Vandetanib for the Treatment of Thyroid Cancer

RET-Altered Cancers-A Tumor-Agnostic Review of Biology, Diagnosis and Targeted Therapy Activity

RET alterations, such as fusions or mutations, drive the growth of multiple tumor types. These alterations are found in canonical (lung and thyroid) and non-canonical (e.g., gastrointestinal, breast, gynecological, genitourinary, histiocytic) cancers. RET alterations are best identified via comprehensive next-generation sequencing, preferably with DNA and RNA interrogation for fusions. Targeted therapies for RET-dependent cancers have evolved from older multikinase inhibitors to selective inhibitors of RET such as selpercatinib and pralsetinib. Prospective basket trials and retrospective reports have demonstrated the activity of these drugs in a wide variety of RET-altered cancers, notably those with RET fusions. This paved the way for the first tumor-agnostic selective RET inhibitor US FDA approval in 2022. Acquired resistance to RET kinase inhibitors can take the form of acquired resistance mutations (e.g., RET G810X) or bypass alterations.

Therapeutic strtegies of glioblastoma (GBM): The current advances in the molecular targets and bioactive small molecule compounds

Glioblastoma (GBM) is the most common aggressive malignant tumor in brain neuroepithelial tumors and remains incurable. A variety of treatment options are currently being explored to improve patient survival, including small molecule inhibitors, viral therapies, cancer vaccines, and monoclonal antibodies. Among them, the unique advantages of small molecule inhibitors have made them a focus of attention in the drug discovery of glioblastoma. Currently, the most used chemotherapeutic agents are small molecule inhibitors that target key dysregulated signaling pathways in glioblastoma, including receptor tyrosine kinase, PI3K/AKT/mTOR pathway, DNA damage response, TP53 and cell cycle inhibitors. This review analyzes the therapeutic benefit and clinical development of novel small molecule inhibitors discovered as promising anti-glioblastoma agents by the related targets of these major pathways. Meanwhile, the recent advances in temozolomide resistance and drug combination are also reviewed. In the last part, due to the constant clinical failure of targeted therapies, this paper reviewed the research progress of other therapeutic methods for glioblastoma, to provide patients and readers with a more comprehensive understanding of the treatment landscape of glioblastoma.

Prospects for Manipulation of Mesenchymal Stem Cells in Tumor Therapy: Anti-Angiogenesis Property on the Spotlight

The interactions between the tumor microenvironment and the tumor cells confers a condition that accelerate or decelerate the development of tumor. Of these cells, mesenchymal stem cells (MSCs) have the potential to modulate the tumor cells. MSCs have been established with double functions, whereby contribute to a tumorigenic or anti-tumor setting. Clinical studies have indicated the potential of MSCs to be used as tool in treating the human cancer cells. One of the advantageous features of MSCs that make them as a well-suited tool for cancer therapy is the natural tumor-trophic migration potential. A key specification of the tumor development has been stablished to be angiogenesis. As a result, manipulation of angiogenesis has become an attractive approach for cancer therapy. This review article will seek to clarify the anti-angiogenesis strategy in modulating the MSCs to treat the tumor cells.

Mesenchymal stem cells and cancer therapy: insights into targeting the tumour vasculature

A crosstalk established between tumor microenvironment and tumor cells leads to contribution or inhibition of tumor progression. Mesenchymal stem cells (MSCs) are critical cells that fundamentally participate in modulation of the tumor microenvironment, and have been reported to be able to regulate and determine the final destination of tumor cell. Conflicting functions have been attributed to the activity of MSCs in the tumor microenvironment; they can confer a tumorigenic or anti-tumor potential to the tumor cells. Nonetheless, MSCs have been associated with a potential to modulate the tumor microenvironment in favouring the suppression of cancer cells, and promising results have been reported from the preclinical as well as clinical studies. Among the favourable behaviours of MSCs, are releasing mediators (like exosomes) and their natural migrative potential to tumor sites, allowing efficient drug delivering and, thereby, efficient targeting of migrating tumor cells. Additionally, angiogenesis of tumor tissue has been characterized as a key feature of tumors for growth and metastasis. Upon introduction of first anti-angiogenic therapy by a monoclonal antibody, attentions have been drawn toward manipulation of angiogenesis as an attractive strategy for cancer therapy. After that, a wide effort has been put on improving the approaches for cancer therapy through interfering with tumor angiogenesis. In this article, we attempted to have an overview on recent findings with respect to promising potential of MSCs in cancer therapy and had emphasis on the implementing MSCs to improve them against the suppression of angiogenesis in tumor tissue, hence, impeding the tumor progression.

