Randomized phase II study of vandetanib alone or with paclitaxel and carboplatin as first-line treatment for advanced non-small-cell lung cancer

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.

Lung cancer outcomes in women

Lung cancer remains the leading cause of cancer death in men and women. Since the 1970s, there has been evidence for improved survival of women with lung cancer compared to men. Multiple analyses have demonstrated a survival advantage in women regardless of stage, histology, or treatment. The etiology for the improved prognosis is not yet fully elucidated, but is likely related to underlying biologic differences, including hormonal interactions. More recently, gender differences in response to newer agents such as epidermal growth factor receptor inhibitors and anti-angiogenesis agents have been identified. Further exploration of tumor molecular, biologic, hormonal, and pharmacogenomic interactions may provide additional insight into the observed survival benefit for women and, ultimately, permit exploitation of these differences in our treatment selection for both women and men.

The effects of vandetanib on paclitaxel tumor distribution and antitumor activity in a xenograft model of human ovarian carcinoma

This study was designed to determine the effects of vandetanib, a small-molecule receptor tyrosine kinase inhibitor of vascular endothelial growth factor and epidermal growth factor receptor, on paclitaxel (PTX) tumor distribution and antitumor activity in xenograft models of human ovarian carcinoma. Nude mice bearing A2780-1A9 xenografts received daily (5, 10, or 15 days) doses of vandetanib (50 mg/kg per os), combined with PTX (20 mg/kg intravenously). Morphologic and functional modifications associated with the tumor vasculature (CD31 and alpha-smooth muscle actin staining and Hoechst 33342 perfusion) and PTX concentrations in plasma and tumor tissues were analyzed. Activity was evaluated as inhibition of tumor growth subcutaneously and spreading into the peritoneal cavity. Vandetanib treatment produced no significant change in tumor vessel density, although a reduced number of large vessels, an increased percentage of mature vessels, and diminished tumor perfusion were evident. Pretreatment with vandetanib led to decreased tumor PTX levels within 1 hour of PTX injection, although 24 hours later, tumor PTX levels were comparable with controls. In efficacy studies, the combination of vandetanib plus PTX improved antitumor activity compared with vandetanib or PTX alone, with greater effects being obtained when PTX was administered before vandetanib. The combination of PTX plus vandetanib reduced tumor burden in the peritoneal cavity of mice and significantly increased their survival. Analysis of vascular changes and PTX tumor uptake in vandetanib-treated tumors may help to guide the scheduling of vandetanib plus PTX combinations and may have implications for the design of clinical trials with these drugs.

Recent development of molecular-targeted drugs in lung cancer

Numerous molecular target drugs have been introduced for the treatment of advanced malignancies. In the treatment of lung cancer, epidermoid growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) demonstrate striking antitumor activity in selected EGFR mutation positive patients. Patient selection by biomarker is extremely important to obtain successful results. The anti-vascular endothelial growth factor (VEGF) antibody, bevacizumab, shows a markedly increased response rate, progression free survival of advanced non-squamous cell lung cancer when combined with cytotoxic drugs. The classification of lung cancer is rapidly changing based on the advances in molecular biology. Here, the recent development of new molecular target drugs against lung cancer is thoroughly reviewed in addition to EGFR-TKIs and bevacizumab with special emphasis on the clinical application.

Compounds in clinical Phase III and beyond

Targeted therapies against cancer have become more and more important. In particular, the inhibition of tumor angiogenesis and vascular targeting have been the focus of new treatment strategies. Numerous new substances were developed as angiogenesis inhibitors and evaluated in clinical trials for safety, tolerance, and efficacy. With positive study results, some of these molecules have already been approved for clinical use. For example, this is true for the vascular endothelial growth factor neutralizing antibody bevacizumab (BEV) in metastatic colorectal cancer, nonsmall cell lung cancer, renal cancer, and breast cancer. The tyrosine kinase (TK) inhibitors sorafenib and sunitinib have been approved for metastatic renal cancer as well as for hepatocellular carcinoma, and sunitinib has also been approved for gastrointestinal stroma tumors. In this chapter we try to give an overview of the substances currently investigated in Phase III studies and beyond with regard to antiangiogenesis in cancer therapy.

