Targeting MET: Discovery of Small Molecule Inhibitors as Non-Small Cell Lung Cancer Therapy

MET has been considered as a promising drug target for the treatment of MET-dependent diseases, particularly non-small cell lung cancer (NSCLC). Small molecule MET inhibitors with mainly three types of binding modes (Ia/Ib, II, and III) have been developed. In this Review, we provide an overview of the structural features, activation mechanism, and dysregulation pathway of MET and summarize progress on the development and discovery strategies utilized for MET inhibitors as well as mechanisms of acquired resistance to current approved inhibitors. The insights will accelerate discovery of new generation MET inhibitors to overcome clinical acquired resistance.

Use of copula to model within-study association in bivariate meta-analysis of binomial data at the aggregate level: A Bayesian approach and application to surrogate endpoint evaluation

Bivariate meta-analysis provides a useful framework for combining information across related studies and has been utilized to combine evidence from clinical studies to evaluate treatment efficacy on two outcomes. It has also been used to investigate surrogacy patterns between treatment effects on the surrogate endpoint and the final outcome. Surrogate endpoints play an important role in drug development when they can be used to measure treatment effect early compared to the final outcome and to predict clinical benefit or harm. The standard bivariate meta-analytic approach models the observed treatment effects on the surrogate and the final outcome outcomes jointly, at both the within-study and between-studies levels, using a bivariate normal distribution. For binomial data, a normal approximation on log odds ratio scale can be used. However, this method may lead to biased results when the proportions of events are close to one or zero, affecting the validation of surrogate endpoints. In this article, we explore modeling the two outcomes on the original binomial scale. First, we present a method that uses independent binomial likelihoods to model the within-study variability avoiding to approximate the observed treatment effects. However, the method ignores the within-study association. To overcome this issue, we propose a method using a bivariate copula with binomial marginals, which allows the model to account for the within-study association. We applied the methods to an illustrative example in chronic myeloid leukemia to investigate the surrogate relationship between complete cytogenetic response and event-free-survival.

Evaluation of the outcomes in patients with chronic myeloid leukemia treated with imatinib in 18-year follow-up

The objective of this paper is to examine the effects of Imatinib on patients who are at the chronic phase of chronic myeloid leukemia (CML). Method: Totally, 79 patients with CML who received the treatment between 2003 and 2020 entered the study. The patients were evaluated in terms of molecular response rate and overall survival (OS). Results: About 75.9% of patients achieved deep molecular response in mean follow-up of 89.92 months. The OS rate was about 91.2%. Conclusion: There was no considerable cumulative toxicity with Imatinib long-term use. A high percent of patients had a deep molecular response.

Association Between Glutathione-S-Transferase Gene Polymorphisms and Responses to Tyrosine Kinase Inhibitor Treatment in Patients with Chronic Myeloid Leukemia: A Meta-analysis

BACKGROUND

Although many earlier studies revealed an effect of glutathione-S-transferase (GST) gene polymorphisms on tyrosine kinase inhibitor (TKI) treatment responses in chronic myeloid leukemia (CML) patients, the significance of this relationship remains controversial.

OBJECTIVE

This study aimed to review and meta-analyze treatment responses to TKIs in patients with CML and GST gene polymorphisms, including GSTT1, GSTM1, and GSTP1.

PATIENTS AND METHODS

We searched four medical databases, PubMed, Web of Science, the Cochrane Library, and Embase, by using keywords related to GST gene polymorphisms and clinical responses in CML patients receiving TKI treatment. The meta-analysis was performed using RevMan version 5.3 and Comprehensive Meta-Analysis software version 3.0. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to examine the association between GSTT1, GSTM1, and GSTP1 polymorphisms and TKI treatment responses in patients with CML.

RESULTS

The null polymorphisms of GSTT1 and GSTM1 did not affect TKI treatment responses, while the GSTP1 Ile105Val polymorphism had a significant impact on responses to TKI. Patients who were GSTP1 variant allele carriers (AG + GG) had poor responses to TKI treatment compared to patients who were wild-type homozygote carriers (AA) (OR 1.85, 95% CI 1.31-2.62; p < 0.001).

CONCLUSIONS

This meta-analysis of patients with CML showed that G allele carriers with GSTP1 Ile105Val polymorphism had significantly worse responses to TKI treatment than wild-type homozygote carriers.

The impact of introducing tyrosine kinase inhibitors on chronic myeloid leukemia survival: a population-based study

BACKGROUND

Chronic myeloid leukemia is associated with a BCR/ABL oncoprotein inhibited by imatinib mesylate, the first tyrosine kinase inhibitor. Although experimental studies have clearly demonstrated the efficacy of imatinib, up-to-date data on its effectiveness at the population level are limited. Our study aims to assess the change in disease-specific survival for chronic myeloid leukemia after introducing tyrosine kinase inhibitors in first-line treatment.

