EUTOS score is not predictive for survival and outcome in patients with early chronic phase chronic myeloid leukemia treated with tyrosine kinase inhibitors: a single institution experience

Influence of Telomere Length on the Achievement of Deep Molecular Response With Imatinib in Chronic Myeloid Leukemia Patients

Tyrosine kinase inhibitors have dramatically changed the outcome of chronic myeloid leukemia (CML), and nowadays, one of the main treatment goals is the achievement of deep molecular responses (DMRs), which can eventually lead to therapy discontinuation approaches. Few biological factors at diagnosis have been associated with this level of response. Telomere length (TL) in peripheral blood cells of patients with CML has been related to disease stage, response to therapy and disease progression, but little is known about its role on DMR. In this study, we analyzed if age-adjusted TL (referred as “delta-TL”) at diagnosis of chronic phase (CP)-CML might correlate with the achievement of DMR under first-line imatinib treatment. TL from 96 CP-CML patients had been retrospectively analyzed at diagnosis by monochrome multiplex quantitative PCR. We observed that patients with longer age-adjusted telomeres at diagnosis had higher probabilities to achieve DMR with imatinib than those with shortened telomeres (P = 0.035 when delta-TL was studied as a continuous variable and P = 0.047 when categorized by the median). Moreover, patients carrying long telomeres also achieved major molecular response significantly earlier (P = 0.012). This study provides proof of concept that TL has a role in CML biology and when measured at diagnosis of CP-CML could help to identify patients likely to achieve DMR to first-line imatinib treatment.

Ultra-deep sequencing mutation analysis of the BCR/ABL1 kinase domain in newly diagnosed chronic myeloid leukemia patients

Ultra-deep sequencing detects low-frequency genetic mutations with high sensitivity. We used this approach to prospectively examine mutations in the BCR/ABL1 tyrosine kinase from patients with newly diagnosed, chronic-phase chronic myeloid leukemia (CML) treated with the tyrosine kinase inhibitor nilotinib. Between May 2013 and November 2014, 50 patients from 18 institutions were enrolled in the study. We screened 103 somatic mutations and found that mutations in the P-loop domain were the most frequent (173/454 mutations in the P-loop) and noted the presence of the V299 L mutation (dasatinib-resistant/nilotinib-sensitive) in 98 % of patients (49/50). No patients had Y253H, E255 V, or F359 V/C/I mutations, which would recommend dasatinib rather than nilotinib treatment. The S417Y mutation was associated with lower achievement of a major molecular response (MMR) at 6 months, and the V371A mutation was associated with reduced MMR and MR^4.5 durations (MMR for 2 years: 100 % for no mutation vs. 75 % for mutation, P=0.039; MR^4.5 for 15 months: 94.1 % vs. 25 %, P=0.002). Patients with known nilotinib-resistant mutations had lower rates of MR^4.5 achievement. In conclusion, ultra-deep sequencing is a sensitive method for genetic-based treatment decisions. Based on the results of these mutational analyses, nilotinib treatment is a promising option for Korean patients with CML.

Higher Red Blood Cell Distribution Width is a Poor Prognostic Factor for Patients with Chronic Myeloid Leukemia

Purpose

Red blood cell distribution width (RDW) has been considered as a potential indicator of the effects of treatment or as a prognostic indicator for various malignancies. Most chronic myeloid leukemia (CML) patients are in the chronic phase, but some have transformed to accelerated phase or blast phase (blast crisis). However, the clinical significance of RDW in CML remains limited.

Patients and Methods

In the present study, detailed clinical information and the RDW of 168 healthy people and 153 CML patients (106 patients for the training cohort and 47 patients for the validation cohort) were retrospectively assessed.

Results

Multivariate analysis demonstrated that patient age (OR, 1.081; 95CI% 1.039~1.125; p < 0.001), platelet counts (OR, 0.997; 95CI% 0.994~0.999; p = 0.001) and RDW at admission (OR,1.469; 95CI% 1.121~1.925; p = 0.005) were significantly associated with the patients with advanced phase. Among CML patients in the chronic phase, higher RDW was significantly associated with overall survival (OS; p = 0.0008) and the event-free survival (EFS; p = 0.0221) among CML patients with chronic phase, but not with Transformation-free survival (TFS; p = 0.0821). Furthermore, higher RDW was associated with higher mortality compared to patients with low RDW (CML-associated deaths; p < 0.0001). In addition, a decline in RDW is associated with the treatment of CML patients with tyrosine kinase inhibitors, especially at 6 and 12 months after the start of treatment.

Conclusion

Higher RDW is a potential prognostic biomarker for chronic CML patients.

CML Chapter

The discovery of the tyrosine kinase inhibitor (TKI) imatinib in the early 2000's revolutionized the treatment and prognosis of patients with chronic myeloid leukemia (CML) [Hochhaus et al. in N Engl J Med 376:917-927, 2017]. The treatment of patients with CML has changed dramatically since the approval of imatinib and other TKIs. Before the TKI era, newly diagnosed patients would undergo HLA typing to try to identify a well-matched donor, and then proceed quickly to allogeneic hematopoietic cell transplantation (HCT). With the introduction of imatinib followed a few years later by dasatinib, nilotinib, then bosutinib, treatment approaches changed in a dramatic way. Transplantation is no longer an upfront treatment option for newly diagnosed CML patients, and in fact, it is very rarely used in the management of a patient with CML currently. The management of CML patients has been a model of personalized medicine or targeted therapy that is being emulated in the treatment of many other hematologic malignancies and solid tumors such as lung cancer [Soverini et al. in Mol Cancer 17:49, 2018]. The Philadelphia Chromosome (Ph) which leads to the formation of the BCR-ABL fusion gene and its product the BCR-ABL protein is the cause of CML. With effective targeting of this protein with the available TKIs, the disease is completely controllable if not curable for most patients. Life expectancy for patients with CML is essentially normal. Quality of life becomes an important goal including the potential for pregnancy, and ultimately the chance to discontinue all TKI therapy permanently. The three cases outlined below serve to highlight some of the important issues in the management of patients with CML in the post-TKI era.

