Electrocardiographic Characterization of the QTc Interval in Patients with Advanced Solid Tumors: Pharmacokinetic- Pharmacodynamic Evaluation of Sunitinib

Sunitinib malate induces cell death in adult human cardiac progenitor cells

Sunitinib malate is known to cause cardiotoxicity in a sub-population of patients, with heart failure seen in more severe cases. Cardiac progenitor cells (CPCs) have been identified in adult human myocardium and contribute to overall tissue maintenance, with previous work identifying negative impacts of sunitinib on these cells. This study aimed to characterise the toxic effects of sunitinib in human CPCs, applying sunitinib concentrations equivalent to clinical plasma levels to these cells in vitro. Cell viability was reduced by 26.5 ± 6.6 % by 2 μM sunitinib for 24 h (p < 0.01); this concentration also induced fold-change increases in gene expression of: calpain (3.1 ± 0.73, p < 0.05), FAS (2.3 ± 0.8, p < 0.05) and BAX (1.9 ± 0.2, p < 0.05), and a decrease in BCL-2 (3.5 ± 0.0, p < 0.001), vs. control (1.0 ± 0.0). This was affirmed by sunitinib inducing fold changes in protein expression of: calpain-1 (2.5 ± 0.5, p < 0.05); FAS receptor (2.1 ± 0.2, p < 0.05) and BAX (2.1 ± 0.2, p < 0.05) vs. control (1.0 ± 0.0). These results indicated that sunitinib induced apoptosis in CPCs, but negative annexin V staining and lack of protection by caspase inhibitors indicated this was not the cell death pathway activated. Further investigation found sunitinib was concentrated in the lysosomes and autophagosomes within CPCs, but did not induce accumulation of acidic organelles. In conclusion, these data confirm that cell death is caused by sunitinib in CPCs at concentrations equivalent to clinical plasma levels, inducing cell death pathway signals that lead to non-apoptotic cell death.

Cardiac Arrhythmias in Oncological Patients-Epidemiology, Risk Factors, and Management within the Context of the New ESC 2022 Guidelines

PURPOSE OF REVIEW

To provide an update on epidemiology, risk factors, and management of cardiac arrhythmias in oncological patients within the context of the new European Society of Cardiology 2022 guidelines on cardio-oncology.

RECENT FINDINGS

One of the side effects of different chemotherapeutics is their pro-arrhythmic activity. Both atrial and ventricular arrhythmias may be induced by cancer itself or by anticancer treatment. Recent studies report on the cardiotoxic activity of such promising therapies as BRAF and MEK inhibitors, or CAR-T therapy. Risk factors of arrhythmias in oncological patients overlap with cardiovascular diseases risk factors, but there are some groups of anticancer drugs that increase the risk of cardiotoxicity. It is crucial to be aware of the risks associated with the oncological treatment and know how to act in case of cardiotoxicity.

Novel inhibitors of breast cancer resistance protein (BCRP, ABCG2) among marketed drugs

Drug-drug interactions (DDIs) are a major concern for the safe use of medications. Breast cancer resistance protein (BCRP) is a clinically relevant ATP-binding cassette (ABC) transporter for drug disposition. Inhibition of BCRP increases the plasma concentrations of BCRP substrate drugs, which potentially could lead to adverse drug reactions. The aim of the present study was to identify BCRP inhibitors amongst a library of 232 commonly used drugs and anticancer drugs approved by the United States Food and Drug Administration (FDA). BCRP inhibition studies were carried out using the vesicular transport assay. We found 75 drugs that reduced the relative transport activity of BCRP to less than 25% of the vehicle control and were categorized as strong inhibitors. The concentration required for 50% inhibition (IC₅₀) was determined for 13 strong inhibitors that were previously poorly characterized for BCRP inhibition. The IC₅₀ ranged from 1.1 to 11 µM, with vemurafenib, dabigatran etexilate and everolimus being the strongest inhibitors. According to the drug interaction guidance documents from the FDA and the European Medicines Agency (EMA), in vivo DDI studies are warranted if the theoretical intestinal luminal concentration of a drug exceeds its IC₅₀ by tenfold. Here, the IC₅₀ values for eight of the drugs were 100-fold lower than their theoretical intestinal luminal concentration. Moreover, a mechanistic static model suggested that vemurafenib, bexarotene, dabigatran etexilate, rifapentine, aprepitant, and ivacaftor could almost fully inhibit intestinal BCRP, increasing the exposure of concomitantly administered rosuvastatin over 90%. Therefore, clinical studies are warranted to investigate whether these drugs cause BCRP-mediated DDIs in humans.

Cardiotoxicity Induced by Protein Kinase Inhibitors in Patients with Cancer

Kinase inhibitors (KIs) represent a growing class of drugs directed at various protein kinases and used in the treatment of both solid tumors and hematologic malignancies. It is a heterogeneous group of compounds that are widely applied not only in different types of tumors but also in tumors that are positive for a specific predictive factor. This review summarizes common cardiotoxic effects of KIs, including hypertension, arrhythmias with bradycardia and QTc prolongation, and cardiomyopathy that can lead to heart failure, as well as less common effects such as fluid retention, ischemic heart disease, and elevated risk of thromboembolic events. The guidelines for cardiac monitoring and management of the most common cardiotoxic effects of protein KIs are discussed. Potential signaling pathways affected by KIs and likely contributing to cardiac damage are also described. Finally, the need for further research into the molecular mechanisms underlying the cardiovascular toxicity of these drugs is indicated.

Polydatin Reduces Cardiotoxicity and Enhances the Anticancer Effects of Sunitinib by Decreasing Pro-Oxidative Stress, Pro-Inflammatory Cytokines, and NLRP3 Inflammasome Expression

Renal cell carcinoma (RCC) represents the main renal tumors and are highly metastatic. Sunitinib, a recently-approved, multi-targeted Tyrosine Kinases Inhibitor (TKi), prolongs survival in patients with metastatic renal cell carcinoma and gastrointestinal stromal tumors, however a dose related cardiotoxicity was well described. Polydatin (3,4’,5-trihydroxystilbene-3-β-d-glucoside) is a monocrystalline compound isolated from Polygonum cuspidatum with consolidated anti-oxidant and anti-inflammatory properties, however no studies investigated on its putative cardioprotective and chemosensitizing properties during incubation with sunitinib. We investigated on the effects of polydatin on the oxidative stress, NLRP3 inflammasome and Myd88 expression, highlighting on the production of cytokines and chemokines (IL-1β, IL-6, IL-8, CXCL-12 and TGF-β) during treatment with sunitinib. Exposure of cardiomyocytes and cardiomyoblasts (AC-16 and H9C2 cell lines) and human renal adenocarcinoma cells (769‐P and A498) to polydatin combined to plasma-relevant concentrations of sunitinib reduces significantly iROS, MDA and LTB4 compared to only sunitinib-treated cells (P<0.001). In renal cancer cells and cardiomyocytes polydatin reduces expression of pro-inflammatory cytokines and chemokines involved in myocardial damages and chemoresistance and down-regulates the signaling pathway of NLRP3 inflammasome, MyD88 and NF-κB. Data of the present study, although in vitro, indicate that polydatin, besides reducing oxidative stress, reduces key chemokines involved in cancer cell survival, chemoresistance and cardiac damages of sunitinib through downregulation of NLRP3-MyD88 pathway, applying as a potential nutraceutical agent in preclinical studies of preventive cardio-oncology.

