Severe adverse events associated with the use of second-line BCR/ABL tyrosine kinase inhibitors: preferential occurrence in patients with comorbidities

Impact of age and comorbidities on the efficacy and tolerability of bosutinib in previously treated patients with chronic myeloid leukemia: results from the phase 4 BYOND study

In the phase 4 BYOND trial, patients with pretreated chronic myeloid leukemia (CML) received bosutinib (starting dose: 500 mg/day). Efficacy and safety after ≥3 years of follow-up in 156 patients with Philadelphia chromosome-positive chronic phase CML by age and Charlson Comorbidity Index scores (without the age component; mCCI) is reported. Cumulative major molecular response rates at any time on treatment were 73.6%, 64.5%, and 74.1% in patients <65, 65-74, and ≥75 years of age, and 77.9%, 63.0%, and 59.3% in patients with mCCI scores 2, 3, and ≥4, respectively. Patients <65, 65-74, and ≥75 years of age experienced grade 3/4 treatment-emergent adverse events (TEAEs) at rates of 74.7%, 78.8%, and 96.4% and permanent discontinuations due to AEs at rates of 22.1%, 39.4%, and 46.4%, respectively. In patients with mCCI 2, 3, and ≥4, respective rates of grade 3/4 TEAEs were 77.8%, 77.8%, and 86.7%, and permanent discontinuations due to AEs were 25.3%, 33.3%, and 43.3%. In conclusion, a substantial proportion of patients maintained/achieved cytogenetic and molecular responses across age groups and mCCI scores. Older patients (≥75 years) and those with high comorbidity burden (mCCI ≥4) may require more careful monitoring due to the increased risk of TEAEs. Clinicaltrials.gov: NCT02228382.

The two facets of receptor tyrosine kinase in cardiovascular calcification-can tyrosine kinase inhibitors benefit cardiovascular system?

Tyrosine kinase inhibitors (TKIs) are widely used in cancer treatment due to their effectiveness in cancer cell killing. However, an off-target of this agent limits its success. Cardiotoxicity-associated TKIs have been widely reported. Tyrosine kinase is involved in many regulatory processes in a cell, and it is involved in cancer formation. Recent evidence suggests the role of tyrosine kinase in cardiovascular calcification, specifically, the calcification of heart vessels and valves. Herein, we summarized the accumulating evidence of the crucial role of receptor tyrosine kinase (RTK) in cardiovascular calcification and provided the potential clinical implication of TKIs-related ectopic calcification. We found that RTKs, depending on the ligand and tissue, can induce or suppress cardiovascular calcification. Therefore, RTKs may have varying effects on ectopic calcification. Additionally, in the context of cardiovascular calcification, TKIs do not always relate to an unfavored outcome-they might offer benefits in some cases.

Pericardial Effusion Secondary to Nilotinib in an Elderly Patient With Chronic Myelogenous Leukemia

Tyrosine kinase inhibitors (TKIs) are the first-line treatment for patients with chronic myelogenous leukemia (CML). Serositis, including pleural and pericardial effusions, is a frequent adverse event with some TKIs while less frequent with others. We present a case of a 76-year-old woman with CML on nilotinib who presented with progressive fatigue and was eventually found to have cardiac tamponade from a large pericardial effusion attributed to nilotinib. The patient required urgent therapeutic pericardiocentesis and switching of TKIs from nilotinib to bosutinib. 

The effect of comorbidities on the choice of tyrosine kinase inhibitors in patients with chronic myeloid leukemia

Tyrosine kinase inhibitors (TKIs) approved for chronic myeloid leukemia known to have similar efficacies but different safety profiles. Therefore, the choice of patient-specific treatments is driven by factors such as tolerability and adverse event profile of TKIs. This review article examines the most up-to-date data and provides practical recommendations for clinical approaches. Nilotinib and ponatinib should be avoided in patients with cardiovascular risk factors, dasatinib in patients with lung damage and bosutinib and nilotinib in patients with liver disease. Considering that certain comorbidities predispose some patients to developing severe adverse events when receiving TKIs, the first- and second-line treatment of chronic myeloid leukemia should be tailored to each patient's individual condition.

BCR-ABL tyrosine kinase inhibitors promote pathological changes in dilator phenotype in the human microvasculature

OBJECTIVE

Treatment with BCR-ABL tyrosine kinase inhibitors (TKIs) is the standard of care for patients with chronic myeloid leukemia, however evidence indicates these compounds may have cardiovascular side-effects. This study sought to determine if ex vivo exposure of human adipose arterioles to the BCR-ABL TKIs imatinib and nilotinib causes endothelial dysfunction.

