A review of the European LeukemiaNet recommendations for the management of CML

Budget Impact of Treatment-Free Remission in Treating Chronic-Phase Philadelphia-Positive Chronic Myeloid Leukemia in Lebanon

PURPOSE

Chronic myeloid leukemia (CML) ranks second in terms of disease-related health care expenditures at the Lebanese Ministry of Public Health (MoPH) after breast cancer. With the introduction of tyrosine kinase inhibitors (TKIs), survival of patients with CML has dramatically improved and approached that of the normal population. In recent years, several studies demonstrated that patients who achieve a deep molecular response while receiving TKI therapy could safely attempt treatment-free remission (TFR), the new treatment goal in patients with CML. The objective is to estimate the budget impact of TFR at the MoPH.

METHODS

Analyses were done on 162 patients with CML receiving imatinib, nilotinib, or dasatinib, as first-line or second-line therapy, over a 4-year time horizon using MoPH drug pricing. The model assumed that patients could attempt TFR after 36 months of TKI therapy, where the last 24 months were at stable molecular response as per MoPH and National Comprehensive Cancer Network guidelines. Duration of TFR was based on European Stop Kinase Inhibitor treatment-free survival curve.

RESULTS

Out of the 162 patients, 83 were eligible to attempt TFR, 36 patients were not eligible, 32 patients were lost to follow-up, two patients died as a result of CML progression, and five died as a result of other causes. The total cost of CML treatment with TFR from the time of analysis and over 4 years can be reduced by more than 7 million US dollars (57%).

CONCLUSION

The model can be used to inform health care decision makers on the importance of TFR and the potential savings.

[Pre-therapeutic and evolutive characteristics of patients suffering from chronic myeloid leukemia, in Abidjan, Ivory Coast]

INTRODUCTION

The diagnosis of chronic myeloid leukemia is based on the presence of translocation t(9,22). Additional cytogenetic abnormalities may exist at diagnosis and have prognostic value. The authors evaluated the relationship between these additional chromosomal abnormalities, clinical presentation, and therapeutic response.

METHOD

In a retrospective and comparative study from 2005 to 2015, at Yopougon university hospital, 51 cases of myeloid leukemia were selected, including 22 cases with additional chromosomal abnormalities.

RESULTS

Thirteen types of additional Ph1 abnormalities were detected in one group, with a median age of 39years (13-73); a sex ratio of 1.4 and a low social class (49%). The median consultation time is 13months (2-29). Hepatomegaly (54%, P=0.05); fever (81.8%, P=0.0017); bone pain (63.6%, P=0.0001); lymphadenopathies (27.3% P=0.014); poor general condition [WHO>1 (77.3%, P=0.001)], high Sokal index (63.6%, P=0.0019), eosinophilia>5% (72.7, P=0.02) and circulating blastosis were found more frequent in the group with additional abnormalities treated with imatinib mesylate. We obtained 13.6% hematologic remission and 22.7% cytogenetic remission (P=0.02). The average survival was relatively short (20months vs. 76.4months, Log-rank<0.0001). We deplored a high death rate (59.1%).

CONCLUSION

The presence of an additional anomaly constitutes a pejorative element refractory to imatinib.

Results of the European survey on the assessment of deep molecular response in chronic phase CML patients during tyrosine kinase inhibitor therapy (EUREKA registry)

PURPOSE

The advent of tyrosine kinase inhibitor (TKI) therapies has revolutionized the treatment of chronic myeloid leukemia (CML). The European LeukemiaNet (ELN) recommends quantification of BCR-ABL1 transcripts by real-time quantitative PCR every 3 months during TKI treatment. Since a proportion of patients in deep molecular response (DMR: MR⁴, MR^4.5, MR⁵) maintain remission after treatment stop, assessment of DMR is crucial. However, systematically collected molecular data, monitored with sensitive standardized assays, are not available outside clinical trials.

METHODS

Data were collected on the standardized assessment of molecular response in the context of real-life practice. BCR-ABL1 transcript levels after > 2 years of TKI therapy were evaluated for DMR by local laboratories as well as standardized EUTOS laboratories. Since standardized molecular monitoring is a prerequisite for treatment discontinuation, central surveillance of the performance of the participating laboratories was carried out.

RESULTS

Between 2014 and 2017, 3377 peripheral blood samples from 1117 CML patients were shipped to 11 standardized reference laboratories in six European countries. BCR-ABL1 transcript types were b3a2 (41.63%), b2a2 (29.99%), b2a2/b3a2 (3.58%) and atypical (0.54%). For 23.72% of the patients, the initial transcript type had not been reported. Response levels (EUTOS laboratory) were: no MMR, n = 197 (6.51%); MMR, n = 496 (16.40%); MR⁴, n = 685 (22.64%); MR^4.5, n = 937 (30.98%); MR⁵, n = 710 (23.47%). With a Cohen's kappa coefficient of 0.708, a substantial agreement between EUTOS-certified and local laboratories was shown.

CONCLUSIONS

Multicenter DMR assessment is feasible in the context of real-life clinical practice in Europe. Information on the BCR-ABL1 transcript type at diagnosis is crucial to accurately monitor patients' molecular response during or after TKI therapy.

How I treat chronic myeloid leukemia in children and adolescents

Evidence-based recommendations have been established for treatment of chronic myeloid leukemia (CML) in adults treated with tyrosine kinase inhibitors (TKIs), but the rarity of this leukemia in children and adolescents makes it challenging to develop similar recommendations in pediatrics. In addition to imatinib, which was approved for pediatric CML in 2003, the second-generation TKIs dasatinib and nilotinib were recently approved for use in children, expanding the therapeutic options and pushing allogeneic stem cell transplantation to a third-line treatment of most pediatric cases. Yet, without sufficient data on efficacy and safety specific to pediatric patients, the selection of a TKI continues to rely on clinical experience in adults. Here, we present 4 case scenarios highlighting common yet challenging issues encountered in the treatment of pediatric CML (suboptimal response, poor treatment adherence, growth retardation, and presentation in advanced phases). Limited experience with very young children, the transition of teenagers to adult medicine, and the goal of achieving treatment-free remission for this rare leukemia are additional significant obstacles that require further clinical investigation through international collaboration.

Gold nanoparticles for sustained antileukemia drug release: development, optimization and evaluation by quality-by-design approach

AIM

To design, develop, optimize and evaluate sustained-release dasatinib-loaded gold nanoparticles (DSB-GNPs) to treat chronic myeloid leukemia (CML) by using quality by design.