Therapeutic Drug Monitoring of Sunitinib in Gastrointestinal Stromal Tumors and Metastatic Renal Cell Carcinoma in Adults-A Review

BACKGROUND

Sunitinib is an inhibitor of multiple receptor tyrosine kinases and is a standard-of-care treatment for advanced and metastatic renal cell carcinoma and a second-line treatment in locally advanced inoperable and metastatic gastrointestinal stromal tumors. A fixed dose of the drug, however, does not produce a uniform therapeutic outcome in all patients, and many face adverse effects and/or toxicity. One of the possible causes of the interindividual variability in the efficacy and toxicity response is the highly variable systemic exposure to sunitinib and its active metabolite. This review aims to summarize all available clinical evidence of the treatment of adult patients using sunitinib in approved indications, addressing the necessity to introduce proper and robust therapeutic drug monitoring (TDM) of sunitinib and its major metabolite, N-desethylsunitinib.

METHODS

The authors performed a systematic search of the available scientific literature using the PubMed online database. The search terms were "sunitinib" AND "therapeutic drug monitoring" OR "TDM" OR "plasma levels" OR "concentration" OR "exposure." The search yielded 520 journal articles. In total, 447 publications were excluded because they lacked sufficient relevance to the reviewed topic. The remaining 73 articles were, together with currently valid guidelines, thoroughly reviewed.

RESULTS

There is sufficient evidence confirming the concentration-efficacy and concentration-toxicity relationship in the indications of gastrointestinal stromal tumors and metastatic renal clear-cell carcinoma. For optimal therapeutic response, total (sunitinib + N-desethylsunitinib) trough levels of 50-100 ng/mL serve as a reasonable target therapeutic range. To avoid toxicity, the total trough levels should not exceed 100 ng/mL.

CONCLUSIONS

According to the current evidence presented in this review, a TDM-guided dose modification of sunitinib in selected groups of patients could provide a better treatment outcome while simultaneously preventing sunitinib toxicity.

Mechanobiology Assays with Applications in Cardiomyocyte Biology and Cardiotoxicity

Cardiomyocytes are the motor units that drive the contraction and relaxation of the heart. Traditionally, testing of drugs for cardiotoxic effects has relied on primary cardiomyocytes from animal models and focused on short-term, electrophysiological, and arrhythmogenic effects. However, primary cardiomyocytes present challenges arising from their limited viability in culture, and tissue from animal models suffers from a mismatch in their physiology to that of human heart muscle. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) can address these challenges. They also offer the potential to study not only electrophysiological effects but also changes in cardiomyocyte contractile and mechanical function in response to cardiotoxic drugs. With growing recognition of the long-term cardiotoxic effects of some drugs on subcellular structure and function, there is increasing interest in using hiPSC-CMs for in vitro cardiotoxicity studies. This review provides a brief overview of techniques that can be used to quantify changes in the active force that cardiomyocytes generate and variations in their inherent stiffness in response to cardiotoxic drugs. It concludes by discussing the application of these tools in understanding how cardiotoxic drugs directly impact the mechanobiology of cardiomyocytes and how cardiomyocytes sense and respond to mechanical load at the cellular level.

The effect of adenosine triphosphate on sunitinib-induced cardiac injury in rats

In this study, we aimed to show the effect of adenosine 5'-triphosphate (ATP) on sunitinib-induced cardiac injury in rats. The rats (n = 30) were divided equally into three groups as sunitinib group (SG), sunitinib plus ATP group (SAG), and healthy group (HG); 2 mg/kg ATP was injected intraperitoneally (ip) to the SAG group. Same volume normal saline as solvent was administered ip to the other two groups. After 1 h, 25 mg/kg sunitinib was applied orally via catheter to stomach in the SAG and SG groups. This procedure was repeated once daily for 5 weeks. At the end of this period, all animals were sacrificed and their cardiac tissue was removed. Malondialdehyde (MDA), total glutathione (tGSH), tumor necrosis factor α (TNF-α), and nuclear factor κB (NF-κB) levels in rats' cardiac tissues and troponin I (Tp-I) levels in rats' blood samples were evaluated. Histopathological analysis was also performed in cardiac tissues of the animals. MDA, TNF-α, NF-κB, and Tp-I levels were higher in the SG group compared to the SAG and HG groups (p < 0.001). tGSH levels of the SG group were lower than the SAG and HG groups (p < 0.001). The structure and morphology of cardiac muscle fibers and blood vessels were normal in the control group. In the SG group, obvious cardiac muscle tissue damage with dilated myofibers, locally atrophic myofibers, and congested blood vessels were observed. In the SAG group, marked amelioration in these findings was observed. We showed this for the first time that ATP administration exerts a protective effect against cardiac effects of sunitinib.

