Prognostic significance of additional chromosomal abnormalities at the time of diagnosis in patients with chronic myeloid leukemia treated with frontline tyrosine kinase inhibitors

Exploring treatment decision-making in chronic myeloid leukemia in chronic phase

The introduction of tyrosine kinase inhibitors (TKIs) has transformed the treatment of chronic myeloid leukemia (CML). Each approved TKI has its own risk-benefit profile, and patients have choices across lines of therapy. Identifying the initial and subsequent treatment that will lead to the best possible outcome for individual patients is challenging. In this review, we summarize data for each approved TKI across lines of therapy in patients with CML in chronic phase, highlighting elements of each agent's safety and efficacy profile that may impact patient selection, and provide insights into individualized treatment sequencing decision-making aimed at optimizing patient outcomes.

Cytogenetics and genomics in CML and other myeloproliferative neoplasms

Chronic myeloid leukemia is defined by the presence of the Philadelphia translocation t (9; 22) resulting in the BCR::ABL1 fusion. The other myeloproliferative neoplasms (MPN) subtypes also carry typical chromosomal abnormalities, which however are not pathognomonic for a specific entity of MPN. According to the WHO classification the distinction between these entities is still based on the integration of cytological, histopathological and molecular findings. Progression of CML into accelerated and blastic phase is usually driven by additional chromosome abnormalities and ABL1 kinase mutations. In the other MPN subtypes the additional mutations besides driver gene mutations in JAK2, MPL and CALR have a decisive impact on the propensity for progression. In addition, the sequence in which the driver mutations and risk conveying additional mutations have been acquired appears to play an important role. Here, we review cytogenetic and molecular changes in CML and MPN that should be evaluated during diagnosis and disease monitoring.

Control of Ph+ and additional chromosomal abnormalities in chronic myeloid leukemia by tyrosine kinase inhibitors

Chronic myeloid leukemia (CML) is a type of blood cancer that is known to affect hematopoietic stem cells. The presence of the Philadelphia chromosome (Ph+) is the major characteristic of CML. A protein expressed by the Philadelphia chromosome shows elevated tyrosine kinase activity and is considered a tumorigenic factor. The first line of therapy that had been established for CML was "imatinib," a potent tyrosine kinase inhibitor. Various other second- and third-generation TKIs are taken into account in cases of imatinib failure/resistance. With the subsequent rise in the development of tyrosine kinase inhibitors, optimization in the treatment of CML and amplified total survival were observed throughout TKI dosage. As the disease progresses, additional chromosomal abnormalities (ACAs) have been reported, but their prognostic effect and impact on the response to treatment are still unknown. However, some substantial understandings have been achieved into the disease transformation mechanisms, including the role of somatic mutations, ACAs, and several different genomic mutations that occur during diagnosis or have evolved during treatment. The acquisition of ACAs impedes CML treatment. Due to additional chromosomal lesions, there are greater chances of future disease progression at the time of CML diagnosis beyond the Ph+ translocation. The synchronous appearance of two or more ACAs leads to lower survival and is classified as a poor prognostic group. The key objective of this review is to provide detailed insights into TKIs and their role in controlling Ph+ and ACAs, along with their response, treatment, overall persistence, and survival rate.

Prognosis in Chronic Myeloid Leukemia: Baseline Factors, Dynamic Risk Assessment and Novel Insights

The introduction of tyrosine kinase inhibitors (TKIs) has changed the treatment paradigm of chronic myeloid leukemia (CML), leading to a dramatic improvement of the outcome of CML patients, who now have a nearly normal life expectancy and, in some selected cases, the possibility of aiming for the more ambitious goal of treatment-free remission (TFR). However, the minority of patients who fail treatment and progress from chronic phase (CP) to accelerated phase (AP) and blast phase (BP) still have a relatively poor prognosis. The identification of predictive elements enabling a prompt recognition of patients at higher risk of progression still remains among the priorities in the field of CML management. Currently, the baseline risk is assessed using simple clinical and hematologic parameters, other than evaluating the presence of additional chromosomal abnormalities (ACAs), especially those at "high-risk". Beyond the onset, a re-evaluation of the risk status is mandatory, monitoring the response to TKI treatment. Moreover, novel critical insights are emerging into the role of genomic factors, present at diagnosis or evolving on therapy. This review presents the current knowledge regarding prognostic factors in CML and their potential role for an improved risk classification and a subsequent enhancement of therapeutic decisions and disease management.