MATERIALS & METHODS

In this study, we performed risk assessment, optimization, in vitro characterizations, stability study, drug release studies, cytotoxicity study and in vivo pharmacokinetic evaluation.

RESULTS

DSB-GNPs of desired size, entrapment, smooth, spherical, stable and sustained drug release for 48 h were achieved. DSB-GNPs exhibited significantly more percentage growth inhibition and enhanced systemic bioavailability compared with pure DSB.

CONCLUSION

The in vitro and in vivo evaluation exhibited that the DSB-GNPs have a potential cytotoxic effect, systemic bioavailability and sustained release making them a promising system of DSB delivery in the treatment of chronic myeloid leukemia.

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.

Tyrosine kinase inhibitor discontinuation in patients with chronic myeloid leukemia: a single-institution experience

Background

Patients with CML treated with TKI can have a life expectancy comparable to that of the general population. Due to the extended duration of TKI administration, treatment discontinuation has been increasingly sought.

Methods

Medical records of 100 patients with CML who were in MR^4.5 and discontinued their TKI outside clinical trials were reviewed.

Results

After a median follow-up of 30 months (range, 5–112 months) after discontinuation, 35% and 17% lost MR^4.5 and major molecular response (MMR), respectively. Only six patients lost MMR 12 months or more after discontinuation. Loss of MR^4.5 was observed in 29% and 7% of patients with sustained MR^4.5 duration of more than 2 and 6 years before discontinuation, respectively. By univariate analysis, there was a higher risk of loss of MR^4.5 for patients who were treated for less than 87 months, received second or subsequent line TKI, never received interferon, or those with sustained MR^4.5 for less than 6 years. By multivariate analysis, sustained MR^4.5 for 6 years or more was the only significant predictor for durable response. Overall, 30% of patients who discontinued while in MR^4.5 were retreated with 93% regaining MR^4.5 at a median of 5 months.

Conclusion

These results demonstrate that under proper conditions, treatment discontinuation is feasible outside of clinical trial setting. MR^4.5 duration of 6 years or more before discontinuation is associated with very low risk of loss of MR^4.5.

Prevalence of BCR-ABL T315I Mutation in Malaysian Patients with Imatinib-Resistant Chronic Myeloid Leukemia

Objective:

Chronic Myeloid Leukemia (CML) is caused by a reciprocal translocation between chromosomes 9 and 22, t(9;22) (q34;q11) which encodes for the BCR-ABL fusion protein. Discovery of Imatinib Mesylate (IM) as first line therapy has brought tremendous improvement in the management of CML. However, emergence of point mutations within the BCR-ABL gene particularly T315I mutation, affects a common BCR-ABL kinase contact residue which impairs drug binding thus contribute to treatment resistance. This study aims to investigate the BCR-ABL T315I mutation in Malaysian patients with CML.

Methods:

A total of 285 patients diagnosed with CML were included in this study. Mutation detection was performed using qualitative real-time PCR (qPCR).

Results:

Fifteen out of 285 samples (5.26%) were positive for T315I mutations after amplification with real-time PCR assay. From the total number of positive samples, six patients were in accelerated phase (AP), four in chronic phase (CP) and five in blast crisis (BC).

Conclusion:

Mutation testing is recommended for choosing various tyrosine kinase inhibitors (TKIs) to optimize outcomes for both cases of treatment failure or suboptimal response to imatinib. Therefore, detection of T315I mutation in CML patients are clinically useful in the selection of appropriate treatment strategies to prevent disease progression.

Cytotoxic and pro-apoptotic action of MjTX-I, a phospholipase A2 isolated from Bothrops moojeni snake venom, towards leukemic cells

Background

Chronic myeloid leukemia (CML) is a BCR-ABL1⁺ myeloproliferative neoplasm marked by increased myeloproliferation and presence of leukemic cells resistant to apoptosis. The current first-line therapy for CML is administration of the tyrosine kinase inhibitors imatinib mesylate, dasatinib or nilotinib. Although effective to treat CML, some patients have become resistant to this therapy, leading to disease progression and death. Thus, the discovery of new compounds to improve CML therapy is still challenging. Here we addressed whether MjTX-I, a phospholipase A₂ isolated from Bothrops moojeni snake venom, affects the viability of imatinib mesylate-resistant Bcr-Abl⁺ cell lines.

Methods

We examined the cytotoxic and pro-apoptotic effect of MjTX-I in K562-S and K562-R Bcr-Abl⁺ cells and in the non-tumor HEK-293 cell line and peripheral blood mononuclear cells, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and the hypotonic fluorescent solution methods, associated with detection of caspases 3, 8, and 9 activation and poly (ADP-ribose) polymerase (PARP) cleavage. We also analyzed the MjTX-I potential to modulate the expression of apoptosis-related genes in K562-S and K562-R cells.

Results

MjTX-I decreased the viability of K562-S and K562-R cells by 60 to 65%, without affecting the viability of the non-tumor cells, i.e. it exerted selective cytotoxicity towards Bcr-Abl⁺ cell lines. In leukemic cell lines, the toxin induced apoptosis, activated caspases 3, 8, and 9, cleaved PARP, downregulated expression of the anti-apoptotic gene BCL-2, and upregulated expression of the pro-apoptotic gene BAD.

Conclusion

The antitumor effect of MjTX-I is associated with its potential to induce apoptosis and cytotoxicity in Bcr-Abl positive cell lines sensitive and resistant to imatinib mesylate, indicating that MjTX-I is a promising candidate drug to upgrade the CML therapy.

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.

Bone marrow core biopsy in 508 consecutive patients with chronic myeloid leukemia: Assessment of potential value

BACKGROUND

The diagnosis of chronic myeloid leukemia (CML) is based on characteristic clinical and laboratory findings and the presence of BCR/ABL1 in the blood and/or bone marrow (BM). The utility of BM core biopsy in the workup of patients with CML has been questioned.

METHODS

The potential added value of BM biopsy versus aspiration in the workup of a single-institution series of 508 patients with CML at their initial presentation was systematically assessed. BM biopsy was considered essential when it was needed to establish the disease phase, often because blast counts derived from aspirate smears were misleading because the biopsy specimen was more representative of the disease. BM biopsy was considered helpful if it was needed for other nonessential reasons.

