Management of hypertension in angiogenesis inhibitor-treated patients

Nitric oxide and adverse events of vascular endothelial growth factor inhibitors

BACKGROUND

Angiogenesis inhibitors targeting the vascular endothelial growth factor (VEGF) signalling pathways have demonstrated therapeutic efficacy in a wide variety of malignancies. With their increased use, adverse events, some common and certain rare but characteristic complications, are being recognized. The exact mechanisms for the development of at least some of these side effects are not entirely clear.

SCOPE

Review of the current literature with respect to mechanisms for the development of side effects to VEGF blocking agents was reviewed.

FINDINGS

Nitric oxide is a key molecule in the downstream signalling pathway for VEGF. Blockade of nitric oxide by the VEGF antagonists results in several class-specific adverse events.

CONCLUSION

Nitric oxide can be considered as an important factor in the development of most of the common and rare adverse events related to VEGF antagonists.

An observational study of bevacizumab-induced hypertension as a clinical biomarker of antitumor activity

BACKGROUND

Hypertension is a common toxicity of bevacizumab, but the frequency of assessment of blood pressure and standardized grading remain to be defined. This study aimed to describe the incidence of bevacizumab-induced hypertension and factors associated with its development, then to retrospectively assess its relation with activity.

PATIENTS AND METHODS

One hundred nineteen patients with advanced or metastatic non-small cell lung cancer, colorectal cancer, or ovarian cancer receiving bevacizumab (2.5 mg/kg per week) and chemotherapy were eligible for this analysis. Blood pressure was measured at home twice daily according to international guidelines, and graded according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC), version 3.0, and the European Society of Hypertension (ESH) criteria.

RESULTS

Home-based measurements detected significantly more cases of hypertension than in-clinic measurements did, according to the ESH criteria (54.6% versus 24.4%; p < .001) or the NCI-CTC (42.9% versus 22.7%; p = .0015). Very early hypertension (within 42 days, according to the ESH criteria) but not hypertension (occurring at any time during treatment period) was predictive of response (p = .0011 and p = .26, respectively).

CONCLUSIONS

Our preliminary results indicate that home-based measurement and grading according to the ESH criteria represents a reliable method to detect bevacizumab-induced hypertension. Whether hypertension is a biomarker of bevacizumab activity remains to be determined in a prospective study.

Looking beyond recurrence: comorbidities in cancer survivors

Cancer recurrence is a very real concern for cancer survivors. Surveillance for recurrence and vigilance for development of new cancers are top priorities during follow-up visits after active treatment ends. However, the cancer survivor also is at risk for the development of comorbid conditions. These conditions, including obesity, diabetes, dyslipidemia, menopause, decreased bone mass, hypertension, and hypothyroidism, are discussed with their relevance for general health and their relationships to disease-specific cancers. All of these conditions should be routinely addressed as part of the patient's survivorship care when appropriate. The oncology nurse is in a prime position to educate survivors about the risks for these conditions, both through evidence-based practice guidelines specific to each condition and also through the use of a treatment summary and care plan. This article discusses these selected comorbidities and offers strategies for nurses to address them with survivors during follow-up visits. Clinical practice guidelines for comorbidities are included, along with oncology implications and relevance for survivors. Recommendations for modifiable risk factors and healthy living also are included, along with Web sites for survivorship care plans.

The use of 24-h ambulatory blood pressure monitoring (ABPM) during the first cycle of sunitinib improves the diagnostic accuracy and management of hypertension in patients with advanced renal cancer

AIM

Hypertension (HT) complicates treatment with antiangiogenic agents, including the tyrosine kinase inhibitor (TKI) sunitinib. To prospectively evaluate the prevalence and management of HT in patients with advanced renal cell carcinoma (RCC) receiving sunitinib we used 24-h ABPM and we treated HT according to guidelines of the Joint National Committee on Prevention, Detection and Evaluation and the Treatment of High Blood Pressure (JNC7).

PATIENTS AND METHODS

Normal 24-h ABPM at the baseline and at 2, 4 and 6 weeks of the first cycle was ensured with the successive use of hydrochlorothiazide+irbesartan, nebivolol and amlodipine. Office BP measurements were used in subsequent cycles to monitor HT. Sunitinib dose was modified only if BP was not controlled with four anti-hypertensive agents.

RESULTS

Forty patients were included in this analysis. Twenty-one patients (53%) had baseline HT, while 12 of 14 (84%) normotensive patients required anti-HT treatment during the 1st cycle of sunitinib. HT was infrequent in subsequent cycles and increase of anti-HT medication was required in only 2 cases. Two patients permanently discontinued sunitinib due to HT. The remaining 34 (94%) required no dose modifications for HT. One cardiac event (2.8%) was observed. There was no correlation of HT with sunitinib efficacy.