METHODS

This study analyzed data from two population-based cancer registries in Italy. Disease-specific survival for chronic myeloid leukemia cases diagnosed before and after the introduction of tyrosine kinase inhibitors (February 2002) were calculated up to 10 years. Hazard ratios were calculated using Cox regression models adjusted for sex, age at diagnosis and residency. An interrupted time series analysis was also performed.

RESULTS

Between 1996 and 2012, 357 new cases of chronic myeloid leukemia were diagnosed (standardized incidence rate of 1.2 per 100,000 residents), quite constant throughout the period. The interrupted time series analysis showed a gain of 40.4% in 5 years of disease-specific survival for chronic myeloid leukemia (from 47.3, 95%CI 38.5-55.5% to 80.8%, 95%CI 74.5-85.8%) after the introduction of tyrosine kinase inhibitors. The hazard ratio was 0.36 (95%CI 0.25-0.52) for cases diagnosed after tyrosine kinase inhibitor introduction, with differences per age at diagnosis: <65yo 0.17 (95%CI 0.08-0.39), >74yo 0.41 (95%CI 0.23-0.73). An improvement in survival (hazard ratio 0.66, 95%CI 0.36-1.20) was also observed in cases diagnosed before, and alive at, tyrosine kinase inhibitors introduction.

CONCLUSIONS

Tyrosine kinase inhibitors increased disease-specific survival both for new and prevalent chronic myeloid leukemia cases. The effectiveness was similar to that observed in trials only in patients ages 65 years or younger.

Cutaneous myeloid sarcoma associated with chronic myeloid leukemia

Myeloid sarcoma is an extramedullary tumor of malignant myeloid cells often associated with acute myeloid leukemia, chronic myeloproliferative disorders and myelodysplastic syndromes. The skin is one of the most commonly affected sites. We report a rare case of cutaneous myeloid sarcoma associated with chronic myeloid leukemia.

Mobile Health Intervention to Increase Oral Cancer Therapy Adherence in Patients With Chronic Myeloid Leukemia (The REMIND System): Clinical Feasibility and Acceptability Assessment

Background

Optimal dosing of oral tyrosine kinase inhibitor therapy is critical to treatment success and survival of patients with chronic myeloid leukemia (CML). Drug intolerance secondary to toxicities and nonadherence are significant factors in treatment failure.

Objective

The objective of this study was to develop and pilot-test the clinical feasibility and acceptability of a mobile health system (REMIND) to increase oral drug adherence and patient symptom self-management among people with CML (chronic phase).

Methods

A multifaceted intervention was iteratively developed using the intervention development framework by Schofield and Chambers, consisting of defining the patient problem and iteratively refining the intervention. The clinical feasibility and acceptability were examined via patient and intervention nurse interviews, which were audiotaped, transcribed, and deductively content analyzed.

Results

The intervention comprised 2 synergistically operating elements: (1) daily medication reminders and routine assessment of side effects with evidence-based self-care advice delivered in real time and (2) question prompt list (QPL) questions and routinely collected individual patient adherence and side effect profile data used to shape nurses’ consultations, which employed motivational interviewing to support adoption of self-management behaviors. A total of 4 consultations and daily alerts and advice were delivered over 10 weeks. In total, 58% (10/17) of patients and 2 nurses participated in the pilot study. Patients reported several benefits of the intervention: help in establishing medication routines, resolution of symptom uncertainty, increased awareness of self-care, and informed decision making. Nurses also endorsed the intervention: it assisted in establishing pill-taking routines and patients developing effective solutions to adherence challenges.

Conclusions

The REMIND system with nurse support was usable and acceptable to both patients and nurses. It has the potential to improve adherence and side-effect management and should be further evaluated.

Neuroendocrine tumor of cecum in patient treated with imatinib mesylate for blastic phase of chronic myeloid leukemia

Imatinib mesylate (IM), a tyrosine kinase inhibitor, is the treatment of choice in patients with chronic myeloid leukemia (CML). It is considered a very safe drug, with mostly mild and reversible side effects. Lately, it has been suggested that adverse events may occur after a long term. We report a case of a 72-year-old woman diagnosed with blastic phase of Philadelphia chromosome positive CML treated with IM for 28 months. The patient presented first with ascites as a side effect of the drug. When the ascites re-occurred, it was caused by neuroendocrine tumor (NET) with peritoneal carcinomatosis. We believe this is the first case of a NET as a secondary malignancy (SM) after IM treatment. SM have been described in patients on IM before. It is unclear whether these tumors are caused by imatinib or found more easily because of close follow-up.