Sirt3 promotes sensitivity to sunitinib-induced cardiotoxicity via inhibition of GTSP1/JNK/autophagy pathway in vivo and in vitro

Sunitinib malate is a multi-targeted tyrosine kinase inhibitor used extensively for treatment of human tumors. However, cardiovascular adverse effects of sunitinib limit its clinical use. It is pivotal to elucidate molecular targets that mediate sunitinib-induced cardiotoxicity. Sirtuin 3 (Sirt3) is an effective mitochondrial deacetylase that has been reported to regulate sensitivity of different types of cells to chemotherapies, but roles of Sirt3 in sunitinib-induced cardiotoxicity have not been investigated. In the present study, we established wild type, Sirt3-knockout, and Sirt3-overexpressing mouse models of sunitinib (40 mg kg^-1 day^-1 for 28 days)-induced cardiotoxicity and examined cardiovascular functions and pathological changes. We further cultured wild type, Sirt3-knockout, and Sirt3-overexpressing primary mouse cardiac pericytes and analyzed sunitinib (10 μMol for 48 h)-induced alterations in cellular viability, cell death processes, and molecular pathways. Our results show that sunitinib predominantly induced hypertension, left ventricular systolic dysfunction, and cardiac pericyte death accompanied with upregulation of Sirt3 in cardiac pericytes, and these cardiotoxicities were significantly attenuated in Sirt3-knockout mice, but aggravated in Sirt3-overexpressing mice. Mechanistically, sunitinib induced cardiac pericyte death through inhibition of GSTP1/JNK/autophagy pathway and Sirt3 interacted with and inhibited GSTP1, further inhibiting the pathway and aggravating sunitinib-induced pericyte death. Conclusively, we demonstrate that Sirt3 promotes sensitivity to sunitinib-induced cardiotoxicity via GSTP1/JNK/autophagy pathway. Our results suggest Sirt3 might be a potential target for developing cardioprotective therapies for sunitinib-receiving patients.

Ageing alters the severity of Sunitinib-induced cardiotoxicity: Investigating the mitogen activated kinase kinase 7 pathway association

Anti-cancer drug Sunitinib is linked to adverse cardiovascular events, which have shown to involve mitogen activated kinase kinase 7 (MKK7) pathway. Sunitinib-induced cardiotoxicity in 3, 12 and 24 months old male Sprague-Dawley rats and MKK7 expression and activation was investigated using the Langendorff perfused heart model followed by Western blot analysis. Cardiac function and infarct size were measured during/after 125 min of Sunitinib treatment. Left ventricular cardiac samples were analysed by qRT-PCR for expression of MKK7 mRNA and cardiac injury associated microRNAs. Infarct size was increased in all Sunitinib treated age groups. Haemodynamic alterations were observed following Sunitinib administration. Left ventricular developed pressure (LVDP) was decreased in all age groups, while heart rate (HR) was decreased in 3 and 12 months groups. Sunitinib treatment decreased the expression of miR-27a in all age groups, while miR-133a and miR-133b levels were increased in 3 months and decreased in 24 months groups. MKK7 mRNA and p-MKK7 levels were decreased in the 3 months group after Sunitinib treatment. MKK7 mRNA level was increased in 24 months group and p-MKK7 levels were increased in 12 months group following Sunitinib treatment. This study highlights the importance and impact of ageing and anti-cancer therapy-induced cardiotoxicity.

The Impact of Pazopanib on the Cardiovascular System

Pazopanib is an approved treatment for renal cell carcinoma and a second-line treatment for nonadipocytic soft-tissue sarcoma. However, its clinical efficacy is limited by its cardiovascular side effects. Pazopanib and other vascular endothelial growth factor receptor tyrosine kinase inhibitors have been associated with the development of hypertension, QT interval prolongation, and other cardiovascular events; however, these mechanisms are largely unknown. Gaining a deeper understanding of these mechanisms is essential for the development of appropriate surveillance strategies and possible diagnostic biomarkers to allow us to monitor patients and modulate therapy prior to significant cardiac insult. This approach will be vital in keeping patients on these life-saving therapies and may be applicable to other tyrosine kinase inhibitors as well. In this review, we provide a comprehensive overview of the preclinical and clinical side effects of pazopanib with a focus on the mechanisms responsible for its toxicity to the cardiovascular system.

Anticancer drugs-related QTc prolongation, torsade de pointes and sudden death: current evidence and future research perspectives

Anticancer drugs may have proarrhythmic effects including drug-induced QT interval prolongation, which is of particular importance because it can lead to a fatal polymorphic ventricular tachycardia termed torsade de pointes (TdP). QT interval prolongation and TdP are rare life-threatening untoward effects of anticancer therapy, particularly with arsenic trioxides and anthracyclines, and even some novel molecular targeted drugs touted as 'tumor specific'. Several factors that affect myocardial repolarization can further increase the risk of TdP. This article reviews the mechanism of QT interval prolongation, risk factors for TdP and the QT toxicity of anticancer drugs as well as its management. Specific attention should be paid to high-risk populations such as patients with underlying heart diseases, electrolyte imbalance and bradycardia. To minimize the occurrence of QT interval prolongation and TdP, it is advisable to conduct a careful risk factor assessment before antitumor therapy. To this end, several new biomarkers have been introduced to predict TdP triggering and recent studies have pointed out the potential clinical relevance of genetic testing.

Genetic and ethnic modulation of cardiovascular toxicity of vascular endothelial growth factor inhibitors

Vascular endothelial growth factor (VEGF) inhibitors, including monoclonal antibodies and tyrosine kinase inhibitors (TKIs), are important as anticancer treatments through curbing tumour angiogenesis and growth. VEGF inhibitors have significant cardiovascular effects. By blocking VEGF receptors, ligands, or signal pathways, VEGF inhibitors disturb the balance between vasodilation and vasoconstriction, undermine endothelial cell integrity, and activate cardiomyocyte apoptosis. VEGF inhibitors increase risks of hypertension, heart failure, thromboembolism and arrhythmia. Genetic and geographic studies showed that genetic polymorphisms likely play significant predictive or prognostic roles in cardiovascular toxicity associated with VEGF inhibitors. This review updates current understandings of VEGF inhibitors on cardiovascular toxicity, explores potential mechanisms, and clarifies whether genetic or ethnic factors contribute to their adverse effects. Key Messages VEGF inhibitors disturb the balance between vasodilation and vasoconstriction, undermine endothelial cell integrity and activate cardiomyocyte apoptosis. VEGF inhibitors increase risks of hypertension, heart failure, thromboembolism and arrhythmia. Genetic and geographic studies showed that genetic polymorphisms likely play significant predictive or prognostic roles in cardiovascular toxicity associated with VEGF inhibitors.

Incidence, Diagnosis, and Management of QT Prolongation Induced by Cancer Therapies: A Systematic Review

Background

The cardiovascular complications of cancer therapeutics are the focus of the burgeoning field of cardio‐oncology. A common challenge in this field is the impact of cancer drugs on cardiac repolarization (ie, QT prolongation) and the potential risk for the life‐threatening arrhythmia torsades de pointes. Although QT prolongation is not a perfect marker of arrhythmia risk, this has become a primary safety metric among oncologists. Cardiologists caring for patients receiving cancer treatment should become familiar with the drugs associated with QT prolongation, its incidence, and appropriate management strategies to provide meaningful consultation in this complex clinical scenario.

