delineate the cellular process facilitating this CCL3-mediated crosstalk between normal and leukemic hematopoiesis, we precisely examined CCL3-expressing cells and their functions in both normal hematopoiesis and CML leukemogenesis. Herein, we demonstrate that basophils can constitutively express CCL3 to negatively regulate the normal hematopoietic process, especially hematopoietic reconstitution after BM transplantation. Moreover, CCL3-expressing basophil-like leukemia cells were found to accumulate in CML BM and supported the predominant expansion of LICs therein. These observations suggest that intra-BM basophil expansion can favor leukemia-tropic hematopoiesis in CML by providing CCL3, a potent inhibitor of normal hematopoiesis and that basophil-derived CCL3 may be a novel target molecule for the treatment of CML.

Estimation of the prevalence and direct medical costs of chronic myeloid leukemia in the I.R. of Iran in the era of tyrosine kinase inhibitors

BACKGROUND

After the introduction of tyrosine kinase inhibitors for chronic myeloid leukemia (CML), the survival of these patients has increased significantly. However, these new drugs are expensive and impose considerable expense to patients and governments. Epidemiologic and economic evaluation studies provide good information for resource allocation and decision making. We estimated the incidence, prevalence and direct medical cost of CML in Iran.

METHODS

We used the National Cancer Registry (NCR) data from 2006 to 2009 to estimate the incidence rate of CML (ICD-10 code C92.1). After adjustment for the underestimation of incidence rates, we used survival rates of CML and estimated the 5-year prevalence for these patients. In addition, we used clinical practice guideline, expert opinions and medical tariffs to estimate the direct medical costs through the prevalence approach.

RESULTS

After an adjustment for the underestimation, the incidence rate of CML was 0.5 per 100 000 in the I.R. of Iran. The 5-year prevalence was about 2263 cases (2.98 per 100 000). The total direct medical cost of CML was $23 089 323 and the majority of the cost (97%) was related to drug costs. The total cost will increase considerably to $40 728 869 if all patients use the new drug nilotinib (800 mg/day) as a second-line treatment.

CONCLUSIONS

The increased survival of CML patients and a possible increase in incidence of CML in Iran will most likely lead to a considerable rise in its prevalence and economic burden.

Immunoglobulin D Multiple Myeloma, Plasma Cell Leukemia and Chronic Myelogenous Leukemia in a Single Patient Treated Simultaneously with Lenalidomide, Bortezomib, Dexamethasone and Imatinib

Multiple myeloma (MM) is a neoplastic lymphoproliferative disorder characterized by uncontrolled monoclonal plasma cell proliferation. Among different isotypes of MM, immunoglobulin D (IgD) MM is very rare, representing only 1 to 2% of all isotypes. Chronic myelogenous leukemia (CML) is a neoplastic myeloproliferative disorder of pluripotent hematopoietic stem cell, which is characterized by the uncontrolled proliferation of myeloid cells. An 88-year-old male was diagnosed simultaneously with IgD kappa MM and CML. A distinctive feature in this patient was the progression to plasma cell leukemia without any symptomatic myeloma stage. He was treated simultaneously with lenalidomide, bortezomib and imatinib. Synchronous occurrence of these rare hematological malignancies in a single patient is an exceedingly rare event. Multiple hypotheses to explain co-occurrence of CML and MM have been proposed; however, the exact etiological molecular pathophysiology remains elusive.

c-MYB is a transcriptional regulator of ESPL1/Separase in BCR-ABL-positive chronic myeloid leukemia

Background

Genomic instability and clonal evolution are hallmarks of progressing chronic myeloid leukemia (CML). Recently, we have shown that clonal evolution and blast crisis correlate with altered expression and activity of Separase, a cysteine endopeptidase that is a mitotic key player in chromosomal segregation and centriole duplication. Hyperactivation of Separase in human hematopoietic cells has been linked to a feedback mechanism that posttranslationally stimulates Separase proteolytic activity after imatinib therapy-induced reduction of Separase protein levels.