New Genetic Variation in BCR gene of Major B3a2 Breakpoint BCR-ABL Fusion Gene in Patients with Chronic Myelogenous Leukemia in Yogyakarta, Indonesia

Background: Polymorphic bases in several exons of the BCR gene have been found in several studies of the BCR-ABL fusion gene . Most of the polymorphisms do not have any implications for the primary structure of the BCR-ABL protein. Nucleotide changes are often located in the area close to the fusion region, and therefore may influence primer annealing. Our previous work failed to amplify 15 of 200 samples from BCR-ABL positive chronic myelogenous leukemia (CML) patients using multiplex PCR, the standard method to detect BCR-ABL transcripts used in our institution. The failure was considered due to problems in primer annealing caused by sequence variations. Sequence analysis of BCR-ABL fusion gene breakpoint types in CML patients has never been hitherto performed in Indonesia. Therefore, the aim of this study was to perform sequence analysis of several samples that did not show amplification using the standard method. Methods: Fifteen samples were qualitatively amplified by two-step PCR using inner primers in the 2nd PCR to determine the breakpoint type of the BCR-ABL fusion gene. The 2nd PCR products were used as templates to perform sequence analysis, and the results were compared to those in genbank. Result: Seven and 5 of 15 samples were confirmed as major b3a2 and major b2a2, respectively. One sample featured a combination of b3a2 and b2a2, and 2 samples a combination of b3a2 and b2a2 with an additional fragment at 500bp. Sequence analysis showed 3 sequence variations in the major b3a2 breakpoint. One had been reported earlier (c.3296T>C) but the others (c.3245C>T and c.3359T>C) were novel. Fragments at 500bp were confirmed as b3a2 and similar sequence b3a2 in genbank. Conclusion: This study found two new genetic variations in the BCR gene in BCR-ABL fusion cases.

The Impact of Recent Generic Drug Price Policies on Pharmaceutical Innovation: A Theoretical Rationale and Proposal of a Method Supporting Innovation in Areas of Unmet Medical Need

New discoveries are a critical priority for the pharmaceutical industry. However, the use of fixed incremental cost-effectiveness (ICER) thresholds for health technology assessment (HTA) may compromise incentives to innovate and affect future treatment options. This paper highlights the impact of generic drug price policies on pharmaceutical innovation in the context of fixed ICER thresholds and proposes a new consideration for the cost-effectiveness analysis (CEA). There is a direct causal relationship between HTA and the market price of a drug; in jurisdictions where HTA agencies apply fixed ICER thresholds as an important reimbursement listing criterion, the incremental cost of a new drug is expected to be proportional to its incremental benefit over the comparator. However, the comparator price is subject to market forces or sudden policies and may change markedly affecting the cost-effectiveness assessment (e.g. where the comparator patent has expired). Since recent generic price regulations increased the price gap between drugs' generic and patented versions, it is harder to achieve a sufficient level of incremental benefits in order to offset incremental prices of new treatments. Consequently, even promising drugs may have challenges to show attractive ICERs and research and development (R&D) investments may become unattractive in certain disease area. In order to promote innovation in therapeutic fields with unmet medical needs, a compromise would be to include the comparator's patented price in the CEA instead of the generic drug. By identifying the relevant disease areas, decision makers and HTA authorities could therefore convey the importance of investing in these therapeutic areas to manufacturers.

Health-related quality of life during bosutinib (SKI-606) therapy in patients with advanced chronic myeloid leukemia after imatinib failure

OBJECTIVES

The tyrosine kinase inhibitor (TKI) bosutinib has demonstrated activity in patients with advanced phase chronic myeloid leukemia (CML), but effects on health-related quality of life (HRQoL) remain unexplored. This study evaluated HRQoL in advanced CML patients receiving bosutinib in an ongoing phase 2 study following resistance or intolerance to prior imatinib therapy.

METHODS

This analysis included data from 76 accelerated-phase (AP) and 64 blast-phase (BP) patients resistant/intolerant to prior imatinib with or without prior exposure to other TKIs. Patient-reported HRQoL assessments completed at baseline; weeks 4, 8, and 12; every 12 weeks thereafter; and at treatment completion included the Functional Assessment of Cancer Therapy-Leukemia (FACT-Leu); general health status was assessed using the 5-item EuroQol (EQ-5D) instrument and a visual analog scale (VAS).

RESULTS

HRQoL at baseline was somewhat worse in BP versus AP CML patients. There was a significant improvement in the mean FACT-Leu Total scale at weeks 24, 36, and 48 in AP CML patients and at weeks 4, 8, 12, 24, 36, 48, and 96 in BP CML patients compared with baseline. EQ-5D Utility scores were stable throughout treatment in AP CML patients but significantly improved versus baseline in BP CML patients at weeks 4, 8, 12, and 36. Mean VAS scores were significantly improved at weeks 8, 36, and 48 in AP CML patients and at weeks 4, 8, 12, 24, 36, and 96 in BP CML patients. The lack of a comparison group limits attribution of improvements in HRQoL specifically to bosutinib treatment; potential bias due to non-ignorable dropout may limit the ability to generalize these findings to situations where durations of therapy exceed the 96-week follow-up duration of the present study.

