The vascular endothelial growth factor proteins: identification of biologically relevant regions by neutralizing monoclonal antibodies

Biology and therapeutic targeting of vascular endothelial growth factor A

The formation of new blood vessels, called angiogenesis, is an essential pathophysiological process in which several families of regulators have been implicated. Among these, vascular endothelial growth factor A (VEGFA; also known as VEGF) and its two tyrosine kinase receptors, VEGFR1 and VEGFR2, represent a key signalling pathway mediating physiological angiogenesis and are also major therapeutic targets. VEGFA is a member of the gene family that includes VEGFB, VEGFC, VEGFD and placental growth factor (PLGF). Three decades after its initial isolation and cloning, VEGFA is arguably the most extensively investigated signalling system in angiogenesis. Although many mediators of angiogenesis have been identified, including members of the FGF family, angiopoietins, TGFβ and sphingosine 1-phosphate, all current FDA-approved anti-angiogenic drugs target the VEGF pathway. Anti-VEGF agents are widely used in oncology and, in combination with chemotherapy or immunotherapy, are now the standard of care in multiple malignancies. Anti-VEGF drugs have also revolutionized the treatment of neovascular eye disorders such as age-related macular degeneration and ischaemic retinal disorders. In this Review, we emphasize the molecular, structural and cellular basis of VEGFA action as well as recent findings illustrating unexpected interactions with other pathways and provocative reports on the role of VEGFA in regenerative medicine. We also discuss clinical and translational aspects of VEGFA. Given the crucial role that VEGFA plays in regulating angiogenesis in health and disease, this molecule is largely the focus of this Review.

Oral mucosal pseudotumor - Novelty complication in patient undergoing bevacizumab therapy

Medication-related osteonecrosis of the jaw (MRONJ) is a manifestation of bone exposure in the maxillofacial region due to use of drugs such as bisphosphonates, anti-resorptive agents and anti-angiogenic agents. This G1- humanized monoclonal antibody neutralizes the activity of the Vascular Endothelial Growth Factor (VEGF), thus reducing the vascularity of the tumor, which in turn, results in the inhibition of its growth. This case report is of a 53-year-old man with metastatic cholangiocarcinoma who received bevacizumab therapy for the past 11 months. Delayed healing of extraction sockets, osteosclerosis, and exposed bone in the mandible with a mucosal swelling was noted a month after extractions were done. The present case reinforces recent observations that the anti-angiogenic properties of bevacizumab may present a source of osteonecrosis of the jaw. To reduce the incidences of MRONJ, it is imperative to emphasize on preventive dental care, strict oral hygiene maintenance, and regular dental follow ups.

The cancer angiogenesis co-culture assay: In vitro quantification of the angiogenic potential of tumoroids

The treatment response to anti-angiogenic agents varies among cancer patients and predictive biomarkers are needed to identify patients with resistant cancer or guide the choice of anti-angiogenic treatment. We present “the Cancer Angiogenesis Co-Culture (CACC) assay”, an in vitro Functional Precision Medicine assay which enables the study of tumouroid induced angiogenesis. This assay can quantify the ability of a patient-derived tumouroid to induce vascularization by measuring the induction of tube formation in a co-culture of vascular cells and tumoroids established from the primary colorectal tumour or a metastasis. Furthermore, the assay can quantify the sensitivity of patient-derived tumoroids to anti-angiogenic therapies. We observed that tube formation increased in a dose-dependent manner upon treatment with the pro-angiogenic factor vascular endothelial growth factor A (VEGF-A). When investigating the angiogenic potential of tumoroids from 12 patients we found that 9 tumoroid cultures induced a significant increase in tube formation compared to controls without tumoroids. In these 9 angiogenic tumoroid cultures the tube formation could be abolished by treatment with one or more of the investigated anti-angiogenic agents. The 3 non-angiogenic tumoroid cultures secreted VEGF-A but we observed no correlation between the amount of tube formation and tumoroid-secreted VEGF-A. Our data suggests that the CACC assay recapitulates the complexity of tumour angiogenesis, and when clinically verified, could prove a valuable tool to quantify sensitivity towards different anti-angiogenic agents.

Efficacy, Safety, and Immunogenicity of HLX04 Versus Reference Bevacizumab in Combination with XELOX or mFOLFOX6 as First-Line Treatment for Metastatic Colorectal Cancer: Results of a Randomized, Double-Blind Phase III Study

Background

HLX04 is a proposed biosimilar of bevacizumab.