Methods and Results

In search for potential therapy-responsive transcriptional mechanisms we have investigated the role of the transcription factor c-MYB for Separase expression in CML cell lines (LAMA-84, K562, BV-173) and in clinical samples. Quantitative RT-PCR and Western blot immunostaining experiments revealed that c-MYB expression levels are decreased in an imatinib-dependent manner and positively correlate with Separase expression levels in cell lines and in clinical CML samples. RNA silencing of c-MYB expression in CML cell lines resulted in reduced Separase protein levels. Gelshift and ChIP assays confirmed that c-MYB binds to a putative c-MYB binding sequence located within the ESPL1 promoter.

Conclusions

Our data suggest that ESPL1/Separase is a regulatory target of c-MYB. Therefore, c-MYB, known to be required for BCR-ABL-dependent transformation of hematopoietic progenitors and leukemogenesis, may also control the Separase-dependent fidelity of mitotic chromosomal segregation and centriole duplication essential for maintenance of genomic stability.

Regain control of p53: Targeting leukemia stem cells by isoform-specific HDAC inhibition

Leukemia stem cells (LSCs) are self-renewable, leukemia-initiating populations that are often resistant to traditional chemotherapy and tyrosine kinase inhibitors currently used for treatment of acute or chronic myeloid leukemia. The persistence and continued acquisition of mutations in resistant LSCs represent a major cause of refractory disease and/or relapse after remission. Understanding the mechanisms regulating LSC growth and survival is critical in devising effective therapies that will improve treatment response and outcome. Several recent studies indicate that the p53 tumor suppressor pathway is often inactivated in de novo myeloid leukemia through oncogenic-specific mechanisms, which converge on aberrant p53 protein deacetylation. Here, we summarize our current understanding of the various mechanisms underlying deregulation of histone deacetylases (HDACs), which could be exploited to restore p53 activity and enhance targeting of LSCs in molecularly defined patient subsets.

Heterogeneity of leukemia-initiating capacity of chronic myelogenous leukemia stem cells

Chronic myelogenous leukemia (CML) results from transformation of a long-term hematopoietic stem cell (LTHSC) by expression of the BCR-ABL fusion gene. However, BCR-ABL-expressing LTHSCs are heterogeneous in their capacity as leukemic stem cells (LSCs). Although discrepancies in proliferative, self-renewal, and differentiation properties of normal LTHSCs are being increasingly recognized, the mechanisms underlying heterogeneity of leukemic LTHSCs are poorly understood. Using a CML mouse model, we identified gene expression differences between leukemic and nonleukemic LTHSCs. Expression of the thrombopoietin (THPO) receptor MPL was elevated in leukemic LTHSC populations. Compared with LTHSCs with low MPL expression, LTHSCs with high MPL expression showed enhanced JAK/STAT signaling and proliferation in response to THPO in vitro and increased leukemogenic capacity in vivo. Although both G0 and S phase subpopulations were increased in LTHSCs with high MPL expression, LSC capacity was restricted to quiescent cells. Inhibition of MPL expression in CML LTHSCs reduced THPO-induced JAK/STAT signaling and leukemogenic potential. These same phenotypes were also present in LTHSCs from patients with CML, and patient LTHSCs with high MPL expression had reduced sensitivity to BCR-ABL tyrosine kinase inhibitor treatment but increased sensitivity to JAK inhibitors. Together, our studies identify MPL expression levels as a key determinant of heterogeneous leukemia-initiating capacity and drug sensitivity of CML LTHSCs and suggest that high MPL-expressing CML stem cells are potential targets for therapy.

In-silico identification of inhibitors against mutated BCR-ABL protein of chronic myeloid leukemia: a virtual screening and molecular dynamics simulation study

Aberrant and proliferative expression of the oncogene BCR-ABL in the bone marrow cells had been proven as the prime cause of chronic myeloid leukemia (CML). It has been established that tyrosine kinase domain of BCR-ABL protein is a potential therapeutic target for the treatment of CML. Imatinib is considered as a first-generation drug that can inhibit the enzymatic action by inhibiting the ATP binding with BCR-ABL protein. Later on, insensitivity of CML cells towards Imatinib has been observed may be due to mutation in tyrosine kinase domain of the ABL receptor. Subsequently, some other second-generation drugs have also been reported viz. Baustinib, Nilotinib, Dasatinib, Ponatinib, Bafetinib, etc., which can able to combat against mutated domain of ABL tyrosine kinase protein. By taking into account of bioavailability and resistance developed, there is an utmost need to find some more inhibitors for the mutated ABL tyrosine kinase protein. For virtual screening, a data-set has been generated by collecting the all available drug like natural compounds from ZINC and Drug Bank databases. Comparative docking analysis was also carried out on the active site of ABL tyrosine kinase receptor with reported reference inhibitors. Molecular dynamics simulation of the best screened interacting complex was done for 50 ns to validate the stability of the system. These selected inhibitors were further validated and analyzed through pharmacokinetics properties and series of ADMET parameters by in silico methods. Considering the above said parameters proposed molecules are concluded as potential leads for drug designing pipeline against CML.