Re-defining Prognosis of Hematological Malignancies by Dynamic Response Assessment Methods: Lessons Learnt in Chronic Myeloid Leukemia, Hodgkin Lymphoma, Diffuse Large B Cell Lymphoma and Multiple Myeloma

Risk-stratification is an essential management tool in defining prognosis of haematological neoplasms, both from patient and physician perspective. We define a new prognostic term "Dynamic Response Assessment Method(s) (DRAM)" as "method(s) used for re-stratifying disease prognosis at fixed intervals during the treatment course". The risk stratification is done after a fixed duration of treatment or chemotherapy cycles using sensitive techniques. The information obtained then can be used for further therapeutic decisions and prognostication. Currently, there is enough evidence that response to treatment improves the prognostic value of baseline disease variables in the management of Chronic Myeloid Leukemia, Hodgkin lymphoma, Diffuse Large B cell Lymphoma, and Multiple Myeloma. Through this review, we discuss the current evidence based application of "DRAM" to guide therapeutic decisions in these malignancies. We also discuss how the results of "DRAM" can be incorporated for redefining prognosis and counselling the patients with these selected hematologic malignancies.

Outcomes of Chronic Phase Chronic Myeloid Leukemia after Treatment with Multiple Tyrosine Kinase Inhibitors

We sought to evaluate the outcomes of chronic phase (CP) chronic myeloid leukemia (CML) in an era where five tyrosine kinase inhibitors (TKIs) are commercially available for the treatment of CML. Records of patients diagnosed with CP CML, treated with TKIs and referred to our center were reviewed. Between January 2005 and April 2016, 206 patients were followed for a median of 48.8 (1.4–190.1) months. A total of 76 (37%) patients received one TKI, 73 (35%) received two TKIs and 57 (28%) were exposed to >3 TKIs (3 TKIs, n = 33; 4 TKIs, n = 17; 5 TKIs, n = 7). Nineteen (9.2%) patients progressed to advanced phases of CML (accelerated phase, n = 6; myeloid blastic phase, n = 4; lymphoid blastic phase, n = 9). One third (n = 69) achieved complete molecular response (CMR) at first-line treatment. An additional 55 patients achieved CMR after second-line treatment. Twenty-five patients (12.1%) attempted TKI discontinuation and 14 (6.8%) stopped TKIs for a median of 6.3 months (range 1–53.4). The 10-year progression-free survival and overall survival (OS) rates were 81% and 87%, respectively. OS after 10-years, based on TKI exposure, was 100% (1 TKI), 82% (2 TKIs), 87% (3 TKIs), 75% (4 TKIs) and 55% (5 TKIs). The best OS was observed in patients tolerating and responding to first line TKI, but multiple TKIs led patients to gain treatment-free remission.

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.

Aplasia in Chronic Phase CML Post-TKI Therapy: A Management Dilemma

Transient cytopenias and bone marrow hypoplasia commonly occur during treatment of CML with TKIs (tyrosine kinase inhibitors). This is usually related to the eradication of CML clones that initially compose the majority of hematopoietic cells in the bone marrow at the time of diagnosis. With continuation of effective therapy, normal blood counts return as normal hematopoiesis is restored and CML clones are reduced. Though rare and more unusual than myelodysplastic syndrome (MDS), isolated instances of persistent marrow aplasia have been documented with chronic use of TKIs. We describe two such instances of chronic phase CML where no significant reduction of CML clones was achieved following treatment with TKIs, but bone marrow aplasia occurred resulting in persistent dysfunctional hematopoiesis. Due to prolonged aplasia/hypoplasia, such patients are no longer amenable to TKI treatment. CML progression to accelerated or blast phase in that setting would likely be fatal.

Chronic myelogenous leukemia, a still unsolved problem: pitfalls and new therapeutic possibilities

Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder of hematopoietic stem cells. At the molecular level, the disorder results from t(9;22)(q34;q11) reciprocal translocation between chromosomes, which leads to the formation of an oncogenic BCR–ABL gene fusion. Instead of progress in the understanding of the molecular etiology of CML and the development of novel therapeutic strategies, clinicians still face many challenges in the effective treatment of patients. In this review, we discuss the pathways of diagnosis and treatment of patients, as well as the problems appearing in the course of disease development. We also briefly refer to several aspects regarding the current knowledge on the molecular basis of CML and new potential therapeutic targets.

Comparative analysis of the Sokal, Euro and European Treatment and Outcome Study score in prognostication of Indian chronic myeloid leukemia-chronic phase patients on imatinib

Introduction:

The ultimate goal for CML management is risk stratification of the patients to design the appropriate treatment approach. The Sokal, Euro and EUTOS risk scores were established to prognosticate the patients on therapy.

Aim:

To perform a comparative assessment of the Sokal, Euro and EUTOS prognostic score in Indian CML-CP patients on imatinib.

Methods:

This is a retrospective study performed in 260 Ph+ CML-CP patients who were administered oral imatinib (400 mg/day).