METHODS

Human adipose arterioles were incubated overnight in cell culture media containing vehicle (PBS), imatinib (10 µmol/L) or nilotinib (100 µmol/L). Arterioles were cannulated onto glass pipettes and flow mediated dilation (FMD) was assessed via video microscopy. To determine the mechanism of vasodilation, FMD was re-assessed in the presence of either the nitric oxide synthase inhibitor L-NAME (100 µmol/L) or the H2 O2 scavenger PEG-Catalase (500 U/mL).

RESULTS

Neither imatinib nor nilotinib affected the magnitude of FMD (max dilation = 78±17% vehicle, 80 ± 24% nilotinib, 73 ± 13% imatinib). FMD was decreased by L-NAME in vehicle-treated arterioles (max dilation = 47±29%). Conversely, L-NAME had no effect on FMD in imatinib- or nilotinib-treated vessels (max dilation = 79±14% and 80 ± 24%, respectively), rather FMD was inhibited by PEG-Catalase (max dilation = 29±11% and 29 ± 14%, respectively).

CONCLUSION

Incubating human arterioles with imatinib or nilotinib switches the mediator of FMD from vasoprotective nitric oxide to pro-inflammatory H2 O2 .

From Molecular Mechanisms to Clinical Management of Antineoplastic Drug-Induced Cardiovascular Toxicity: A Translational Overview

Significance: Antineoplastic therapies have significantly improved the prognosis of oncology patients. However, these treatments can bring to a higher incidence of side-effects, including the worrying cardiovascular toxicity (CTX). Recent Advances: Substantial evidence indicates multiple mechanisms of CTX, with redox mechanisms playing a key role. Recent data singled out mitochondria as key targets for antineoplastic drug-induced CTX; understanding the underlying mechanisms is, therefore, crucial for effective cardioprotection, without compromising the efficacy of anti-cancer treatments. Critical Issues: CTX can occur within a few days or many years after treatment. Type I CTX is associated with irreversible cardiac cell injury, and it is typically caused by anthracyclines and traditional chemotherapeutics. Type II CTX is generally caused by novel biologics and more targeted drugs, and it is associated with reversible myocardial dysfunction. Therefore, patients undergoing anti-cancer treatments should be closely monitored, and patients at risk of CTX should be identified before beginning treatment to reduce CTX-related morbidity. Future Directions: Genetic profiling of clinical risk factors and an integrated approach using molecular, imaging, and clinical data may allow the recognition of patients who are at a high risk of developing chemotherapy-related CTX, and it may suggest methodologies to limit damage in a wider range of patients. The involvement of redox mechanisms in cancer biology and anticancer treatments is a very active field of research. Further investigations will be necessary to uncover the hallmarks of cancer from a redox perspective and to develop more efficacious antineoplastic therapies that also spare the cardiovascular system.

Tyrosine kinase inhibitors and mesenchymal stromal cells: effects on self-renewal, commitment and functions

The hope of selectively targeting cancer cells by therapy and eradicating definitively malignancies is based on the identification of pathways or metabolisms that clearly distinguish “normal” from “transformed” phenotypes. Some tyrosine kinase activities, specifically unregulated and potently activated in malignant cells, might represent important targets of therapy. Consequently, tyrosine kinase inhibitors (TKIs) might be thought as the “vanguard” of molecularly targeted therapy for human neoplasias. Imatinib and the successive generations of inhibitors of Bcr-Abl1 kinase, represent the major successful examples of TKI use in cancer treatment. Other tyrosine kinases have been selected as targets of therapy, but the efficacy of their inhibition, although evident, is less definite. Two major negative effects exist in this therapeutic strategy and are linked to the specificity of the drugs and to the role of the targeted kinase in non-malignant cells. In this review, we will discuss the data available on the TKIs effects on the metabolism and functions of mesenchymal stromal cells (MSCs). MSCs are widely distributed in human tissues and play key physiological roles; nevertheless, they might be responsible for important pathologies. At present, bone marrow (BM) MSCs have been studied in greater detail, for both embryological origins and functions. The available data are evocative of an unexpected degree of complexity and heterogeneity of BM-MSCs. It is conceivable that this grade of intricacy occurs also in MSCs of other organs. Therefore, in perspective, the negative effects of TKIs on MSCs might represent a critical problem in long-term cancer therapies based on such inhibitors.