Methods and Results

In this article, we performed a systematic review (using Preferred Reporting Items of Systematic Reviews and Meta‐Analyses (PRISMA) guidelines) of commonly used cancer drugs to determine the incidence of QT prolongation and clinically relevant arrhythmias. We calculated summary estimates of the incidence of all and clinically relevant QT prolongation as well as arrhythmias and sudden cardiac death. We then describe strategies to prevent, identify, and manage QT prolongation in patients receiving cancer therapy. We identified a total of 173 relevant publications. The weighted incidence of any corrected QT (QTc) prolongation in our systematic review in patients treated with conventional therapies (eg, anthracyclines) ranged from 0% to 22%, although QTc >500 ms, arrhythmias, or sudden cardiac death was extremely rare. The risk of QTc prolongation with targeted therapies (eg, small molecular tyrosine kinase inhibitors) ranged between 0% and 22.7% with severe prolongation (QTc >500 ms) reported in 0% to 5.2% of the patients. Arrhythmias and sudden cardiac death were rare.

Conclusions

Our systematic review demonstrates that there is variability in the incidence of QTc prolongation of various cancer drugs; however, the clinical consequence, as defined by arrhythmias or sudden cardiac death, remains rare.

Management of QT prolongation induced by anti-cancer drugs: Target therapy and old agents. Different algorithms for different drugs

The side effects of anticancer drugs still play a critical role in survival and quality of life. Although the recent progresses of cancer therapies have significantly improved the prognosis of oncologic patients, side effects of antineoplastic treatments are still responsible for the increased mortality of cancer survivors. Cardiovascular toxicity is the most dangerous adverse effect induced by anticancer therapies. A survey conducted by the National Health and Nutrition Examination, showed that 1807 cancer survivors followed up for seven years: 51% died of cancer and 33% of heart disease (Vejpongsa and Yeh, 2014). Moreover, the risk of cardiotoxicity persists even with the targeted therapy, the newer type of cancer treatment, due to the presence of on-target and off-target effects related to this new class of drugs. The potential cardiovascular toxicity of anticancer agents includes: QT prolongation, arrhythmias, myocardial ischemia, stroke, hypertension (HTN), thromboembolism, left ventricular dysfunction and heart failure (HF). Compared to other cardiovascular disorders, the interest in QT prolongation and its complications is fairly recent. However, oncologists have to deal with it and to evaluate the risk-benefit ratio before starting the treatment or during the same. Electrolyte abnormalities, low levels of serum potassium and several drugs may favour the acquired QT prolongation. Treatment of marked QT prolongation includes cardiac monitoring, caution in the use or suspension of cancer drugs and correction of electrolyte abnormalities (hypokalaemia, hypomagnesaemia, hypocalcaemia). Syndrome of QT prolongation can be associated with potentially fatal cardiac arrhythmias and its treatment consists of intravenous administration of magnesium sulphate and the use of electrical cardioversion.

Kinase inhibitor screening using artificial neural networks and engineered cardiac biowires

Kinase inhibitors are often used as cancer targeting agents for their ability to prevent the activation of cell growth and proliferation signals. Cardiotoxic effects have been identified for some marketed kinase inhibitors that were not detected during clinical trials. We hypothesize that more predictive cardiac functional assessments of kinase inhibitors on human myocardium can be established by combining a high-throughput two-dimensional (2D) screening assay and a high-content three-dimensional (3D) engineered cardiac tissue (Biowire^TM) based assay, and using human induced pluripotent stem cell-derived CMs (hiPSC-CMs). A subset (80) of compounds from the GlaxoSmithKline published kinase inhibitor set were tested on hiPSC-CM monolayers and significant effects on cell viability, calcium transients, and contraction frequency were observed. Artificial neural network modelling was then used to analyze the experimental results in an efficient and unbiased manner to select for kinase inhibitors with minimal effects on cell viability and function. Inhibitors of specific interest based on the modeling were evaluated in the 3D Biowire tissues. The three-dimensional Biowire platform eliminated oversensitivity in detecting both Ca²⁺ transient amplitude enhancements as well as the acute detrimental effects on cell viability due to the kinase inhibitor application as compared to the monolayer testing.

Thorough QT (TQT) studies: concordance with torsadogenesis and an evolving cardiac safety testing paradigm

Since 2005, when the International Conference on Harmonisation (ICH) E14 guideline was adopted, no drug has been withdrawn because of QTc prolongation or torsade de pointes arrhythmia. There are, however, costs associated with this success. In addition to the time and money invested, thorough QT (TQT) studies have limited the efficiency of the drug development pipeline. In this paper, we discuss the relevance of TQT trials as a tool for proarrhythmic risk prediction as a part of the debate regarding their usefulness.

A Novel Positron Emission Tomography (PET) Approach to Monitor Cardiac Metabolic Pathway Remodeling in Response to Sunitinib Malate

Sunitinib is a tyrosine kinase inhibitor approved for the treatment of multiple solid tumors. However, cardiotoxicity is of increasing concern, with a need to develop rational mechanism driven approaches for the early detection of cardiac dysfunction. We sought to interrogate changes in cardiac energy substrate usage during sunitinib treatment, hypothesising that these changes could represent a strategy for the early detection of cardiotoxicity. Balb/CJ mice or Sprague-Dawley rats were treated orally for 4 weeks with 40 or 20 mg/kg/day sunitinib. Cardiac positron emission tomography (PET) was implemented to investigate alterations in myocardial glucose and oxidative metabolism. Following treatment, blood pressure increased, and left ventricular ejection fraction decreased. Cardiac [¹⁸F]-fluorodeoxyglucose (FDG)-PET revealed increased glucose uptake after 48 hours. [¹¹C]Acetate-PET showed decreased myocardial perfusion following treatment. Electron microscopy revealed significant lipid accumulation in the myocardium. Proteomic analyses indicated that oxidative metabolism, fatty acid β-oxidation and mitochondrial dysfunction were among the top myocardial signalling pathways perturbed. Sunitinib treatment results in an increased reliance on glycolysis, increased myocardial lipid deposition and perturbed mitochondrial function, indicative of a fundamental energy crisis resulting in compromised myocardial energy metabolism and function. Our findings suggest that a cardiac PET strategy may represent a rational approach to non-invasively monitor metabolic pathway remodeling following sunitinib treatment.