Design and synthesis of 4-anilinoquinazolines as Raf kinase inhibitors. Part 1. Selective B-Raf/B-RafV600E and potent EGFR/VEGFR2 inhibitory 4-(3-hydroxyanilino)-6-(1H-1,2,3-triazol-4-yl)quinazolines

This paper presents the design and synthesis of 4-(3-hydroxyanilino)-6-(1H-1,2,3-triazol-4-yl)quinazolines of scaffold 9 as selective B-Raf/B-Raf^V600E and potent EGFR/VEGFR2 kinase inhibitors. Total 14 compounds of scaffold 9 having different side chains at the triazolyl group with/without fluoro substituents at the anilino group were synthesized and investigated. Among them, 9m with a 2-carbamoylethyl side chain and C-4'/C-6' difluoro substituents was the most potent, which selectively inhibited B-Raf (IC₅₀: 57 nM) and B-Raf^V600E (IC₅₀: 51 nM) over C-Raf (IC₅₀: 1.0 μM). Compound 9m also actively inhibited EGFR (IC₅₀: 73 nM) and VEGFR2 (IC₅₀: 7.0 nM) but not EGFR^T790M and PDGFR-β (IC₅₀: >10 μM). Despite having good potency for B-Raf and B-Raf^V600E in the enzymatic assays, 9m was less active to inhibit melanoma A375 cells which proliferate due to constitutively activated B-Raf^600E. The inferior activity of 9m for A375 was similar to that of sorafenib (6), suggesting that 9m might bind to the inactive conformations of B-Raf and B-Raf^V600E. Docking simulations could thus be performed to reveal the binding poses of 9m in B-Raf, B-Raf^V600E, and VEGFR2 kinases.

Synthesis and evaluation of [18F]FP-Lys-GE11 as a new radiolabeled peptide probe for epidermal growth factor receptor (EGFR) imaging

INTRODUCTION

The epidermal growth factor receptor (EGFR) has emerged as an attractive target in the treatment of various cancers. Radiolabeled small molecules, antibodies, and peptides that specifically target EGFR are promising probes for tumor imaging to guide personalized treatment with EGFR-targeted drugs. This study aimed to radiolabel GE11 (an EGFR-specific targeting peptide) with 18-fluorine to develop a new EGFR-targeting positron emission tomography (PET) probe, [18F]FP-Lys-GE11, for imaging tumors overexpressing EGFR.

METHODS

[18F]FP-Lys-GE11 was produced by radiolabeling a GE11 peptide with the prosthetic group 4-nitrophenyl-2-[18F]fluoropropionate ([18F]NFP). Stability in PBS and mice serum, affinity for A431 cell line, U87 and PC-3 cells uptake and blocking studies, and biodistribution of [18F]FP-Lys-GE11 were determined. 2 h dynamic and static PET scans of probe for tumor-bearing mice normal and inhibition uptake were performed.

RESULTS

[18F]FP-Lys-GE11 was stable in PBS and mice serum. The Kd and Bmax values of probe for A431 were 42.43 ± 3.75 nM and 3383 ± 81.73 CPM, respectively. In cell uptake and blocking experiments, a significant reduction in radioactivity accumulation (over 4-fold) was observed by blocking U87 and PC-3 cells with unlabeled peptide. PET imaging of U87 and PC-3 tumor-bearing mice revealed clear tumor imaging (tumor radioactivity accumulation was 3.48 ± 0.44 and 3.68 ± 0.76%ID/g respectively, tumor-to-muscle ratio was 3.45 ± 0.43 and 3.64 ± 0.76 respectively). Blocking imaging revealed that the U87 tumor uptake was significantly inhibited (2.21 ± 0.41%ID/g). The biodistribution and dynamic PET imaging showed that [18F]FP-Lys-GE11 was mainly excreted by the kidneys and the rest was excreted through the bile and intestines.

CONCLUSION

The current results showed that [18F]FP-Lys-GE11was a good radiolabeled peptide probe for EGFR overexpression tumor's imaging.

Cabozantinib and vandetanib for unresectable locally advanced or metastatic medullary thyroid cancer: a systematic review and economic model

BACKGROUND

Medullary thyroid cancer (MTC) is a rare form of cancer that affects patients' health-related quality of life (HRQoL) and survival. Cabozantinib (Cometriq^®; Ipsen, Paris, France) and vandetanib (Caprelsa^®; Sanofi Genzyme, Cambridge, MA, USA) are currently the treatment modality of choice for treating unresectable progressive and symptomatic MTC.

OBJECTIVES

(1) To evaluate the clinical effectiveness and safety of cabozantinib and vandetanib. (2) To estimate the incremental cost-effectiveness of cabozantinib and vandetanib versus each other and best supportive care. (3) To identify key areas for primary research. (4) To estimate the overall cost of these treatments in England.

DATA SOURCES

Peer-reviewed publications (searched from inception to November 2016), European Public Assessment Reports and manufacturers' submissions.

REVIEW METHODS

A systematic review [including a network meta-analysis (NMA)] was conducted to evaluate the clinical effectiveness and safety of cabozantinib and vandetanib. The economic analysis included a review of existing analyses and the development of a de novo model.