Understanding and Challenges in Taking Tyrosine Kinase Inhibitors among Malaysian Chronic Myeloid Leukemia Patients: A Qualitative Study

Background:

In Malaysia, the treatment for chronic myeloid leukemia (CML) has long been delivered under the Malaysian Patient Assistance Program (MYPAP), but research on identifying factors contributing to non-adherence to tyrosine kinase inhibitors (TKIs) is still limited. The current study explored understanding and challenges of Malaysian CML patients in taking imatinib and nilotinib.

Methods:

Semi-structured, face-to-face interviews were conducted with 13 CML patients receiving treatment at a public tertiary care center, and were analyzed using the content analysis approach.

Results:

The patients generally demonstrated inadequate knowledge, particularly of the natural history and staging of CML, the function of TKIs, and the methods used for monitoring the effectiveness of treatment. A number of them also had experiences of withholding, skipping or altering the treatment, mainly due to the life-disturbing adverse drug effects (ADRs), forgetfulness, and religious and social issues. Besides, most of them were found having limited skills in managing the ADRs, and not using prompts as reminders to take the medications. Furthermore, even though nilotinib was generally perceived as better tolerated as compared with imatinib, the inconvenience caused by the need to take it twice daily and on an empty stomach was constantly highlighted by the patients.

Conclusion:

While TKIs are widely used for CML treatment in Malaysia, the findings have revealed a lack of patient education and awareness, which warrants an integrated plan to reinforce medication adherence.

Risk factors and mechanisms contributing to TKI-induced vascular events in patients with CML

Vascular adverse events (VAE) are an emerging problem in patients with chronic myeloid leukemia (CML) receiving second-generation BCR-ABL1 tyrosine kinase inhibitors (TKI). Relevant VAE comprise peripheral, cerebral, and coronary artery changes in patients receiving nilotinib, venous and arterial occlusive events during ponatinib therapy, and pulmonary hypertension in patients receiving dasatinib. Although each TKI binds to a unique profile of molecular targets in leukemic cells and vascular cells, the exact etiology of drug-induced vasculopathies remains uncertain. Recent data suggest that predisposing molecular factors, pre-existing cardiovascular risk factors as well as certain comorbidities contribute to the etiology of VAE in these patients. In addition, direct effects of these TKI on vascular endothelial cells have been demonstrated and are considered to contribute essentially to VAE evolution. In the current article, we discuss mechanisms underlying the occurrence of VAE in TKI-treated patients with CML, with special emphasis on vascular and perivascular target cells and involved molecular (vascular) targets of VAE-triggering TKI. In addition, we discuss optimal patient selection and drug selection through which the risk of occurrence of cardiovascular events can hopefully be minimized while maintaining optimal anti-leukemic effects in CML, thereby following the principles of personalized medicine.

Quality of life in chronic myeloid leukaemia patients after haematopoietic cell transplantation pretreated with second-generation tyrosine kinase inhibitors

Aim of the study

The majority of patients with chronic myeloid leukaemia (CML) respond to tyrosine kinase inhibitors (TKI), while allogeneic haematopoietic cell transplantation (HCT) is indicated in selected clinical situations. HCT carries the risk of severe complications, while the toxicity profile of dasatinib and nilotinib may lead to adverse reactions affecting the quality of life (QoL). We present the results of observational analysis of CML patients who underwent HCT after exposure to second-generation TKI (TKI2), with respect to their quality of life assessed comparatively after transplantation.

Material and methods

Eligible subjects included 19 patients. The quality of life and global health assessment were performed with a questionnaire comparing the signs and symptoms present during the TKI2-therapy with those related to post-transplant complications, including psychosocial problems.

Results and conclusions

Most patients had no/few problems with exhausting activities, no/few difficulties during long-distance walks, and do not/rarely rest in the daytime. Seventeen (89.5%) patients reported at least one symptom related to TKI2-therapy and most of them disappeared after HCT. Thirteen (68.4%) patients noted no serious complication after HCT. Most patients claimed to have a very good QoL and general health compared to the period prior to HCT. We found statistically significant improvement in global health (p = 0.016) and QoL (p = 0.043) after HCT.

From the survivors perspective, HCT influence positively general health and QoL comparing to TKI2-therapy period. Further studies on larger group of patients will more precisely define the QoL level and possible predictors of changes in QoL, to assess which group of patients needs psychological support.