RESULTS

In 127 patients (25%), BM biopsy was either essential (109 patients) or helpful (18 patients). Patients with accelerated-phase (AP) or blast-phase (BP) disease often required a biopsy related to essential reasons. High-grade myelofibrosis (MF) was more frequent in patients with AP/BP disease than patients with chronic-phase disease (P = .0005), and the identification of BP disease required a BM biopsy assessment in 75% of the patients (P = .001). A follow-up BM evaluation more often yielded inadequate aspirates in patients with inadequate BM aspirates at the time of their initial diagnosis.

CONCLUSIONS

BM core biopsy remains valuable in the workup of 25% of patients with CML because it facilitates identification of the disease phase or MF. The initial grade of MF is associated with the disease stage and outcome after therapy. BM biopsy is, therefore, indicated for patients with CML who have AP/BP disease or other findings suggestive of progressive disease.

Quantitative prediction of long-term molecular response in TKI-treated CML - Lessons from an imatinib versus dasatinib comparison

Longitudinal monitoring of BCR-ABL transcript levels in peripheral blood of CML patients treated with tyrosine kinase inhibitors (TKI) revealed a typical biphasic response. Although second generation TKIs like dasatinib proved more efficient in achieving molecular remission compared to first generation TKI imatinib, it is unclear how individual responses differ between the drugs and whether mechanisms of drug action can be deduced from the dynamic data. We use time courses from the DASISION trial to address statistical differences in the dynamic response between first line imatinib vs. dasatinib treatment cohorts and we analyze differences between the cohorts by fitting an established mathematical model of functional CML treatment to individual time courses. On average, dasatinib-treated patients show a steeper initial response, while the long-term response only marginally differed between the treatments. Supplementing each patient time course with a corresponding confidence region, we illustrate the consequences of the uncertainty estimate for the underlying mechanisms of CML remission. Our model suggests that the observed BCR-ABL dynamics may result from different, underlying stem cell dynamics. These results illustrate that the perception and description of CML treatment response as a dynamic process on the level of individual patients is a prerequisite for reliable patient-specific response predictions and treatment optimizations.

Precision immunotherapy, mutational landscape, and emerging tools to optimize clinical outcomes in patients with classical myeloproliferative neoplasms

Following the 47th American Society of Hematology Meeting in 2005, the late John Goldman and Tariq Mughal commenced a conference, the 1st Post-ASH Workshop, which brought together clinicians and scientists, to accelerate the adoption of new therapies for patients with myeloproliferative neoplasms (MPNs). The concept began with recognition of the CML success story following imatinib therapy, the discovery of JAK2^V617F , and the demonstration that BCR-ABL1-negative MPNs are driven by abnormal JAK2 activation. This review is based on the presentations and deliberations at the XIIth Post-ASH Workshop on BCR-ABL1 positive and negative MPNs that took place on December 12 to 13, 2017, in Atlanta, Georgia, immediately following the 59th American Society of Hematology Meeting. We have selected some of the translational research and clinical topics, rather than an account of the proceedings. We discuss the role of immunotherapy in MPNs and the impact of the mutational landscape on TKI treatment in CML. We also consider how we might reduce TKI cardiovascular side effects, the potential role of nutrition as adjunctive nonpharmacologic intervention to reduce chronic inflammation in MPNs, and novel investigational therapies for MPNs.

A Systems Biology-Based Approach to Uncovering Molecular Mechanisms Underlying Effects of Traditional Chinese Medicine Qingdai in Chronic Myelogenous Leukemia, Involving Integration of Network Pharmacology and Molecular Docking Technology

Background

The method of multiple targets overall control is increasingly used to predict the main active ingredient and potential target group of Chinese traditional medicines and to determine the mechanisms involved in their curative effects. Qingdai is the main traditional Chinese medicine used in the treatment of chronic myelogenous leukemia (CML), but the complex active ingredients and antitumor targets in treatment of CML have not been clearly defined in previous studies.

Material/Methods

We constructed a protein-protein interaction network diagram of CML with 638 nodes (proteins) and 1830 edges, based on the biological function of chronic myelocytic leukemia by use of Cytoscape, and we determined 19 key gene nodes in the CML molecule by network topological properties analysis in a data bank. Then, we used the Surflex-dock plugin in SYBYL7.3 docking and acquired the protein crystal structures of key genes involved in CML from the chemical composition of the traditional Chinese medicine Qingdai with key proteins in CML networks.

Results

According to the score and the spatial structure, the pharmacodynamically active ingredients of Qingdai are Isdirubin, Isoindigo, N-phenyl-2-naphthylamine, and Isatin, among which Isdirubin is the most important. We further screened the most effective activity key protein structures of CML to find the best pharmacodynamically active ingredients of Qingdai, according to the binding interactions of the inhibitors at the catalytic site performed in best docking combinations.

Conclusions

The results suggest that Isdirubin plays a role in resistance to CML by altering the expressions of PIK3CA, MYC, JAK2, and TP53 target proteins. Network pharmacology and molecular docking technology can be used to search for possible reactive molecules in traditional chinese medicines (TCM) and to elucidate their molecular mechanisms.

Life after ponatinib failure: outcomes of chronic and accelerated phase CML patients who discontinued ponatinib in the salvage setting

Ponatinib is a pan-tyrosine kinase inhibitor (TKI) with efficacy in multirefractory CML patients who have failed other TKIs. Despite excellent response rates, resistance or intolerance may develop. We conducted a retrospective review of the outcome of patients with chronic (CP) and accelerated (AP) phase CML refractory to prior TKI who discontinued ponatinib for resistance or intolerance. Nineteen CP patients, discontinued due to resistance (n = 13), toxicity (n = 5) and to pursue stem cell transplantation (n = 1). At discontinuation, 14 were still in CP, three had progressed to AP and two to blast phase (BP). Three CP patients improved their cytogenetic response (CyR) to complete CyR (CCyR), two after SCT and one on omacetaxine. None of the 12 patients, without a major cytogenetic response at ponatinib discontinuation, including all patients treated with subsequent TKIs, responded to therapy. Seventeen AP patients, stopped ponatinib due to resistance (n = 15) or intolerance (n = 2). At discontinuation, 14 were still in AP and three had progressed to BP. Four patients were treated with SCT and one achieved major molecular response. None of the 12 patients treated with non-SCT approaches responded to subsequent therapy. Median survival for all patients was 16.6 months after ponatinib discontinuation (31, 9 and 13 months for patients in CP, AP and BP, respectively). Median survival was 60 months for patients who discontinued ponatinib for toxicity and 11 months for those who discontinued for resistance. Long-term outcome of patients with ponatinib failure are poor with estimated one-year OS and EFS rates of 54% and 40%, respectively. New treatment options are required for this subset of patients.