CONCLUSION

Sunitinib-associated HT is more frequent than previously reported. The use of 24-h ABPM for diagnosis and tailoring of HT according to JNC7 guidelines may achieve uninterrupted, full dose therapy in most patients. The substitution of such protocols for currently used Toxicity Criteria may be warranted.

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.

Noncardiac vascular toxicities of vascular endothelial growth factor inhibitors in advanced cancer: a review

The introduction of molecularly targeted anticancer therapies has brought the promise of longer survival times for select patients with cancers previously considered untreatable. However, it has also brought new toxicities that require understanding and management, sometimes for long periods of time. Vascular endothelial growth factor inhibitors are associated with a broad range of adverse effects, with vascular toxicity being particularly serious. This review focuses on the current understanding of the pathophysiology and mechanisms of macrovascular toxicities (hypertension, hemorrhage, and thromboembolism), their incidence and severity, the current clinical management, and implications in the advanced cancer setting. Movement of these agents into the early disease setting will alter the impact of these toxicities. Search Strategy and Selection Criteria. Information for this review was collected by searching PubMed/Medline and American Society of Clinical Oncology abstract databases. The medical subject heading terms used included toxicity, hypertension, thromboembolism, hemorrhage, intestinal perforation, risk factors, pharmacokinetics, and metabolism, combined with free text search terms including, but not limited to, VEGF inhibitor*, bevacizumab, sunitinib, and sorafenib. Articles published in English before March 2010 were included, in addition to information from case reports and pharmaceutical agent package inserts.

Clinical results and pharmacokinetics of sorafenib in chronic hemodialysis patients with metastatic renal cell carcinoma in a single center

OBJECTIVE

We investigated the safety and feasibility of sorafenib in patients with end-stage renal disease undergoing hemodialysis by examining the influence of pharmacokinetic parameters to their benefit and also the occurrence of drug-related adverse events of sorafenib.

METHODS

Ten patients with metastatic renal cell carcinoma undergoing hemodialysis received sorafenib. Initial dose was 200 mg once daily, and the dose was increased up to the maintenance dose of 200 mg twice daily. The pharmacokinetic study was performed after a steady state was reached with 200 mg twice daily in six patients.

RESULTS

Complete response occurred in one patient, partial response in three, stable disease in four and progressive disease in two. Median progression-free survival was 6.3 months. Serious adverse events were found in nine patients, including a Grade 5 subarachnoid hemorrhage and a Grade 4 cerebellar hemorrhage. In the pharmacokinetic study, the geometric mean of maximum concentration and area under the curve from 0 to 10 h of plasma concentration were similar on the day of hemodialysis and the day off hemodialysis. These data were lower than those from Japanese people with healthy kidneys and normal kidney function. There was no association between objective response or the occurrence of serious adverse events and pharmacokinetic parameters.

CONCLUSIONS

Treatment with sorafenib of patients with metastatic renal cell carcinoma undergoing hemodialysis appears to be feasible, but we express some concern about the higher incidence of serious adverse events even with the reduced dose. However, clinical efficacy was not compromised.

Posterior Reversible Encephalopathy Syndrome and Anti-Angiogenic Agents: A Case Report

Posterior reversible encephalopathy syndrome is an increasingly recognised clinico-radiological entity, associated with several medical conditions (such as systemic arterial hypertension) and characterised by seizures, altered mental status, headaches, and visual symptoms. Magnetic resonance imaging is a key component in this diagnosis, with hyperintense foci in T₂-weighted images, corresponding to vasogenic oedema. The pathophysiology is not fully understood but probably involves loss of auto-regulation of cerebral vasculature or endothelial dysfunction or both. A 56-year-old male, suffering from a gastro-intestinal stromal tumour with hepatic metastasis resistant to imatinib, on therapy with sunitinib, came to the Emergency Department because of headaches, hallucinations, and loss of vision. There was no previous history of high blood pressure. A hypertensive crisis was diagnosed; ophthalmological examination on admission showed no light perception bilaterally. Brain imaging displayed bilateral parieto-occipital and frontal vasogenic oedema, consistent with the clinical diagnosis of posterior reversible encephalopathy syndrome. After treatment of hypertension and suspension of sunitinib, the patient recovered from his symptoms. Control imaging showed no oedema. Angiogenesis inhibitors, such as sunitinib and bevacizumab, can cause hypertension, one of the many medical conditions associated with the posterior reversible encephalopathy syndrome. This syndrome should be considered in cases of acute visual loss, particularly in view of its reversible nature when diagnosed and treated promptly.