It takes two to tango: combinations of conventional cytotoxics with compounds targeting the vascular endothelial growth factor-vascular endothelial growth factor receptor pathway in patients with solid malignancies

Through advances in molecular biology, insight into the mechanisms driving malignancies has improved immensely and as a result, various factors playing an essential role in the biology of numerous tumor types have been revealed. By using compounds that specifically block the function of a single factor being crucial for tumor pathogenesis, it was hoped to exert antitumor activity while avoiding toxicities characteristic for conventional chemotherapy. One of the processes of crucial importance in the development of cancer, and consequently an attractive target, is angiogenesis. In recent years, several key factors for angiogenesis have been identified, including ligands, receptors, and transduction signaling factors. Of these, the vascular endothelial growth factor (VEGF) pathway has been found to be activated in numerous tumor types and considered one of the main drivers of angiogenesis. Roughly, VEGF-mediated angiogenesis can be inhibited by two approaches: either by monoclonal antibodies directed towards VEGF or its corresponding receptors, or by kinase inhibitors targeting the signal transduction of the VEGF receptors. As monotherapy, several kinase inhibitors exert antitumor activity in tumor types such as renal cell carcinoma. However, in most tumor types, the antitumor activity of compounds targeting the VEGF pathway is limited. In recent years, evidence is mounting that the paradigm of one single factor that drives malignant behavior applies rarely and is an oversimplification for most tumors in which there are multiple driving pathways. Consequently, multitargeting rather than single-targeting approaches are required. One of the means is by combining targeted agents with conventional cytotoxics. As the VEGF pathway also affects the sensitivity of tumor cells to chemotherapeutics, combinations of compounds targeting this pathway and conventional cytotoxics have been explored. This review addresses such combinations.

Distinct patterns of cytokine and angiogenic factor modulation and markers of benefit for vandetanib and/or chemotherapy in patients with non-small-cell lung cancer

PURPOSE

There is an unmet need for biomarkers for identifying patients likely to benefit from anticancer treatments, selecting dose, and understanding mechanisms of resistance. Plasma vascular endothelial growth factor (VEGF) and soluble VEGF receptor 2 (sVEGFR-2) are known to be modulated by VEGF pathway inhibitors. It is unknown whether chemotherapy or VEGFR inhibitor/chemotherapy combinations induce changes in these or other cytokines and angiogenic factors (CAFs) and whether such changes could be markers of benefit.

METHODS

Thirty-five plasma CAFs were analyzed using multiplexed bead arrays and enzyme-linked immunosorbent assays from 123 patients with non-small-cell lung cancer in a randomized phase II study who received vandetanib, a VEGFR and epidermal growth factor receptor inhibitor, monotherapy carboplatin and paclitaxel (CP), or the combination (VCP). Changes in CAFs at days 8, 22, and 43 from baseline were correlated with progression risk.

RESULTS

VEGF increased and sVEGFR-2 decreased by day 43 in the vandetanib arm, whereas a distinct pattern was observed in the CP and VCP arms, with significant decreases in interleukin (IL) -12, IL-1 receptor antagonist, and matrix metalloproteinase 9 (MMP-9) and increased macrophage chemoattractant protein 1. In each treatment arm, changes in different markers were associated with progression risk. For example, increases in IL-8 with VCP, MMP-9 with CP, and VEGF with vandetanib monotherapy were associated with increased progression risk, and increase in intercellular adhesion molecule 1 with vandetanib was associated with decreased risk.

CONCLUSION

Vandetanib and chemotherapy treatment led to distinct patterns of CAF changes; the combination resembled chemotherapy alone. Changes in specific CAFs correlated with clinical outcome, but markers differed for each treatment arm. CAF profiling may provide insights into the biologic effects of treatment and identify drug-specific markers of activity and clinical benefit.

Targeted therapies in the treatment of advanced/metastatic NSCLC

The treatment of advanced non-small cell lung cancer (NSCLC) has evolved substantially during the last years. Chemotherapy remains the cornerstone of treatment and prolongs survival with a positive impact on quality of life. However, we seem to have reached a plateau of activity in the treatment of NSCLC. Recently, the addition of bevacizumab or cetuximab to chemotherapy doublets has improved the outcome in selected patients with advanced NSCLC. Furthermore, the use of erlotinib and gefitinib is an alternative for second line treatment. Advances in our understanding of molecular biology of cancer and mechanisms of tumourigenesis have further enabled the discovery of several potential molecular targets and development of novel 'targeted therapies'. The purpose of this study is to review current data on the role of targeted therapies in the treatment of advanced NSCLC.

DCE-MRI assessment of the effect of vandetanib on tumor vasculature in patients with advanced colorectal cancer and liver metastases: a randomized phase I study

BACKGROUND

Vandetanib is a once-daily oral inhibitor of VEGFR, EGFR and RET signaling pathways. In patients with advanced colorectal cancer and liver metastases, the effect of vandetanib on tumor vasculature was assessed using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

METHODS

Eligible patients received vandetanib 100 or 300 mg/day. DCE-MRI (iAUC(60 )and K(trans)) was used to quantify the primary endpoints of tumor perfusion and vascular permeability. An exploratory assessment of tumor oxygenation was performed using MRI/T2*. All MRI parameters were measured at baseline (twice) and on days 2, 8, 29 and 57.