Results:

166/260 were males and 94/260 were females (M: F::1.6:1) with median age 35 years (range 20-70). 92 (35.38%), 125 (48.07%) and 43 (16.5%) patients were divided into low, intermediate and high risk Sokal score respectively. 102 (39.23%), 106 (40.76%) and 52 (20%) patients were discriminated into low, intermediate and high risk Euro score respectively. 210 (80.7%) and 50 (19.2%) patients were divided into low and high risk EUTOS score. Cumulative incidence of MMR for low, intermediate and high-risk Sokal score was 87%, 76% and 84% respectively (P = 0.016). Incidence of MMR in low, intermediate and high-risk Euro score was 93%, 85% and 68% respectively (P = 0.001). Incidence of MMR was 80 % and 81% for low and high risk EUTOS score (P = 0.764). Both EFS and OS are significantly correlated with Sokal score (P = 0.004, P = 0.007) and Euro score (P = 0.009, P = 0.001) but not with EUTOS score (P = 0.581, P = 0.927).

Conclusion:

The present study highlights the significant prognostic role of Sokal and Euro score in predicting the treatment outcome of the CML- CP patients on imatinib.

First-line therapy for chronic phase CML: selecting the optimal BCR-ABL1-targeted TKI

Patients diagnosed with chronic myeloid leukemia (CML) and treated with BCR-ABL1 tyrosine kinase inhibitors (TKIs) have long life spans. Selection of an appropriate first-line therapy can be difficult as both the unique characteristics of each TKI and patient need to be taken into account to find the optimal match. Patient characteristics include comorbidities, concomitant medications, lifestyle, risk factors, BCR-ABL1 transcript type (e.g. b2a2 or b3a2) and additional chromosomal abnormalities. Just as patients differ, side effects, drug-drug interactions, administration plans, dosing schedules and treatment-related expenses across TKIs also vary. Alignment of these characteristics with the appropriate TKI is key to successfully initiating CML treatment. Continued success relies on communication between the patient and the healthcare team, adherence and optimization of therapy once it is initiated. In this review, we discuss these factors, in addition to TKI efficacy and safety, the cost of therapy, the future of treating CML and treatment-free remission.

Moderate anemia at diagnosis is an independent prognostic marker of the EUTOS, Sokal, and Hasford scores for survival and treatment response in chronic-phase, chronic myeloid leukemia patients with frontline imatinib

OBJECTIVES

This study aimed to examine the prognostic value of anemia for the diagnosis of chronic myeloid leukemia in the chronic phase (CML-CP) receiving imatinib.

METHODS

One hundred and fifty-four CML-CP patients were enrolled. The influences of moderate anemia with hemoglobin (Hb) < 10 g/dl, four scoring systems, and the early molecular response at 3 months (BCR-ABL ≤10%; 3M-EMR) on the achievement of a deep molecular response (DMR, MR4.5), progression-free survival (PFS), event-free survival (EFS), and overall survival (OS) were compared.

RESULTS

Moderate anemia was identified in 44 (28.6%) patients. These patients had more aggressive baseline features and higher risks, as assessed by scoring systems, and less favorable treatment responses vs those without anemia, including 3M-EMR (50.0% vs 69.1%), a complete cytogenetic response at 6 months (20.5% vs 50.9%), and a major molecular response at 12 months (22.5% vs 45.2%), with a median follow-up of 54.0 months. Furthermore, an Hb of 10 g/dl better distinguished DMR, EFS, PFS, and OS than the EUTOS, Sokal, and Hasford scores, and better predicted the responses and survivals in combination with 3M-EMR than 3M-EMR alone.

CONCLUSIONS

This finding highlights the significance of anemia in CML-CP, and suggests that patients with anemia at diagnosis should be carefully monitored and might benefit from more potent TKIs if not achieving 3M-EMR.

Introduction of second-generation tyrosine kinase inhibitors may reduce the prognostic impact of high-risk patients, according to the European treatment and outcome study (EUTOS) score

Our study aims to highlight the critical role of the introduction of second generation tyrosine kinase inhibitors (2nd TKIs) on the prognosis of patients with chronic myeloid leukemia (CML) in chronic phase (CML-CP), as determined by European Treatment and Outcome Study (EUTOS) system. Patients who were diagnosed with CML-CP before March 2009 were classified into the imatinib group, and those diagnosed after April 2009 were classified into the 2nd TKI group. EUTOS high-risk patients exhibited significantly worse outcomes in terms of event-free survival (EFS), progression-free survival (PFS), and CML-associated death than those considered to be low-risk. Risk stratification by EUTOS score was predictive of risk-associated clinical outcomes in patients classified into the imatinib group; however, the EUTOS score failed to predict the outcomes of patients classified into the 2nd TKI group. Our data suggest that the introduction of 2nd TKIs might have improved treatment outcomes, particularly in EUTOS high-risk patients.

Insights into the management of chronic myeloid leukemia in resource-poor settings: a Mexican perspective

INTRODUCTION

The arrival of targeted therapy for chronic myeloid leukemia (CML) was revolutionary. However, due to the high cost of tyrosine kinase inhibitors, access to this highly effective therapy with strict monitoring strategies is limited in low to middle-income countries. In this context, following standard recommendations proposed by experts in developed countries is difficult. Areas covered: This review aims to provide an insight into the management of patients with CML living in a resource-limited setting. It addresses several issues: diagnosis, initial treatment, disease monitoring, and additional treatment alternatives including allogeneic hematopoietic stem cell transplantation. Expert commentary: Imatinib is probably the most cost-effective TKI for initial treatment in developing and underdeveloped countries. Generic imatinib preparations should be evaluated before considering their widespread use. Adherence to treatment should be emphasized. Adequate monitoring can be performed through several methods successfully and is important for predicting outcomes, particularly early in the first year, and if treatment suspension is being considered. Access to further therapeutic alternatives should define our actions after failure or intolerance to imatinib, preferring additional TKIs if possible. Allogeneic transplantation in chronic phase is a viable option in this context.

Predictive parameters for imatinib failure in patients with chronic myeloid leukemia

OBJECTIVE

Until recently, imatinib was the standard first-line treatment in chronic myeloid leukemia (CML). The inclusion of nilotinib and dasatinib as first-line options in CML raised a debate on treatment selection. The aim of our study was to analyze predictive parameters for imatinib response as the first-line treatment of CML patients.