Prevalence of Abelson murine leukemia viral oncogene homolog-breakpoint cluster region fusions and correlation with peripheral blood parameters in chronic myelogenous leukemia patients in Lorestan Province, Iran

Context:

Chronic myelogenous leukemia (CML) is a chronic malignancy of myeloid linage associated with a significant increase in granulocytes in bone marrow and peripheral blood. CML diagnosis is based on detection of Philadelphia chromosome and “Abelson murine leukemia viral oncogene homolog” (ABL)-“breakpoint cluster region protein” fusions (ABL-BCR fusions).

Aims:

In this study, patients with CML morphology were studied according to ABL-BCR fusions and the relationship between the fusions and peripheral blood cell changes was examined.

Materials and Methods:

All patients suspected to chronic myeloproliferative disorders in Lorestan Province visiting subspecialist hematology clinics who were confirmed by oncologist were studied over a period of 5 years. After completing basic data questionnaire, blood samples were obtained with informed consent from the patients. Blood cell count and morphology were investigated and RNA was extracted from blood samples. cDNA was synthesized from RNA and ABL-BCR fusions including b3a2 and b2a2 (protein 210 kd or p210), e1a2 (protein 190 kdor p190), and e19a2 (protein 230 kdor p230) were studied by multiplex reverse transcription polymerase chain reaction method. Coexistence of e1a2 and b2a2 (p210/p190) fusions was also studied. The prevalence of mutations and their correlation with the blood parameters were statistically analyzed.

Results:

Of 58 patients positive for ABL-BCR fusion, 18 (30.5%) had b2a2 fusion, 37 (62.71%) had b3a2 fusion and three (3.08%) had e1a2 fusion. Coexistence of e1a2 and b2a2 (p210/p190) was not observed. There was no significant correlation between ABL-BCR fusions and white blood cell count, platelet count, and hemoglobin concentration.

Conclusions:

The ABL-BCR fusions in Lorestan Province were similar to other studies in Iran, and b3a2 fusion had the highest prevalence in the studied patients studied.

Development of Alkyne-Containing Pyrazolopyrimidines To Overcome Drug Resistance of Bcr-Abl Kinase

Despite the success of imatinib at inhibiting Bcr-Abl and treating chronic myelogenous leukemia (CML), resistance to the therapy occurs over time in patients. In particular, the resistance to imatinib caused by the gatekeeper mutation T315I in Bcr-Abl remains a challenge in the clinic. Inspired by the successful development of ponatinib to curb drug resistance, we hypothesize that the incorporation of an alkyne linker in other heterocyclic scaffolds can also achieve potent inhibition of Bcr-Abl(T315I) by allowing for simultaneous occupancy of both the active site and the allosteric pocket in the Abl kinase domain. Herein, we describe the design, synthesis, and characterization of a series of alkyne-containing pyrazolopyrimidines as Bcr-Abl inhibitors. Our results demonstrate that some alkyne-containing pyrazolopyrimidines potently inhibit not only Abl(T315I) in vitro but also Bcr-Abl(T315I) in cells. These pyrazolopyrimidines can serve as lead compounds for future development of novel targeted therapy to overcome drug resistance of CML.

Patients' perceptions about diagnosis and treatment of chronic myeloid leukemia: a cross-sectional study among Brazilian patients

CONTEXT AND OBJECTIVES

Chronic myeloid leukemia (CML) requires strict daily compliance with oral medication and regular blood and bone marrow control tests. The objective was to evaluate CML patients' perceptions about the disease, their access to information regarding the diagnosis, monitoring and treatment, adverse effects and associations of these variables with patients' demographics, region and healthcare access.