Sorafenib: rays of hope in thyroid cancer

BACKGROUND

Sorafenib (BAY 43-9006) is an inhibitor of multiple-receptor tyrosine kinases involved in tumor growth and angiogenesis, which can be advantageously administered orally. Initially used as monotherapy in advanced renal cell carcinoma, sorafenib was proven to increase progression-free survival while enhancing disease control. Clinical trials on sorafenib are at present ongoing for the treatment of various malignancies, including thyroid cancer (TC).

SUMMARY

Specifically, in two phase II studies recently conducted on papillary TC, although the respective results were not entirely compatible as regard partial response rate and progression-free survival, sorafenib demonstrated a relatively favorable benefit/risk profile. In another more recent phase II study, whose primary endpoint was the reinduction of radioactive iodine uptake at 26 weeks, although no reinduction of radioactive iodine uptake was observed, 59% had a beneficial response and 34% had stable disease. Sorafenib hence appears to be a valid alternative to conventional treatment of metastatic papillary TC refractory to radioiodine therapy.

CONCLUSIONS

Further prospective investigations are required to define the characteristics of tumor response to the drug and the factors inducing resistance to treatment. A major issue demanding immediate attention involves optimization of sorafenib treatment: this concerns multidrug combination with different tyrosine kinase inhibitors or immunomodulating agents with the aim of reducing doses and thereby improving drug tolerability and antineoplastic capability.

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.

Toxicity of sorafenib: clinical and molecular aspects

IMPORTANCE OF THE FIELD

Sorafenib is a novel oral bis-aryl urea compound originally developed as an inhibitor of RAF kinase for its anti-proliferative property. Sorafenib also inhibits receptor tyrosine kinases of multiple pro-angiogenic factors such as VEGFR-1/2/3, Flt-3 and PDGFR-beta. The combination of both its anti-proliferative and anti-angiogenic properties makes sorafenib an attractive agent in cancer treatment. Sorafenib has been approved for the treatment of metastatic renal cell carcinoma as well as hepatocellular cancer. Despite its inherent selectivity, sorafenib can cause unusual adverse events whose the management represents a challenge for oncologists.

AREAS COVERED IN THIS REVIEW

Relevant literature was identified using a Pubmed search of articles published up to June 2009. Search terms included 'sorafenib' and 'toxicity'. Original articles were reviewed and relevant citations from these articles were also considered.

WHAT THE READER WILL GAIN

The clinical aspect of sorafenib-induced adverse events and the molecular basis behind this toxicity are discussed. Finally, recommendations for the management of these adverse events are proposed.

TAKE HOME MESSAGE

Although not life-threatening, toxicity of sorafenib can severely impact the physical, psychological and social well-being of patients. The management of this unusual toxicity highlights the particular need of new pluridisciplinarities linking oncologist, cardiologist and dermatologist.

Insights into cardiovascular side-effects of modern anticancer therapeutics

PURPOSE OF REVIEW

Modern anticancer therapeutics can be associated with significant cardiovascular side-effects. Detection, risk assessment, and treatment of these unwanted effects are an important task for treating physicians. The purpose of this review is to focus on approved novel cancer therapeutics and discuss the most important cardiovascular side-effects, prognosis, and potential treatment. We will contrast these effects to those of conventional cardiotoxic chemotherapeutics.

RECENT FINDINGS

Modern anticancer therapeutics can cause cardiovascular ischemia, arrhythmias, cardiac dysfunction, heart failure, and arterial hypertension. Anti-HER2 drugs, or more specifically trastuzumab, can induce cardiac dysfunction and heart failure. Newer data show that these effects occur predominantly during treatment and patients who experience the side-effects often have a good cardiovascular prognosis. Antiangiogenic agents can induce arterial hypertension, arterial and venous thromboembolism, and less frequently QTc prolongation. Recent findings indicate that a high rate of patients treated with antivascular endothelial growth factor drugs develop arterial hypertension and may experience related complications. Preventive strategies or optimal treatment have been tested but controlled studies are missing.

SUMMARY

Cardiovascular side-effects of modern anticancer drugs can be a serious problem and need careful attention, prevention, or treatment.

Blood pressure control in patients receiving bevacizumab in an outpatient cancer center

Purpose. Hypertension is a common adverse effect of vascular endothelial growth factor (VEGF) signaling inhibitors, such as bevacizumab, with an incidence upwards of 35%. The management of bevacizumab-induced hypertension is important in order to avoid dose interruption/discontinuation and/or end organ damage. The efficacy of antihypertensive medications for this cause of hypertension has not been demonstrated. This study seeks to determine if antihypertensives are effective in treating anti-VEGF-induced hypertension from bevacizumab and determine which classes of antihypertensive agents are effective.