Advances in molecular evaluation of myeloproliferative neoplasms

Myeloproliferative neoplasms (MPN) are a group of clonal hematopoietic stem cell disorders with uncontrolled proliferation of one or more hematopoietic cell types, including myeloid, erythroid and megakaryocytic lineages, and minimal defect in maturation. Most MPN are associated with well-defined molecular abnormalities involving genes that encode protein tyrosine kinases that lead to constitutive activation of the downstream signal transduction pathways and confer cells proliferative and survival advantage. Genome-wide sequencing analyses have discovered secondary cooperating mutations that are shared by most of the MPN subtypes as well as other myeloid neoplasms and play a major role in disease progression. Without appropriate management, the natural history of most MPN consists of an initial chronic phase and a terminal blast phase. Molecular aberrations involving protein tyrosine kinases have been used for the diagnosis, classification, detection of minimal/measurable residual disease, and target therapy. We review recent advances in molecular genetic aberrations in MPN with a focus on MPN associated with gene rearrangements or mutations involving tyrosine kinase pathways.

Chronic Myeloid Leukemia, from Pathophysiology to Treatment-Free Remission: A Narrative Literature Review

Chronic myeloid leukemia (CML) is one of the most common leukemias occurring in the adult population. The course of CML is divided into three phases: the chronic phase, the acceleration phase, and the blast phase. Pathophysiology of CML revolves around Philadelphia chromosome that constitutively activate tyrosine kinase through BCR-ABL1 oncoprotein. In the era of tyrosine kinase inhibitors (TKIs), CML patients now have a similar life expectancy to people without CML, and it is now very rare for CML patients to progress to the blast phase. Only a small proportion of CML patients have resistance to TKI, caused by BCR-ABL1 point mutations. CML patients with TKI resistance should be treated with second or third generation TKI, depending on the BCR-ABL1 mutation. Recently, many studies have shown that it is possible for CML patients who achieve a long-term deep molecular response to stop TKIs treatment and maintain remission. This review aimed to provide an overview of CML, including its pathophysiology, clinical manifestations, the role of stem cells, CML treatments, and treatment-free remission.

Chromosomal Instability in Chronic Myeloid Leukemia: Mechanistic Insights and Effects

The most recent two decades have seen tremendous progress in the understanding and treatment of chronic myeloid leukemia, a disease defined by the characteristic Philadelphia chromosome and the ensuing BCR::ABL fusion protein. However, the biology of the disease extends beyond the Philadelphia chromosome into a nebulous arena of chromosomal and genetic instability, which makes it a genetically heterogeneous disease. The BCR::ABL oncoprotein creates a fertile backdrop for oxidative damage to the DNA, along with impairment of genetic surveillance and the favoring of imprecise error-prone DNA repair pathways. These factors lead to growing chromosomal instability, manifested as additional chromosomal abnormalities along with other genetic aberrations. This worsens with disease progression to accelerated and blast phase, and modulates responses to tyrosine kinase inhibitors. Treatment options that target the genetic aberrations that mitigate chromosome instability might be a potential area for research in patients with advanced phase CML.

BCR-ABL1 Tyrosine Kinase Complex Signaling Transduction: Challenges to Overcome Resistance in Chronic Myeloid Leukemia

The constitutively active BCR-ABL1 tyrosine kinase, found in t(9;22)(q34;q11) chromosomal translocation-derived leukemia, initiates an extremely complex signaling transduction cascade that induces a strong state of resistance to chemotherapy. Targeted therapies based on tyrosine kinase inhibitors (TKIs), such as imatinib, dasatinib, nilotinib, bosutinib, and ponatinib, have revolutionized the treatment of BCR-ABL1-driven leukemia, particularly chronic myeloid leukemia (CML). However, TKIs do not cure CML patients, as some develop TKI resistance and the majority relapse upon withdrawal from treatment. Importantly, although BCR-ABL1 tyrosine kinase is necessary to initiate and establish the malignant phenotype of Ph-related leukemia, in the later advanced phase of the disease, BCR-ABL1-independent mechanisms are also in place. Here, we present an overview of the signaling pathways initiated by BCR-ABL1 and discuss the major challenges regarding immunologic/pharmacologic combined therapies.