RESULTS

The systematic review identified two placebo-controlled trials. The Efficacy of XL184 (Cabozantinib) in Advanced Medullary Thyroid Cancer (EXAM) trial evaluated the efficacy and safety of cabozantinib in patients with unresectable locally advanced, metastatic and progressive MTC. The ZETA trial evaluated the efficacy and safety of vandetanib in patients with unresectable locally advanced or metastatic MTC. Both drugs significantly improved progression-free survival (PFS) more than the placebo (p < 0.001). The NMA suggested that, within the symptomatic and progressive MTC population, the effects on PFS were similar (vandetanib vs. cabozantinib: hazard ratio 1.14, 95% credible interval 0.41 to 3.09). Neither trial demonstrated a significant overall survival benefit for cabozantinib or vandetanib versus placebo, although data from ZETA were subject to potential confounding. Both cabozantinib and vandetanib demonstrated significantly better objective response rates and calcitonin (CTN) and carcinoembryonic antigen (CEA) response rates than placebo. Both cabozantinib and vandetanib produced frequent adverse events, often leading to dose interruption or reduction. The assessment group model indicates that, within the EU-label population (symptomatic and progressive MTC), the incremental cost-effectiveness ratios (ICERs) for cabozantinib and vandetanib are > £138,000 per quality-adjusted life-year (QALY) gained. Within the restricted EU-label population (symptomatic and progressive MTC with CEA/CTN doubling times of ≤ 24 months), the ICER for vandetanib is expected to be > £66,000 per QALY gained. The maximum annual budget impact within the symptomatic and progressive population is estimated to be ≈£2.35M for cabozantinib and ≈£5.53M for vandetanib. The costs of vandetanib in the restricted EU-label population are expected to be lower.

LIMITATIONS

The intention-to-treat populations of the EXAM and ZETA trials are notably different. The analyses of ZETA subgroups may be subject to confounding as a result of differences in baseline characteristics and open-label vandetanib use. Attempts to statistically adjust for treatment switching were unsuccessful. No HRQoL evidence was identified for the MTC population.

CONCLUSIONS

The identified trials suggest that cabozantinib and vandetanib improve PFS more than the placebo; however, significant OS benefits were not demonstrated. The economic analyses indicate that within the EU-label population, the ICERs for cabozantinib and vandetanib are > £138,000 per QALY gained. Within the restricted EU-label population, the ICER for vandetanib is expected to be > £66,000 per QALY gained.

FUTURE RESEARCH PRIORITIES

(1) Primary research assessing the long-term effectiveness of cabozantinib and vandetanib within relevant subgroups. (2) Reanalyses of the ZETA trial to investigate the impact of adjusting for open-label vandetanib use using appropriate statistical methods. (3) Studies assessing the impact of MTC on HRQoL.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016050403.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

New Insights Into Implementation of Mesenchymal Stem Cells in Cancer Therapy: Prospects for Anti-angiogenesis Treatment

Tumor microenvironment interacts with tumor cells, establishing an atmosphere to contribute or suppress the tumor development. Among the cells which play a role in the tumor microenvironment, mesenchymal stem cells (MSCs) have been demonstrated to possess the ability to orchestrate the fate of tumor cells, drawing the attention to the field. MSCs have been considered as cells with double-bladed effects, implicating either tumorigenic or anti-tumor activity. On the other side, the promising potential of MSCs in treating human cancer cells has been observed from the clinical studies. Among the beneficial characteristics of MSCs is the natural tumor-trophic migration ability, providing facility for drug delivery and, therefore, targeted treatment to detach tumor and metastatic cells. Moreover, these cells have been the target of engineering approaches, due to their easily implemented traits, in order to obtain the desired expression of anti-angiogenic, anti-proliferative, and pro-apoptotic properties, according to the tumor type. Tumor angiogenesis is the key characteristic of tumor progression and metastasis. Manipulation of angiogenesis has become an attractive approach for cancer therapy since the introduction of the first angiogenesis inhibitor, namely bevacizumab, for metastatic colorectal cancer therapy. This review tries to conclude the approaches, with focus on anti-angiogenesis approach, in implementing the MSCs to combat against tumor cell progression.

Angiogenesis inhibitors as therapeutic agents in cancer: Challenges and future directions

Angiogenesis has become an attractive target for cancer therapy since the US Food and Drug Administration (FDA) approved the first angiogenesis inhibitor (bevacizumab) for the treatment of metastatic colorectal cancer in 2004. In following years, a large number of angiogenesis inhibitors have been discovered and developed, ranging from monoclonal antibodies, endogenous peptides, to small organic molecules and microRNAs. Many of them are now entering the clinical trial, or achieving approval for clinical use. However, major limitations have been observed about angiogenesis inhibitors by continued clinical investigations, such as resistance, enhancing tumor hypoxia and reducing delivery of chemotherapeutic agents, which might be the main reason for poor improvement in overall survival after angiogenesis inhibitor administration in clinic. Therefore, optimal anti-angiogenic therapy strategies become critical. The present review summarizes recent researches in angiogenesis inhibitors, and proposes a perspective on future directions in this field.