Methods. A retrospective review of all patients who received bevacizumab between January 2007 and September 2009 at two medical centers was conducted. Patients were included if they experienced new onset or exacerbation of preexisting hypertension, during bevacizumab treatment. Efficacy of antihypertensives was determined by recording a 28-day change in systolic blood pressure from the initiation or dose increase of individual antihypertensive medications. Secondary endpoints included an efficacy analysis of antihypertensive classes.

Results. Five-hundred thirteen patients were identified as receiving bevacizumab during the indicated time period. Fifty-seven patients met the full inclusion/exclusion criteria for analysis. The average systolic blood pressure declined by 23 mm Hg with 4 weeks of treatment ( p < 0.0001). Each class had a statistically significant decline in systolic blood pressure of 15.5–57 mm Hg with the exception of diuretics and a group of miscellaneous antihypertensives.

Conclusions. This is the first data that demonstrates individual classes of antihypertensives are effective in bevacizumab-induced hypertension. Most antihypertensives were effective in reducing blood pressure, with the exception of diuretics and miscellaneous antihypertensives, which may be due to a limited sample size.

New markers in preeclampsia

Preeclampsia (PE) is one of the most common diseases worldwide, complicating ~5% of all pregnancies. Although no major progress has been achieved in the treatment of PE, our ability to identify women at high-risk has increased considerably during the past decade. Thus, the soluble form of the type-1 receptor of vascular endothelial growth factor (sFlt1) and of endoglin (sEng), an endothelial receptor for transforming growth factor beta, have been shown to increase dramatically in the maternal blood of the women affected some weeks before the onset of clinical symptoms. A relative concomitant fall in VEGF and placental growth factor (PlGF) has also been reported. In 2010, they are the most promising biomarkers for PE. The extent to which they are involved in the pathophysiology of the maternal syndrome and of the primary placental disorder responsible for PE is being actively investigated. In parallel, defective placental steroidogenesis, as well as the loss of tolerance towards the angiotensin-2 receptor have also been found to be critically involved in mouse models of PE. Although there is not much data to support their role in human PE, these two biological pathways are a potential future source of both new biomarkers, and new therapeutic strategies. The aim of this review is to compare the likely value of these molecules at the bedside, and to discuss their implication in the pathophysiology of what used to be known as "the disease of theories".

Sunitinib: a multitargeted receptor tyrosine kinase inhibitor in the era of molecular cancer therapies

Sunitinib is an oral oxindole multitargeted kinase inhibitor that inhibits certain receptor tyrosine kinases (RTKs). These include vascular endothelial growth factor receptors (VEGFR type 1 and 2), platelet-derived growth factor receptors (PDGFR-alpha and PDGFR-beta), stem cell factor receptor (KIT), FMS-like tyrosine kinase-3 (FLT3), glial cell-line derived neurotrophic factor receptor (RET) and the receptor of macrophage-colony stimulating factor (CSF1R). Examination of the antitumor effect of sunitinib in a variety of cell lines in vitro suggested an antiproliferative activity that is dependent on the presence of constitutively active RTK targets. The use of sunitinib as first-line therapy in advanced renal cell carcinoma (RCC) has improved the overall survival compared with that observed after cytokine therapy, while its administration in patients with gastrointestinal stromal tumors (GISTs) after progression or intolerance to imatinib achieved an objective response of 7%. Sunitinib is currently approved for the treatment of GISTs in this setting, and as first-line therapy for the treatment of advanced RCC. The relatively long half-life of sunitinib and its major metabolite allow for a once-daily dosing schedule. An interesting antitumor activity of sunitinib was reported in phase II studies of patients with a variety of malignancies, such as hepatocellular cancer, pancreatic neuroendocrine tumors, and non-small cell lung cancer; results of phase III studies are urgently anticipated. Fatigue is one of the most common adverse effects of sunitinib, as 50-70% of patients with advanced RCC and GIST complained of this adverse effect. Other adverse effects are diarrhea, anorexia, nausea and vomiting, oral changes and bleeding events. Most toxicities are reversible and should not result in discontinuation of sunitinib. If necessary, dose adjustments or interruptions should be made. Hypothyroidism has been described in the first 2 weeks of sunitinib therapy and its incidence increases progressively with the duration of therapy. Sunitinib may exert its hypertensive activity through a direct effect on the vasculature, while its most important cardiac adverse effect is left ventricular dysfunction. A variety of skin adverse effects have been described with the use of sunitinib such as hand-foot syndrome, yellow discoloration of the skin, dry skin, subungual splinter hemorrhages, acral erythema, and generalized skin rashes. Administration of sunitinib in the adjuvant and neoadjuvant setting of patients with RCC and of its combination with chemotherapy and other targeted therapies are currently under intense investigation.