METHODS

The study included 168 consecutive patients with chronic phase Philadelphia-positive CML who were diagnosed and treated with Imatinib 400 mg once daily at a single university hospital. Numerous parameters were analyzed in terms of imatinib response including comorbidities as well as occurrence of second malignancies.

RESULTS

After the median follow-up of 87 months in 61 patients (36.3%), the imatinib failure was verified. Cox regression analysis identified hepatomegaly (p = 0.001), leukocytosis ≥ 100 × 109/l (p = 0.001), blood blasts ≥ 1% (p = 0.002), and the presence of additional cytogenetic aberrations (p = 0.002) as predictors of Imatinib failure. Based on these findings, a new prognostic model was developed according to which imatinib failure had 17% (8/47) of patients in low risk, 34.9% (30/86) of patients in intermediate risk, and 76.7% (23/30) of patients in high-risk group (HR = 3.973, 95% CI for HR 2.237-7.053, p < 0.001).

CONCLUSION

The new score allows better selection of patients who are suitable for treatment with imatinib and may guideline the clinical decision for front-line treatment of CML.

Changing Treatment May Affect the Predictive Ability of European Treatment Outcome Study Scoring for the Prognosis of Patients with Chronic Myeloid Leukemia

Objective:

Previous studies compared the predictive ability of the European Treatment Outcome Study (EUTOS), Sokal, and Hasford scoring systems and demonstrated inconsistent findings with unknown reasons. This study was conducted to determine a useful scoring system to predict the prognosis of patients with chronic myeloid leukemia (CML) and identify the probable factors that affect the scoring.

Materials and Methods:

This is a retrospective cohort study. The predictive ability of EUTOS and the factors that affect scoring were analyzed in 234 Chinese chronic-phase CML patients treated with frontline imatinib, including a few patients temporarily administered hydroxyurea for cytoreduction before imatinib. Patients were stratified into different risk groups according to each scoring system to assess the treatment outcomes and the predictive ability of EUTOS scores between patients who received imatinib during the entire follow-up period and patients who received altered treatment because of intolerance, progression, and treatment failure.

Results:

Sixty-one (26.0%) patients received altered treatments during the follow-up. In the EUTOS low- and high-risk groups, the 5-year overall survival was 94.6% and 84.7% (p=0.011), 5-year event-free survival was 92.6% and 77.6% (p=0.001), and 5-year progression-free survival (PFS) was 95.3% and 82.4% (p=0.001), respectively. The predictive ability of EUTOS was better than that of the Sokal and Hasford scores (p=0.256, p=0.062, p=0.073) without statistical significance. All three scoring systems were valid in predicting early optimal response. Kaplan-Meier analysis showed a high association between overall PFS and the EUTOS scores in the standard-dose imatinib group (p<0.001).

Conclusion:

This study suggests that the EUTOS scoring system could predict the outcome of chronic-phase CML patients treated with standard-dose imatinib. Altered treatment is a crucial factor that affects the prognostic impact of EUTOS scoring. Achieving complete cytogenetic response at 18 months is an essential factor in predicting the prognosis of patients with CML.

Modelling Predictors of Molecular Response to Frontline Imatinib for Patients with Chronic Myeloid Leukaemia

BACKGROUND

Treatment of patients with chronic myeloid leukaemia (CML) has become increasingly difficult in recent years due to the variety of treatment options available and challenge deciding on the most appropriate treatment strategy for an individual patient. To facilitate the treatment strategy decision, disease assessment should involve molecular response to initial treatment for an individual patient. Patients predicted not to achieve major molecular response (MMR) at 24 months to frontline imatinib may be better treated with alternative frontline therapies, such as nilotinib or dasatinib. The aims of this study were to i) understand the clinical prediction 'rules' for predicting MMR at 24 months for CML patients treated with imatinib using clinical, molecular, and cell count observations (predictive factors collected at diagnosis and categorised based on available knowledge) and ii) develop a predictive model for CML treatment management. This predictive model was developed, based on CML patients undergoing imatinib therapy enrolled in the TIDEL II clinical trial with an experimentally identified achieving MMR group and non-achieving MMR group, by addressing the challenge as a machine learning problem. The recommended model was validated externally using an independent data set from King Faisal Specialist Hospital and Research Centre, Saudi Arabia.

PRINCIPLE FINDINGS

The common prognostic scores yielded similar sensitivity performance in testing and validation datasets and are therefore good predictors of the positive group. The G-mean and F-score values in our models outperformed the common prognostic scores in testing and validation datasets and are therefore good predictors for both the positive and negative groups. Furthermore, a high PPV above 65% indicated that our models are appropriate for making decisions at diagnosis and pre-therapy. Study limitations include that prior knowledge may change based on varying expert opinions; hence, representing the category boundaries of each predictive factor could dramatically change performance of the models.

The Hasford Score May Predict Molecular Response in Chronic Myeloid Leukemia Patients: A Single Institution Experience

The Sokal, Hasford, and EUTOS scores were established in different treatment eras of chronic myeloid leukemia (CML). None of them was reported to predict molecular response. In this single center study we tried to reevaluate the usefulness of three main scores in TKI era. The study group included 88 CML patients in first chronic phase treated initially with standard imatinib dose. All of them achieved major molecular response (MMR) in time points defined by European LeukemiaNet (ELN). 42 patients lost MMR in a median time of 47 months and we found a significant difference in MMR maintenance between intermediate-risk (IR) and low-risk (LR) patients assessed by Hasford score. All 42 patients were switched to second-generation TKI (2G-TKI) treatment. At 18 months of 2G-TKI therapy we have still found a significant difference in BCR-ABL transcript levels and MMR rate between IR and LR groups. We did not find any of the described differences discriminating patients by Sokal or EUTOS score. In this retrospective single center analysis we found Hasford score to be useful in predicting molecular response in first chronic phase of CML patients.

