Increased risk of high-grade hypertension with bevacizumab in cancer patients: a meta-analysis

Cardiovascular toxicity of anticancer-targeted therapy: emerging issues in the era of cardio-oncology

Over the last decade, the advent of molecular targeted therapy radically changed the treatment of several forms of cancer. However, these innovative anticancer drugs, namely monoclonal antibodies and small molecule tyrosine kinase inhibitors were found to adversely affect cardiovascular function. These "on-target" and "off-target" drug side effects encompass a wide range of cardio toxicities, including left ventricular dysfunction leading to heart failure, electrocardiographic abnormalities with dysrhythmias, hypertension, myocardial ischemia and thromboembolic events. The unclear incidence of drug-induced cardiovascular events together with uncertainty on their reversibility and long-term safety call for a multidisciplinary effort embracing cardio-oncological expertise supported by primary care physicians, pharmacologists and toxicologists. Here we address emerging cardiovascular events associated with targeted anticancer drugs by offering a concise review on: (1) mechanistic basis subtending cardiotoxicity and (2) clinical advice for effective patient management (i.e., detection, treatment, monitoring and reporting of cardiovascular side effects). In this scenario, onco-vigilance (i.e., pharmacovigilance oriented to oncologic drugs) is emerging as a key to support cardio-oncologists in appropriateness [corrected].

Risks and benefits with bevacizumab: evidence and clinical implications

With the 1997 filing of an investigational new drug application for the first agent to target angiogenesis, bevacizumab entered into phase I clinical trials and has now become a mainstay in the treatment of several cancers. Bevacizumab has changed the treatment approach for cancers due to its efficacy as well as toxicity. This article serves as a review of current efficacy data including recently published safety analyses and the direction of future pharmacodynamic evaluation to hopefully better guide its utilization.

Is the toxicity of anti-angiogenic drugs predictive of outcome? A review of hypertension and proteinuria as biomarkers of response to anti-angiogenic therapy

INTRODUCTION

The prototypic anti-angiogenic agents, VEGF inhibitors, are increasingly used in clinical practice to treat a variety of tumours. Although generally well tolerated, their toxicities can be significant or occasionally life threatening. The ability to identify those patients whose disease will respond to VEGF inhibitors would minimise exposure to ineffective drugs for some patients. To date, there are no validated predictive or prognostic biomarkers for anti-angiogenic drugs. Toxicities such as hypertension and proteinuria are related to the effect of VEGF inhibition on the vasculature. This has led to the investigation of these toxicities as potential biomarkers of clinical outcome in patients treated with these agents.

AREAS COVERED

Putative mechanisms for the development of hypertension and proteinuria, and their potential role as clinically useful biomarkers in relation to anti-angiogenic drugs are discussed in this article. PUBMED, EMBASE and abstracts presented at the American Society of Clinical Oncology until July 2011 were searched to identify relevant English language articles. Studies of anti-angiogenic therapies testing the relationship of either hypertension or proteinuria with outcome were included.

EXPERT OPINION

The evidence in support of the hypothesis that hypertension and proteinuria are biomarkers of response to anti-angiogenic drugs is inconclusive. Current evidence suggests that hypertension is a pharmacodynamic effect of anti-angiogenic agents. Future studies should aim to measure and report toxicities in a standardised manner to facilitate comparisons between studies.

Management of treatment-related toxicity with targeted therapies for renal cell carcinoma: evidence-based practice and best practices

The advent of targeted agents for the treatment of advanced renal cell carcinoma has led to dramatic improvements in therapy. However, the chronic use of these medications has also led to the identification of new toxicities that require long-term management. Effective management of toxicity is needed to maximize the benefits of treatment and improve patients' quality of life. In addition, toxicity from these agents may affect treatment compliance, particularly with daily oral agents. This review delineates the toxicities that require monitoring, the underlying pathophysiology (when known), and treatments that may have benefits in relieving symptoms and side effects.