Managing chronic myeloid leukaemia in the elderly with intermittent imatinib treatment

The aim of this study was to investigate the effects of a non-standard, intermittent imatinib treatment in elderly patients with Philadelphia-positive chronic myeloid leukaemia and to answer the question on which dose should be used once a stable optimal response has been achieved. Seventy-six patients aged ⩾65 years in optimal and stable response with ⩾2 years of standard imatinib treatment were enrolled in a study testing a regimen of intermittent imatinib (INTERIM; 1-month on and 1-month off). With a minimum follow-up of 6 years, 16/76 patients (21%) have lost complete cytogenetic response (CCyR) and major molecular response (MMR), and 16 patients (21%) have lost MMR only. All these patients were given imatinib again, the same dose, on the standard schedule and achieved again CCyR and MMR or an even deeper molecular response. The probability of remaining on INTERIM at 6 years was 48% (95% confidence interval 35-59%). Nine patients died in remission. No progressions were recorded. Side effects of continuous treatment were reduced by 50%. In optimal and stable responders, a policy of intermittent imatinib treatment is feasible, is successful in about 50% of patients and is safe, as all the patients who relapsed could be brought back to optimal response.

Pretransplantation use of the second-generation tyrosine kinase inhibitors has no negative impact on the HCT outcome

Introduction

Allogeneic hematopoietic cell transplantation (HCT) was a standard therapy in chronic phase (CP) chronic myeloid leukemia (CML). As a result of the effective therapy with tyrosine kinase inhibitors (TKI), HCT was shifted to defined clinical situations. We present the results of observational prospective analysis of 28 CML patients undergoing HCT after exposure to, at least, two lines of TKI (including dasatinib and/or nilotinib), with respect to response, overall survival (OS), treatment toxicity, graft versus host disease (GVHD), and progression/relapse incidence.

Results

All the patients but one engrafted with median time 19 days. OS for patients in CP1 and CP2/accelerated phase (AcP) were 92.9 and 85.7 %, respectively. Six patients allotransplanted in blast crisis (BC) CML died early after HCT.

Eighteen patients achieved deep molecular remission (MR^4.5 or MR^4.0). Relapse incidence was 29.6 %. Median time to progression (TTP) differs significantly depending on the CML phase prior to HCT, the best response achieved after HCT and development of chronic GvHD.

NRM yielded the values 7.1, 12.5, and 50 % in CP1, CP2/AcP, and BC, respectively. Fatal outcome, due to veno-occlusive disease (VOD), was observed in two (7 %) patients. In five (17.9 %) patients, mild or moderate VOD was observed with no negative impact of preceding therapy with TKI2. Acute GvHD was diagnosed in 25.9 % of patients, while chronic GvHD developed in 42.9 % of individuals.

Conclusion

Pretransplantation therapy with TKI2 in CP CML is safe and reasonable. In BC, the optimal approach before HCT is to reduce the leukemic burden and achieve subsequent CP.

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.

Endocrine side effects of anti-cancer drugs: effects of anti-cancer targeted therapies on lipid and glucose metabolism

During the past years, targeted therapies for cancer have been developed using drugs that have significant metabolic consequences. Among them, the mammalian target of rapamycin (mTOR) inhibitors and, to a much lesser extent, the tyrosine kinase inhibitors (TKIs) are involved. mTOR plays a key role in the regulation of cell growth as well as lipid and glucose metabolism. Treatment with mTOR inhibitors is associated with a significant increase in plasma triglycerides and LDL cholesterol. mTOR inhibitors seem to increase plasma triglycerides by reducing the activity of the lipoprotein lipase which is in charge of the catabolism of triglyceride-rich lipoproteins. The increase in LDL cholesterol observed with mTOR inhibitors seems to be due to a decrease in LDL catabolism secondary to a reduction of LDL receptor expression. In addition, treatment with mTOR inhibitors is associated with a high incidence of hyperglycemia, ranging from 13 to 50% in the clinical trials. The mechanisms responsible for hyperglycemia with new onset diabetes are not clear, but are likely due to the combination of impaired insulin secretion and insulin resistance. TKIs do not induce hyperlipidemia but alter glucose homeostasis. Treatment with TKIs may be associated either with hyperglycemia or hypoglycemia. The molecular mechanism by which TKIs control glucose homeostasis remains unknown. Owing to the metabolic consequences of these agents used as targeted anti-cancer therapies, a specific and personalized follow-up of blood glucose and lipids is recommended when using mTOR inhibitors and of blood glucose when using TKIs.