Making the diagnosis, the tools, and risk stratification: More than just BCR-ABL

The implementation of cytogenetic and molecular techniques into standard clinical practice has improved our ability to more accurately diagnose and monitor CML. Routine peripheral blood BCR-ABL transcript testing can help monitor response, predict outcome, and detect early resistance or poor adherence to TKI therapy. The widely-used Sokal, Hasford and EUTOS clinical risk stratification scores were developed in patients receiving chemotherapy, interferon and imatinib, respectively; their predictive ability in patients receiving next-generation tyrosine kinase inhibitors (TKIs) remains to be established. Newer more sensitive molecular techniques are being developed that may aid in the expanding emphasis on discontinuing therapy in patients with a deep and consistent molecular response.

Prognostic and predictive implications of Sokal, Euro and EUTOS scores in chronic myeloid leukaemia in the imatinib era-experience from a tertiary oncology centre in Southern India

Chronic myeloid leukaemia (CML) is a myeloproliferative disorder. Over the years many prognostic models have been developed to better risk stratify this disease at baseline. Sokal, Euro, and EUTOS scores were developed in varied populations initially receiving various therapies. Here we try to identify their predictive and prognostic implication in a larger population of Indian patients with CML-CP (chronic phase) in the imatinib era.

Role of tyrosine-kinase inhibitors in myeloproliferative neoplasms: comparative lessons learned

An important pathogenetic distinction in the classification of myeloproliferative neoplasms (MPNs) is the presence or absence of the BCR–ABL fusion gene, which encodes a unique oncogenic tyrosine kinase. The BCR–ABL fusion, caused by the formation of the Philadelphia chromosome (Ph) through translocation, constitutes the disease-initiating event in chronic myeloid leukemia. The development of successive BCR–ABL-targeted tyrosine-kinase inhibitors has led to greatly improved outcomes in patients with chronic myeloid leukemia, including high rates of complete hematologic, cytogenetic, and molecular responses. Such levels of treatment success have long been elusive for patients with Ph-negative MPNs, because of the difficulties in identifying specific driver proteins suitable as drug targets. However, in recent years an improved understanding of the complex pathobiology of classic Ph-negative MPNs, characterized by variable, overlapping multimutation profiles, has prompted the development of better and more broadly targeted (to pathway rather than protein) treatment options, particularly JAK inhibitors. In classic Ph-negative MPNs, overactivation of JAK-dependent signaling pathways is a central pathogenic mechanism, and mutually exclusive mutations in JAK2, MPL, and CALR linked to aberrant JAK activation are now recognized as key drivers of disease progression in myelofibrosis (MF). In clinical trials, the JAK1/JAK2 inhibitor ruxolitinib – the first therapy approved for MF worldwide – improved disease-related splenomegaly and symptoms independent of JAK2^V617F mutational status, and prolonged survival compared with placebo or standard therapy in patients with advanced MF. In separate trials, ruxolitinib also provided comprehensive hematologic control in patients with another Ph-negative MPN – polycythemia vera. However, complete cytogenetic or molecular responses with JAK inhibitors alone are normally not observed, underscoring the need for novel combination therapies of JAK inhibitors and complementary agents that better address the complexity of the pathobiology of classic Ph-negative MPNs. Here, we discuss the role of tyrosine-kinase inhibitors in the current MPN-treatment landscape.

Selecting the best frontline treatment in chronic myeloid leukemia

With the discovery of Philadelphia chromosome, understanding of chronic myeloid leukemia (CML) pathobiology has tremendously increased. Development of tyrosine kinase inhibitors (TKI) targeting the BCR/ABL1 oncoprotein has changed the landscape of the disease. Today, the expected survival of CML patients, if properly managed, is likely to be similar to the general population. Imatinib is the first-approved TKI in CML treatment, and for several years, it was the only option in the frontline setting. Four years ago, second-generation TKIs (nilotinib and dasatinib) were approved as alternative frontline options. Now, clinicians are faced the challenge of making decision for which TKI to chose upfront. Second-generation TKIs have been demonstrated to induce deeper and faster responses compared to imatinib; however, none of three TKIs have been shown to have a clear survival advantage, they all are reasonable options. In contrast, when considering therapy in individual patients, the case may be stronger for a specific TKI. Co-morbidities of the patient and side effect profile of the TKI of interest should be an important consideration in decision making. At present, the cost nilotinib or dasatinib is not remarkably different from imatinib. However, patent for imatinib is expected to expire soon, and it will be available as a generic. Clinicians, then, need to weigh the advantages some patients gain with nilotinib or dasatinib in the frontline setting against the difference in cost. Whatever TKI is chosen as frontline, intolerance, non-compliance, or treatment failure should be recognized early as a prompt intervention increases the chance of achieving best possible response.