Association of GSTM1, GSTT1 and GSTP1 Ile105Val polymorphisms with clinical response to imatinib mesylate treatment among Malaysian chronic myeloid leukaemia patients

The detoxifying activity of glutathione S-transferases (GST) enzymes not only protect cells from the adverse effects of xenobiotics, but also alters the effectiveness of drugs in cancer cells, resulting in toxicity or drug resistance. In this study, we aimed to evaluate the association of GSTM1, GSTT1 and GSTP1 Ile105Val polymorphisms with treatment response among Malaysian chronic myeloid leukaemia (CML) patients who everyday undergo 400 mg of imatinib mesylate (IM) therapy. Multiplex polymerase chain reaction (multiplex-PCR) was performed to detect GSTM1 and GSTT1 polymorphisms simultaneously and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was conducted to detect the GSTP1 Ile195Val polymorphism. On evaluating the association of the variant genotype with treatment outcome, heterozygous variant (AG) and homozygous variant (GG) of GSTP1 Ile105Val showed significantly a higher risk for the development of resistance to IM with OR: 1.951 (95% CI: 1.186-3.209, P = 0.009) and OR: 3.540 (95% CI: 1.305-9.606, P = 0.013), respectively. Likewise, GSTT1 null genotype was also associated with a significantly higher risk for the development of resistance to IM with OR = 1.664 (95% CI: 1.011-2.739, P = 0.045). Our results indicate the potential usefulness of GST polymorphism genotyping in predicting the IM treatment response among CML patients.

Overexpression of miR-202 resensitizes imatinib resistant chronic myeloid leukemia cells through targetting Hexokinase 2

Chronic myeloid leukemia (CML) is a myeloproliferative disease which uniquely expresses a constitutively active tyrosine kinase, BCR/ABL. As a specific inhibitor of the BCR-ABL tyrosine kinase, imatinib becomes the first choice for the treatment of CML due to its high efficacy and low toxicity. However, the development of imatinib resistance limits the long-term treatment benefits of it in CML patients. In the present study, we aimed to investigate the roles of miR-202 in the regulation of imatinib sensitivity in CML cell lines and the possible mechanisms involved in this process. We found miR-202 was down-regulated in seven CML cell lines by quantitative reverse-transcription PCR (qRT-PCR) analysis. Overexpression of miR-202 significantly suppressed proliferation rates of CML cells. By establishing imatinib resistant cell lines originating from K562 and KU812 cells, we observed expressions of miR-202 were down-regulated by imatinib treatments and imatinib resistant CML cell lines exhibited lower level of miR-202. On the contrary, imatinib resistant CML cell lines displayed up-regulated glycolysis rate than sensitive cells with the evidence that glucose uptake, lactate production, and key glycolysis enzymes were elevated in imatinib resistant cells. Importantly, the imatinib resistant CML cell lines were more sensitive to glucose starvation and glycolysis inhibitors. In addition, we identified Hexokinase 2 (HK2) as a direct target of miR-202 in CML cell lines. Overexpression of miR-202 sensitized imatinib resistant CML through the miR-202-mediated glycolysis inhibition by targetting HK2. Finally, we provided the clinical relevance that miR-202 was down-regulated in CML patients and patients with lower miR-202 expression displayed higher HK2 expression. The present study will provide new aspects on the miRNA-modulated tyrosine kinase inhibitor (TKI) sensitivity in CML, contributing to the development of new therapeutic anticancer drugs.

Laboratory Monitoring of Chronic Myeloid Leukemia in Patients on Tyrosine Kinase Inhibitors

Chronic Myeloid Leukemia (CML) is a myeloproliferative neoplasm characterized by translocation of genetic material from chromosome 9 to chromosome 22 to form a fusion gene (BCR-ABL1) that is responsible for abnormal tyrosine kinase activity and alteration of various downstream signaling pathways. In addition to morphological diagnosis of CML phase, it is essential to detect BCR-ABL1 fusion by either metaphase cytogenetics or reverse transcriptase polymerase chain reaction that also determines type of mRNA transcript. Once treatment begins, monitoring the response to Tyrosine Kinase Inhibitor (TKI) using standardized techniques and guidelines is important to check for failure of response and thus, plan timely intervention by increasing the dose of TKI or opting for second line TKIs. The goal is to stop evolution of CML to accelerated phase or blast crisis that has poor response to treatment. Also, it is desirable to achieve good outcomes and even treatment free remission in patients of CML on TKI. Thus, molecular monitoring by reverse transcriptase quantitative PCR (RT-qPCR) is done at regular intervals. There are international recommendations and quality control measures to standardize the reporting of fusion gene transcript levels by quantitative PCR (RT-qPCR) in CML to achieve and maintain sensitivity in molecular detection of CML disease burden. Various state-of-the-art molecular techniques have emerged to accurately determine the number of fusion-gene transcript levels. This review highlights various methodologies and their practical implications in management of CML patients on TKI.

When to Stop Tyrosine Kinase Inhibitors for the Treatment of Chronic Myeloid Leukemia

Strict criteria for when to stop tyrosine kinase inhibitor (TKI) therapy in clinical practice are not easily defined without an agreement on what probability of achieving a treatment-free remission (TFR) constitutes a medically acceptable standard and consideration of the potential medical risks of continued TKI therapy and/or patient preferences. Patients in sustained deep molecular response (DMR) have no significant chronic myelogenous leukemia-related risk of progression and death, and thus, safety is of paramount importance. Patients with prior history of advanced disease, additional chromosomal abnormalities (ACA), atypical transcripts, TKI resistance, high Sokal score, or who cannot be relied upon to come for regular molecular monitoring should generally be excluded from TKI cessation in clinical practice. Similarly, stopping TKIs should not be attempted without the availability of standardized BCR-ABL1 testing with a sensitivity of at least MR4.5 and a turnaround time of less than 4 weeks. Prior TKI therapy of 5 years and stable MR4.0 of 2 years or more constitutes reasonable minimal criteria for stopping TKIs with approximately a 50% chance of success. The risk of morbidity with continued TKI therapy and patient preferences need to be considered to determine to what extent these minimal criteria should be exceeded and at what threshold to re-initiate therapy whether on the loss of major molecular response or at a lower molecular endpoint.