Effect of an Outreach Programme on Vandetanib Safety in Medullary Thyroid Cancer

OBJECTIVES

Effective management of adverse events (AEs) following vandetanib treatment is important to maximize clinical benefits. We examined whether more frequent contact with vandetanib-treated patients reduced AEs of CTCAE grade 2 or higher.

STUDY DESIGN

In this open-label, multicentre, phase III study, patients with locally advanced or metastatic medullary thyroid cancer were randomized to a patient outreach programme (outreach) or a standard AE monitoring schedule (vandetanib control) for 52 weeks. In addition to standard AE monitoring, patients in the outreach arm were contacted every 2 weeks by telephone/during their clinic visit for specific AE questioning related to diarrhoea, nausea, vomiting, fatigue, headache and rash. Patients received vandetanib at 200 or 300 mg/day, depending on the creatinine levels at screening.

RESULTS

Altogether, 205 patients were randomized (outreach, n = 103; vandetanib control, n = 102). This study did not meet its primary objective; the mean percentage of time patients experienced at least one AE of grade 2 or higher was higher for the outreach group (51.65%) than for the vandetanib control group (45.19%); the difference was not statistically significant (t statistic: 1.29; 95% CI -3.44 to 16.37%; p = 0.199). The most frequently reported AEs were diarrhoea (56.9% for the outreach group vs. 46.6% for the vandetanib controls), hypertension (36.3 vs. 31.1%), rash (25.5 vs. 24.3%) and nausea (25.5% vs. 18.4%), and the most frequently reported AEs of grade 2 or higher were hypertension (33.3 vs. 23.3%), diarrhoea (26.5 vs. 24.3%) and dermatitis acneiform (11.8 vs. 9.7%).

CONCLUSIONS

Additional outreach to patients treated with vandetanib had no impact on the rate or severity of AEs compared to the standard AE monitoring schedule. AEs were consistent with the known safety profile of vandetanib.

Anilinoquinazoline inhibitors of the RET kinase domain-Elaboration of the 7-position

We have previously reported a series of anilinoquinazoline derivatives as potent and selective biochemical inhibitors of the RET kinase domain. However, these derivatives displayed diminished cellular potency. Herein we describe further optimisation of the series through modification of their physicochemical properties, delivering improvements in cell potency. However, whilst cellular selectivity against key targets could be maintained, combining cell potency and acceptable pharmacokinetics proved challenging.

Phase I trial of vandetanib in combination with gemcitabine and capecitabine in patients with advanced solid tumors with an expanded cohort in pancreatic and biliary cancers

BACKGROUND

Vandetanib is a multitargeted tyrosine kinase inhibitor that affects vascular endothelial growth factor receptor (VEGF), epidermal growth factor (EGF), and rearranged during transfection (RET) mediated receptors which are important for growth and invasion of biliary and pancreatic cancers. This phase I study evaluated the safety profile of vandetanib in combination with standard doses of gemcitabine and capecitabine in order to determine the maximum tolerated dose (MTD).

METHODS

In this single center phase I trial, patients received gemcitabine intravenously (i.v.) at 1000 mg/m2 days 1, 8, 15 in a 28 day cycle, capecitabine orally at 850 mg/m2 twice daily on days 1-21, and escalating doses of vandetanib (200 or 300 mg orally daily). Once the MTD was defined, an expansion cohort of patients with advanced biliary cancers and locally advanced or metastatic pancreatic cancer was enrolled. Blood samples were also collected at predetermined time points for biomarker analysis.

RESULTS

Twenty-three patients were enrolled: 9 in the dose escalation and 14 in the dose expansion cohort. One dose limiting toxicity (DLT), of grade 4 neutropenia, occurred in the 200 mg vandetanib cohort. The most common adverse effects were diarrhea (39 %), nausea and vomiting (34%), and rash (33%). There were 3 partial responses and stable disease of >2 months (range 2-45, median 5) was observed in 15/23 patients. There was no association between changes in biomarker analytes and disease response.

CONCLUSION

The combination of gemcitabine, capecitabine and vandetanib is well tolerated at the recommended phase II dose of gemcitabine 1000 mg/m2 weekly for three consecutive weeks, capecitabine 850 mg/m2 BID days 1-21, and vandetanib 300 mg daily, every 28 days. This combination demonstrated promising activity in pancreaticobiliary cancers and further evaluation is warranted in these diseases. NCT00551096.