Defining Higher-Risk Chronic Myeloid Leukemia: Risk Scores, Genomic Landscape, and Prognostication

PURPOSE OF REVIEW

The chronic myeloid leukemia (CML) treatment success story is incomplete as some patients still fail therapy, leading to end-stage disease and death. Here we discuss recent research into CML incidence, the role of comorbidities on survival and detecting patients at risk of failing therapy.

RECENT FINDINGS

The incidence of CML has fallen markedly in high social-demographic index (SDI) regions of the world but there is disturbing evidence that this is not the case in low and low-middle SDI countries. Now that CML patients more frequently die from their co-morbid conditions than from CML the Adult Comorbidity Evaluation-27 score can assist in risk assessment at diagnosis. Non-adherence to therapy contributes greatly to treatment failure. A good doctor-patient relationship and social support promote good adherence, but patient age, gender, and financial burden have negative effects, suggesting avenues for intervention. Mutations in cancer-associated genes adversely affect outcome and their detection at diagnosis may guide therapeutic choice and offer non-BCR::ABL1 targeted therapies. A differential gene expression signature to assist risk detection is a highly sought-after diagnostic tool being actively researched on several fronts. Detecting patients at risk of failing therapy is being assisted by recent technological advances enabling highly sensitive genomic and expression analysis of insensitive cells. However, patient lifestyle, adherence to therapy, and comorbidities are critical risk factors that need to be addressed by interventions such as social and financial support.

Which Tyrosine Kinase Inhibitors Should Be Selected as the First-Line Treatment for Chronic Myelogenous Leukemia in Chronic Phase?

Simple Summary

This review discusses the optimal selection of BCR-ABL1 tyrosine kinase inhibitors (TKIs) as the first-line treatment for newly diagnosed chronic myelogenous leukemia in chronic phase (CML-CP). With the advent of TKIs, the treatment goals for CML-CP patients have changed from “simply survival” to “survival with adequate quality of life”, hence the number of CML-CP patients aiming to achieve treatment-free remission has increased, irrespective of age or comorbidities. Therefore, optimal selection of TKIs for maximizing the number of patients to achieve treatment-free remission is an important factor for consideration in future studies. To this end, we must understand the advantages and disadvantages of each TKI in terms of treatment response, disease risk at diagnosis, comorbidities, and medical expenses, and use of effective 2GTKIs based on patient background. This review provides insights into “shared decision-making” in individual cases, including the elderly population.

Abstract

With the use of tyrosine kinase inhibitors (TKIs), chronic myelogenous leukemia in chronic phase (CML-CP) has been transformed into a non-fatal chronic disease. Hence, “treatment-free remission (TFR)” has become a possible treatment goal of patients with CML-CP. Currently, four types of TKIs (imatinib, nilotinib, dasatinib, and bosutinib) are used as the first-line treatment for newly diagnosed CML-CP. However, the second-generation TKI (2GTKI), the treatment response of which is faster and deeper than that of imatinib, is not always recommended as the first-line treatment for CML-CP. Factors involved in TKI selection in the first-line treatment of CML-CP include not only patients’ medical background, but also patients’ choice regarding the desired treatment goal (survival or TFR?). Therefore, it is important that clinicians select an appropriate TKI to successfully achieve the desired treatment goal for each patient, while minimizing the development of adverse events. This review compares the pros and cons of using imatinib and 2GTKI for TKI selection as the first-line treatment for CML-CP, mainly considering treatment outcomes, medical history (i.e., desire for pregnancy, aging factor, and comorbidity), and cost. The optimal use of 2GTKIs is also discussed.