Targeted therapies in thyroid cancer: an extensive review of the literature

INTRODUCTION

Patients with progressive, metastatic, RAI-refractory differentiated thyroid cancer (DTC), as well as patients with advanced medullary (MTC) and anaplastic thyroid cancer represent a cohort for which therapeutic options are limited. The recent discoveries in the molecular mechanisms implicated in TC have provided insight of the pathogenesis and progression of disease. In that respect, targeted therapies have emerged as a promising alternative for the treatment of those patients. Areas covered: Tyrosine Kinase Inhibitors (TKIs) have been studied extensively in TC: sorafenib and lenvatinib have been approved by the FDA for the treatment of metastatic, RAI-refractory DTC, while vandetanib and cabozantinib are FDA approved for use in advanced MTC. Moreover, several additional TKIs, multi-targeted or specific, are currently under investigation in TC. The current manuscript provides an extensive review of the literature regarding targeted therapies in TC including the rationale behind their use, the clinical trials and an expert opinion on their use. Literature in English appearing at PubMed was thoroughly reviewed, especially manuscripts of the last 5 years. Expert commentary: Patients with advanced, progressive, metastatic TC should be evaluated for enrollment in a clinical trial or should be placed on treatment with one of the FDA- and EMA- approved agents.

Electrocardiographic Characterization of Ramucirumab on the Corrected QT Interval in a Phase II Study of Patients With Advanced Solid Tumors

LESSONS LEARNED

Cardiotoxicity can be a serious complication of anticancer therapies. To enable earlier identification of drug-related cardiac effects, the International Conference on Harmonization (ICH) adopted the ICH E14 Guidelines for evaluating the potential for QT/corrected QT (QTc) interval prolongation and proarrhythmic potential for nonantiarrhythmic drugs.The results of the evaluation of ramucirumab on the QT/QTc interval show a lack of effect on QTc prolongation in patients with advanced cancer.

BACKGROUND

Ramucirumab is a human immunoglobulin G1 monoclonal antibody that specifically blocks vascular endothelial growth factor receptor-2 and is approved for the treatment of advanced gastric, non-small cell lung, and colorectal cancers. This phase II study was conducted to determine if treatment with ramucirumab causes prolongation of the corrected QT interval using Fridericia's formula (QTcF) in patients with advanced cancer.

METHODS

Patients received intravenous ramucirumab (10 mg/kg) every 21 days for 3 cycles. The first 16 patients received moxifloxacin (400 mg orally), an antibiotic associated with mild QT prolongation as a positive control. During cycle 3, determination of QTcF prolongation was made with triplicate electrocardiograms at multiple time points to compare with baseline.

RESULTS

Sixty-six patients received therapy; 51 patients completed 9 or more weeks of therapy for the complete QTcF evaluation period. The upper limit of the 90% two-sided confidence intervals for the least square means of change in QTcF from baseline at each time point was less than 10 milliseconds. Concentration-QTcF analysis showed a visible, but not significant, negative association between ramucirumab concentration and QTcF change from baseline.

CONCLUSION

Ramucirumab at a dose of 10 mg/kg administered every 21 days for 3 cycles did not produce a statistically or clinically significant prolongation of QTcF.

Benefits of Centralized ECG Reading in Clinical Oncology Studies

BACKGROUND

Many clinical trials of investigational oncologic agents utilize electrocardiogram (ECG) machine measurements of QTc, for inclusion/exclusion and dosing decisions, though their reliability in this setting has not been established.

METHODS

We compared the digital ECG machine QTc measurements with those obtained by a centralized ECG core lab on more than 270,000 consecutive ECGs collected from 299 clinical oncology trials.

RESULTS

The mean difference between the ECG machine measurements and the central measured QTcF was 1.8 ± 15.7 milliseconds. In addition, 29.7% of ECGs with an ECG machine-measured QTcF >450 milliseconds had a centrally measured QTcF <450 milliseconds, 44.6% of ECGs with an ECG machine-measured QTcF >470 milliseconds had a centrally measured QTcF <470 milliseconds, and 77.2% of ECGs with an ECG machine-measured QTcF >500 milliseconds had a centrally measured QTcF <500 milliseconds. The likelihood of a large discrepancy between the ECG machine- and centrally measured value for QTcF increased at both the high and low ends of the range of ECG machine QTcF measurements.

CONCLUSIONS

While on average ECG machine-measured QTcF values were very similar to the central core lab measurements; there were very significant discrepancies which will have important implications for patient recruitment for clinical oncology trials as well as for patient safety during dosing with new oncologic agents. Reliance on ECG machine QTc measurements during clinical oncology trials may lead to unnecessary exclusion of patients as well as unneeded treatment interruptions.

Cardiac safety of afatinib: a review of data from clinical trials

BACKGROUND

Afatinib is an oral irreversible ErbB family blocker that targets epidermal growth factor receptor (EGFR/ErbB1), human epidermal growth factor receptor 2 (HER2/ErbB2), and HER4 (ErbB4) and is approved for the first-line treatment of advanced non-small cell lung cancer (NSCLC) with certain sensitizing EGFR mutations. As anti-HER2 therapies have been associated with cardiac dysfunction, we report cardiac safety data for afatinib.

METHODS

Cardiac data were analyzed from phase III trials of afatinib 40 mg in treatment-naive patients with EGFR mutation-positive NSCLC (LUX-Lung 3 [LL3]; n = 229 afatinib, n = 111 chemotherapy) and afatinib 50 mg in EGFR tyrosine kinase inhibitor-pretreated NSCLC patients (LUX-Lung 1 [LL1]; n = 390 afatinib, n = 195 placebo). Additional pooled data from 49 trials (n = 3865 afatinib-treated patients) is reported. Cardiac failure adverse events (CF-AEs), including symptomatic cardiac failure and depressed left ventricular ejection fraction (LVEF), were analyzed.

RESULTS

Time at risk-adjusted CF-AE rates (events/100 patient-years) were similar for afatinib versus placebo in LL1 (2.40 vs 2.23) and versus chemotherapy in LL3 (2.28 vs 2.92); the pooled afatinib CF-AE rate (2.88) was consistent with that for both trials. The frequency of clinically significant LVEF reductions was higher for chemotherapy in LL3 (2/15 [13.3 %], afatinib 13/208 [6.3 %]; p = 0.267) and similar to placebo in LL1 (5/122 [4.1 %], afatinib 14/304 [4.6 %]; p = 1.000).

CONCLUSION

Afatinib was not associated with cardiac failure or LVEF reductions in the afatinib clinical trial program.