Treatment recommendations for chronic myeloid leukemia

The first treatment of chronic myeloid leukemia (CML) included spleen x-radiation and conventional drugs, mainly Busulfan and Hydroxyurea. This therapy improved the quality of life during the chronic phase of the disease, without preventing nor significantly delaying the progression towards advanced phases. The introduction of allogeneic stem cell transplantation (alloSCT) marked the first important breakthrough in the evolution of CML treatment, because about 50% of the eligible patients were cured. The second breakthrough was the introduction of human recombinant interferon-alfa, able to achieve a complete cytogenetic remission in 15% to 30% of patients, with a significant survival advantage over conventional chemotherapy. At the end of the last century, about 15 years ago, all these treatments were quickly replaced by a class of small molecules targeting the tyrosine kinases (TK), which were able to induce a major molecular remission in most of the patients, without remarkable side effects, and a very prolonged life-span. The first approved TK inhibitor (TKI) was Imatinib Mesylate (Glivec or Gleevec, Novartis). Rapidly, other TKIs were developed tested and commercialized, namely Dasatinib (Sprycel, Bristol-Myers Squibb), Nilotinib (Tasigna, Novartis), Bosutinib (Busulif, Pfizer) and Ponatinib (Iclusig, Ariad). Not all these compounds are available worldwide; some of them are approved only for second line treatment, and the high prices are a problem that can limit their use. A frequent update of treatment recommendations is necessary. The current treatment goals include not only the prevention of the transformation to the advanced phases and the prolongation of survival, but also a length of survival and of a quality of life comparable to that of non-leukemic individuals. In some patient the next ambitious step is to move towards a treatment-free remission. The CML therapy, the role of alloSCT and the promising experimental strategies are reviewed in the context of the new therapeutic goals.

A critical history of chromic myeloid leukemia

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European LeukemiaNet recommendations for the management of chronic myeloid leukemia: 2013

Advances in chronic myeloid leukemia treatment, particularly regarding tyrosine kinase inhibitors, mandate regular updating of concepts and management. A European LeukemiaNet expert panel reviewed prior and new studies to update recommendations made in 2009. We recommend as initial treatment imatinib, nilotinib, or dasatinib. Response is assessed with standardized real quantitative polymerase chain reaction and/or cytogenetics at 3, 6, and 12 months. BCR-ABL1 transcript levels ≤10% at 3 months, <1% at 6 months, and ≤0.1% from 12 months onward define optimal response, whereas >10% at 6 months and >1% from 12 months onward define failure, mandating a change in treatment. Similarly, partial cytogenetic response (PCyR) at 3 months and complete cytogenetic response (CCyR) from 6 months onward define optimal response, whereas no CyR (Philadelphia chromosome-positive [Ph+] >95%) at 3 months, less than PCyR at 6 months, and less than CCyR from 12 months onward define failure. Between optimal and failure, there is an intermediate warning zone requiring more frequent monitoring. Similar definitions are provided for response to second-line therapy. Specific recommendations are made for patients in the accelerated and blastic phases, and for allogeneic stem cell transplantation. Optimal responders should continue therapy indefinitely, with careful surveillance, or they can be enrolled in controlled studies of treatment discontinuation once a deeper molecular response is achieved.

Clinical cardiac safety profile of nilotinib

BACKGROUND

Nilotinib is a second-generation tyrosine kinase inhibitor with significant efficacy as first- or second-line treatment in patients with chronic myeloid leukemia. Despite preclinical evidence indicating a risk of prolongation of the QT interval, which was confirmed in clinical trials, detailed information on nilotinib's cardiac safety profile is lacking.

DESIGN AND METHODS

Here, we retrospectively assessed cardiovascular risk factors in 81 patients who were being or had previously been treated with nilotinib therapy and evaluated cardiovascular parameters by longitudinal monitoring of the QT interval and left ventricular ejection fraction. Detailed information on the occurrence and management of defined cardiac adverse events was extracted.

RESULTS

The median duration of nilotinib therapy was 26 months (range, 1-72). The median QT interval at baseline was 413 msec (range, 368-499 msec). During follow-up, the median QT was not significantly different from the baseline value at any time-point. Sixteen of 81 patients (20%) had new electrocardiographic changes. Cardiac function, as assessed by measurement of left ventricular ejection fraction, did not change significantly from baseline at any time-point. During a median follow-up of 44 months (range, 2-73), seven patients (9%), all of whom had received prior imatinib therapy, developed 11 clinical cardiac adverse events requiring treatment. The median time from the start of nilotinib therapy to an event was 14.5 months (range, 2-68). Five of seven patients were able to continue nilotinib therapy with only one brief interruption.

CONCLUSIONS

Whereas new electrocardiographic abnormalities were recorded in 20% of all patients and some of them developed severe or even life-threatening coronary artery disease, QT prolongation, changes in left ventricular ejection fraction, and clinical cardiac adverse events were uncommon in patients treated with nilotinib.