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.

NCCN Task Force report: update on the management of patients with gastrointestinal stromal tumors

The standard of care for managing patients with gastrointestinal stromal tumors (GISTs) rapidly changed after the introduction of effective molecularly targeted therapies involving tyrosine kinase inhibitors (TKIs), such as imatinib mesylate and sunitinib malate. A better understanding of the molecular characteristics of GISTs have improved the diagnostic accuracy and led to the discovery of novel immunomarkers and new mechanisms of resistance to TKI therapy, which in turn have resulted in the development of novel treatment strategies. To address these issues, the NCCN organized a task force consisting of a multidisciplinary panel of experts in the fields of medical oncology, surgical oncology, molecular diagnostics, and pathology to discuss the recent advances, identify areas of future research, and recommend an optimal approach to care for patients with GIST at all stages of disease. The task force met for the first time in October 2003 and again in December 2006 and October 2009. This supplement describes the recent developments in the field of GIST as discussed at the October 2009 meeting.

[Metastatic renal cell carcinoma: pretherapeutic approach before antiangiogenic treatment. A case report]

Antiangiogenic treatment initiation justifies a clinical and biological pretherapeutic assessment and a close follow-up of side effects according to each drug. Because of potential healing complications, a deadline of 4 weeks after surgery is recommended before starting antiangiogenic treatment. The optimal sequence and the potential role of neo-adjuvant therapies remain to define. In the absence of prospective data, nephrectomy is still recommended in renal cell carcinoma management.

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

BACKGROUND

Hypertension is associated with the use of bevacizumab, an angiogenesis inhibitor widely used in cancer therapy. Currently, the risk of severe hypertension associated with bevacizumab is unclear. We performed a systematic review and meta-analysis of published randomized-controlled clinical trials (RCTs) to assess the risk of high-grade hypertension in cancer patients treated with bevacizumab.

METHODS

Databases from PUBMED, the Web of Science, and abstracts presented at the American Society of Clinical Oncology conferences until May 2009 were searched to identify relevant studies. Eligible studies included prospective RCTs in which bevacizumab was directly compared with controls in cancer patients receiving concurrent antineoplastic therapy. Summary incidence, relative risk (RR), and 95% confidence interval (CI) were calculated employing a fixed- or random-effects model based upon the heterogeneity of the included studies.

RESULTS

A total of 12,656 patients with a variety of tumors from 20 studies were included for the analysis. The incidence of all-grade hypertension in patients receiving bevacizumab was 23.6% (95% CI: 20.5-27.1) with 7.9% (95% CI: 6.1-10.2) being high-grade (grade 3 or 4). Patients treated with bevacizumab had a significantly increased risk of developing high-grade hypertension with an RR of 5.28 (95% CI: 4.15-6.71, P < 0.001) in comparison with controls. Even though not statistically significant, there was a trend suggesting that bevacizumab may increase the risk of hypertensive crisis (grade 4) with an RR of 3.16 (95% CI: 0.91-10.90). The increased risk of high-grade hypertension was observed in patients receiving bevacizumab at 2.5 mg/kg/week (RR = 4.78, 95% CI: 3.59-6.36) as well as 5 mg/kg/week (RR = 5.39, 95% CI: 3.68-7.90). The risk of high-grade hypertension may vary with tumor types, with RRs ranging from 2.49 (95% CI: 0.94-6.59) in patients with mesothelioma to 14.80 (95% CI: 0.92-238.51) in patients with breast cancer.

CONCLUSION

Bevacizumab may significantly increase the risk of high-grade hypertension in cancer patients. Close monitoring and adequate management are highly recommended to decrease cardiovascular complications.

Collateral damage: toxic effects of targeted antiangiogenic therapies in ovarian cancer

First-line chemotherapy fails in more than 20% of patients with epithelial ovarian cancer and about 40-50% of women who respond to initial treatment relapse within 2 years. In the recurrent setting, second-line chemotherapeutic agents have a 15-20% response rate with no cures. Fortunately, clinical investigations that have assessed the efficacy of new, biologically targeted therapies have reinvigorated therapeutic options for patients living with ovarian and other malignancies. In view of the fact that ovarian cancer is one of the most angiogenic neoplasms, there is great hope that implementing targeted agents with antiangiogenic properties will improve outcomes. However, as experience grows with the antitumour activity of these drugs, new toxic effects are emerging. The effects of antiangiogenic agents on molecules and processes that also have physiologically important roles in healthy tissues are at the crux of these toxic effects, or "collateral damage". This review discusses the leading toxic effects encountered and anticipated in clinical investigation and practice with antiangiogenic agents in patients with ovarian cancer, with particular focus on potential management strategies.