Molecular mechanisms of hypertension and heart failure due to antiangiogenic cancer therapies

Targeted antiangiogenic cancer therapies have revolutionized the treatment of highly vascularized cancers such as metastatic renal cell carcinoma and gastrointestinal stromal tumors. Such agents act by inhibiting the actions of proangiogenic growth factors and their receptor tyrosine kinases, which are known to be overexpressed in cancer. However, these factors also play an important role in normal cardiovascular physiology. This article summarizes the incidences of cardiovascular toxicities (namely hypertension and heart failure) associated with the most commonly used antiangiogenic therapies, and then presents data from preclinical and clinical studies to provide some insight into the underlying molecular mechanisms.

Cardiotoxicity of molecularly targeted agents

Cardiac toxicity of molecularly targeted cancer agents is increasingly recognized as a significant side effect of chemotherapy. These new potent therapies may not only affect the survival of cancer cells, but have the potential to adversely impact normal cardiac and vascular function. Unraveling the mechanisms by which these therapies affect the heart and vasculature is crucial for improving drug design and finding alternative therapies to protect patients predisposed to cardiovascular disease. In this review, we summarize the classification and side effects of currently approved molecularly targeted chemotherapeutics.

Tumor angiogenesis: pericytes and maturation are not to be ignored

Angiogenesis, an essential component of tumor growth and survival, is regulated by complex interactions between several cell types and soluble mediators. Heterogeneous tumor vasculature originates from the collective effect of the nature of carcinoma and the complexity of the angiogenic network. Although the application of angiogenesis inhibitors in some types of cancers has shown clinical benefits, predictive markers to assess treatment effects have yet to be established. In this review, we focus on tumor vessel maturity as a potential marker for evaluating treatment response.

Bevacizumab-induced hypertension: pathogenesis and management

Bevacizumab, a recombinant humanized monoclonal antibody targeting the vascular endothelial growth factor (VEGF), has been approved in the US as first- and second-line treatment of colorectal cancer and in the first-line treatment of advanced non-small cell lung cancer. The US FDA has also granted approval for the use of bevacizumab for the treatment of patients with metastatic renal cell carcinoma and glioblastoma, and in Europe, it is also approved in metastatic breast cancer in combination with paclitaxel. Bevacizumab is under investigation in the first-line and adjuvant setting of almost all types of solid tumors. However, anti-VEGF therapy is associated with significant toxicity. The incidence of grade 3-4 hypertension differs among the various malignancies in which bevacizumab is administered, possibly because of drug interactions with co-administered chemotherapy drugs. Hypertension appears to be dose dependent, and it is under investigation as a biomarker for VEGF inhibition efficacy. There are three main theories concerning the underlying pathophysiology: (i) the nitric oxide theory; (ii) the renal impairment theory; and (iii) the pre-eclampsia-like theory. The correct evaluation of the levels of hypertension is of critical importance and home blood pressure monitoring seems to be the most effective technique. A baseline assessment and follow-up monitoring of blood pressure is considered necessary for all patients receiving bevacizumab. There are no evidence-based recommendations regarding which antihypertensives are more appropriate for the management of bevacizumab-related hypertension. It has been suggested that the benefits from antihypertensive treatment are largely independent of the drugs used, as long as they adequately lower blood pressure. Randomized prospective studies are necessary to provide data that will be useful for the development of specific guidelines for the management of bevacizumab-related hypertension. In the meantime, treatment of anti-VEGF-induced hypertension should follow current guidelines for diagnosis and management of hypertension in general.

Therapeutic promise and challenges of targeting DLL4/NOTCH1

DLL4-mediated NOTCH1 signaling represents an essential pathway for vascular development and has emerged as an attractive target for angiogenesis-based cancer therapies. However, newly reported toxicity findings raise safety concerns of chronic pathway blockade. Lessons learned from the development of γ-secretase inhibitors (GSIs) might offer insights into how to safely harness this important signaling pathway.