DESIGN AND SETTING

Prospective cross-sectional study among CML patients registered with the Brazilian Lymphoma and Leukemia Association (ABRALE).

METHODS

CML patients receiving treatment through the public healthcare system were interviewed by telephone.

RESULTS

Among 1,102 patients interviewed, the symptoms most frequently leading them to seek medical care were weakness or fatigue. One third were diagnosed by means of routine tests. The time that elapsed between first symptoms and seeking medical care was 42.28 ± 154.21 days. Most patients had been tested at least once for Philadelphia chromosome, but 43.2% did not know the results. 64.8% had had polymerase chain reaction testing for the BCR/ABL gene every three months. 47% believed that CML could be controlled, but 33.1% believed that there was no treatment. About 24% reported occasionally stopping their medication. Imatinib was associated with nausea, cramps and muscle pain. Self-reported treatment adherence was significantly associated with normalized blood count, and positively associated with imatinib.

CONCLUSIONS

There is a lack of information or understanding about disease monitoring tools among Brazilian CML patients; they are diagnosed quickly and have good access to treatment. Correct comprehension of CML control tools is impaired in Brazilian patients.

Outcome of 3 pregnancies in a patient with chronic myeloid leukemia who received 3 types of tyrosine kinase inhibitors each in different pregnancy: follow-up of the case with a review of published reports

The management of patients with chronic myeloid leukemia (CML) during pregnancy remains a matter of continuous debate. Tyrosine kinase inhibitors (TKIs) have become the standard of care in managing patients with CML. These drugs have a good safety profile, but animal studies have shown that they are potentially teratogenic. Therefore, these drugs are not recommended for use during pregnancy or if a female patient plans to conceive. Despite the extensive clinical experience with TKIs, the available information about the effects of TKIs on fertility, pregnancy, and outcome of babies who were exposed to TKIs during pregnancy and lactation is limited. We reported on 1 female CML patient who conceived 3 times while being on different types of TKIs in each pregnancy. All 3 pregnancies were uneventful, and only 1 of the babies was diagnosed with a minor cardiac malformation at the age of 30 months, which was corrected surgically.

Treatment Outcomes in CML Patients Treated With Tyrosine Kinase Inhibitors at a Tertiary Teaching Hospital in South Africa

BACKGROUND

Chronic myeloid leukemia (CML) has become one of the most treatable hematologic neoplasms since the advent of the tyrosine kinase inhibitors (TKIs), but it was not known if similar treatment outcomes could be achieved in a resource-limited country. We tested the hypothesis that, despite challenges to access to second-generation TKIs, excellent responses could be replicated in the setting of limited resources.

PATIENTS AND METHODS

Records of 58 patients with newly diagnosed CML in the chronic phase treated with TKIs at a tertiary teaching hospital in Cape Town, South Africa between 2003 and 2012 were reviewed and assessed according to European LeukemiaNet (ELN) criteria.

RESULTS

After a median follow-up of 60.5 months, progression-free survival at 60 and 96 months was 79.98% and 68.4%, respectively. Overall survival at 60 and 96 months was 92.9% and 83.6%, respectively. Progression to blast phase at 60 months was associated with poorer survival (P = .0002) but progression to accelerated phase was not (P = .1456). Attainment of a complete cytogenetic response at 12 months (P = .28) or major molecular response at 18 months (P = .268) did not have prognostic significance.

CONCLUSION

Despite delays in achievement of the target responses defined according to ELN criteria, the use of imatinib mesylate as a first-line treatment can still result in treatment outcomes comparable with those in developed countries. These data suggest opportunities for improvement and success might be even greater with uninterrupted access to second-generation or newer TKIs.