RESULTS

Twenty-two patients received vandetanib (n = 10, 100 mg; n = 12, 300 mg). Baseline measurements of iAUC(60 )and K(trans )were reproducible, with low intrapatient coefficients of variation (11% and 24%, respectively). Estimates of mean % changes from baseline were -3.4% (100 mg) and -4.6% (300 mg) for iAUC(60), and -4.6% (100 mg) and -2.7% (300 mg) for K(trans); these changes were not significantly different between doses. The exploratory T2* measurement showed a significant increase at 300 mg versus 100 mg (P = 0.006). Both doses of vandetanib were generally well tolerated; common toxicities were fatigue, rash and diarrhea (majority CTC grade 1 or 2). The pharmacokinetic profile of vandetanib was similar to that observed previously. There were no RECIST-defined objective responses; five patients experienced stable disease >/=8 weeks.

CONCLUSION

In this study in patients with advanced colorectal cancer, vandetanib did not modulate gadolinium uptake in tumor vasculature and tissue measured by the DCE-MRI parameters iAUC(60 )and K(trans).

TRIAL REGISTRATION

NCT00496509 (ClinicalTrials.gov); D4200C00050 (AstraZeneca).

Angiogenesis inhibitors in the treatment of non-small cell lung cancer

A therapeutic plateau seems to have been reached with the standard treatment of cytotoxic chemotherapy alone for advanced stage non-small cell lung cancer (NSCLC) and new treatment options are urgently needed. Recent insight into the molecular biology of cancer has identified angiogenesis as one of the key biological processes. The major player in tumor angiogenesis is the vascular endothelial growth factor (VEGF) pathway. VEGF is expressed in the majority of NSCLC and overexpression is associated with a poor prognosis. The VEGF pathway can be inhibited in two main ways: targeting VEGF directly or inhibiting the VEGF receptors. The development of angiogenesis inhibitors has shown great promise in the treatment of NSCLC. Bevacizumab, an anti-VEGF antibody, has been approved for the treatment of advanced NSCLC and other drugs are undergoing phase III investigation. However, a number of unresolved issues remain. In this review, we discuss the main angiogenesis inhibitors in development for the treatment of NSCLC focusing on the VEGF pathway.

Abrogation of mitogen-activated protein kinase and Akt signaling by vandetanib synergistically potentiates histone deacetylase inhibitor-induced apoptosis in human glioma cells

Vandetanib is a multitargeted tyrosine kinase inhibitor. Our initial studies demonstrated that this agent blocks vascular endothelial growth factor receptor, epidermal growth factor receptor, and platelet-derived growth factor receptor phosphorylation and mitogen-activated protein kinase (MAPK)-mediated signaling in glioma cell lines in a dose-dependent manner. Despite these effects, we observed that vandetanib had little effect on apoptosis induction at clinically achievable concentrations. Because histone deacetylase inhibitors (HDACIs) have been suggested to regulate signaling protein transcription and downstream interactions via modulation of protein chaperone function through the 90-kDa heat shock protein, we investigated whether combining vandetanib with an HDACI could synergistically potentiate signaling pathway inhibition and apoptosis induction in a panel of malignant human glioma cell lines. Proliferation assays, apoptosis induction studies, and Western immunoblot analysis were conducted in cells treated with vandetanib and HDACIs as single agents or in combination. Vandetanib and suberoylanalide hydroxamic acid reduced proliferation in all cell lines when used as single agents, and the combination produced marked potentiation of growth inhibition as assessed by combinatorial methods. These effects were paralleled by potentiation of Akt signaling inhibition and apoptosis induction. Our results indicate that inhibition of histone deacetylation enhances the antiproliferative effect of vandetanib in malignant human glioma cell lines by enhancing inhibition of MAPK, Akt, and other downstream effectors that may have application in combinatorial therapeutics for these tumors.

Targeted therapy for malignant glioma patients: lessons learned and the road ahead

Molecularly targeted therapies are transforming the care of patients with malignant gliomas, including glioblastoma, the most common malignant primary brain tumor of adults. With an arsenal of small molecule inhibitors and antibodies that target key components of the signal transduction machinery that are commonly activated in gliomas, neuro-oncologists and neurosurgeons are poised to transform the care of these patients. Nonetheless, successful application of targeted therapies remains a challenge. Strategies are lacking for directing kinase inhibitor or other pathway-specific therapies to individual patients most likely to benefit. In addition, response to targeted agents is determined not only by the presence of the key mutant kinases, but also by other critical changes in the molecular circuitry of cancer cells, such as loss of key tumor suppressor proteins, the selection for kinase-resistant mutants, and the deregulation of feedback loops. Understanding these signaling networks, and studying them in patients, will be critical for developing rational combination therapies to suppress resistance for malignant glioma patients. Here we review the current status of molecular targeted therapies for malignant gliomas. We focus initially on identifying some of the insights gained to date from targeting the EGFR/PI3K/Akt/mTOR signaling pathway in patients and on how this has led toward a reconceptualization of some of the challenges and directions for targeted treatment. We describe how advances from the world of genomics have the potential to transform our approaches toward targeted therapy, and describe how a deeper understanding of the complex nature of cancer, and its adeptness at rewiring molecular circuitry to evade targeted agents, has raised new challenges and identified new leads.