Mechanical induction of the tumorigenic β-catenin pathway by tumour growth pressure

The tumour microenvironment may contribute to tumorigenesis owing to mechanical forces such as fibrotic stiffness or mechanical pressure caused by the expansion of hyper-proliferative cells. Here we explore the contribution of the mechanical pressure exerted by tumour growth onto non-tumorous adjacent epithelium. In the early stage of mouse colon tumour development in the Notch(+)Apc(+/1638N) mouse model, we observed mechanistic pressure stress in the non-tumorous epithelial cells caused by hyper-proliferative adjacent crypts overexpressing active Notch, which is associated with increased Ret and β-catenin signalling. We thus developed a method that allows the delivery of a defined mechanical pressure in vivo, by subcutaneously inserting a magnet close to the mouse colon. The implanted magnet generated a magnetic force on ultra-magnetic liposomes, stabilized in the mesenchymal cells of the connective tissue surrounding colonic crypts after intravenous injection. The magnetically induced pressure quantitatively mimicked the endogenous early tumour growth stress in the order of 1,200 Pa, without affecting tissue stiffness, as monitored by ultrasound strain imaging and shear wave elastography. The exertion of pressure mimicking that of tumour growth led to rapid Ret activation and downstream phosphorylation of β-catenin on Tyr654, imparing its interaction with the E-cadherin in adherens junctions, and which was followed by β-catenin nuclear translocation after 15 days. As a consequence, increased expression of β-catenin-target genes was observed at 1 month, together with crypt enlargement accompanying the formation of early tumorous aberrant crypt foci. Mechanical activation of the tumorigenic β-catenin pathway suggests unexplored modes of tumour propagation based on mechanical signalling pathways in healthy epithelial cells surrounding the tumour, which may contribute to tumour heterogeneity.

Mechanical induction of the tumorigenic β-catenin pathway by tumour growth pressure

The tumour microenvironment may contribute to tumorigenesis owing to mechanical forces such as fibrotic stiffness or mechanical pressure caused by the expansion of hyper-proliferative cells. Here we explore the contribution of the mechanical pressure exerted by tumour growth onto non-tumorous adjacent epithelium. In the early stage of mouse colon tumour development in the Notch(+)Apc(+/1638N) mouse model, we observed mechanistic pressure stress in the non-tumorous epithelial cells caused by hyper-proliferative adjacent crypts overexpressing active Notch, which is associated with increased Ret and β-catenin signalling. We thus developed a method that allows the delivery of a defined mechanical pressure in vivo, by subcutaneously inserting a magnet close to the mouse colon. The implanted magnet generated a magnetic force on ultra-magnetic liposomes, stabilized in the mesenchymal cells of the connective tissue surrounding colonic crypts after intravenous injection. The magnetically induced pressure quantitatively mimicked the endogenous early tumour growth stress in the order of 1,200 Pa, without affecting tissue stiffness, as monitored by ultrasound strain imaging and shear wave elastography. The exertion of pressure mimicking that of tumour growth led to rapid Ret activation and downstream phosphorylation of β-catenin on Tyr654, imparing its interaction with the E-cadherin in adherens junctions, and which was followed by β-catenin nuclear translocation after 15 days. As a consequence, increased expression of β-catenin-target genes was observed at 1 month, together with crypt enlargement accompanying the formation of early tumorous aberrant crypt foci. Mechanical activation of the tumorigenic β-catenin pathway suggests unexplored modes of tumour propagation based on mechanical signalling pathways in healthy epithelial cells surrounding the tumour, which may contribute to tumour heterogeneity.

[Vandetanib, in the management of patients with locally advanced or metastatic medullary thyroid carcinomas]

Medullary thyroid cancer (MTC) is a rare cancer. Vandetanib, a RET tyrosine-kinase inhibitor, significantly increased progression free survival and is the first treatment approved in France for unresectable, locally advanced or metastatic MTC that is symptomatic or progressive. Most frequents adverse events are diarrhea, folliculitis and asthenia. The prolongation of the QT interval on electrocardiogram is frequent but in the most of cases not clinically relevant. A good selection of the patients who could benefit from this treatment and management of side effect are important for the risk-benefit assessment.

EGFR biomarkers predict benefit from vandetanib in combination with docetaxel in a randomized phase III study of second-line treatment of patients with advanced non-small cell lung cancer

Analysis of tumor samples from the ZODIAC study showed that EGFR gene mutation or EGFR gene amplification predicted greater benefits from vandetanib plus docetaxel treatment compared with docetaxel treatment alone. In contrast, KRAS mutations were associated with poor outcomes to docetaxel therapy, and addition of vandetanib did not appear to confer any additional benefit over docetaxel alone.

Background

ZODIAC was a randomized phase III study of second-line treatment in patients with advanced non-small cell lung cancer (NSCLC) that evaluated the addition of vandetanib to docetaxel. The study showed a statistically significant improvement in progression-free survival and objective response rate, but not in overall survival for unselected patients. This study evaluated epidermal growth factor receptor (EGFR) gene mutation, copy number gain, and protein expression, and KRAS gene mutation, in pretreatment tumor samples as potential biomarkers predicting benefit from vandetanib as second-line treatment of NSCLC.