CONCLUSION

These findings suggest that bosutinib therapy is associated with improved HRQoL in advanced phase CML patients.

CLINICAL TRIAL REGISTRATION

NCT00261846.

Management of advanced-phase chronic myeloid leukemia

The management of chronic myeloid leukemia (CML) in accelerated or blast phase (advanced phase) remains a significant challenge despite the introduction of very effective tyrosine kinase inhibitors (TKIs). The biology of advanced-phase CML is complex and engages several pathways that are not optimally targeted by TKIs. Allogeneic stem cell transplantation remains the only potentially curative therapy, but the effectiveness of this conventional approach is limited. New strategies are required to improve the outlook for these patients.

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.

Spontaneous Soft Tissue Haematomas- A Rare Presentation of Chronic Myeloid Leukemic (CML)

Spontaneous soft tissue haematomas are rarely found in haematological malignancies. Chronic myeloid leukemia (CML) is a myeloproliferative disorder which rarely present with thrombo-haemorrhagic phenomenon. It is a malignant clonal disorder of pleuripotent stem cells that results in increase in myeloid, erythroid and platelets cells in peripheral blood and marked myeloid hyperplasia in bone marrow. It is characterized by the presence of Philadelphia chromosome (Ph) with BCR - ABL 1 fusion gene. This gene is responsible for the formation of 210 KDa chimeric proteins with enhanced tyrosine kinase activity which leads to the abnormal bone marrow cell proliferation and to the clinical and morphologic manifestations of leukemia. Cutaneous and mucous membrane bleeding is common in CML whereas bleeding in deep soft tissue is rarely found because of qualitative and quantitative platelet abnormalities. Here, we report a case of CML (BCR-ABL rearrangement positive) who presented with large haematoma in the anterior as well as posterior compartment of left thigh and treated successfully with hydroxyurea and imatinib.

Low educational level but not low income impairs the achievement of cytogenetic remission in chronic myeloid leukemia patients treated with imatinib in Brazil

OBJECTIVES

In Brazil, imatinib mesylate is supplied as the first-line therapy for chronic myeloid leukemia in the chronic phase through the public universal healthcare program, Sistema Único de Saúde (SUS). We studied the socio-demographic factors that influenced therapy success in a population in the northeast region of Brazil.

METHODS

Patients with chronic myeloid leukemia from the state of Piauí were treated in only one reference center. Diagnosis was based on WHO 2008 criteria. Risk was assessed by Sokal, Hasford and EUTOS scores. Patients received 400 mg imatinib daily. We studied the influence of the following factors on the achievement of complete cytogenetic response within one year of treatment: age, clinical risk category, time interval between diagnosis and the start of imatinib treatment, geographic distance from the patient's home to the hospital, years of formal education and monthly income.

RESULTS

Among 103 patients studied, the median age was 42 years; 65% of the patients had 2-9 years of formal education, and the median monthly income was approximately 100 US$. Imatinib was started in the first year after diagnosis (early chronic phase) in 69 patients. After 12 months of treatment, 68 patients had a complete cytogenetic response. The Hasford score, delay to start imatinib and years of formal education influenced the attainment of a complete cytogenetic response, whereas income and the distance from the home to the healthcare facility did not.

CONCLUSION

Patients require additional healthcare information to better understand the importance of long-term oral anticancer treatment and to improve their compliance with the treatment.

A retrospective study of the prescribing and outcomes of tyrosine kinase inhibitors in chronic myeloid leukaemia over a period of more than 10 years

WHAT IS KNOWN AND OBJECTIVE

Since their introduction, tyrosine kinase inhibitors (TKIs) have been increasingly used in clinical practice. We describe the prescribing and the clinical and biological consequences of two such inhibitors, imatinib and erlotinib, in patients with chronic myeloid leukaemia (CML) in a practice setting over a period of more than 10 years.

METHODS

All patients who received at least one TKI for chronic phase CML between 2001 and 2012 in our university hospital were included in the study.