Molecular screening and the clinical impacts of BCR-ABL KD mutations in patients with imatinib-resistant chronic myeloid leukemia

The present study aimed to detect the frequency of kinase domain (KD) mutations in order to evaluate their clinical significance and functional importance in 45 patients with chronic myeloid leukemia (CML) who were resistant to imatinib therapy. Sanger sequencing was used (45 patients), along with allele-specific oligonucleotide polymerase chain reaction (ASO-PCR; 3 patients), for the screening of mutations. BCR/ABL KD was amplified by nested PCR and sequencing was performed. Secondly, ASO-PCR was performed to confirm the results of the sequence analysis for E255K mutations. Mutations were detected in 11/45 patients (24.44%) via Sanger sequencing. D241G (4.4%), C369C (4.4%), K285N (2.2%), A380T (2.2%) and A366V (2.2%) mutations were detected. E255K (8.8%) was detected by ASO-PCR and Sanger sequencing. Mutations are a primary reason for suboptimal responses, loss of response and resistance to imatinib. In particular, the E255K mutation, which is characterized by resistance to imatinib and nilotinib, was detected in four patients. Analyzing the mutations and monitoring patients with CML may improve their prognosis and survival rate. ASO-PCR assays will be beneficial for the routine monitoring of mutations.

How is the relationship between TWIST-1 and BCR-ABL1 gene expressions in chronic myeloid leukaemia patients?

BACKGROUND

The activation and increased expression of BCR-ABL1 lead to malignant chronic myelogenous leukaemia (CML) cells, as well as the resistance to antitumour agents and apoptosis inducers. Moreover, TWIST-1 protein is a prognostic factor of leukemogenesis, and its level is raised in CML patients with cytogenetic resistance to imatinib. So, there is a likely relationship between BCR-ABL1 and TWIST-1 genes.

OBJECTIVE

The aim of the study was to assess the relationship between TWIST-1 and BCR-ABL1 expressions.

METHODS

Peripheral blood samples were obtained from 44 CML patients under treatment and also from ten healthy subjects as normal controls. The expression of TWIST-1 and BCR-ABL1 genes was measured using real-time PCR, and ABL1 was used as the reference gene. The gene expression was evaluated by REST software.

RESULTS

The expression levels of TWIST-1 and BCR-ABL1 genes in CML patients was changed 40.23 ± 177.75-fold and 6 ± 18-fold, respectively.

DISCUSSION

No significant relationship was observed between the expressions of TWIST-1 and BCR-ABL1 genes. All patients with TWIST-1 expression levels ≥100-fold had failure of response to treatment.

CONCLUSION

The probability of the relationship between BCR-ABL1 and TWIST-1 is still debatable, and the average of TWIST-1 expression has been higher in patients without response to treatment. Definitive conclusion needs further investigations.

Multifunctional microfluidic chip for optical nanoprobe based RNA detection - application to Chronic Myeloid Leukemia

Many diseases have their treatment options narrowed and end up being fatal if detected during later stages. As a consequence, point-of-care devices have an increasing importance for routine screening applications in the health sector due to their portability, fast analyses and decreased cost. For that purpose, a multifunctional chip was developed and tested using gold nanoprobes to perform RNA optical detection inside a microfluidic chip without the need of molecular amplification steps. As a proof-of-concept, this device was used for the rapid detection of chronic myeloid leukemia, a hemato-oncological disease that would benefit from early stage diagnostics and screening tests. The chip passively mixed target RNA from samples, gold nanoprobes and saline solution to infer a result from their final colorimetric properties. An optical fiber network was used to evaluate its transmitted spectra inside the chip. Trials provided accurate output results within 3 min, yielding signal-to-noise ratios up to 9 dB. When compared to actual state-of-art screening techniques of chronic myeloid leukemia, these results were, at microscale, at least 10 times faster than the reported detection methods for chronic myeloid leukemia. Concerning point-of-care applications, this work paves the way for other new and more complex versions of optical based genosensors.

Pulmonary arterial hypertension in a patient treated with dasatinib: a case report

Background

There have been several reports on dasatinib-induced reversible pulmonary hypertension. This is the first reported case in Latvia; the patient did not discontinue the drug after the first adverse effects in the form of pleural effusions, which we speculate led only to partial reversion of the disease.

Case presentation

A 67-year-old white man with chronic myelogenous leukemia was treated with the dual Src and BCR-ABL tyrosine kinase inhibitor dasatinib. After treatment with dasatinib he had multiple pleural effusions which were suspected to be caused by congestive heart failure. Later a transthoracic Doppler echocardiography and right-sided heart catheterization revealed severe pulmonary hypertension with pulmonary vascular resistance of 12 Wood units and mean pulmonary artery pressure of 53 mmHg. Computed tomography ruled out a possible pulmonary embolism; laboratory specific tests for human immunodeficiency virus, rheumatoid factor, and anti-nuclear antibodies were negative, and dasatinib-induced pulmonary arterial hypertension was diagnosed.

A follow-up right-sided heart catheterization and 6-minute walk test done a month after the discontinuation of dasatinib showed significant improvement: mean pulmonary artery pressure of 34 mmHg and pulmonary vascular resistance of 4 Wood units.

Conclusions

Patients should always be closely monitored when using dasatinib for a prolonged time. Dasatinib-induced pulmonary hypertension may be fully reversible after the therapy is suspended, but the key factors involved are still unclear and need to be further studied.