Targeting angiogenesis with multitargeted tyrosine kinase inhibitors in the treatment of non-small cell lung cancer

It has been >35 years since the link between angiogenesis and the growth of tumors was first reported. Targeting angiogenesis became feasible with the availability of bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody. Initial studies revealed that the combination of bevacizumab and chemotherapy led to longer overall survival times than with chemotherapy alone in patients with advanced colorectal cancer. Since then, drug development strategies have added small molecule tyrosine kinase inhibitors to the panel of antiangiogenic agents under evaluation; data from numerous trials are now available. The challenge now is to identify the optimal antiangiogenic agent for specific patient groups and to understand not only the mechanistic differences between agents, but also the variability in their antitumor activity across different tumor types and their differing side-effect profiles. As in other solid tumors, angiogenesis contributes to the development of non-small cell lung cancer (NSCLC), and this review summarizes the role of angiogenesis in this disease. We review the current developmental status of antiangiogenic tyrosine kinase inhibitors (including vandetanib, sunitinib, axitinib, sorafenib, vatalanib, and pazopanib) in NSCLC and conclude by briefly discussing the need for optimal patient selection and potential future directions.

Pharmacokinetic/pharmacodynamic modeling of biomarker response to sunitinib in healthy volunteers

A pharmacokinetic/pharmacodynamic (PK/PD) study of the tyrosine kinase inhibitor sunitinib was conducted in 12 healthy volunteers using blood pressure and circulating biomarker levels as PD markers. Blood pressure was measured, and plasma concentration-time courses of sunitinib, its major metabolite SU12662, vascular endothelial growth factors VEGF-A and VEGF-C, and soluble VEGF receptor-2 (sVEGFR-2) were studied in healthy subjects receiving 50 mg of sunitinib orally for 3-5 consecutive days. Using NONMEM, PK/PD models were established that predicted changes (expressed as multiples relative to baseline values) in systolic blood pressure, diastolic blood pressure, VEGF-A level, and sVEGFR-2 level, of 1.10, 1.18, 2.24, and 0.76, respectively, for a typical subject after 4 weeks of treatment with 50 mg/day. Simulated blood pressure-time courses compare excellently with published data in patients, whereas changes in circulating biomarkers were greater in patients than simulations suggest for healthy subjects. In conclusion, the tumor-independent pharmacological response to sunitinib could be described by PK/PD models, thereby facilitating model-based investigations with antiangiogenic drugs, using blood pressure and circulating proteins as biomarkers.

NCCN Task Force report: update on the management of patients with gastrointestinal stromal tumors

The standard of care for managing patients with gastrointestinal stromal tumors (GISTs) rapidly changed after the introduction of effective molecularly targeted therapies involving tyrosine kinase inhibitors (TKIs), such as imatinib mesylate and sunitinib malate. A better understanding of the molecular characteristics of GISTs have improved the diagnostic accuracy and led to the discovery of novel immunomarkers and new mechanisms of resistance to TKI therapy, which in turn have resulted in the development of novel treatment strategies. To address these issues, the NCCN organized a task force consisting of a multidisciplinary panel of experts in the fields of medical oncology, surgical oncology, molecular diagnostics, and pathology to discuss the recent advances, identify areas of future research, and recommend an optimal approach to care for patients with GIST at all stages of disease. The task force met for the first time in October 2003 and again in December 2006 and October 2009. This supplement describes the recent developments in the field of GIST as discussed at the October 2009 meeting.

Initial assessment, surveillance, and management of blood pressure in patients receiving vascular endothelial growth factor signaling pathway inhibitors

Hypertension is a mechanism-based toxic effect of drugs that inhibit the vascular endothelial growth factor signaling pathway (VSP). Substantial evidence exists for managing hypertension as a chronic condition, but there are few prospectively collected data on managing acute hypertension caused by VSP inhibitors. The Investigational Drug Steering Committee of the National Cancer Institute convened an interdisciplinary cardiovascular toxicities expert panel to evaluate this problem, to make recommendations to the Cancer Therapy Evaluation Program on further study, and to structure an approach for safe management by treating physicians. The panel reviewed: the published literature on blood pressure (BP), hypertension, and specific VSP inhibitors; abstracts from major meetings; shared experience with the development of VSP inhibitors; and established principles of hypertension care. The panel generated a consensus report including the recommendations on clinical concerns summarized here. To support the greatest possible number of patients to receive VSP inhibitors safely and effectively, the panel had four recommendations: 1) conduct and document a formal risk assessment for potential cardiovascular complications, 2) recognize that preexisting hypertension will be common in cancer patients and should be identified and addressed before initiation of VSP inhibitor therapy, 3) actively monitor BP throughout treatment with more frequent assessments during the first cycle of treatment, and 4) manage BP with a goal of less than 140/90 mmHg for most patients (and to lower, prespecified goals in patients with specific preexisting cardiovascular risk factors). Proper agent selection, dosing, and scheduling of follow-up should enable maintaining VSP inhibition while avoiding the complications associated with excessive or prolonged elevation in BP.