Effects of acute and chronic sunitinib treatment on cardiac function and calcium/calmodulin-dependent protein kinase II

BACKGROUND AND PURPOSE

Calcium/calmodulin-dependent protein kinase IIδ (CaMKIIδ) is an important regulator of cardiac contractile function and dysfunction and may be an unwanted secondary target for anti-cancer drugs such as sunitinib and imatinib that have been reported to alter cardiac performance. This study aimed to determine whether anti-cancer kinase inhibitors may affect CaMKII activity and expression when administered in vivo.

EXPERIMENTAL APPROACH

Cardiovascular haemodynamics in response to acute and chronic sunitinib treatment, and chronic imatinib treatment, were assessed in guinea pigs and the effects compared with those of the known positive and negative inotropes, isoprenaline and verapamil. Parallel studies from the same animals assessed CaMKIIδ expression and CaMKII activity following drug treatments.

KEY RESULTS

Acute administration of sunitinib decreased left ventricular (LV) dP/dtmax. Acute administration of isoprenaline increased LVdP/dtmax dose-dependently, while LVdP/dtmax was decreased by verapamil. CaMKII activity was decreased by acute administration of sunitinib and was increased by acute administration of isoprenaline, and decreased by acute administration of verapamil. CaMKIIδ expression following all acute treatments remained unchanged. Chronic imatinib and sunitinib treatments did not alter fractional shortening; however, both CaMKIIδ expression and CaMKII activity were significantly increased. Chronic administration of isoprenaline and verapamil decreased LV fractional shortening with parallel increases in CaMKIIδ expression and CaMKII activity.

CONCLUSIONS AND IMPLICATIONS

Chronic sunitinib and imatinib treatment increased CaMKIIδ expression and CaMKII activity. As these compounds are associated with cardiac dysfunction, increased CaMKII expression could be an early indication of cellular cardiotoxicity marking potential progression of cardiac contractile dysfunction.

Integrated nonclinical and clinical risk assessment of the investigational proteasome inhibitor ixazomib on the QTc interval in cancer patients

BACKGROUND

Ixazomib is the first oral, proteasome inhibitor to reach phase III trials. Here, we present an integrated nonclinical and clinical assessment of ixazomib's effect on QTc intervals.

METHODS

Nonclinical studies assessed (1) the in vitro binding of ixazomib to the hERG channel and (2) its effect on QT/QTc in dogs (N = 4) via telemetry. Pharmacokinetic-matched triplicate electrocardiograms were collected in four clinical phase I studies of intravenous (0.125-3.11 mg/m(2), N = 125, solid tumors/lymphoma) or oral (0.24-3.95 mg/m(2), N = 120, multiple myeloma) ixazomib. The relationship between ixazomib plasma concentration and heart rate (HR)-corrected QT using Fridericia (QTcF) or population (QTcP) methods was analyzed using linear mixed-effects models with fixed effects for day and time.

RESULTS

In vitro binding potency for ixazomib to the hERG channel was weak (K i 24.9 μM; IC50 59.6 μM), and nonclinical telemetry studies showed no QT/QTc prolongation at doses up to 4.2 mg/m(2). In cancer patients, ixazomib, when evaluated at doses yielding various plasma concentrations (with 26 % of data greater than mean C max for the 4 mg phase 3 dose), had no meaningful effect on QTc based on model-predicted mean change in QTcF/QTcP from baseline. There was no relationship between ixazomib concentration and RR, suggesting no effect on HR.

CONCLUSIONS

Ixazomib has no clinically meaningful effects on QTc or HR. Integrating preclinical data and concentration-QTc modeling of phase 1 data may obviate the need for a dedicated QTc study in oncology. A framework for QT assessment in oncology drug development is proposed.

Incidence and relevance of QTc-interval prolongation caused by tyrosine kinase inhibitors

BACKGROUND

Tyrosine kinase inhibitors (TKIs) are associated with prolongation of the QTc interval on the electrocardiogram (ECG). The QTc-interval prolongation increases the risk of life-threatening arrhythmias. However, studies evaluating the effects of TKIs on QTc intervals are limited and only consist of small patient numbers.

METHODS

In this multicentre trial in four centres in the Netherlands and Italy we screened all patients who were treated with any TKI. To evaluate the effects of TKIs on the QTc interval, we investigated ECGs before and during treatment with erlotinib, gefitinib, imatinib, lapatinib, pazopanib, sorafenib, sunitinib, or vemurafenib.

RESULTS

A total of 363 patients were eligible for the analyses. At baseline measurement, QTc intervals were significantly longer in females than in males (QTcfemales=404 ms vs QTcmales=399 ms, P=0.027). A statistically significant increase was observed for the individual TKIs sunitinib, vemurafenib, sorafenib, imatinib, and erlotinib, after the start of treatment (median ΔQTc ranging from +7 to +24 ms, P<0.004). The CTCAE grade for QTc intervals significantly increased after start of treatment (P=0.0003). Especially patients who are treated with vemurafenib are at increased risk of developing a QTc of ⩾470 ms, a threshold associated with an increased risk for arrhythmias.

CONCLUSIONS

These observations show that most TKIs significantly increase the QTc interval. Particularly in vemurafenib-treated patients, the incidence of patients at risk for arrhythmias is increased. Therefore, especially in case of combined risk factors, ECG monitoring in patients treated with TKIs is strongly recommended.

Physiological, pharmacological and toxicological considerations of drug-induced structural cardiac injury

The incidence of drug-induced structural cardiotoxicity, which may lead to heart failure, has been recognized in association with the use of anthracycline anti-cancer drugs for many years, but has also been shown to occur following treatment with the new generation of targeted anti-cancer agents that inhibit one or more receptor or non-receptor tyrosine kinases, serine/threonine kinases as well as several classes of non-oncology agents. A workshop organized by the Medical Research Council Centre for Drug Safety Science (University of Liverpool) on 5 September 2013 and attended by industry, academia and regulatory representatives, was designed to gain a better understanding of the gaps in the field of structural cardiotoxicity that can be addressed through collaborative efforts. Specific recommendations from the workshop for future collaborative activities included: greater efforts to identify predictive (i) preclinical; and (ii) clinical biomarkers of early cardiovascular injury; (iii) improved understanding of comparative physiology/pathophysiology and the clinical predictivity of current preclinical in vivo models; (iv) the identification and use of a set of cardiotoxic reference compounds for comparative profiling in improved animal and human cellular models; (v) more sharing of data (through publication/consortia arrangements) on target-related toxicities; (vi) strategies to develop cardio-protective agents; and (vii) closer interactions between preclinical scientists and clinicians to help ensure best translational efforts.