[Analysis of clinical features and prognosis of patients with chronic myelogenous leukemia harboring additional chromosomal abnormalities in Ph-positive cells]

Objective: To investigate the effects of additional chromosomal abnormalities (ACA) in Philadelphia chromosome-positive (Ph(+)) cells on biological characteristics, therapy efficacy, and prognosis of patients with primary chronic myeloid leukemia (CML) -chronic phase (CP) and those who developed CML-accelerated phase/blast phase (AP/BP) during therapy. Methods: The clinical data of 410 patients with Ph(+) CML, including 348 patients with primary CML-CP and 62 patients who progressed to CML-AP/BP during treatment, who were admitted to Henan People's Hospital from January 2013 to June 2020 were retrospectively analyzed to categorize into high-risk, non-high-risk, and non-ACA groups according to the ELN2020 criteria. The effects of high- and non-high-risk ACA on biological characteristics, therapy efficacy, and prognosis were compared. Results: ①Among the 348 patients with primary CML-CP, 20 patients (5.75% ) had ACA, including 3 and 17 patients with high-risk and non-high-risk ACA, respectively, whereas the remaining 328 patients did not have ACA. There were no significant differences in baseline clinical characteristics between those with and without ACA (P>0.05 for all) . The rates of complete hematological response, complete cytogenetic response, major molecular remission, and 5-year overall survival (OS) were not significantly different between the non-high-risk ACA and non-ACA groups (P>0.05 for all) ; however, the 5-year progression-free survival of the non-high-risk ACA group (42.0% ) was significantly lower than that of the non-ACA group (74.5% ) (χ(2)=4.766, P=0.029) .②Of the 62 patients who progressed to CML-AP/BP during treatment, 41 patients (66.13% ) had ACA, including 28 and 13 patients with high-risk and non-high-risk ACA, respectively, whereas the remaining 21 patients did not have ACA. Platelet counts of the high-risk ACA group (42.5×10(9)/L) were lower than those of the non-high-risk (141×10(9)/L) and non-ACA groups (109×10(9)/L) (χ(2)=4.968, P=0.083) . There was no significant difference in the incidence of point mutations in ABL kinase among the three groups (P=0.652) . The complete cytogenetic response of the high-risk ACA group (5.3% ) was significantly lower than that of the non-ACA group (46.7% ) (χ(2)=5.851, P=0.016) . The 5-year OS of the high-risk ACA group was lower than that of the non-ACA group (46.2% vs 77.8% , χ(2)=3.878, P=0.049) . Subgroup analysis revealed that the 5-year OS rate of the high-risk group Ⅱ, which included -7/7q-, i (17q) , and complex karyotype comprising ≥2 high-risk ACA, was significantly lower than that of the non-ACA group (28.6% vs 77.8% , χ(2)=8.035, P=0.005) whereas the 5-year OS rate was not significantly different between high-risk group Ⅰ, which included +8,+Ph, and complex ACA with +8/+Ph, and the non-ACA group (54.5% vs 77.8% , χ(2) =1.514, P=0.219) . Conclusion: Due to different disease stages and ACA/Ph(+) types, treatment response and prognosis vary among patients with CML harboring ACA/Ph(+). The emergence of high-risk ACA during therapy suggests worse therapy efficacy and prognosis. Strict and standardized cytogenetic monitoring is critical for early detection, precise diagnosis, and treatment of these patients.

Oncogene-independent resistance in Philadelphia chromosome - positive (Ph+) acute lymphoblastic leukemia (ALL) is mediated by activation of AKT/mTOR pathway