RESULTS AND DISCUSSION

Of the 139 patients, with a median age of 57 years, who were surveyed, imatinib and nilotinib were prescribed as the first TKI in 131 (94%) and 8 (6%) patients, respectively. With a median follow-up of 6 years, 342 treatment modifications were observed: 113 (33%) increased doses, 109 (32%) decreased doses, 89 (26%) TKI changes, 14 (4%) definitive discontinuations, 13 (4%) temporary discontinuations and 4 (1%) additions of IFN-α. The main reasons for the 342 treatment modifications were adverse events (n = 112, 33%), long-term optimal response (n = 58, 17%) and failure (n = 57, 17%). Eighty-five (61%), 31 (22%), 18 (13%) and 5 (4%) patients had no, 1, 2 and 3 TKI changes, respectively. Imatinib was the most prescribed TKI (75%). Adverse events resulting in treatment modifications occurred in 18% of patients for imatinib, 49% for nilotinib and 41% for dasatinib (P < 0·001). Median time to TKI change whatever the reason was >50 months (not achieved) for imatinib, 22 months for nilotinib and 27 months for dasatinib (log-rank test, P < 0·001).

WHAT IS NEW AND CONCLUSION

Imatinib was the most prescribed TKI both in the first and in subsequent therapeutic lines for chronic phase CML. Our study showed a very good efficacy-safety profile for imatinib at a median follow-up of 6 years in an unselected French population.

cDNA synthesis for BCR-ABL1 detection at the MMR level: the importance of using the appropriate kit

Background

The synthesis of complementary DNA (cDNA) for use in the detection of BCR-ABL1 at the Major Molecular Response (MMR) level is a well-established method used by clinical laboratories world-wide. However, the quality of cDNA provides sensitivity challenges and consequently affects the detection of Minimal Residual Disease (MRD).

Results

Herein, we evaluated six commercially available kits for the synthesis of cDNA according to amplification success rate, linearity and ABL1 copy number. Based on our results, the Invitrogen SuperScript® III Reverse Transcriptase kit performed better, among the ones used in this study, for the cDNA synthesis, followed by the First Strand cDNA Synthesis Kit for RT-PCR (AMV), available from Roche Applied Sciences.

Conclusions

Accurate and sensitive testing for the detection of abnormal transcripts, allows the correct stratification and treatment of patients. Hence, the use of a suitable kit for the cDNA synthesis is of great importance. This study provides a comprehensive point of reference for clinical laboratories in an attempt to optimize BCR-ABL1 detection. We propose that the Invitrogen SuperScript® III Reverse Transcriptase kit is the most suitable, among the ones used in this study, for the cDNA synthesis to be used for the detection of BCR-ABL1 at the MMR level in a CML MRD assay.

Electronic supplementary material

The online version of this article (doi:10.1186/s12575-015-0014-x) contains supplementary material, which is available to authorized users.

Coexistence of JAK2 and BCR-ABL mutation in patient with myeloproliferative neoplasm

The World Health Organisation (WHO) classifies myeloproliferative neoplasm (MPN) into BCR-ABL positive chronic myeloid leukaemia (CML Ph(+)) and Ph(-) MPN. The JAK2 V617F mutation is specific for Ph(-) MPN and occurs in approximately 50% of primary myelofibrosis. Earlier reports suggest that the occurrence of JAK2 and BCR-ABL mutations are mutually exclusive. However, recent reports have documented the coexistence of BCR-ABL and JAK2 mutation in the same patient mostly following treatment with tyrosine kinase inhibitors (TKIs). We thus report a 60-year-old male with atypical clinical and laboratory features of MPN and the presence of both BCR-ABL and JAK2 Mutations.

First-line treatment of 102 chronic myeloid leukemia patients with imatinib: a long-term single institution analysis

Imatinib mesylate radically changed the natural history of chronic myeloid leukemia (CML). The recent availability of alternative tyrosine kinase inhibitors (TKIs) renders the clinical management of CML more complex. In this article, we summarize our long-term single institution experience. From 2003 to 2012, 102 patients with newly diagnosed chronic phase CML were referred to our institution and treated with imatinib mesylate as first-line therapy. All patients were followed inside a dedicated CML clinic. At 1 year, 82/95 patients (86.3%) achieved complete cytogenetic response (CCyR) using a treatment performed analysis (TPA); when using an intention to treat analysis, 85/102 patients (83.3%) obtained CCyR. At 3 months, 58 patients (64.4% TPA) obtained a BCR-ABL transcripts level <10%. A major molecular response (MMR) was obtained by 38% and 53% of patients at 1 and 2 years. Twenty patients (19.6%) discontinued treatment with imatinib; six of them did so in the initial 2 years of treatment (4 for resistance and 2 for adverse events). We observed seven deaths (6.86%). Overall survival (OS) at 6 years is 95.1% (95% C.I. 90-100%) and is not different from that of the general population. No patient experienced progression of disease (95% C.I.: 0-3%). Our results suggest that patient management is a crucial point to obtain a successful therapeutic outcome: at 1 year CCyR and MMR rates are similar to the results obtained with second generation TKIs and OS is not different from that of the general population.