Prognostic factors associated with a stable MR4.5 achievement in chronic myeloid leukemia patients treated with imatinib

Deep molecular response in chronic myeloid leukemia (CML) patients treated with imatinib is a prerequisite for possible discontinuation. We identify clinico-biologic features linked with the probability of reaching MR4.5 (BCR-ABL/ABL ≤ 0.0032% IS) as a stable response (confirmed on two or more consecutive determinations). In a series of 208 patients treated with imatinib first-line outside clinical trials, after a median follow-up of 7 years the incidence of stable MR4.5 was 34.6%, obtained in median time of 5.4 years. In univariate analysis, female gender (p = 0.02), lower median age (56.4 vs 58.6, p = 0.03), Sokal risk stratification (p = 0.01) and e14a2 type of transcript (43% vs 31%, p = 0.02) are associated to achievement of a stable MR4.5. In multivariate regression analysis, female gender (HR 1.6, 95% CI: 1.1–2.6; P = 0.022), Sokal risk (HR 1.4, 95% CI: 1.1–2.3; p = 0.03), type of transcript (e14a2 vs e13a2 type, HR 1.6, 95% CI: 1.3–2.9; P = 0.03) and achievement of an early molecular response (EMR) at 3 months (HR 1.5, 95% CI: 1.2–2.8; P = 0.01), retained statistical significance. These clinical and biologic features associated with the achievement of a stable deep molecular response should be taken into account at a time when treatment-free remission strategies are being actively pursued in the management of CML.

Pharmacology and pharmacokinetics of imatinib in pediatric patients

INTRODUCTION

The tyrosine kinase inhibitor (TKI) imatinib was rationally designed to target BCR-ABL1 which is constitutively activated in chronic myeloid leukemia (CML). Following the tremendous success in adults, imatinib also became licensed for treatment of CML in minors. The rarity of pediatric CML hampers the conduction of formal trials. Thus, imatinib is still the single TKI approved for CML treatment in childhood. Areas covered: This review attempts to provide an overview of the literature on pharmacology, pharmacokinetic, and pharmacogenetic of imatinib concerning pediatric CML treatment. Articles were identified through a PubMed search and by reviewing abstracts from relevant hematology congresses. Additional information was provided from the authors' libraries and expertise and from our own measurements of imatinib trough plasma levels in children. Pharmacokinetic variables (e.g. alpha 1-acid glycoprotein binding, drug-drug/food-drug interactions via cytochrome P450 3A4/5, cellular uptake mediated via OCT-1-influx variations and P-glycoprotein-mediated drug efflux) still await to be addressed in pediatric patients systematically. Expert commentary: TKI response rates vary among different individuals and pharmacokinetic variables all can influence CML treatment success. Adherence to imatinib intake may be the most prominent factor influencing treatment outcome in teenagers thus pointing towards the potential benefits of regular drug monitoring.

Non-Classic Myeloproliferative Neoplasms: Are We Really Aware of These Rare Diseases in Daily Practice?

Chronic neutrophilic leukaemia (CNL), chronic eosinophilic leukaemia-not otherwise specified (CEL-NOS), and myeloproliferative neoplasm (MPN), unclassifiable are rare clonal diseases, known as ‘non-classic myeloproliferative neoplasms’. They are diagnosed largely based on exclusion of underlying reactive causes by patient history, physical examination, serological tests, and imaging studies. As well as peripheral blood testing, bone marrow examination is mandatory to exclude bone marrow infiltrating conditions such as multiple myeloma, acute leukaemias, etc. Today, molecular genetic classification should be undertaken to establish accurate diagnosis, in addition to the traditional morphological classification of MPN. Therefore, molecular genetic testing should take part in the diagnostic work-up of suspected patients with rare MPN. Of CNL patients, 90% (and in some datasets 100%) have mutations in CSF3R, which has led to the addition of this finding to the diagnostic criteria for CNL. The absence of rearrangements of FIP1L1/PDGFRA, PDGFRA, PDGFRB, FGFR1, and PCM1-JAK2 fusions should prompt consideration of a diagnosis of chronic eosinophilic leukaemia-not otherwise specified. MPN, unclassifiable, the least frequent type, is considered when an MPN has definite MPN features but does not meet diagnostic criteria for either the classic or the other non-classic MPN. They all share common symptoms and findings. Transformation to acute leukaemia is still a major clinical problem. Since no standard of care exists, the treatment approach is still symptomatic for all. This is an indicator that we really need disease-modifying drugs against initial diagnostic molecular markers, such as CSF3R inhibitors, which might change the natural history of these disorders. Therefore, participation in clinical trials is mandatory for this extremely rare patient population.

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.

An economic analysis of high-dose imatinib, dasatinib, and nilotinib for imatinib-resistant chronic phase chronic myeloid leukemia in China: A CHEERS-compliant article

BACKGROUND

The aim of the study was to test the cost-effectiveness of dasatinib compared to high-dose imatinib and nilotinib in Chinese patients who were diagnosed with imatinib-resistant chronic myeloid leukemia in the chronic phase (CML-CP).

METHODS

A Markov model combined with clinical effectiveness, utility, and cost data was used. The sensitivity analyses were conducted to determine the robustness of the model outcomes. The impact of patient assistance programs (PAPs) was assessed.

RESULTS

Treatment with dasatinib is expected to produce 3.65, 0.59, and 0.15 more quality-adjusted life years (QALYs) in comparison with high-dose imatinib (600 and 800 mg) and nilotinib, respectively. When a PAP was available, dasatinib yielded an incremental cost of $16,417 per QALY compared to imatinib (600 mg) and was cost-saving compared to imatinib (800 mg) and nilotinib.

CONCLUSION

When PAP is available in the Chinese setting, dasatinib is likely to be a cost-effective strategy for patients with CML-CP standard-dose imatinib resistance. The results should be carefully explained due to the assumptions and limitations used in the study.

19F-NMR-Based Dual-Site Reporter Assay for the Discovery and Distinction of Catalytic and Allosteric Kinase Inhibitors

In modern kinase drug discovery, allosteric inhibitors have become a focus of attention due to their potential selectivity, but such compounds are difficult to identify. Here we describe an NMR-based competition assay using ¹⁹F-containing reporter molecules, which allows for rapid identification and discrimination between ATP-competitive and allosteric kinase inhibitors. We illustrate the principle of such a dual-site competition assay with the example of catalytic and allosteric ABL1 kinase inhibitors. The assay can also be used to identify and characterize mixed binding modes of well-known drugs, as shown for crizotinib and fingolimod.