Tyrosine kinase inhibitors (TKIs) such as imatinib, nilotinib, dasatinib, and ponatinib have significantly improved the life expectancy of Philadelphia chromosome-positive (Ph⁺) acute lymphocytic leukemia (ALL) patients; however, resistance to TKIs remains a major clinical challenge. Point mutations in the tyrosine kinase domain (TKD) of BCR-ABL1 have emerged as the predominant cause of acquired resistance. In approximately 30% of patients, the mechanism of resistance to TKIs remains elusive. This study aimed to investigate mechanisms of nonmutational resistance in Ph⁺ ALL. Here we report the development of a nonmutational resistance cell line SupB15-RT; conferring resistance to approved ABL kinase inhibitors (AKIs) and allosteric inhibitors GNF-2, ABL001, and crizotinib, except for dasatinib (IC90 50nM), a multitarget kinase inhibitor. We found that the AKT/mTOR pathway is activated in these cells and their proliferation inhibited by Torin-1 with an IC50 of 24.7 nM. These observations were confirmed using 3 different ALL patient-derived long term cultures (PDLTCs): (1) HP (BCR-ABL1 negative), (2) PH (BCR-ABL1 positive and responsive to TKIs) and (3) BV (BCR-ABL1 positive and nonmutational resistant to TKIs). Furthermore, Torin-1 and NVP-BEZ235 induced apoptosis in PH and BV cells but not in HP cells.

Our experiments provide evidence of the involvement of AKT/mTOR pathway in the evolution of nonmutational resistance in Ph⁺ ALL which will assist in developing novel targeted therapy for Ph⁺ ALL patients with BCR-ABL1 independent nonmutational resistance.

Measuring prognosis in chronic myeloid leukemia: what's new?

Introduction: The outcome of chronic myeloid leukemia (CML) patients in chronic phase has changed after the introduction of tyrosine kinase inhibitors (TKIs). The life expectancy is actually similar to that of the general population. Prognostic stratification at baseline is part of a patient-centered approach to decide the best therapeutic approach.Areas covered: In this review, the current prognostic factors examined at baseline are detailed and the meaning is explained. A broad research on Medline, Embase and archives from EHA and ASH congresses, was performed. Prognostic factors have been divided into patient-related (age, gender, comorbidities, etc.) and disease-related (additional cytogenetic abnormalities, type of transcript, etc). New information about genomic data and the potential role of patient-reported outcomes is also discussed.Expert Opinion: Prognostic factors at baseline should be considered to evaluate the long-term probability of disease-related death, the possible toxicity, and the projected long-term overall survival. The genomic assessment would provide the basis for a genomic-based risk and help in oriented decision-making process.

Additional chromosomal abnormalities at chronic myeloid leukemia diagnosis predict an increased risk of progression

At diagnosis of chronic-phase chronic myeloid leukemia (CML), there are conflicting data as to whether additional cytogenetic abnormalities (ACAs) beyond a standard Philadelphia (Ph) translocation confer a higher risk of subsequent disease progression. In the United Kingdom SPIRIT2 trial comparing imatinib 400 mg daily with dasatinib 100 mg daily, diagnostic karyotypes were available in 763 of the 814 patients recruited. Of these, 27 had ACAs in either/both the original 4 major route group (trisomy 8 or 19, iso17q or a second Ph) or the 5 additional lesions recently described (trisomy 21, 3q26.2, monosomy 7/7q-, 11q23, and complex karyotypes), and their progression rate was significantly higher (22.2%) than in patients without one of these ACAs (2.2%; P < .001). Patients with ACAs had worse progression-free survival (PFS; hazard ratio [HR], 5.21; 95% confidence interval [CI], 2.59-10.50; P < .001) and freedom from progression (FFP; HR, 12.66; 95% CI, 4.95-32.37; P < .001) compared with patients without ACAs. No association was seen between the Sokal or European Treatment and Outcome Study long-term survival (ELTS) scores and the presence of ACAs. Univariate analysis showed that higher Sokal and ELTS scores and the presence of ACAs were associated with poorer PFS, though only ACAs and high-risk ELTS scores were associated with poorer FFP. Multivariable models identified both the Sokal/ELTS score and ACAs as significant independent factors for PFS but only ELTS score and ACAs as significant independent factors for FFP. The data support the view that certain ACAs are predictive of disease progression independently of Sokal or ELTS scores.

First-generation vs second-generation tyrosine kinase inhibitors: which is best at diagnosis of chronic phase chronic myeloid leukemia?