Systemic therapies for metastatic renal cell carcinoma in older adults

The introduction of targeted therapies has radically changed the treatment paradigm for metastatic renal cell carcinoma (mRCC). However, multiple clinical dilemmas have emerged. For instance, limited data are available to juxtapose the safety and efficacy profile of targeted therapies between older and younger adults. Herein, pivotal trials of vascular endothelial growth factor (VEGF)- and mammalian target of rapamycin (mTOR)-directed therapies are assessed in the context of their implications in treating older adults with mRCC. In general, subset analyses from these pivotal studies suggest similar efficacy of targeted therapies amongst older adults. Aging is accompanied by a multitude of physiological changes, as well as an increased prevalence of co-morbidities. The age-related toxicity profiles of targeted agents for mRCC are detailed to provide a framework for the risks and benefits of these therapies in older adults. Ultimately, tools such as the Comprehensive Geriatric Assessment (CGA) that account for physiological (as opposed to chronological) age may prove useful in the evaluation and treatment of older adults with mRCC.

Incidence and risk of congestive heart failure in patients with renal and nonrenal cell carcinoma treated with sunitinib

PURPOSE

Sunitinib is a multitargeted receptor tyrosine kinase inhibitor approved for treatment of renal cell carcinoma (RCC) and GI stromal tumor. Congestive heart failure (CHF) is an important adverse effect that has been reported with sunitinib, but overall incidence and relative risk (RR) remain undefined. We performed an up-to-date meta-analysis to determine the risk of developing CHF in patients with both RCC and non-RCC tumors treated with sunitinib.

METHODS

Medline databases were searched for articles published between January 1966 and February 2011. Eligible studies were limited to phase II and III trials of sunitinib with adequate safety reporting in patients with cancer of any tumor type. Summary incidence, RR, and 95% CIs were calculated using random- or fixed-effects models based on the heterogeneity of included studies.

RESULTS

A total of 6,935 patients were included. Overall incidence for all- and high-grade CHF in sunitinib-treated patients was 4.1% (95% CI, 1.5% to 10.6%) and 1.5% (95% CI, 0.8% to 3.0%), respectively. RR of all- and high-grade CHF in sunitinib-treated patients compared with placebo-treated patients was 1.81 (95% CI, 1.30 to 2.50; P < .001) and 3.30 (95% CI, 1.29 to 8.45; P = .01), respectively. On subgroup analysis, there was no difference observed in CHF incidence for patients with RCC versus non-RCC or in trials with or without cardiac monitoring. No evidence of publication bias was observed.

CONCLUSION

Sunitinib use is associated with increased risk of CHF in patients with cancer.

A phase I open-label study evaluating the cardiovascular safety of sorafenib in patients with advanced cancer

PURPOSE

To characterize the cardiovascular profile of sorafenib, a multitargeted kinase inhibitor, in patients with advanced cancer.

METHODS

Fifty-three patients with advanced cancer received oral sorafenib 400 mg bid in continuous 28-day cycles in this open-label study. Left ventricular ejection fraction (LVEF) was evaluated using multigated acquisition scanning at baseline and after 2 and 4 cycles of sorafenib. QT/QTc interval on the electrocardiograph (ECG) was measured in triplicate with a Holter 12-lead ECG at baseline and after 1 cycle of sorafenib. Heart rate (HR) and blood pressure (BP) were obtained in duplicate at baseline and after 1 and 4 cycles of sorafenib. Plasma pharmacokinetic data were obtained for sorafenib and its 3 main metabolites after 1 and 4 cycles of sorafenib.

RESULTS

LVEF (SD) mean change from baseline was -0.8 (±8.6) LVEF(%) after 2 cycles (n = 31) and -1.2 (±7.8) LVEF(%) after 4 cycles of sorafenib (n = 24). The QT/QTc mean changes from baseline observed at maximum sorafenib concentrations (t(max)) after 1 cycle (n = 31) were small (QTcB: 4.2 ms; QTcF: 9.0 ms). Mean changes observed after 1 cycle in BP (n = 31) and HR (n = 30) at maximum sorafenib concentrations (t(max)) were moderate (up to 11.7 mm Hg and -6.6 bpm, respectively). No correlation was found between the AUC and C(max) of sorafenib and its main metabolites and any cardiovascular parameters.