Gold Nanoparticles for BCR-ABL1 Gene Silencing: Improving Tyrosine Kinase Inhibitor Efficacy in Chronic Myeloid Leukemia

Introduction of tyrosine kinase inhibitors for chronic myeloid leukemia treatment is associated with a 63% probability of maintaining a complete cytogenetic response, meaning that over 30% patients require an alternative methodology to overcome resistance, tolerance, or side effects. Considering the potential of nanotechnology in cancer treatment and the benefits of a combined therapy with imatinib, a nanoconjugate was designed to achieve BCR-ABL1 gene silencing. Gold nanoparticles were functionalized with a single-stranded DNA oligonucleotide that selectively targets the e14a2 BCR-ABL1 transcript expressed by K562 cells. This gold (Au)-nanoconjugate showed great efficacy in gene silencing that induced a significant increase in cell death. Variation of BCL-2 and BAX protein expression, an increase of caspase-3 activity, and apoptotic bodies in cells treated with the nanoconjugate demonstrate its aptitude for inducing apoptosis on K562 BCR-ABL1-expressing cells. Moreover, the combination of the silencing Au-nanoconjugate with imatinib prompted a decrease of imatinib IC₅₀. This Au-nanoconjugate was also capable of inducing the loss of viability of imatinib-resistant K562 cells. This strategy shows that combination of Au-nanoconjugate and imatinib make K562 cells more vulnerable to chemotherapy and that the Au-nanoconjugate alone may overcome imatinib-resistance mechanisms, thus providing an effective treatment for chronic myeloid leukemia patients who exhibit drug tolerance.

Presence of novel compound BCR-ABL mutations in late chronic and advanced phase imatinib sensitive CML patients indicates their possible role in CML progression

BCR-ABL kinase domain (K_D) mutations are well known for causing resistance against tyrosine kinase inhibitors (TKIs) and disease progression in chronic myeloid leukemia (CML). In recent years, compound BCR-ABL mutations have emerged as a new threat to CML patients by causing higher degrees of resistance involving multiple TKIs, including ponatinib. However, there are limited reports about association of compound BCR-ABL mutations with disease progression in imatinib (IM) sensitive CML patients. Therefore, we investigated presence of ABL-K_D mutations in chronic phase (n = 41), late chronic phase (n = 33) and accelerated phase (n = 16) imatinib responders. Direct sequencing analysis was used for this purpose. Eleven patients (12.22%) in late-CP CML were detected having total 24 types of point mutations, out of which 8 (72.72%) harbored compound mutated sites. SH2 contact site mutations were dominant in our study cohort, with E355G (3.33%) being the most prevalent. Five patients (45%) all having compound mutated sites, progressed to advanced phases of disease during follow up studies. Two novel silent mutations G208G and E292E/E were detected in combination with other mutants, indicating limited tolerance for BCR-ABL1 kinase domain for missense mutations. However, no patient in early CP of disease manifested mutated ABL-K_D. Occurrence of mutations was found associated with elevated platelet count (p = 0.037) and patients of male sex (p = 0.049). The median overall survival and event free survival of CML patients (n = 90) was 6.98 and 5.8 y respectively. The compound missense mutations in BCR-ABL kinase domain responsible to elicit disease progression, drug resistance or disease relapse in CML, can be present in yet Imatinib sensitive patients. Disease progression observed here, emphasizes the need of ABL-K_D mutation screening in late chronic phase CML patients for improved clinical management of disease.

Short overview on the current treatment of chronic myeloid leukemia in chronic phase

This short review on current treatment options in chronic myeloid leukemia (CML) in the chronic phase summarizes the latest version of the ELN treatment recommendations dating from 2013 and indicates treatment situations not yet reflected in these recommendations. Daily practice in CML management is complicated by the recently observed treatment-emergent vascular and pulmonary adverse events in second- or later-generation tyrosine kinase inhibitors (TKIs), the lack of guidance with respect to the best TKI for initial treatment, as well as the optimal TKI sequence because no prospective randomized comparative data for second- and third-generation TKIs are available. Physicians have to balance the efficacy issues and safety aspects of the respective TKI and consider patient-specific factors such as comorbidities. Patients with any cardiovascular or pulmonary disease or treatment-requiring cardiovascular risk factor should receive nilotinib or ponatinib only if risk factors and comorbidities are treated accordingly and are further monitored. If these comorbidities are insufficiently controlled, other TKIs might be preferred. Dasatinib treatment should be critically evaluated in patients with pulmonary disease and other TKIs might be preferred in this setting. For as long as CML treatment is considered to be maintained lifelong, and no survival benefit for later-generation TKIs has been demonstrated, safety issues dominate the choice of treatment options. The concept of discontinuing TKI treatment after achieving a deep molecular response might in future change these considerations.

Current trends in molecular diagnostics of chronic myeloid leukemia

Nearly 1.5 million people worldwide suffer from chronic myeloid leukemia (CML), characterized by the genetic translocation t(9;22)(q34;q11.2), involving the fusion of the Abelson oncogene (ABL1) with the breakpoint cluster region (BCR) gene. Early onset diagnosis coupled to current therapeutics allow for a treatment success rate of 90, which has focused research on the development of novel diagnostics approaches. In this review, we present a critical perspective on current strategies for CML diagnostics, comparing to gold standard methodologies and with an eye on the future trends on nanotheranostics.

Impact of Membrane Drug Transporters on Resistance to Small-Molecule Tyrosine Kinase Inhibitors

Small-molecule inhibitors of tyrosine kinases (TKIs) are the mainstay of treatment for many malignancies and represent novel treatment options for other diseases such as idiopathic pulmonary fibrosis. Twenty-five TKIs are currently FDA-approved and >130 are being evaluated in clinical trials. Increasing evidence suggests that drug exposure of TKIs may significantly contribute to drug resistance, independently from somatic variation of TKI target genes. Membrane transport proteins may limit the amount of TKI reaching the target cells. This review highlights current knowledge on the basic and clinical pharmacology of membrane transporters involved in TKI disposition and their contribution to drug efficacy and adverse drug effects. In addition to non-genetic and epigenetic factors, genetic variants, particularly rare ones, in transporter genes are promising novel factors to explain interindividual variability in the response to TKI therapy.