Interpreting molecular monitoring results and international standardization in chronic myeloid leukemia

Important advances in the understanding of the molecular basis of chronic myeloid leukemia have resulted in the development of new therapies and changed the paradigm for managing this myeloproliferative disease. Translocation of chromosomes 9 and 22 (known as the Philadelphia chromosome) results in a fusion BCR-ABL gene that produces a dysregulated BCR-ABL tyrosine kinase protein and triggers events leading to malignant transformation. The tyrosine kinase inhibitors imatinib, nilotinib, and dasatinib block the BCR-ABL protein and prevent activation of the transformation pathways. Molecular monitoring, the most sensitive approach currently available to assess treatment response, measures BCR-ABL messenger RNA levels and serves as a surrogate marker of disease. Further, molecular responses are predictive of patient outcomes. It is important for advanced practitioners to become familiar with the technology and interpretation of molecular monitoring results as well as efforts to standardize this type of testing so they can educate their patients and aid their understanding of test results. Undetectable BCR-ABL levels can bring feelings of relief, whereas an increasing level can lead to anxiety. Advanced practitioners, therefore, are an important resource for interpreting results for patients, answering questions, alleviating concerns, and encouraging continued adherence to treatment.

Oral cancer after prolonged immunosuppression for multiorgan chronic graft-versus-host disease

Long-term survivors of hematopoietic stem cell transplantation are recognized as a risk group for malignization. Malignant oral neoplasms are increasingly being reported in the literature as a consequence of lesions of chronic graft-versus-host disease, and prolonged multidrug treatment to control its manifestations. This report describes a 43-year-old patient who, after allogeneic bone marrow transplantation, developed an oral squamous cell carcinoma secondary to the use of azathioprine, cyclosporine, prednisone, and tacrolimus, associated with multiorgan chronic graft-versus-host disease involving the oral mucosa, skin, eyes, and liver. This report aims to discuss the possible role of immunosuppressant therapy for chronic graft-versus-host disease on the development of oral squamous cell carcinoma, and the relevance of a close oral follow-up of patients to detect dysplastic or malignant alterations at an early stage.

© 2014 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier Editora Ltda. All rights reserved.

Measurement of adherence to BCR-ABL inhibitor therapy in chronic myeloid leukemia: current situation and future challenges

BCR-ABL inhibitors for treating chronic myeloid leukemia in chronic phase have transformed a previously incurable malignancy into a manageable condition. However, suboptimal medication adherence has been observed with these agents affecting clinical outcomes and healthcare costs. In order to raise awareness of the problem of adherence, and before developing pragmatic strategies to enhance medication adherence, a deep understanding of the best approaches for measuring adherence in chronic myeloid leukemia patients and identifying non-adherence is required. A systematic literature review on the prevalence, measurement methods, consequences and risk factors for non-adherence to BCR-ABL inhibitors and adherence-enhancing interventions was performed and critically appraised. Of the 19 included articles, 9 were retrospective. Average adherence varied from 19% to almost 100% of the proportion of prescribed drug taken, but it was measured through various different methods and within different study groups. Suboptimal adherence was associated with a negative impact on both clinical and economic outcomes. There is a lack of supportive evidence demonstrating a difference in adherence across BCR-ABL inhibitors and even contradictory results between the 2(nd) generation inhibitors. Drug-related adverse events and forgetfulness were common reasons for intentional and unintentional non-adherence, respectively, but further research is required to identify additional reasons behind non-adherence or patients at risk of non-adherence. Non-adherence in chronic myeloid leukemia patients treated with BCR-ABL inhibitors is common and associated with critical outcomes. However, this review highlights important existing gaps, reveals inconsistent definitions, and a lack of standardized methods for measuring adherence in chronic myeloid leukemia. All require further investigation.

Complete cytogenetic response and major molecular response as surrogate outcomes for overall survival in first-line treatment of chronic myelogenous leukemia: a case study for technology appraisal on the basis of surrogate outcomes evidence

OBJECTIVES

In 2012, the National Institute for Health and Care Excellence assessed dasatinib, nilotinib, and standard-dose imatinib as first-line treatment of chronic phase chronic myelogenous leukemia (CML). Licensing of these alternative treatments was based on randomized controlled trials assessing complete cytogenetic response (CCyR) and major molecular response (MMR) at 12 months as primary end points. We use this case study to illustrate the validation of CCyR and MMR as surrogate outcomes for overall survival in CML and how this evidence was used to inform National Institute for Health and Care Excellence's recommendation on the public funding of these first-line treatments for CML.

METHODS

We undertook a systematic review and meta-analysis to quantify the association between CCyR and MMR at 12 months and overall survival in patients with chronic phase CML. We estimated life expectancy by extrapolating long-term survival from the weighted overall survival stratified according to the achievement of CCyR and MMR.

RESULTS

Five studies provided data on the observational association between CCyR or MMR and overall survival. Based on the pooled association between CCyR and MMR and overall survival, our modeling showed comparable predicted mean duration of survival (21-23 years) following first-line treatment with imatinib, dasatinib, or nilotinib.