Tumor angiogenesis and novel antiangiogenic strategies

Angiogenesis is essential for the development and growth of tumors. It is a highly regulated process that requires cross-talk between signaling pathways at all stages of blood vessel development and tumor growth, from the recruitment of endothelial cells to vessel maturation. This review summarizes tumor angiogenesis and describes the key signaling pathways governing blood vessel development. The role of angiogenesis in various tumor types is discussed, but the focus is on invasive breast cancer, a disease that will affect approximately 182,000 women in the USA in 2008. Research efforts over the past decade have identified numerous potential, as well as proven therapies with activity in breast cancer. These include chemotherapeutics as well as therapies that inhibit specific angiogenic pathways known as targeted agents. Some of the data from single- and multitargeted antiangiogenic agents are described in this review. "Published 2008 Wiley-Liss, Inc. This article is a US Government work, and, as such, is in the public domain in the United States of America."

[Use of sorafenib in patients with hepatocellular or renal carcinoma]

Therapeutic approaches of cancers have been recently improved by the development of targeted therapies. Amongst these new drugs, some anti-angiogenic molecules have been approved by either the EMEA or the Food and Drug Administration. Sorafenib, one of these inhibitors of angiogenesis, has been established as the standard of care for advanced hepatocellular and renal carcinoma. This paper reviews the safety profile of sorafenib and presents guidelines for the prevention and the treatment of the main side effects associated with this molecule.

Clinical course of advanced non-small-cell lung cancer patients experiencing hypertension during treatment with bevacizumab in combination with carboplatin and paclitaxel on ECOG 4599

PURPOSE Bevacizumab is a monoclonal antibody that targets vascular endothelial growth factor (VEGF) with demonstrated efficacy in combination with carboplatin and paclitaxel (PCB) for the treatment of advanced non-small-cell lung cancer (NSCLC). Administration of bevacizumab is postulated to decrease nitric oxide synthesis and lead to hypertension, which may be a physiological sign that the VEGF pathway is more actively being blocked and could result in improved outcomes. PATIENTS AND METHODS Eastern Cooperative Oncology Group (ECOG) 4599 randomly assigned patients with nonsquamous NSCLC to carboplatin and paclitaxel (PC) versus PCB. Hypertensive patients were compared with nonhypertensive patients with respect to overall survival (OS) and progression-free survival (PFS) using blood pressure data and adverse event data separately. High blood pressure (HBP) by the end of cycle 1 was defined as blood pressure > 150/100 at any previous time or at least a 20-mmHg increase in diastolic blood pressure from baseline. Results In a multivariable Cox model adjusting for HBP as a time-varying covariate, comparing those on PCB with HBP with those on PC gave an OS hazard ratio (HR) of 0.60 (95% CI, 0.43 to 0.81; P = .001); comparing those on PCB without HBP with those on PC alone, the OS HR was 0.86 (95% CI, 0.74 to 1.00; P = .05). Comparing the PCB HBP group with PC gave an adjusted PFS HR of 0.54 (95% CI, 0.41 to 0.73; P < .0001) and comparing those on PCB without HBP to those on PC, the HR was 0.72 (95% CI, 0.62 to 0.84; P < .0001). The 6-month cumulative incidence of hypertension was 6.2% (95% CI, 3.9% to 8.6%). CONCLUSION Data from ECOG 4599 suggest that onset of HBP during treatment with PCB may be associated with improved outcomes, and additional studies of the downstream effects of VEGF suppression and hypertension are needed.

Vandetanib, designed to inhibit VEGFR2 and EGFR signaling, had no clinical activity as monotherapy for recurrent ovarian cancer and no detectable modulation of VEGFR2

PURPOSE

To evaluate clinical activity and target modulation of vandetanib in women with recurrent ovarian cancer.

EXPERIMENTAL DESIGN

A phase II trial of orally administered vandetanib 300 mg daily was designed to include analyses of target inhibition through paired biopsies and dynamic imaging. Core 18-gauge needle biopsies and dynamic contrast-enhanced magnetic resonance imaging were obtained before initiation of therapy and 6 weeks into therapy. Biopsy samples were subjected to reverse-phase protein lysate array endpoint analysis. Cytokine concentrations were measured by enzyme-linked immunosorbent assay in serially collected plasma samples.