CONCLUSIONS

The effects of sorafenib on changes in QT/QTc interval on the ECG, LVEF, BP, and HR were modest and unlikely to be of clinical significance in the setting of advanced cancer treatment.

Vascular endothelial growth factors and receptors: anti-angiogenic therapy in the treatment of cancer

Vascular endothelial growth factors (VEGFs) are critical regulators of vascular and lymphatic function during development, in health and in disease. There are five mammalian VEGF ligands and three VEGF receptor tyrosine kinases. In addition, several VEGF co-receptors that lack intrinsic catalytic activity, but that indirectly modulate the responsiveness to VEGF contribute to the final biological effect. This review describes the molecular features of VEGFs, VEGFRs and co-receptors with focus on their role in the treatment of cancer.

Crescentic glomerulonephritis associated with vascular endothelial growth factor (VEGF) inhibitor and bisphosphonate administration

Bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor, has been widely used in a variety of malignancies offering substantial clinical benefit. Hypertension and proteinuria are the most commonly reported manifestations of bevacizumab-related nephrotoxicity with the risk increasing along with the dose and with the concomitant use of bisphosphonates. We describe the first case of a patient with small-cell lung cancer who developed diffuse extracapillary necrotizing crescentic glomerulonephritis, temporarily necessitating haemodialysis, following administration of bevacizumab and zolendronate. Renal function improved without any specific treatment and the patient remained off dialysis after withdrawal of bevacizumab-zolendronate. Special caution is required when VEGF inhibitors are combined with bisphosphonates. Such a combination can cause crescentic necrotizing glomerular lesions. Withdrawal of the offending medications may be adequate for the alleviation of this severe glomerulonephritis.

Hypertension and overall survival in metastatic colorectal cancer patients treated with bevacizumab-containing chemotherapy

BACKGROUND

Hypertension (HTN) is a common toxicity of anti-VEGF (vascular endothelial growth factor) antibody treatment. It may be a marker of VEGF signalling pathway inhibition and therefore represent a cancer biomarker in metastatic colorectal cancer (mCRC) patients treated with chemotherapy and bevacizumab.

METHODS

A total of 101 consecutive patients with mCRC were treated with standard chemotherapy combined with bevacizumab at dose of 2.5 mg kg(-1) per week in a single centre. The median follow-up time of the patients alive was 64 months. Blood pressure was measured before each bevacizumab infusion, and HTN was graded according to common toxicity criteria for adverse events version 3.0.

RESULTS

Overall, 57 patients (56%) developed ≥grade 1 HTN (median blood pressure 168/97 mm Hg), whereas 44 (44%) remained normotensive when treated with bevacizumab-containing chemotherapy regimen. Overall response rate was higher among patients with HTN (30 vs 20%; P=0.025). Hypertension was associated with improved progression-free survival (10.5 vs 5.3 months; P=0.008) and overall survival (25.8 vs 11.7 months; P<0.001), and development of HTN within 3 months had an independent, prognostic influence in a multivariate landmark survival analysis together with other known mCRC prognostic factors (P=0.007). There was no association between HTN and development of thromboembolic complications.

CONCLUSION

Hypertension may predict outcome of bevacizumab-containing chemotherapy in mCRC. These data require confirmation in prospective studies including pharmacodynamic and pharmacokinetic analyses.

Anti-angiogenic therapy: adapting strategies to overcome resistant tumors

Healthy cells, as well as benign and malignant tumors, depend upon the body's blood supply to bring in oxygen and nutrients and carry away waste products. Using this property against tumors, anti-angiogenic therapy targets the tumor vasculature with the aim of starving the tumor, and has demonstrated exceptional clinical efficacy against a number of tumors. This review discusses the current state of knowledge regarding anti-angiogenic therapies presently available to patients, and garners from both preclinical and clinical literature the benefits and side effects associated with anti-angiogenic therapies, the unfortunate mechanisms of acquired resistance to these novel therapeutics, and highlights promising next generation anti-angiogenics that may overcome the limitations encountered with first generation therapies.