Patients and methods

After progression following first-line chemotherapy, 1391 patients with locally advanced or metastatic (stage IIIB/IV) NSCLC were randomized 1 : 1 to receive vandetanib (100 mg/day) plus docetaxel (75 mg/m² every 21 days) or placebo plus docetaxel in the ZODIAC study. Archival tumor samples (n = 570) were collected from consenting patients (n = 958) for predefined, prospective biomarker analyses.

Results

Of evaluable samples, 14% were EGFR mutation positive, 35% were EGFR FISH positive, 88% were EGFR protein expression positive, and 13% were KRAS mutation positive. Compared with the overall study population, in which progression-free survival (PFS) [hazard ratio (HR) = 0.79] but not OS (HR = 0.91) were significantly improved with vandetanib, there was greater relative clinical benefit for patients with EGFR mutation-positive tumors [PFS HR 0.51, confidence interval (CI) 0.25–1.06 and OS HR 0.46, CI 0.14–1.57] and EGFR FISH-positive tumors (PFS HR 0.61, CI 0.39–0.94 and OS HR 0.48, CI 0.28–0.84). Similarly, patients with EGFR mutation or FISH-positive tumor samples who received vandetanib had an increased chance of objective tumor response (odds ratios 3.34, CI 0.8–13.89, and 3.90, CI 1.02–14.82, respectively). There did not appear to be benefit for vandetanib in patients with KRAS mutation-positive tumors.

Conclusions

High EGFR gene copy number or activating EGFR mutations may identify patient subgroups who receive increased clinical benefit from vandetanib in combination with docetaxel in second-line NSCLC.

ClinicalTrials.gov

NCT00312377.

Clinical pharmacokinetics of tyrosine kinase inhibitors: implications for therapeutic drug monitoring

The treatment of many malignancies has been improved in recent years by the introduction of molecular targeted therapies. These drugs interact preferentially with specific targets that are mutated and/or overexpressed in malignant cells. A group of such targets are the tyrosine kinases, against which a number of inhibitors (tyrosine kinase inhibitors, TKIs) have been developed. Imatinib, a TKI with targets that include the breakpoint cluster region-Abelson (bcr-abl) fusion protein kinase and mast/stem cell growth factor receptor kinase (c-Kit), was the first clinically successful drug of this type and revolutionized the treatment and prognosis of chronic myeloid leukemia and gastrointestinal stromal tumors. This success paved the way for the development of other TKIs for the treatment of a range of hematological malignancies and solid tumors. To date, 14 TKIs have been approved for clinical use and many more are under investigation. All these agents are given orally and are substrates of a range of drug transporters and metabolizing enzymes. In addition, some TKIs are capable of inhibiting their own transporters and metabolizing enzymes, making their disposition and metabolism at steady-state unpredictable. A given dose can therefore give rise to markedly different plasma concentrations in different patients, favoring the selection of resistant clones in the case of subtherapeutic exposure, and increasing the risk of toxicity if dosage is excessive. The aim of this review was to summarize current knowledge of the clinical pharmacokinetics and known adverse effects of the TKIs that are available for clinical use and to provide practical guidance on the implications of these data in patient management, in particular with respect to therapeutic drug monitoring.

Identification of a Peptide from In vivo Bacteriophage Display with Homology to EGFL6: A Candidate Tumor Vasculature Ligand in Breast Cancer

Background

A crucial step in tumorigenesis is the recruitment of novel vasculature to the site of neoplasia. Currently, a number of high throughput techniques are employed to identify genes, mRNA and proteins that are aberrantly expressed in tumor vasculature. One drawback of such techniques is the lack of functional in vivo data that they provide. Bacteriophage (phage) display has been demonstrated in vivo to select peptides that home to tumors and tumor vasculature. The peptides can be compared to sequences of putative cancer-related proteins, in order to identify novel proteins essential for tumorigenesis.

Objectives

It was hypothesized that an in vivo selection for phage which targeted human breast cancer xenografts could identify peptides with homology to cancer-related proteins for in vivo imaging of breast cancer.

Methods

Following four rounds of in vivo selection in human MDA-MB-435 breast cancer xenografted mice, peptide 3-G03 was discovered with significant homology to a putative secreted protein termed EGFL6. Egfl6 mRNA is upregulated in several transcriptomic analyses of human cancer biopsies, and the protein may play a role in tumor vascularization.

Results

Egfl6 mRNA expression was demonstrated in MDA-MB-435 cells and EGFL6 protein was secreted from these cells. Based on homology of 3-G03 to EGFL6, an EGFL6 peptide was synthesized and shown to target MDA-MB-435 cells. EGFL6 peptide was radiolabeled with ¹¹¹In and analyzed for biodistribution and tumor imaging capabilities. Single photon emission computed tomography imaging revealed uptake of the peptide in a manner consistent with other tumor vasculature targeting agents.