Effect of axitinib on the QT interval in healthy volunteers

PURPOSE

Axitinib is a potent and selective inhibitor of vascular endothelial growth factor receptors 1-3, approved for second-line treatment of advanced renal cell carcinoma (RCC). Preclinical studies did not indicate potential for axitinib-induced delayed cardiac repolarization.

METHODS

The effect of axitinib on corrected QT (QTc) prolongation was evaluated with one-stage concentration-QTc response modeling using data from a definitive randomized crossover QT phase I study in healthy volunteers administered one single 5-mg axitinib dose alone or in the presence of steady-state ketoconazole (400 mg once daily).

RESULTS

Axitinib and ketoconazole had opposite effects on heart rate: Axitinib lowered it, ketoconazole raised it. The final analysis showed a flat relationship between QTc and axitinib concentration (slope -0.0314 ms·mL/ng) for axitinib alone. Mean highest placebo-matched change from baseline in QTc was -3.0 [90 % confidence interval (CI) -5.4, -0.6] ms. At supratherapeutic axitinib exposures achieved with potent cytochrome P450 3A4/5 inhibition by ketoconazole, the model predicted mean QTc change of 6.5 (90 % CI 4.4-8.5) ms. The slope population mean estimate was -0.331 (95 % CI -0.860, 0.198) ms·mL/µg for ketoconazole alone and 0.0725 (0.0445-0.1005) ms·mL/ng for axitinib in the presence of ketoconazole. The results were then compared with those obtained based on more widely used Fridericia's, Bazett's, and study-specific correction methods.

CONCLUSIONS

Since axitinib plasma concentrations observed in this study exceeded the range of concentrations observed in patients with RCC at the highest approved clinical dose (10 mg twice daily), axitinib was not associated with clinically significant QTc prolongation in target populations.

QTc interval prolongation with vascular endothelial growth factor receptor tyrosine kinase inhibitors

Background:

Multi-targeted vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs) are known to cause cardiac toxicity, but the relative risk (RR) of QTc interval prolongation and serious arrhythmias associated with them are not reported.

Methods:

We conducted a trial-level meta-analysis of randomised phase II and III trials comparing arms with and without a US Food and Drug Administration-approved VEGFR TKI (sunitinib, sorafenib, pazopanib, axitinib, vandetanib, cabozantinib, ponatinib and regorafenib). A total of 6548 patients from 18 trials were selected. Statistical analyses were conducted to calculate the summary incidence, RR and 95% CIs.

Results:

The RR for all-grade and high-grade QTc prolongation for the TKI vs no TKI arms was 8.66 (95% CI 4.92–15.2, P<0.001) and 2.69 (95% CI 1.33–5.44, P=0.006), respectively, with most of the events being asymptomatic QTc prolongation. Respectively, 4.4% and 0.83% of patients exposed to VEGFR TKI had all-grade and high-grade QTc prolongation. On subgroup analysis, only sunitinib and vandetanib were associated with a statistically significant risk of QTc prolongation, with higher doses of vandetanib associated with a greater risk. The rate of serious arrhythmias including torsades de pointes did not seem to be higher with high-grade QTc prolongation. The risk of QTc prolongation was independent of the duration of therapy.

Conclusions:

In the largest study to date, we show that VEGFR TKI can be associated with QTc prolongation. Although most cases were of low clinical significance, it is unclear whether the same applies to patients treated off clinical trials.

Prevention of Pazopanib-Induced Prolonged Cardiac Repolarization and Proarrhythmic Effects

Background

Pazopanib (PZP) may induce prolonged cardiac repolarization and proarrhythmic effects, similarly to other tyrosine kinase inhibitors.

Objectives

To demonstrate PZP-induced prolonged cardiac repolarization and proarrhythmic electrophysiological effects and to investigate possible preventive effects of metoprolol and diltiazem on ECG changes (prolonged QT) in an experimental rat model.

Methods

Twenty-four Sprague-Dawley adult male rats were randomly assigned to 4 groups (n = 6). The first group (normal group) received 4 mL of tap water and the other groups received 100 mg/kg of PZP (Votrient^® tablet) perorally, via orogastric tubes. After 3 hours, the following solutions were intraperitoneally administered to the animals: physiological saline solution (SP), to the normal group and to the second group (control-PZP+SP group); 1 mg/kg metoprolol (Beloc, Ampule, AstraZeneca), to the third group (PZP+metoprolol group); and 1mg/kg diltiazem (Diltiazem, Mustafa Nevzat), to the fourth group (PZP+diltiazem group). One hour after, and under anesthesia, QTc was calculated by recording ECG on lead I.

Results

The mean QTc interval values were as follows: normal group, 99.93 ± 3.62 ms; control-PZP+SP group, 131.23 ± 12.21 ms; PZP+metoprolol group, 89.36 ± 3.61 ms; and PZP+diltiazem group, 88.86 ± 4.04 ms. Both PZP+metoprolol and PZP+diltiazem groups had significantly shorter QTc intervals compared to the control-PZP+SP group (p < 0.001).

Conclusion

Both metoprolol and diltiazem prevented PZP-induced QT interval prolongation. These drugs may provide a promising prophylactic strategy for the prolonged QTc interval associated with tyrosine kinase inhibitor use.

Concurrent evolution of cancer cachexia and heart failure: bilateral effects exist

Cancer cachexia is defined as a multifactorial syndrome of involuntary weight loss characterized by an ongoing loss of skeletal muscle mass and progressive functional impairment. It is postulated that cardiac dysfunction/atrophy parallels skeletal muscle atrophy in cancer cachexia. Cardiotoxic chemotherapy may additionally result in cardiac dysfunction and heart failure in some cancer patients. Heart failure thus may be a consequence of either ongoing cachexia or chemotherapy-induced cardiotoxicity; at the same time, heart failure can result in cachexia, especially muscle wasting. Therefore, the subsequent heart failure and cardiac cachexia can exacerbate the existing cancer-induced cachexia. We discuss these bilateral effects between cancer cachexia and heart failure in cancer patients. Since cachectic patients are more susceptible to chemotherapy-induced toxicity overall, this may also include increased cardiotoxicity of antineoplastic agents. Patients with cachexia could thus be doubly unfortunate, with cachexia-related cardiac dysfunction/heart failure and increased susceptibility to cardiotoxicity during treatment. Cardiovascular risk factors as well as pre-existing heart failure seem to exacerbate cardiac susceptibility against cachexia and increase the rate of cardiac cachexia. Hence, chemotherapy-induced cardiotoxicity, cardiovascular risk factors, and pre-existing heart failure may accelerate the vicious cycle of cachexia-heart failure. The impact of cancer cachexia on cardiac dysfunction/heart failure in cancer patients has not been thoroughly studied. A combination of serial echocardiography for detection of cachexia-induced cardiac remodeling and computed tomography image analysis for detection of skeletal muscle wasting would appear a practical and non-invasive approach to develop an understanding of cardiac structural/functional alterations that are directly related to cachexia.