Combination of White Blood Cell Count at Presentation With Molecular Response at 3 Months Better Predicts Deep Molecular Responses to Imatinib in Newly Diagnosed Chronic-Phase Chronic Myeloid Leukemia Patients

The aim of this study was to evaluate the impact of white blood cell (WBC) counts at presentation on the achievement of deep molecular response.A total of 362 newly diagnosed chronic-phase chronic myeloid leukemia patients (CML-CP) receiving 400 mg/day imatinib were serially monitored for a median of 36 months (range 6-115).Patients showing an optimal response at 3, 6, and 12 months as defined by the 2013 European LeukemiaNet recommendations had significantly lower WBC counts at presentation than those showing nonoptimal responses (all P < 0.0001). Among the cutoff values with a similar Youden index, 150 × 10E9/L (abbreviated WBC > 150) was selected to identify the greatest amount of patients with the potential to achieve a sustained molecular response of 4.5 (MR4.5). Regardless of whether the Sokal risk score was included, the BCR-ABL value at 3 months, WBC counts at presentation, hemoglobin levels, and sex were the common independent predictors for an MR4.5, with the former 2 presenting the highest hazard risk. Low Sokal risk scores did not independently predict the achievement of an MR4.5. Patients with concurrent WBC > 150 and BCR-ABL(IS) ≤ 10% had a similar incidence of 4-year MR4.5 compared with patients with concurrent WBC ≤ 150 and BCR-ABL(IS) > 10% and concurrent WBC > 150 and BCR-ABL(IS) > 10% (13.5% vs 13.2% vs 8.8%, P = 0.47), and all of these values were significantly lower than the values for patients with concurrent WBC ≤ 150 and BCR-ABL(IS) ≤ 10% (55.0%, all P < 0.0001). Patients with concurrent WBC ≤ 150 and BCR-ABL(IS) ≤ 10% had better 4-year event-free survival rates, progression-free survival rates, and overall survival rates compared with patients with WBC > 150 or BCR-ABL(IS) > 10%. The combination of WBC count at presentation and BCR-ABL(IS) at 3 months provides improved predictions of deep molecular response in imatinib-treated CML-CP patients. Therefore, the WBC count at presentation might be used to differentiate patients at the beginning of imatinib treatment.

Diagnosis and Treatment of Chronic Myeloid Leukemia in 2015

Few neoplastic diseases have undergone a transformation in a relatively short period like chronic myeloid leukemia (CML) has in the last few years. In 1960, CML was the first cancer in which a unique chromosomal abnormality was identified and a pathophysiologic correlation suggested. Landmark work followed, recognizing the underlying translocation between chromosomes 9 and 22 that gave rise to this abnormality and, shortly afterward, the specific genes involved and the pathophysiologic implications of this novel rearrangement. Fast forward a few years and this knowledge has given us the most remarkable example of a specific therapy that targets the dysregulated kinase activity represented by this molecular change. The broad use of tyrosine kinase inhibitors has resulted in an improvement in the overall survival to the point where the life expectancy of patients today is nearly equal to that of the general population. Still, there are challenges and unanswered questions that define the reasons why the progress still escapes many patients, and the details that separate patients from ultimate cure. In this article, we review our current understanding of CML in 2015, present recommendations for optimal management, and discuss the unanswered questions and what could be done to answer them in the near future.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Diagnosing and managing advanced chronic myeloid leukemia

Clinical staging of chronic myeloid leukemia (CML) distinguishes between chronic phase (CP-CML), accelerated phase (AP-CML), and blastic phase (BP-CML), reflecting its natural history in the absence of effective therapy. Morphologically, transformation from CP-CML to AP/BP-CML is characterized by a progressive or sudden loss of differentiation. Multiple different somatic mutations have been implicated in transformation from CP-CML to AP/BC-CML, but no characteristic mutation or combination of mutations have emerged. Gene expression profiles of AP-CML and BP-CML are similar, consistent with biphasic evolution at the molecular level. Gene expression of tyrosine kinase inhibitor (TKI)-resistant CP-CML and second CP-CML resemble AP/BP-CML, suggesting that morphology alone is a poor predictor of biologic behavior. At the clinical level, progression to AP/BP-CML or resistance to first-line TKI therapy distinguishes a good risk condition with survival close to the general population from a disease likely to reduce survival. Progression while receiving TKI therapy is frequently caused by mutations in the target kinase BCR-ABL1, but progression may occur in the absence of explanatory BCR-ABL1 mutations, suggesting involvement of alternative pathways. Identifying patients in whom milestones of TKI response fail to occur or whose disease progress while receiving therapy requires appropriate molecular monitoring. Selection of salvage TKI depends on prior TKI history, comorbidities, and BCR-ABL1 mutation status. Despite the introduction of novel TKIs, therapy of AP/BP-CML remains challenging and requires accepting modalities with substantial toxicity, such as hematopoietic stem cell transplantation (HSCT).

Improved prediction of clinical outcome in chronic myeloid leukemia

We sought to develop and compare prognostic models, based on clinical and/or morphometric diagnostic data, to enable better prediction of complete cytogenetic response (CCgR). This prospective longitudinal study included a consecutive series of patients with chronic myeloid leukemia (CML) who were started on imatinib therapy. Logistic regression analysis using backward selection was performed with CCgR at 6, 12, and 18 months as the outcome variables. We evaluated both calibration and discrimination of the model. Internal validation of the model was performed with bootstrapping techniques. A total of 40 patients on imatinib therapy were included in the final analysis. Of these, 25 (62.5 %), 29 (72.5 %), and 32 (80 %), respectively, achieved CCgR at 6, 12, and 18 months after initiation of imatinib. Models included EUTOS score on diagnosis and one of the following morphometric parameters: microvascular density, length of the minor axis, area or circularity of the blood vessel. Models including morphometric parameters and EUTOS score were superior for prediction of CCgR at 6, 12, and 18 months. In particular, the superior models showed better specificity than EUTOS score alone. Using morphometric parameters in conjunction with EUTOS score improves prediction of CCgR. If validated, these models could aid in individual patient risk stratification.