Cytogenetic landscape and impact in blast phase of chronic myeloid leukemia in the era of tyrosine kinase inhibitor therapy

The landscape of additional chromosomal alterations (ACAs) and their impact in chronic myeloid leukemia, blast phase (CML-BP) treated with tyrosine kinase inhibitors (TKIs) have not been well studied. Here, we investigated a cohort of 354 CML-BP patients treated with TKIs. We identified +8, an extra Philadelphia chromosome (Ph), 3q26.2 rearrangement, -7 and isochromosome 17q (i(17q)) as the major-route changes with a frequency of over 10%. In addition, +21 and +19 had a frequency of over 5%. These ACAs demonstrated lineage specificity: +8, 3q26.2 rearrangement, i(17q) and +19 were significantly more common in myeloid BP, and -7 more common in lymphoid BP; +Ph and +21 were equally distributed between two groups. Pearson correlation analysis revealed clustering of common ACAs into two groups: 3q26.2 rearrangement, -7 and i(17q) formed one group, and other ACAs formed another group. The grouping correlated with risk stratification of ACAs in CML, chronic phase. Despite the overall negative prognostic impact of ACAs, stratification of ACAs into major vs minor-route changes provided no prognostic relevance in CML-BP. The emergence of 3q26.2 rearrangement as a major-route change in the TKI era correlated with a high frequency of ABL1 mutations, supporting a role for TKI resistance in the changing cytogenetic landscape in CML-BP.

The L-amino acid oxidase from Calloselasma rhodostoma snake venom modulates apoptomiRs expression in Bcr-Abl-positive cell lines

Anti-apoptotic genes and apoptomiRs deregulated expression contribute to apoptosis resistance in chronic myeloid leukemia (CML) Bcr-Abl(+) cells. Here, the L-amino acid oxidase from Calloselasma rhodostoma (CR-LAAO) venom altered the apoptotic machinery regulation by modulating the expression of the miR-145, miR-26a, miR-142-3p, miR-21, miR-130a, and miR-146a, and of the apoptosis-related proteins Bid, Bim, Bcl-2, Ciap-2, c-Flip, and Mcl-1 in Bcr-Abl(+) cells. CR-LAAO is a potential tool to instigate apoptomiRs regulation that contributes to drive CML therapy.

Case of relentless chronic phase of chronic myeloid leukaemia

Initial treatment of chronic phase chronic myeloid leukaemia is straightforward in today's era of tyrosine kinase inhibitors. However, managing refractory cases remain a major challenge due to the multiple factors that can influence decision-making, including medication tolerance, disease burden, mutation status, comorbidities, availability of donor, and fitness for an ablative conditioning. We report a male patient presenting with chronic phase chronic myeloid leukaemia who was treated with 5 different tyrosine kinase inhibitors either due to intolerance and/or failed response. He subsequently received 2 haploidentical haematopoietic stem cells transplants before achieving complete remission. This case highlights various treatment options, need for vigilant disease monitoring, and the possibility of complete positive response even after many lines of therapy failure.

Colorimetric assessment of BCR-ABL1 transcripts in clinical samples via gold nanoprobes

Gold nanoparticles functionalized with thiolated oligonucleotides (Au-nanoprobes) have been used in a range of applications for the detection of bioanalytes of interest, from ions to proteins and DNA targets. These detection strategies are based on the unique optical properties of gold nanoparticles, in particular, the intense color that is subject to modulation by modification of the medium dieletric. Au-nanoprobes have been applied for the detection and characterization of specific DNA sequences of interest, namely pathogens and disease biomarkers. Nevertheless, despite its relevance, only a few reports exist on the detection of RNA targets. Among these strategies, the colorimetric detection of DNA has been proven to work for several different targets in controlled samples but demonstration in real clinical bioanalysis has been elusive. Here, we used a colorimetric method based on Au-nanoprobes for the direct detection of the e14a2 BCR-ABL fusion transcript in myeloid leukemia patient samples without the need for retro-transcription. Au-nanoprobes directly assessed total RNA from 38 clinical samples, and results were validated against reverse transcription-nested polymerase chain reaction (RT-nested PCR) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The colorimetric Au-nanoprobe assay is a simple yet reliable strategy to scrutinize myeloid leukemia patients at diagnosis and evaluate progression, with obvious advantages in terms of time and cost, particularly in low- to medium-income countries where molecular screening is not routinely feasible. Graphical abstract Gold nanoprobe for colorimetric detection of BCR-ABL1 fusion transcripts originating from the Philadelphia chromosome.

Targeted Therapy for Cancer in the Genomic Era

The advent of cancer genomics has led to the development of many highly successful targeted therapies, primarily inhibitors of growth factor receptors and related kinases, including imatinib for chronic myeloid leukemia and trastuzumab for HER2-positive breast cancer. This approach has become highly successful for certain cancers. However, as the list of targeted therapies expands, their efficacy becomes more limited, and toxicity accumulates. What we have learned in the past decades is that while the targeted therapeutics approach may be highly successful in less complex tumors, cancers defined by carcinogen-induced genomic chaos, such a UV-induced melanoma or tobacco-induced lung cancer, are driven by a multitude of competing molecular pathways and, as such, are not as successfully managed by a similar approach. Luckily, in the past years, the field of cancer immunotherapy has become more fully developed with the emergence of checkpoint blockade inhibitor therapy. These promising new agents are particularly well suited for tumors with a high mutational burden due to underlying genomic disarray. While still in its infancy, we predict that cancer immunotherapy will offer a better alternative to our current targeted approach and eagerly await the results of several ongoing clinical trials that will elucidate this new direction in cancer therapy.

Quantitative Analysis of Mutant Subclones in Chronic Myeloid Leukemia: Comparison of Different Methodological Approaches

Identification and quantitative monitoring of mutant BCR-ABL1 subclones displaying resistance to tyrosine kinase inhibitors (TKIs) have become important tasks in patients with Ph-positive leukemias. Different technologies have been established for patient screening. Various next-generation sequencing (NGS) platforms facilitating sensitive detection and quantitative monitoring of mutations in the ABL1-kinase domain (KD) have been introduced recently, and are expected to become the preferred technology in the future. However, broad clinical implementation of NGS methods has been hampered by the limited accessibility at different centers and the current costs of analysis which may not be regarded as readily affordable for routine diagnostic monitoring. It is therefore of interest to determine whether NGS platforms can be adequately substituted by other methodological approaches. We have tested three different techniques including pyrosequencing, LD (ligation-dependent)-PCR and NGS in a series of peripheral blood specimens from chronic myeloid leukemia (CML) patients carrying single or multiple mutations in the BCR-ABL1 KD. The proliferation kinetics of mutant subclones in serial specimens obtained during the course of TKI-treatment revealed similar profiles via all technical approaches, but individual specimens showed statistically significant differences between NGS and the other methods tested. The observations indicate that different approaches to detection and quantification of mutant subclones may be applicable for the monitoring of clonal kinetics, but careful calibration of each method is required for accurate size assessment of mutant subclones at individual time points.