CONCLUSIONS

This case study illustrates the consideration of surrogate outcome evidence in health technology assessment. Although it is often recommended that the acceptance of surrogate outcomes be based on randomized controlled trial data demonstrating an association between the treatment effect on both the surrogate outcome and the final outcome, this case study shows that policymakers may be willing to accept a lower level of evidence (i.e., observational association).

Disparities in chronic myeloid leukemia survival by age, gender, and ethnicity in pre- and post-imatinib eras in the US

BACKGROUND

Since May 2001, imatinib mesylate has become the first-line therapy for chronic myeloid leukemia (CML) but the survival pattern by age, sex, and ethnicity is not clear.

MATERIAL AND METHODS

We analyzed the Surveillance, Epidemiology, and End Results (SEER*Stat) database to compare survival rates in CML among Caucasians, African-Americans (AA), and other races, and also within each race to see survival differences from the pre-imatinib (1973-2000) to post-imatinib eras (2002-2008). We used Z-tests in SEER*Stat to compare relative survival rates categorized by race, gender, and age groups (all ages, < 50, 50+ years).

RESULTS

The three-year relative survival rates among Caucasians, AA, and other races in the pre-imatinib era were 44.9 ± 0.6%, 46.8 ± 1.8%, and 48.0 ± 2.2%, respectively, and in the post-imatinib era 64.4 ± 0.8%, 67.3 ± 2.4%, and 69.6 ± 1.6%, respectively. The relative survival increased from the pre-to post-imatinib era for all ethnic groups. In the post-imatinib era, three-year relative survival rates among young AA women were significantly lower (Z-value = -2.54, p = 0.011) than young Caucasian women, 80.5 ± 4.5% (n = 105) vs. 90.3 ± 1.4% (n = 589).

CONCLUSIONS

The relative survival rates of CML patients have improved in the post-imatinib era. However, the improvement in survival rates has been modest in this population-based data compared to those reported from randomized trials. Improvement in survival among older patients is lower than in younger patients. Young (<50 years) AA women with CML had lower relative survival rates compared to young Caucasian women in the post-imatinib era.

Health-related quality of life in chronic myeloid leukemia

The increased survival associated with treatments for CML emphasize the importance of understanding the HRQOL of newly diagnosed and previously treated CML patients with all phases of disease. Functional Assessment of Cancer Therapy-Leukemia results from a phase 3 and a phase 2 trial are reported for over 900 1st, 2nd, 3rd line CP, AP, and BP patients. Physical Well-being and Leukemia symptoms were worse for patients in later lines of therapy. Individuals with AP and BP CML had poorer HRQOL than individuals with CP CML. HRQOL of CML patients was predominantly consistent with the longitudinal clinical trajectory of the disease.

Second-generation TKIs: which and when?

Impressive response rates and good tolerability have led imatinib 400 mg once a day to become the standard frontline therapy for chronic myeloid leukemia (CML) patients. However, approximately one-third of the treated patients do not respond in an optimal manner to this drug, and the appropriate type and rhythm of CML monitoring, as well as the correct action to be undertaken in case of failure or suboptimal responses to imatinib therapy have been published in specific recommendations by European Leukemia Net and National Comprehensive Cancer Network. Failure and also cytogenetic suboptimal responses strongly demand for a change in treatment and for a switch from imatinib to one of the two second-generation tyrosine kinase inhibitors (TKIs) so far registered, dasatinib and nilotinib, for which efficacy as second-line therapy in imatinib-resistant or intolerant cases has been clearly demonstrated in phase II studies, and for which 4-year updates are now available. Other TKIs, at the moment, still under clinical investigation for imatinib-resistant patients include bosutinib and the next-generation TKI ponatinib. Different efficacy and safety criteria characterize each of the mentioned compounds and may help to decide on the one to be preferably used in individual patients.

Molecular monitoring 101: helping your patients with chronic myeloid leukemia to understand the meaning of molecular response

For patients with chronic myeloid leukemia (CML), measurement of molecular response (i.e. the level of BCR-ABL1 transcripts) is firmly established as a key element of disease monitoring. Assessment of BCR-ABL1 levels may help to identify early signs of resistance to treatment and enable a timely switch to alternative therapies. Hence, regular and accurate monitoring of BCR-ABL1 transcripts helps to maximize the chance of successful outcomes in CML. Because the incidence of CML is relatively low, many community oncologists encounter only a limited number of cases; measuring and interpreting BCR-ABL1 measurements in a clinically relevant fashion may be challenging. The team at our institution often encounters questions regarding real-time quantitative polymerase chain reaction assessments of BCR-ABL1 levels, International Scale standardization, the implications of achieving or losing molecular responses and mutation monitoring. The aim of this article is to provide practical advice for effective long-term monitoring of patients with CML by addressing frequently asked questions and common case scenarios using guideline- and evidence-based approaches.