Serum-tryptase at diagnosis: a novel biomarker improving prognostication in Ph(+) CML

Basophilia is an established prognostic variable in Ph-chromosome+ chronic myeloid leukemia (CML). However, in CML, basophils are often immature and thus escape microscopic quantification. We have previously shown that tryptase is produced and secreted by immature CML basophils. In the current study, serum samples of 79 CML patients (chronic phase=CP, n=69; accelerated/blast phase=AP/BP, n=10) treated with BCR/ABL inhibitors, were analyzed for their tryptase content. Serum-tryptase levels at diagnosis were found to correlate with basophil counts and were higher in AP/BP patients (median tryptase: 29.9 ng/mL) compared to patients with CP (11.7 ng/mL; p<0.05). In 20/69 patients with CP, progression occurred. The progression-rate was higher in patients with tryptase >15 ng/mL (31%) compared to those with normal tryptase levels (9%, p<0.05). To validate tryptase as new prognostic variable, we replaced basophils by tryptase levels in the EUTOS score. This modified EUTOS-T score was found to predict progression-free and event-free survival significantly better, with p values of 0.000064 and 0.00369, respectively, compared to the original EUTOS score (progression-free survival: p=0.019; event-free survival: p=0.156). In conclusion, our data show that the serum-tryptase level at diagnosis is a powerful prognostic biomarker in CML. Inclusion of tryptase in prognostic CML scores may improve their predictive value.

The European Treatment and Outcome Study score is associated with clinical outcomes and treatment response following European LeukemiaNet 2013 recommendations in chronic-phase chronic myeloid leukemia

The introduction of tyrosine kinase inhibitors has dramatically improved outcomes for many patients with chronic myeloid leukemia (CML), but some cases are resistant to this treatment. To compare the prognostic performance of Sokal, Hasford, and European Treatment and Outcome Study (EUTOS) scores, patient outcomes and treatment responses were investigated following the European LeukemiaNet (ELN) 2013 recommendations. Seventy-three patients with newly diagnosed chronic-phase CML (CML-CP) treated with any tyrosine kinase inhibitor as initial therapy were analyzed. All scoring systems significantly predicted treatment response at 3 and 6 months; however, only the EUTOS score significantly predicted treatment response at 12 months, following the ELN 2013 recommendations. The 5-year event-free survival rates were 93 and 35 % in the low- and high-risk groups according to the EUTOS score (P < 0.0001). Moreover, the 5-year overall survival rates were 98 and 51 % in the low- and high-risk groups by EUTOS score (P < 0.0001). We suggest that the EUTOS score may provide a better stratification of CML-CP patients for predicting treatment response.

Response to tyrosine kinase inhibitors in chronic myeloid leukemia: experience from a west Asian developing country

Tyrosine Kinase inhibitors (TKIs) have dramatically changed the prospects for patients with chronic myeloid leukemia (CML); however, information on CML and response to TKIs from Asia are limited, particularly from West Asia, including Iraq. To address the latter issue we evaluated and monitored a cohort of 108 Iraqi patients diagnosed as chronic phase-CML, enrolled in a government-sponsored national program. The patients were all treated initially by imatinib mesylate. Ninety-two percent of patients had a complete hematological response, 38% had a major molecular response, while 79% had a major cytogenetic response after a median follow-up of 35.7 months. The 3-year Event-Free, Progression-Free, and Overall survival rates were 79.6, 87 and 98.1%, respectively. A total of 26 patients (24.1%) were shifted to an alternative TKI (Nilotinib). After one year of therapy in seventeen of the latter patients, 24% had major molecular response. In conclusion, our results compare favorably with those reported from the West and some Asian countries, and have demonstrated the importance of molecular as well as cytogenetic monitoring, and confirmed the relative success of the national CML program in our country.

European Treatment and Outcome Study score does not predict imatinib treatment response and outcome in chronic myeloid leukemia patients

The Sokal and Hasford scores were developed in the chemotherapy and interferon era and are widely used as prognostic indicators in patients with chronic myeloid leukemia (CML). Recently, a new European Treatment and Outcome Study (EUTOS) scoring system was developed. We performed a multicenter retrospective study to validate the effectiveness of each of the three scoring systems. The study cohort included 145 patients diagnosed with CML in chronic phase who were treated with imatinib. In the EUTOS low- and high-risk groups, the cumulative incidence of complete cytogenetic response (CCyR) at 18 months was 86.9% and 87.5% (P = 0.797) and the 5-year overall survival rate was 92.6% and 93.3% (P = 0.871), respectively. The cumulative incidence of CCyR at 12 months, 5-year event-free survival and 5-year progression-free survival were not predicted using the EUTOS scoring system. However, there were significant differences in both the Sokal score and Hasford score risk groups. In our retrospective validation study, the EUTOS score did not predict the prognosis of patients with CML in chronic phase treated with imatinib.

EUTOS score predicts long-term outcome but not optimal response to imatinib in patients with chronic myeloid leukaemia

To test the recently developed EUTOS score in predicting optimal response to imatinib and the long-term outcome, 265 patients with early chronic phase chronic myeloid leukaemia treated with standard dose imatinib were analysed. Achievement of optimal response endpoints were higher in low-risk patients, though the difference was not statistically significant: PCyR at 6th month 86% vs 67% (p=0.06), CCyR at 12th month 80% vs 63% (p=0.09), MMR at 18th month 61% vs 36% (p=0.11). However, EUTOS score was predictive for the long-term response. With a median follow-up of 61 months, 53% high-risk patients experienced imatinib failure, compared to 23% in the low-risk group (p=0.013). Among high-risk patients, 4/17 (23%) progressed to accelerated/blastic phase or died, compared to 11/248 (5%) low-risk patients, with 5-year progression-free survival rates of 84±10% and 96±1%, respectively (p=0.04). Our data confirm that EUTOS score envisions the long-term outcome of imatinib therapy.