Vandetanib in advanced medullary thyroid cancer: review of adverse event management strategies

Introduction

Vandetanib has recently demonstrated clinically meaningful benefits in patients with unresectable, locally advanced or metastatic medullary thyroid cancer (MTC). Given the potential for long-term vandetanib therapy in this setting, in addition to treatment for disease-related symptoms, effective management of related adverse events (AEs) is vital to ensure patient compliance and maximize clinical benefit with vandetanib therapy.

Methods

This expert meeting-based review aims to summarize published data on AEs associated with vandetanib therapy and to provide clinicians with specific practical guidance on education, monitoring, and management of toxicities induced in patients treated with vandetanib in advanced and metastatic MTC. The content of this review is based on the expert discussions from a multidisciplinary meeting held in October 2012.

Results

Characteristics, frequency, and risk data are outlined for a number of dermatological, cardiovascular, gastrointestinal, and general AEs related to vandetanib treatment. Preventive strategies, practical treatment suggestions, and points for clinical consideration are provided.

Conclusions

Good patient and team communication is necessary for the prevention, early detection, and management of AEs of vandetanib. Physicians, nurses, and other healthcare providers play a critical role in providing AE management and patient support to optimize outcomes with vandetanib in MTC.

New developments in the diagnosis and treatment of thyroid cancer

Thyroid cancer exists in several forms. Differentiated thyroid cancers include those with papillary and follicular histologies. These tumors exist along a spectrum of differentiation, and their incidence continues to climb. A number of advances in the diagnosis and treatment of differentiated thyroid cancers now exist. These include molecular diagnostics and more advanced strategies for risk stratification. Medullary cancer arises from the parafollicular cells and not the follicular cells. Therefore, diagnosis and treatment differs from those of differentiated thyroid tumors. Genetic testing and newer adjuvant therapies have changed the diagnosis and treatment of medullary thyroid cancer. This review will focus on the epidemiology, diagnosis, workup, and treatment of both differentiated and medullary thyroid cancers, focusing specifically on newer developments in the field.

Autophagy inhibition induces enhanced proapoptotic effects of ZD6474 in glioblastoma

BACKGROUND

Autophagy is a lysosomal degradation pathway that can provide energy through its recycling mechanism to act as a cytoprotective adaptive response mediating treatment resistance in cancer cells. We investigated the autophagy-inducing effects of ZD6474, a small-molecule inhibitor that blocks activities of vascular endothelial growth factor receptor (VEGFR), epidermal growth factor receptor (EGFR), and RET tyrosine kinases.

METHODS

We investigated the effects of ZD6474 on autophagy in glioblastomas cells. The ZD6474 mechanism of action was determined by western blot. We then examined the impacts of the inhibition of autophagy in combination with ZD6474 on cell apoptosis in vitro. Furthermore, we evaluated the synergistic anticancer activity of combination treatment with an autophagy inhibitor (chloroquine) and ZD6474 in U251 glioblastoma cells xenograft model.

RESULTS

ZD6474-induced autophagy was dependent on signalling through the phosphoinositide 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway. ZD6474-induced autophagy was inhibited by both knockdown of the ATG7 and Beclin 1 gene, essential autophagy genes, and pharmacologic agents (chloroquine and 3-methyalanine) treatment. Both treatments also dramatically sensitised glioblastoma cells to ZD6474-induced apoptosis, decreasing cell viability in vitro. Furthermore, in a xenograft mouse model, combined treatment with ZD6474 and chloroquine significantly inhibited U251 tumour growth, and increased the numbers of apoptotic cells compared with treatment with either agent alone.

CONCLUSION

Autophagy protects glioblastoma cells from the proapoptotic effects of ZD6474, which might contribute to tumour resistance against ZD6474 treatment.

Body composition variation and impact of low skeletal muscle mass in patients with advanced medullary thyroid carcinoma treated with vandetanib: results from a placebo-controlled study

OBJECTIVES

Vandetanib was approved by the U.S. Food and Drug Association for the treatment of advanced medullary thyroid cancer (MTC). Because body weight (BW) loss is observed in MTC and because low skeletal muscle mass (SM) is associated with drug toxicity, this study assessed effects of vandetanib on SM and adipose tissue (AT) and explored the association between SM, toxicity, and serum concentration of vandetanib.

METHODS

Thirty-three patients with MTC received vandetanib (n = 23) or placebo (n = 10) in the ZETA study. Visceral AT (VAT), sc AT (SAT), and SM were assessed with computed tomography imaging by measuring tissue cross-sectional areas (square centimers per square meter). Dose-limiting toxicities (DLTs) were prospectively recorded.