Determinants of Overall and Progression-Free Survival of Nigerian Patients with Philadelphia-Positive Chronic Myeloid Leukemia

Objective. The tyrosine kinase inhibitors have markedly changed the disease course for patients with Ph(+) and/or BCR-ABL1 (+) chronic myeloid leukemia (CML). This study was embarked upon to assess the long-term effects of imatinib therapy on survival in adult Nigerian patients with CML. Methods. All adult patients on imatinib (400-600 mg) seen from July 2003 to December 2010 were assessed. Male/female distribution was 171/101, with a median age of 38 (range, 20-75) years. Overall survival (OS) and progression-free survival (PFS) were determined using the Kaplan-Meier techniques. Results. Of all the 272 patients, 205 were in chronic phase, 54 in accelerated phase, and five in blastic phase, at commencement of imatinib. As at December 2010, 222 were alive. OS at 1 and 5 years was 94% and 63%, while PFS was 89% and 54%, respectively. Similarly, amongst the 205 patients in chronic phase, OS at 1 and 5 years was 97% and 68%, while PFS was 92% and 57%. Conclusion. Imatinib's place as first-line therapy in the treatment of CML has further been reinforced in our patients, with improved survival and reduced morbidity, comparable with outcomes in other populations.

An Overview and Update of Chronic Myeloid Leukemia for Primary Care Physicians

Chronic myeloid leukemia (CML) accounts for approximately 15% of adult leukemias. Forty percent of patients with CML are asymptomatic, in whom the disease is detected solely based on laboratory abnormalities. Since the introduction of tyrosine kinase inhibitor therapy in 2001, CML has become a chronic disease for the majority of patients. Primary care physicians may be the first to recognize a new diagnosis of CML. In patients with known CML, the primary care physician may be the first to detect disease progression or adverse effects to therapy. This article provides an overview of the clinical presentation, diagnostic approach, and treatment considerations of CML.

Determinants of Overall and Progression-Free Survival of Nigerian Patients with Philadelphia-Positive Chronic Myeloid Leukemia

Objective. The tyrosine kinase inhibitors have markedly changed the disease course for patients with Ph(+) and/or BCR-ABL1 (+) chronic myeloid leukemia (CML). This study was embarked upon to assess the long-term effects of imatinib therapy on survival in adult Nigerian patients with CML. Methods. All adult patients on imatinib (400-600 mg) seen from July 2003 to December 2010 were assessed. Male/female distribution was 171/101, with a median age of 38 (range, 20-75) years. Overall survival (OS) and progression-free survival (PFS) were determined using the Kaplan-Meier techniques. Results. Of all the 272 patients, 205 were in chronic phase, 54 in accelerated phase, and five in blastic phase, at commencement of imatinib. As at December 2010, 222 were alive. OS at 1 and 5 years was 94% and 63%, while PFS was 89% and 54%, respectively. Similarly, amongst the 205 patients in chronic phase, OS at 1 and 5 years was 97% and 68%, while PFS was 92% and 57%. Conclusion. Imatinib's place as first-line therapy in the treatment of CML has further been reinforced in our patients, with improved survival and reduced morbidity, comparable with outcomes in other populations.

Comparison of Dasatinib, Nilotinib, and Imatinib in the Treatment of Chronic Myeloid Leukemia

To overcome the drug resistance phenomenon induced by Imatibib (IM), in clinical practice, are often used second generation of tyrosine kinase inhibitors as Nilotinib (NIL); a such potent inhibitor of the BCR/ABL kinase and Dasatinib (DAS), a inhibitor of BCR/ABL kinase, and inhibitor SrC family kinase. In this study we evaluated the in vivo effect of DAS, NIL, and IM on intracellular calcium concentration, oxidative stress, and apoptosis in peripheral blood leukocytes of 45 newly diagnosed patients with chronic myeloid leukaemia (CML-PBM). Our data demonstrated that treatment with DAS and NIL showed an higher modulating potential than IM on intracellular calcium concentration by inhibiting the thapsigargin, a sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) inhibitor, and Lithium (Li) an inositol 1,4,5-triphosphate (InsP3) receptor inhibitor activities. Moreover our data demonstrated that NIL and DAS have significantly increased apoptosis more than IM by involving both intracellular calcium signaling as well as oxidative stress. The acquisition of the oxidative stress and calcium channels receptors values data could help the hematologist to modulate and improve the treatment of chronic myeloid leukaemia (CML) pathology.

MicroRNAs in the pathogenesis of myelodysplastic syndromes and myeloid leukaemia

PURPOSE OF REVIEW

This review highlights recent insights into the roles of microRNAs (miRNAs) in pathogenesis of myeloid malignancies and tantalising prospects of miRNA therapy.