Biomarkers for determining the prognosis in chronic myelogenous leukemia

The introduction of BCR-ABL1 tyrosine kinase inhibitors (TKIs) for treatment of chronic myelogenous leukemia in chronic phase (CML-CP) has revolutionized therapy, altering the outcome from one of shortened life expectancy to long-term survival. With over 10 years of long-term treatment with imatinib and several years of experience with the next generation of TKIs, including nilotinib, dasatinib, bosutinib, and ponatinib, it is becoming clear that many clinical parameters have great impact on the prognosis of patients with CML. Emerging novel gene expression profiling and molecular techniques also provide new insights into CML pathogenesis and have identified potential prognostic markers and therapeutic targets. This review presents the supporting data and discusses how certain clinical characteristics at diagnosis, the depth of early response, the presence of certain kinase domain mutations, and additional molecular changes serve as prognostic factors that may guide individualized treatment decisions for patients with CML-CP.

Tyrosine kinase inhibitor usage, treatment outcome, and prognostic scores in CML: report from the population-based Swedish CML registry

Clinical management guidelines on malignant disorders are generally based on data from clinical trials with selected patient cohorts. In Sweden, more than 95% of all patients diagnosed with chronic myeloid leukemia (CML) are reported to the national CML registry, providing unique possibilities to compile population-based information. This report is based on registry data from 2002 to 2010, when a total of 779 patients (425 men, 354 women; median age, 60 years) were diagnosed with CML (93% chronic, 5% accelerated, and 2% blastic phase) corresponding to an annual incidence of 0.9/100,000. In 2002, approximately half of the patients received a tyrosine kinase inhibitor as initial therapy, a proportion that increased to 94% for younger (<70 years) and 79% for older (>80 years) patients during 2007-2009. With a median follow-up of 61 months, the relative survival at 5 years was close to 1.0 for patients younger than 60 years and 0.9 for those aged 60 to 80 years, but only 0.6 for those older than 80 years. At 12 months, 3% had progressed to accelerated or blastic phase. Sokal, but not European Treatment and Outcome Study, high-risk scores were significantly linked to inferior overall and relative survival. Patients living in university vs nonuniversity catchment areas more often received tyrosine kinase inhibitors up front but showed comparable survival.

The EUTOS prognostic score: review and validation in 1288 patients with CML treated frontline with imatinib

The introduction of tyrosine kinase inhibitors (TKI) in the treatment of Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML) has revolutionized the outcome, but the prognosis of the disease is still based on prognostic systems that were developed in the era of conventional chemotherapy and interferon (IFN)-alfa. A new prognostic score including only two variables, spleen size and basophils, was developed for the prediction of complete cytogenetic response (CCyR) and progression-free survival (PFS). The score was based on a large series of patients who were enrolled in prospective multicenter studies of first-line imatinib treatment. The prognostic value of the EUTOS (European Treatment and Outcome Study for CML) score has now been tested in an independent, multicenter, multinational series of 1288 patients who were treated first-line with imatinib outside prospective studies. It was found that also in these patients, the EUTOS prognostic score was predictive for CCyR, PFS and overall survival (OS). In addition, the prognostic value of the score was reported to be significant in seven of the eight other independent studies of almost 2000 patients that were performed in Europe, the Americas and Asia. The EUTOS risk score is a valid tool for the prediction of the therapeutic effects of TKI, particularly imatinib.

EUTOS CML prognostic scoring system predicts ELN-based 'event-free survival' better than Euro/Hasford and Sokal systems in CML patients receiving front-line imatinib mesylate

OBJECTIVES

The validity of the three currently used chronic myeloid leukemia (CML) scoring systems (Sokal CML prognostic scoring system, Euro/Hasford CML scoring system, and the EUTOS CML prognostic scoring system) were compared in the CML patients receiving frontline imatinib mesylate.

PATIENTS AND METHODS

One hundred and fourty-three chronic phase CML patients (71 males, 72 females) taking imatinib as frontline treatment were included in the study. The median age was 44 (16-82) years. Median total and on-imatinib follow-up durations were 29 (3.8-130) months and 25 (3-125) months, respectively.

RESULTS

The complete hematological response (CHR) rate at 3 months was 95%. The best cumulative complete cytogenetic response (CCyR) rate at 24 months was 79.6%. Euro/Hasford scoring system was well-correlated with both Sokal and EUTOS scores (r = 0.6, P < 0.001 and r = 0.455, P < 0.001). However, there was only a weak correlation between Sokal and EUTOS scores (r = 0.2, P = 0.03). The 5-year median estimated event-free survival for low and high EUTOS risk patients were 62.6 (25.7-99.5) and 15.3 (7.4-23.2) months, respectively (P < 0.001). This performance was better than Sokal (P = 0.3) and Euro/Hasford (P = 0.04) scoring systems. Overall survival and CCyR rates were also better predicted by the EUTOS score.

DISCUSSION

EUTOS CML prognostic scoring system, which is the only prognostic system developed during the imatinib era, predicts European LeukemiaNet (ELN)-based event-free survival better than Euro/Hasford and Sokal systems in CML patients receiving frontline imatinib mesylate. This observation might have important clinical implications.

How I treat newly diagnosed chronic phase CML

The progress made in the understanding of chronic myeloid leukemia (CML) since the recognition of a common chromosomal abnormality to the introduction of ever more effective tyrosine kinase inhibitors is unprecedented in cancer. The expected survival for patients diagnosed with CML today, if properly managed, is probably similar to that of the general population. When managing patients with CML the goal is to achieve the best long-term outcome and we should base the treatment decisions on the data available. The results from cytogenetic and molecular analyses have to be interpreted judiciously and all available treatment options integrated into the treatment plan properly. The availability of several treatment options in CML is an asset, but the temptation of rapid succession of treatment changes because of perceived suboptimal response or for adverse events that could be managed needs to be avoided. Any decision to change therapy needs to weigh the expected long-term outcome with the current option versus the true expectations with any new option, particularly as it relates to irreversible outcomes, such as transformation to blast phase and death. In this manuscript, we discuss the treatment approach that has helped us manage successfully a large CML population.