DNA damage response in imatinib resistant chronic myeloid leukemia K562 cells

Resistance to imatinib in patients with chronic myeloid leukemia can lead to advanced disease and blast crisis. Conventional chemotherapy with DNA damaging agents is then used, alone or in combination with other tyrosine kinase inhibitors (TKIs). Our aim was to assess whether imatinib resistant K562 cells were also resistant to DNA damaging agents. After treatment with H(2)O(2) and doxorubicin, but not camptothecin, cell survival was higher in imatinib resistant cells compared to parental cells. DNA damage, measured by comet and γ-H2AX assays, was lower in imatinib resistant cells. mRNA expression levels of 50 genes of the DNA damage response pathway showed increased expression of the base excision repair (BER) genes MBD4 and NTHL1. Knockdown of MBD4 and NTHL1 expression in resistant cells using siRNA decreased cell survival after treatment with H(2)O(2) and doxorubicin. Our results indicate that imatinib resistant cells display cross-resistance to oxidative agents, partly through up-regulation of BER genes. Expression of these genes in imatinib resistant patients was not significantly different compared to sensitive patients. However, the strategy followed in this study could help identify chemotherapeutic agents that are more effective as alternative agents in cases of resistance to TKIs.

Patterns and prognostic indicators of response to CML treatment in a multi-country medical record review study

We conducted a review of patient medical records to assess treatment response patterns and prognostic indicators of response among chronic myeloid leukemia (CML) patients in the United States, the United Kingdom, Germany, and Japan. All 1,063 patients selected met the following inclusion criteria: aged 18 or older and in chronic phase at the time of diagnosis, Philadelphia chromosome and/or BCR-ABL positive, received first-line treatment with imatinib, and not enrolled in a randomized clinical trial during the period of retrospective review. Multivariable logistic regression models were used to evaluate prognostic indicators of complete hematological response (CHR), complete cytogenetic response (CCyR), and complete or major molecular response (C/MMR). Among patients treated with first-line imatinib, CHR at three months, CCyR at 12 months, and C/MMR at 18 months were observed in 53, 53.1, and 57.8 % of patients, respectively. Among patients treated with second-line dasatinib or nilotinib, CHR was achieved at three months in 49 and 42 %, CCyR at 12 months in 32 and 23 %, and MMR at 18 months in 30.5 and 26.1 % of patients, respectively. Prognostic indicators of first-line response included age, race, and Sokal score. For second-line treatment, duration of first-line hematological response and choice of drug used were also significant.

Health-related quality of life of bosutinib (SKI-606) in imatinib-resistant or imatinib-intolerant chronic phase chronic myeloid leukemia

Understanding the impact of second-line tyrosine kinase inhibitor therapy on the health-related quality of life (HRQOL) of imatinib (IM)-resistant and IM-intolerant chronic phase chronic myeloid leukemia (CP CML) patients is important given the increased survival that comes with therapy. As part of a bosutinib single-arm phase 2 trial, 200 IM-resistant and 88 IM-intolerant CP CML patients' HRQOL was assessed prior to and throughout treatment with the Functional Assessment of Cancer Therapy-Leukemia (FACT-Leu). Little HRQOL impairment was demonstrated at baseline. Over the course of 96 weeks on bosutinib therapy, patients noted statistically significant and/or clinically meaningful improvements on several FACT-Leu scales.

Higher dose imatinib for children with de novo chronic phase chronic myelogenous leukemia: a report from the Children's Oncology Group

PURPOSE

To determine the efficacy of imatinib in children with newly diagnosed chronic phase (CP) chronic myelogenous leukemia (CML).

METHODS

This was an open label, multi-center phase II clinical trial. Courses were defined as consecutive 28-day intervals. Oral imatinib was administered daily at 340 mg/m² without interruption in the absence of toxicity.

RESULTS

Fifty-one children received 978 28-day courses of imatinib. The most common toxicities encountered were hematologic. Forty-one patients (80%) achieved a complete hematologic response by the end of course 2. Nineteen children (38%) obtained a complete cytogenetic response (CCyR) at the end of course 3. Overall, 72% achieved CCyR at a median time of 5.6 months. The rate of complete molecular response (>3 log reduction) was 27%. Progression-free and overall survival at 3 years were 72%  ± 6.4% and 92%  ± 3.9%, respectively.

CONCLUSIONS

Daily oral imatinib at a dose of 340 mg/m² is well tolerated in children. In addition, imatinib therapy is effective in inducing a high percent of hematologic, cytogenetic and molecular responses, comparable to adults with CML. (This study was registered at ClinicalTrials.gov under identifier NCT00030394.).