Chemotherapy and QT Prolongation: Overview With Clinical Perspective

OPINION STATEMENT

Cardiotoxic adverse events are of concern to physicians treating cancer patients; they are encountered with a variety of agents. Cardiac events may delay the approval of new drugs or impose burdensome monitoring requirements as either part of the pre-approval process or in the daily use of these agents. Among the cardiac issues are the development of QT prolongation and the fear of torsades de pointes (TdP), an unusual yet potentially fatal form of ventricular tachycardia associated with QT prolongation. Several risk factors, including electrolyte imbalance and polypharmacy with concomitant QT prolonging agents use can increase the risk of TdP in cancer patients; separating the individual contributions of the various triggers for TdP remains problematic. Understanding the individual risk of QT prolongation associated with particular chemotherapies can better differentiate between those shown to have higher risk vs. those with lower risk potential. Cardiac monitoring and electrocardiogram analysis require recognition of the common challenges with regard to the precise measurement of the QT interval such as the presence of U waves, intraventricular conduction delays, and heart rate correction. Rapid identification and treatment of QT prolongation and TdP is critical in mitigating the risk of sudden cardiac death in cancer patients. A multidisciplinary treatment approach among cardiologists and oncologists should be employed to help facilitate an appropriate balance between oncologic efficacy and adverse cardiac events.

The effect of sunitinib on the plasma exposure of intravenous paracetamol and its major metabolite: paracetamol glucuronide

The study aimed to examine the effect of sunitinib on the plasma exposure of intravenous paracetamol and its major metabolite, paracetamol glucuronide. Both drugs share metabolic pathways in the liver, and the drug interactions between sunitinib and paracetamol administered in higher doses were reported. These interactions resulted in hepatotoxicity. The adult New Zealand male rabbits were divided into three groups (6 animals each): rabbits receiving sunitinib and paracetamol (SUN + PC), rabbits receiving sunitinib (SUN), and a control group receiving paracetamol (PC). Sunitinib was administered orally (25 mg) and paracetamol was administrated intravenously (35 mg/kg). Blood samples for sunitinib and SU12662 assays were collected up to 96 h after drug administration and for paracetamol and paracetamol glucuronide up to 300 min after drug administration. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and bilirubin were analysed before and after drug administration. A number of pharmacokinetic parameters were analysed. There were no differences in the levels of AST, ALT, and bilirubin among the groups at either time point. Significantly higher values of AUC_0–t, AUC_0–∞, and C_max and lower clearance and volume of distribution of paracetamol were observed in group PC vs. group SUN + PC (p < 0.01). The maximum plasma concentration of paracetamol glucuronide tended to be higher in group PC 213.27 μg/mL (90 % CI 1.06, 1.25; p = 0.0267). Statistically significant differences were revealed for paracetamol glucuronide mean residence time (MRT); MRT was higher in group SUN + PC than in group PC (p = 0.0375). The mean t_max of paracetamol glucuronide was similar in both groups: SUN + PC and group PC (15 and 20 min, respectively). The mean t_max of sunitinib was different in groups SUN + PC and SUN (10.0 and 7.0, respectively; p = 0.0134). At the studied doses, neither of the drugs, whether administered alone or together, had hepatotoxic effects. The present study was not able to confirm that sunitinib, administered at low doses in conjunction with paracetamol, displays a hepatoprotective effect. Significant differences were observed in some pharmacokinetic parameters of paracetamol.

Drug interactions with sunitinib

PURPOSE

Sunitinib is a tyrosine kinase inhibitor indicated for the treatment of gastrointestinal stromal tumor, advanced renal cell carcinoma, and pancreatic neuroendocrine tumors. The aim of this article is to describe the pharmacological interactions between sunitinib and commonly prescribed drugs.

METHOD

We reviewed available information on pharmacological interactions between sunitinib and concomitantly prescribed drugs. Drugs were grouped into different therapeutic groups according to the Anatomical Therapeutic Chemical (ATC) classification.

RESULTS

Sunitinib interacts with CYP3A4 inducers or inhibitors and with P-glycoprotein and ABCG2 substrates. Pharmacodynamic interactions with drugs have also been found.

CONCLUSION

Current information on drug interactions between sunitinib and other drugs is scarce and most of the times it is difficult to apply to clinical practice. Even so, this difficulty in managing drug interactions should not be a reason to ignore them as they can help to explain intolerances and treatment failures.

A randomized, double-blind, placebo-controlled study to assess QTc interval prolongation of standard dose aflibercept in cancer patients treated with docetaxel

: The effect of repeated doses of aflibercept on ventricular repolarization in cancer patients was evaluated in an intensive electrocardiogram trial. This randomized, placebo-controlled, double-blind trial was conducted in 87 treated solid tumor patients. Treatment was with 6 mg/kg aflibercept, 1-hour intravenous (n = 43), or placebo (n = 44), combined with ≤75 mg/m docetaxel, every 3 weeks. Electrocardiograms were collected for 6 hours posttreatment using digital 12-lead Holter recorders, at day 1, in cycles 1 and 3. Free and vascular endothelial growth factor-bound aflibercept concentrations were assessed at similar time points. Eighty-four patients (43 placebo and 41 aflibercept) were evaluable for QT interval, Fridericia correction (QTcF) at cycle 1 and 59 (31 placebo and 28 aflibercept) at cycle 3. During cycle 3, from 30 minutes to 6 hours after the start of aflibercept, the maximum observed upper limit of the QTcF 90% confidence interval was 16 ms, for a mean of 8.4 ms. QTcF prolongation above 480 ms and 60 ms above baseline was observed in 1 aflibercept patient (2%). The slope of the relationship between free aflibercept concentration and QTcF was 0.048 (95% confidence interval, 0.013-0.082), corresponding to a 5-ms increase per 100 µg/mL increase in concentration. These results exclude a clinically important effect of aflibercept on ventricular repolarization.