RESULTS

Early at 3 months, compared with placebo group who lost BW, muscle, and SAT, patients treated with vandetanib gained 1.5 kg BW (P = 0.02), 1.3 cm(2)/m(2) (∼0.7 kg) of SM (P = 0.009), and 4.5 cm(2)/m(2) (∼0.5 kg) of SAT (P = 0.004) and gained more VAT, 5.1 cm(2)/m(2) (∼0.7 kg) (P = 0.02). Patients with DLT had lower SM index (37.2 vs 44.3 cm(2)/m(2), P = 0.003) and a higher vandetanib serum concentration (1091 vs 739 ng/mL, P = 0.03). Patients with SM index <43.1 cm(2)/m(2) had a higher probability of DLT (73% vs 14%, P = 0.004) and a higher vandetanib serum concentration (1037 vs 745 ng/mL, P = 0.04). Patients with the highest compared with the intermediate and lower levels of vandetanib serum concentration experienced more DLT, respectively, 78% vs 40% vs 20% (P = 0.04).

CONCLUSIONS

Muscle and adipose tissues are restored after only 3 months of vandetanib treatment. Patients with low muscle mass had high vandetanib serum concentration and high incidence of toxicities.

Recent new drug approvals, part 2: drugs undergoing active clinical studies in children

The objective of this 2-part review is to provide information about drugs that have been recently approved by the US Food and Drug Administration. Part 1 reviewed recently approved drugs with pediatric indications. Part 2 reviews drugs recently approved only in adults and have published or ongoing studies in children.

Vandetanib: a guide to its use in advanced medullary thyroid cancer

Vandetanib (Caprelsa™) provides an acceptable treatment option in patients with advanced medullary thyroid cancer for whom, historically, there have been no effective therapies. Vandetanib, an orally active, multitargeted tyrosine kinase inhibitor, improves progression-free survival and tumor response in patients with unresectable, locally advanced or metastatic medullary thyroid cancer. It has an acceptable tolerability profile in this patient population, although it does have the potential to prolong the corrected QT interval.

Emerging role of multikinase inhibitors for refractory thyroid cancer

Thyroid cancer incidence continues to increase, remaining the most common endocrine malignancy. The need for effective systemic therapies combined with high incidence of driver mutations and overexpression of molecular pathways make refractory thyroid cancer an ideal candidate for treatment with novel agents. Multikinase inhibitors have caused a paradigm shift in the treatment of patients with advanced iodine-refractory thyroid cancer. These agents have shown to be the most effective systemic therapy for this disease not only causing prolonged responses but also improving survival. The activity of these agents inhibiting several pathways simultaneously, such as rearranged during transfection protooncogene, mitogen-activated protein kinase, and angiogenesis, can probably explain the effectiveness in controlling the progression of this malignancy. Several of these agents are currently on clinical studies in patients with differentiated and medullary thyroid cancer and most of them are showing promising clinical activity. With the approval of vandetanib for the treatment of medullary thyroid cancer, a new era in the management of this disease has begun. The molecular rationale for the use of these drugs for thyroid cancer is discussed as well as their promising clinical results.

Synthesis and in vitro evaluation of [18F](R)-FEPAQ: a potential PET ligand for VEGFR2

Synthesis and in vitro evaluation of [(18)F](R)-N-(4-bromo-2-fluorophenyl)-7-((1-(2-fluoroethyl)piperidin-3-yl)methoxy)-6-methoxyquinazolin-4-amine ((R)-[(18)F]FEPAQ or [(18)F]1), a potential imaging agent for the VEGFR2, using phosphor image autoradiography are described. Synthesis of 2, the desfluoroethyl precursor for (R)-FEPAQ was achieved from t-butyl 3-(hydroxymethyl)piperidine-1-carboxylate (3) in five steps and in 50% yield. [(18)F]1 was synthesized by reaction of sodium salt of compound 2 with [(18)F]fluoroethyl tosylate in DMSO. The yield of [(18)F]1 was 20% (EOS based on [(18)F]F(-)) with >99% radiochemical purity and specific activity of 1-2 Ci/μmol (n=10). The total synthesis time was 75 min. The radiotracer selectively labeled VEGFR2 in slide-mounted sections of human brain and higher binding was found in surgically removed human glioblastoma sections as demonstrated by in vitro phosphor imager studies. These findings suggest [(18)F]1 may be a promising radiotracer for imaging VEGFR2 in brain using PET.

Anti-angiogenesis therapy in cancer: current challenges and future perspectives

It has been nearly 9years since the FDA (Food and Drug Administration) approved the first anti-angiogenic drug (bevacizumab) for treatment of metastatic colorectal cancer. Other angiogenic inhibitors have since been approved or are in different stages of clinical trials. However, continued clinical and preclinical investigations have identified major drawbacks associated with the application of this class of agents, including inherent/acquired resistance and induction of tumor invasiveness. In addition, lack of thoroughly validated predictive biomarkers has been one of the major hurdles to stratify cancer patients and to monitor tumor progression and response to the therapy. Investigations in clinic and preclinical models have provided some molecular and cellular mechanisms for the above challenges. This review aims to provide a concise update from recent findings.