Role of reactive oxygen species during hypertension in response to chronic antiangiogenic factor (sFlt-1) excess in pregnant rats

BACKGROUND

Preeclampsia is associated with increased levels of reactive oxygen species (ROS) and the antiangiogenic factor, soluble fms-like tyrosine kinase-1 (sFlt-1). Moreover, recent studies have indicated that chronic sFlt-1 excess causes hypertension in pregnant animals. The purpose of this study was to evaluate the role of ROS in mediating sFlt-1-induced hypertension in the pregnant rat.

METHODS

Mean arterial pressure (MAP), and plasma sFlt-1 and tissue ROS levels were measured in the following groups: (i) pregnant controls; (ii) sFlt-1-treated pregnant rats; (iii) Tempol-treated pregnant rats; (iv) sFlt-1- and Tempol-treated pregnant rats.

RESULTS

MAP increased from 104 ± 2 mm Hg in pregnant control rats to 118 ± 3 mm Hg (P = 0.002) in sFlt-1-infused rats. Basal and nicotinamide adenine dinucleotide phosphate (NADPH)-stimulated levels of tissue ROS were increased in response to excess sFlt-1 during pregnancy. Pretreatment with Tempol attenuated oxidative stress and hypertension in response to sFlt-1.

CONCLUSIONS

ROS play an important role in mediating hypertension in response to chronic sFlt-1 excess during pregnancy.

Treatment of bevacizumab-induced hypertension by amlodipine

BACKGROUND

Hypertension is a common toxicity of anti-VEGF agents, but its optimal treatment remains to define. This study aimed to describe the efficacy and tolerability of amlodipine, a calcium channel blocker, in patients with metastatic malignancies treated with bevacizumab, a humanized monoclonal antibody to VEGF.

PATIENTS AND METHODS

One hundred and eighty-seven patients with advanced or metastatic NSCLC, colorectal or ovarian cancer receiving bevacizumab (5 mg/kg every 2 weeks or 7.5 mg/kg every 3 weeks) and chemotherapy were eligible for this analysis. Blood pressure was measured at home twice daily according to international guidelines. Patients received amlodipine 5 mg daily for grade ≥ 2 bevacizumab-induced hypertension.

RESULTS

Twenty-six patients received amlodipine 5 mg daily for de novo hypertension (group A), and another 10 patients received amlodipine for exacerbation of previously existing hypertension (group B). Hypertension was controlled within 7 days under amlodipine in 23/26 (88.5%, 95%CI: 76.2-100) patients in group A, and 8/10 (80%, 95%CI: 55.2-100) patients in group B, with a favourable toxicity profile.

CONCLUSIONS

Amlodipine 5 mg daily appears safe and efficient for the treatment of hypertension in patients receiving bevacizumab at a dose-intensity of 2.5 mg/kg/week. Further prospective studies are warranted to confirm these results.

Cardiovascular safety of VEGF-targeting therapies: current evidence and handling strategies

Treatment with the angiogenesis inhibitors bevacizumab, sunitinib, and sorafenib as single agents or in combination with conventional chemotherapy is becoming a cornerstone of modern anticancer therapy. However, the potential toxicity of these drugs, mainly to the cardiovascular system, is still being investigated. Patient assessment at baseline, of crucial importance in candidates for treatment, involves the evaluation of risk factors and screening for past or present cardiovascular disease. Strict monitoring of treatment-related adverse effects must be conducted in order to allow the early detection of cardiovascular toxicities and their prompt medication. In the present paper, the most frequent cardiovascular toxicities and their underlying mechanisms are investigated, with a view to providing indications for effective patient management.