In 2020, for the great majority of patients with chronic phase chronic myeloid leukemia (CML), life expectancy is unaffected by a diagnosis of CML because of the unparalleled efficacy of ABL-targeted tyrosine kinase inhibitors (TKIs) in halting disease progression. A wealth of choices exist for first-line treatment selection, including the first-generation TKI imatinib and the second-generation TKIs bosutinib, dasatinib, and nilotinib. How I select first-line therapy between first-generation and second-generation TKIs is discussed in the context of patient-specific CML disease risk, therapy-related risks, and treatment goals. Although rare, identifying patients with CML at higher risk for disease progression or resistance is important and influences first-line TKI selection. I review the impact of first-generation vs second-generation TKI selection on treatment response and outcomes; the ability to achieve, as well as the timing of, treatment-free remission; and the impact of specific TKIs on longer-term health.

Chronic Myeloid Leukemia, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

Chronic myeloid leukemia (CML) is defined by the presence of Philadelphia chromosome (Ph) which results from a reciprocal translocation between chromosomes 9 and 22 [t(9;22] that gives rise to a BCR-ABL1 fusion gene. CML occurs in 3 different phases (chronic, accelerated, and blast phase) and is usually diagnosed in the chronic phase. Tyrosine kinase inhibitor therapy is a highly effective first-line treatment option for all patients with newly diagnosed chronic phase CML. This manuscript discusses the recommendations outlined in the NCCN Guidelines for the diagnosis and management of patients with chronic phase CML.

Managing chronic myeloid leukemia for treatment-free remission: a proposal from the GIMEMA CML WP

Several papers authored by international experts have proposed recommendations on the management of BCR-ABL1+ chronic myeloid leukemia (CML). Following these recommendations, survival of CML patients has become very close to normal. The next, ambitious, step is to bring as many patients as possible into a condition of treatment-free remission (TFR). The Gruppo Italiano Malattie EMatologiche dell'Adulto (GIMEMA; Italian Group for Hematologic Diseases of the Adult) CML Working Party (WP) has developed a project aimed at selecting the treatment policies that may increase the probability of TFR, taking into account 4 variables: the need for TFR, the tyrosine kinase inhibitors (TKIs), the characteristics of leukemia, and the patient. A Delphi-like method was used to reach a consensus among the representatives of 50 centers of the CML WP. A consensus was reached on the assessment of disease risk (EUTOS Long Term Survival [ELTS] score), on the definition of the most appropriate age boundaries for the choice of first-line treatment, on the choice of the TKI for first-line treatment, and on the definition of the responses that do not require a change of the TKI (BCR-ABL1 ≤10% at 3 months, ≤1% at 6 months, ≤0.1% at 12 months, ≤0.01% at 24 months), and of the responses that require a change of the TKI, when the goal is TFR (BCR-ABL1 >10% at 3 and 6 months, >1% at 12 months, and >0.1% at 24 months). These suggestions may help optimize the treatment strategy for TFR.

The Hidden Pathogenesis of CML: Is BCR-ABL1 the First Event?

PURPOSE OF REVIEW

Identification of the BCR-ABL1 fusion oncogene in patients diagnosed with chronic myeloid leukemia (CML) led to the development of targeted therapy responsible for the dramatic survival benefits observed in the past two decades. However, despite these revolutionary findings, there remains marked disparity in patient outcomes. Why do some patients present de novo while others evolve to the more aggressive stages of CML? Why can select patients successfully discontinue therapy as part of a treatment-free remission attempt whereas others fail to meet specific molecular milestones?

RECENT FINDINGS

BCR-ABL1 kinase mutations are only identified in approximately 50% of patients with poor responses and disease progression, suggesting the presence of alternative resistance mechanisms. Numerous institutions have identified the presence of additional genomic events in addition to BCR-ABL1 with the increasing availability of next-generation sequencing. We explore the potential pathways and events that may cooperate with BCR-ABL1 to answer these questions but also challenge the fundamental tenet that BCR-ABL1 is always the sole event initiating CML.