Combined vascular endothelial growth factor receptor and epidermal growth factor receptor (EGFR) blockade inhibits tumor growth in xenograft models of EGFR inhibitor resistance

PURPOSE

The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) gefitinib and erlotinib benefit some non-small cell lung cancer (NSCLC) patients, but most do not respond (primary resistance) and those who initially respond eventually progress (acquired resistance). EGFR TKI resistance is not completely understood and has been associated with certain EGFR and K-RAS mutations and MET amplification.

EXPERIMENTAL DESIGN

We hypothesized that dual inhibition of the vascular endothelial growth factor (VEGF) and EGFR pathways may overcome primary and acquired resistance. We investigated the VEGF receptor/EGFR TKI vandetanib, and the combination of bevacizumab and erlotinib in vivo using xenograft models of EGFR TKI sensitivity, primary resistance, and three models of acquired resistance, including models with mutated K-RAS and secondary EGFR T790M mutation.

RESULTS

Vandetanib, gefitinib, and erlotinib had similar profiles of in vitro activity and caused sustained tumor regressions in vivo in the sensitive HCC827 model. In all four resistant models, vandetanib and bevacizumab/erlotinib were significantly more effective than erlotinib or gefitinib alone. Erlotinib resistance was associated with a rise in both host and tumor-derived VEGF but not EGFR secondary mutations in the KRAS mutant-bearing A549 xenografts. Dual inhibition reduced tumor endothelial proliferation compared with VEGF or EGFR blockade alone, suggesting that the enhanced activity of dual inhibition is due at least in part to antiendothelial effects.

CONCLUSION

These studies suggest that erlotinib resistance may be associated with a rise in both tumor cell and host stromal VEGF and that combined blockade of the VEGFR and EGFR pathways can abrogate primary or acquired resistance to EGFR TKIs. This approach merits further evaluation in NSCLC patients.

ZD6474 inhibits Src kinase leading to apoptosis of imatinib-resistant K562 cells

ZD6474 is an orally available, small-molecule tyrosine kinase inhibitor. This study explores the effect of ZD6474 on imatinib-resistant K562 cell lines, which show markedly increased SRC family kinases (SFKs) activity. ZD6474 induces growth arrest and apoptosis of imatinib-resistant and parental K562 cells, as well as inhibition of Src activity and its downstream effectors, the anti-apoptotic Bcl-2 family. ZD6474 treatment also inhibits the activity of STAT3 and reactivation of its activity results in suppression of the anti-tumor effects of SFKs inhibitors. A single oral administration of ZD6474 produced dose-dependent inhibition of imatinib-resistant K562 cells xenograft tumors. These results suggest that clinical assessment of ZD6474 against imatinib-resistant CML is warranted.

Vandetanib with FOLFIRI in patients with advanced colorectal adenocarcinoma: results from an open-label, multicentre Phase I study

PURPOSE

The safety and tolerability of vandetanib (ZACTIMA; ZD6474) plus FOLFIRI was investigated in patients with advanced colorectal cancer (CRC).

METHODS

Patients eligible for first- or second-line chemotherapy received once-daily oral doses of vandetanib (100 or 300 mg) plus 14-day treatment cycles of FOLFIRI.

RESULTS

A total of 21 patients received vandetanib 100 mg (n = 11) or 300 mg (n = 10) + FOLFIRI. Combination therapy was well tolerated at both vandetanib dose levels. There were no DLTs in the vandetanib 100 mg cohort and one DLT of hypertension (CTCAE grade 3) in the 300 mg cohort. The most common adverse events were diarrhoea (n = 20), nausea (n = 12) and fatigue (n = 10). Two patients (one in each cohort) discontinued vandetanib due to adverse events (rash, 100 mg cohort; hypertension, 300 mg cohort). There was no apparent pharmacokinetic interaction between vandetanib and FOLFIRI. Preliminary efficacy results included two confirmed partial responses in the 100 mg cohort and 9 patients with stable disease > or =8 weeks (100 mg, n = 7; 300 mg, n = 2).

CONCLUSIONS

Once-daily vandetanib (100 or 300 mg) in combination with a standard FOLFIRI regimen was generally well tolerated in patients with advanced CRC.