RECENT FINDINGS

New roles for miRNAs in biological and disease processes are constantly being discovered. Although great effort has been put into identifying and cataloguing aberrantly expressed miRNAs in leukaemia, very little is known about the functional consequences of their deregulation in myeloid malignancies. This review will discuss the significance of powerful oncogenic miRNAs such as miR-22 in self-renewal and transformation of haematopoietic stem cells, as well as their ability to induce epigenetic alterations in the pathogenesis of the stem cell disorder myelodysplastic syndromes and myeloid leukaemia.

SUMMARY

Improved understanding of biological roles of miRNAs in the pathogenesis of haematological malignancies will allow rational stratification of patients and provide new therapeutic entries for the treatment of myelodysplastic syndromes and leukaemia.

Expanding the structural diversity of Bcr-Abl inhibitors: Hybrid molecules based on GNF-2 and Imatinib

In order to expand the structural diversity of Bcr-Abl inhibitors, twenty hybrids (series E and P) have been synthesized and characterized based on Imatinib and GNF-2. Their biological activities were evaluated in vitro against human leukemia cells. Most compounds exhibited potent antiproliferative activity against K562 cells, especially for compounds E4, E5 and E7. Furthermore, these new hybrids were also screened for Abl kinase inhibitory activity, and some of them inhibited Abl kinase with low micromolar IC50 values. In particular, compound P3 displayed the most potent activity with IC50 value of 0.017 μM comparable with that of Imatinib. Molecular docking studies indicated that these novel hybrids fitted well with the active site of Bcr-Abl. These results suggested the great potential of these compounds as novel Bcr-Abl inhibitors.

Modulatory effects of mesenchymal stem cells on leucocytes and leukemic cells: A double-edged sword?

Mesenchymal stem cells (MSCs) have drawn much attention amongst stem cell researchers in the past few decades. The ability of the MSC to differentiate into cells of mesodermal and non-mesodermal origins has made them an attractive approach for cell-based therapy and regenerative medicine. The MSCs have immunosuppressive activities that may have considerable therapeutic values in autoimmune diseases. However, despite the many beneficial effects reported, there is a growing body of evidence, which suggests that MSCs could be a culprit of enhanced tumour growth, metastasis and drug resistance in leukaemia, via some modulatory effects. Many controversies regarding the interactions between MSCs and leukaemia still exist. Furthermore, the role of MSCs in leukemogenesis and its progression remain largely unknown. Hence it is important to understand how the MSCs modulate leukaemia before these cells could be safely used in the treatment of leukaemia patients.

Accelerated phase chronic myeloid leukemia: evaluation of clinical criteria as predictors of survival, major cytogenetic response and progression to blast phase

Background

Published criteria defining the accelerated phase in chronic myeloid leukemia are heterogeneous and little is known about predictors of poor outcome.

Methods

This is a retrospective study of 139 subjects in the accelerated phase of chronic myeloid leukemia treated with imatinib at a single center in Brazil. The objective was to identify risk factors for survival, major cytogenetic response and progression to blast phase in this population. The factors analyzed were: blasts 10–29%, basophils ≥ 20%, platelets > 1 × 10⁶/μL or <1 × 10⁵/μL and white blood cells > 1 × 10⁵/μL in the peripheral blood, as well as clonal evolution, splenomegaly, hemoglobin < 10 g/dL, time between diagnosis of chronic myeloid leukemia and imatinib treatment, and hematologic toxicity.

Results

Risk factors for poor survival in multivariate analysis were Grades 3–4 hematologic toxicity (p-value = 0.001), blasts 10–29% (p-value = 0.023), and hemoglobin < 10 g/dL (p-value = 0.04). Risk factors for not achieving major cytogenetic response were blasts 10–29% (p-value = 0.007), hemoglobin < 10 g/dL (p-value = 0.001), and previous use of interferon (p-value = 0.032). Risk factors for progression to the blast phase were hemoglobin < 10 g/dL (p-value = 0.005), basophils ≥ 20% (p-value = 0.023), and time from diagnosis of chronic myeloid leukemia to imatinib treatment > 12 months (p-value = 0.030).

Conclusion

These data indicate that patients with the above risk factors have a worse prognosis. This information can guide the therapy to be used.