Mechanisms of Disease Progression and Resistance to Tyrosine Kinase Inhibitor Therapy in Chronic Myeloid Leukemia: An Update

Chronic myeloid leukemia (CML) is characterized by the presence of the BCR-ABL1 fusion gene, which encodes a constitutive active tyrosine kinase considered to be the pathogenic driver capable of initiating and maintaining the disease. Despite the remarkable efficacy of tyrosine kinase inhibitors (TKIs) targeting BCR-ABL1, some patients may not respond (primary resistance) or may relapse after an initial response (secondary resistance). In a small proportion of cases, development of resistance is accompanied or shortly followed by progression from chronic to blastic phase (BP), characterized by a dismal prognosis. Evolution from CP into BP is a multifactorial and probably multistep phenomenon. Increase in BCR-ABL1 transcript levels is thought to promote the onset of secondary chromosomal or genetic defects, induce differentiation arrest, perturb RNA transcription, editing and translation that together with epigenetic and metabolic changes may ultimately lead to the expansion of highly proliferating, differentiation-arrested malignant cells. A multitude of studies over the past two decades have investigated the mechanisms underlying the closely intertwined phenomena of drug resistance and disease progression. Here, we provide an update on what is currently known on the mechanisms underlying progression and present the latest acquisitions on BCR-ABL1-independent resistance and leukemia stem cell persistence.

Impact of Additional Chromosomal Aberrations Present at Diagnosis on Outcome of Adolescent and Young Adult Chronic Myeloid Leukemia Patients: A Single Center Experience

Studying the influence of additional chromosomal aberrations (ACAs) present at diagnosis on the outcome of adolescent and young adult (AYA) chronic myeloid leukemia (CML) patients as it has not been addressed previously. Eighty-six AYA CML patients have been analyzed for occurrence of ACAs at diagnosis through performing bone marrow karyotyping. All patients received imatinib mesylate upon diagnosis of CML. Overall response, molecular response, survival status, progression and occurrence of events were monitored during the follow up period. There was a statistically significant difference between patients with and without ACAs regarding overall response (P = 0.049). There was insignificant difference between the two groups regarding achievement of major molecular response (MMR) (P = 0.594), MR⁴ (P = 0.282) and MR^4.5 (P = 0.704). There was a significant difference between patients with and without ACAs regarding time to MMR (P = 0.042) and time to MR⁴ (P = 0.048) but not regarding time to MR^4.5 (P = 0.065). There was insignificant impact of ACAs at diagnosis on overall survival (P = 0.152), progression free survival (P = 0.112), failure free survival (P = 0.114), event free survival (P = 0.194) and alternative treatment free survival (P = 0.731). The presence of ACAs at diagnosis does not signal worse prognosis in AYA CML patients but it may delay molecular response to imatinib mesylate.

Early Management of CML

PURPOSE OF REVIEW

The marked improvement in clinical outcomes for patients with chronic myeloid leukaemia (CML) can be solely attributed to the introduction of targeted therapies against the fusion oncoprotein, BCR-ABL1. However, patient responses, although generally positive, remain heterogenous. Careful drug selection, ensuring the optimal TKI, is chosen for each patient and involves a complex decision process which incorporates consideration of numerous factors.

RECENT FINDINGS

For some patients, with disease characteristics that indicate adverse intrinsic disease biology, more potent BCR-ABL1 inhibition is often appropriate, whereas other patients with major co-morbidities will benefit from a less aggressive approach to avoid life-shortening toxicities. For the vast majority of patients, the long-term goal of therapy will be the achievement of a deep molecular response and subsequent treatment-free remission and this consideration will play a large part in the drug selection process. We explore early management of CML, from the first presentation through to frontline therapy selection.

Heterogeneous BCR-ABL1 signal patterns identified by fluorescence in situ hybridization are associated with leukemic clonal evolution and poorer prognosis in BCR-ABL1 positive leukemia

Background

Although extensive use of tyrosine kinase inhibitors has resulted in high and durable response rate and prolonged survival time in patients with BCR-ABL1 positive chronic myeloid leukemia (CML) and acute leukemia, relapse and drug resistance still remain big challenges for clinicians. Monitoring the expression of BCR-ABL1 fusion gene and identifying ABL kinase mutations are effective means to predict disease relapse and resistance. However, the prognostic impact of BCR-ABL1 signal patterns detected by fluorescence in situ hybridization (FISH) remains largely unaddressed.