RESULTS

Twelve patients entered the study, and accrual was terminated in the first stage because of lack of response or disease stabilization beyond 6 months. Adverse events included rash, diarrhea, and prolonged QT interval corrected for heart rate, but not hypertension. Exploratory analyses showed that epidermal growth factor receptor (EGFR) phosphorylation was reduced in the eight paired biopsy sets obtained; vascular endothelial growth factor (VEGF) receptor-2 phosphorylation was not consistently affected nor were dynamic contrast-enhanced MRI permeability and flow parameters. Serial plasma VEGF concentrations were variable and did not significantly change in the 11 patients assessed.

CONCLUSIONS

Vandetanib 300 mg daily monotherapy had no significant clinical benefit in this disease setting. Proteomic analysis of paired biopsies detected both phosphorylated-EGFR and phosphorylated-VEGF receptor-2 in ovarian tumor tissue, but only phosphorylated-EGFR was measurably inhibited by vandetanib.

Safety assessment considerations and strategies for targeted small molecule cancer therapeutics in drug discovery

Less than 10% of all experimental drugs introduced into clinical trials ever achieve the approval of regulatory agencies for marketing. For experimental small molecule oncology therapeutics, the approval rate is even less (5%). Clinical safety and efficacy are the two main causes of failure for oncologic drugs in development. Because these failures of experimental drugs are tremendously expensive for pharmaceutical companies, strategies have been developed and refined for reducing this attrition. While these strategic activities can take place in drug development, more benefit may be gained by increasing efforts in drug discovery in the form of (1) target validation; (2) compound selectivity analysis from the perspective of balancing efficacy and toxicity; and (3) investigation of ancillary means to abrogate toxicity, especially with respect to undesirable target-related effects. Most pharmaceutical companies recognize the benefit of lead compound optimization, but the degree to which it is applied seems to vary greatly. This article presents concepts and strategies to reduce the attrition of small molecule oncology therapeutic drug candidates due to toxicity.

Early detection of hypertension in a patient treated with sunitinib by measuring cardio-ankle vascular index

Cardio-ankle vascular index (CAVI) has been established as a marker of arterial stiffness, which is increased in hypertensive patients. CAVI reflects the stiffness of the aorta, femoral artery, and tibial artery. Sunitinib, multi-targeted tyrosine kinase inhibitor with both anti-angiogenic and anti-tumor activities, has been proved effective in patients with gastrointestinal stromal tumors. However, the treatment with sunitinib is often complicated by side effects such as hypertension. We describe an 84-year-old woman with gastrointestinal stromal tumor, who showed changes in arterial stiffness preceding the appearance of hypertension in the early phase after sunitinib initiation. The patient received sunitinib (50 mg given daily) for gastrointestinal stromal tumor. We assessed the influence of sunitinib on arterial stiffness every 7 days by measuring CAVI. The CAVI, which reflects arterial stiffness, was increased from 9.95 at baseline to 11.65 at 7 days after the initiation of sunitinib, whereas the blood pressure remained unchanged (117/72 and 119/76 mmHg). At 14 days after sunitinib initiation, the blood pressure was increased to 159/89 mmHg, indicating the occurrence of hypertension, while the CAVI was 11.90, the similar level detected at 7 days. Subsequently, sunitinib treatment was discontinued, because of the marked decrease in blood platelets. Both blood pressure and CAVI, together with blood platelets, were restored to the baseline values at 12 days after cessation of sunitinib. In conclusion, the increase in the CAVI preceded the appearance of sunitinib-induced hypertension. Arterial stiffness assessed by CAVI may be useful for early detection of sunitinib-induced hypertension.

Inhibition of vascular endothelial growth factor receptor signaling in angiogenic tumor vasculature

Neovascularization takes place in a large number of pathologies, including cancer. Significant effort has been invested in the development of agents that can inhibit this process, and an increasing number of such agents, known as antiangiogenic drugs, are entering clinical trials or being approved for clinical use. The key players involved in the development and maintenance of tumor neovasculature are vascular endothelial growth factor (VEGF) and its receptors (VEGFRs), and therefore VEGF/VEGFR signaling pathways have been a focus of anticancer therapies for several decades. This review focuses on two main approaches designed to selectively target VEGFRs, inhibiting VEGFR with small molecule inhibitors of receptor tyrosine kinase activity and inhibiting the binding of VEGF to VEGFRs with specific antibodies or soluble decoy VEGF receptors. The major problem with these strategies is that they appeared to be effective only in relatively small and unpredictable subsets of patients. An alternative approach would be to subvert VEGFR for intracellular delivery of cytotoxic molecules. We describe here one such molecule, SLT-VEGF, a fusion protein containing VEGF121 and the highly cytotoxic catalytic subunit of Shiga-like toxin.