Methods

BCR-ABL1 signal patterns were analyzed using FISH in 243 CML-chronic phase (CML-CP), 17 CML-blast phase (CML-BP) and 52 BCR-ABL1 positive acute lymphoblastic leukemia (ALL) patients.

Results

The patterns of BCR-ABL1 signals presented complexity and diversity. A total of 12 BCR-ABL1 signals were observed in this cohort, including 1R1G2F, 1R1G1F, 2R1G1F, 1R2G1F, 2R2G1F, 1R2G2F, 1R1G3F, 1G3F, 2G3F, 1G4F, 1R1G4F and 1R4F. Complex BCR-ABL1 signal patterns (≥ two types of signal patterns) were observed in 52.9% (n = 9) of the CML-BP patients, followed by 30.8% (n = 16) of the ALL patients and only 2.1% (n = 5) of the CML-CP patients. More importantly, five clonal evolution patterns related to disease progression and relapse were observed, and patients with complex BCR-ABL1 signal patterns had a poorer overall survival (OS) time compared with those with single patterns (5.0 vs.15.0 months, p = 0.006).

Conclusions

Our data showed that complex BCR-ABL1 signal patterns were associated with leukemic clonal evolution and poorer prognosis in BCR-ABL1 positive leukemia. Monitoring BCR-ABL1 signal patterns might be an effective means to provide prognostic guidance and treatment choices for these patients.

SIGNIFICANCE OF ADDITIONAL CHROMOSOMAL ABNORMALITIES FOR THE OUTCOMES AFTER THE SECOND LINE NILOTINIB THERAPY IN THE CHRONIC MYELOID LEUKEMIA PATIENTS

Background. There is limited information about impact of additional chromosome aberrations (ACA) on the efficacy of the 2nd line nilotinib therapy. Objective. The aim of the study was to analyze significance of ACAs for the outcome after second line tyrosine kinase inhibitors (TKI) therapy with nilotinib in the chronic myeloid leukemia (CML) patients, who experienced previous imatinib therapy failure. Methods. The CML patients in chronic phase treated with nilotinib after imatinib failure were analyzed for outcomes. Results. Among a total of 114 patients, 18 patients (15.8%) had ACAs at the beginning of the 2nd line therapy with nilotinib. Seven patients (38.9%) of 18 had variant translocations and 11 patients (61.1%) had other chromosomal abnormalities in addition to t(9;22), known as clonal evolution. Complete cytogenetic response (CCR) at 12 months was achieved in 37.5%, 42.8% and 45.5% (p=0.842) of patients with classic t(9;22) translocation, variant translocations and ACAs respectively. In the patients with variant translocations t(9;V;22) or clonal evolution treated with nilotinib after the imatinib failure, the CCR and major molecular response (MMR), event free survival (EFS), progression free survival (PFS) and overall survival (OS) rates did not differ from those in the CML patients with t(9;22) only. At the same time quantitative characteristics of leukemic and ACA clones had prognostic value for CCR. The increased number of Ph-positive cells and the number of cells with the ACA at the start of nilotinib therapy reduced the probability of CCR. Conclusions. Higher nilotinib inhibitory activity compare with imatinib allows us to overcome imatinib resistance in the CML patients regardless of the ACA presence at the beginning of nilotinib therapy.

[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.

Deep sequencing of BCR-ABL1 kinase domain mutations in chronic myeloid leukemia patients with resistance to tyrosine kinase inhibitors

Tyrosine kinase inhibitor (TKI) therapy is the current treatment of choice for patients with chronic phase chronic myeloid leukemia (CML) leading to rapid and durable hematological as well as molecular responses. However, emergence of resistance to TKIs has been the major obstacle to treatment success on long term. In this regard kinase domain mutations are the most common mechanism of therapy failure. In this study, we analyzed peripheral blood samples from 17 CML patients who had developed resistance to various TKIs by using next-generation sequencing parallel to Sanger sequencing. BCR-ABL1 kinase domain mutations have been found in 59% of the cohort. Our results demonstrate that next-generation sequencing results in a higher mutational detection rate than reported with conventional sequencing methodology. Furthermore, it showed the clonal diversity more accurately.