Objective

This phase III study aimed to evaluate the efficacy, safety, and immunogenicity of HLX04 compared with reference bevacizumab in combination with XELOX or mFOLFOX6 as first-line treatment for recurrent/metastatic colorectal cancer (CRC).

Methods

In this double-blind, parallel-group study, patients were randomized 1:1 to receive HLX04 or bevacizumab (7.5 mg/kg every 3 weeks when combined with XELOX; 5 mg/kg every 2 weeks when combined with mFOLFOX6). The primary endpoint was progression-free survival rate at week 36 (PFSR_36w) per Response Evaluation Criteria in Solid Tumors (RECIST v1.1). Prespecified equivalence margins of PFSR_36w were set as − 11 to 15% (rate difference) and 0.8 to 1.25 (rate ratio). Secondary endpoints included efficacy, safety, immunogenicity, and pharmacokinetics.

Results

A total of 677 patients were randomized (HLX04 n = 340; bevacizumab n = 337) between April 2018 and April 2020. PFSR_36w was 46.4% (95% confidence interval [CI] 41.1–51.8) with HLX04 and 50.7% (95% CI 45.4–56.1) with bevacizumab. The rate difference (− 4.2%; 90% CI − 10.6 to 2.1) and rate ratio (0.92; 90% CI 0.80–1.05) both fell within the prespecified equivalence margins. No notable differences were observed between treatment groups in any efficacy endpoints or their subgroup analyses. Safety, immunogenicity, and pharmacokinetic profiles were comparable between the two treatment groups.

Conclusions

HLX04 demonstrated equivalent efficacy with similar safety and immunogenicity profiles to reference bevacizumab among patients with recurrent/metastatic CRC, thus offering an alternative treatment option to patients.

Trial registration

Chinadrugtrials.org.cn, CTR20171503 (18 March 2018); ClinicalTrials.gov, NCT03511963 (30 April 2018).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40259-021-00484-9.

Colorectal cancer (CRC) is the third most common cancer worldwide. Approximately 20% of patients with CRC have metastases at their first visit. Bevacizumab is a biologic antibody approved in many countries for the treatment of metastatic CRC. However, high treatment costs significantly limit patient access to bevacizumab. Therefore, HLX04, a potential bevacizumab biosimilar, which is almost identical to bevacizumab but less expensive and more accessible, has been developed. This randomized clinical trial was designed to evaluate the efficacy (ability of a drug to produce the desired treatment effects), safety, and immunogenicity (ability of a drug to induce immune response that would affect its efficacy and safety) of HLX04 compared with the reference bevacizumab in patients with recurrent/metastatic CRC. Efficacy of the tested drug was evaluated by comparing the proportion of patients without disease progression or death at week 36 (PFSR_36w). Safety was monitored using adverse events and other clinical evaluations. Immunogenicity was assessed by the incidence of antidrug antibodies. Of the 677 patients enrolled in the study, 340 received HLX04 and 337 received bevacizumab. Statistical analyses showed that HLX04 was equivalent to bevacizumab in efficacy evaluations (the difference in PFSR_36w between the two treatment groups fell within the prespecified “equivalence margins”). Moreover, the two treatments were similar with respect to safety and immunogenicity evaluations. In summary, patients responded equally well to HLX04 and bevacizumab, supporting the development of HLX04 as a proposed biosimilar to bevacizumab for patients with recurrent/metastatic CRC.

Identification of COL6A1 as the Key Gene Associated with Antivascular Endothelial Growth Factor Therapy in Glioblastoma Multiforme

Background: Vascular endothelial growth factors (VEGFs) are important for glioblastoma multiforme (GBM) growth and development. However, the effects of VEGF-targeting drugs in primary GBM remain poorly understood. Aim: We aimed to explore the key genes correlated with VEGF expression and prognosis and elucidate their potential implications in GBM anti-VEGF therapy. Materials and Methods: RNA-seq data with the corresponding clinicopathological information was retrieved from The Cancer Genome Atlas and the Chinese Glioma Genome Atlas. Weighted gene coexpression network analyses was performed on differentially expressed genes to construct coexpression modules and investigate their correlation with VEGFs. Functional enrichment analyses were performed based on the coexpressed genes from the most promising modules. CytoHubba and Kaplan-Meier analyses were implemented to identify the key genes in the modules of interest. The oncomine database, quantitative reverse transcription PCR, and the Human Protein Atlas were used to investigate the expression characteristics of the identified key genes. Results: Four modules (cyan, green, purple, and tan) correlated significantly with VEGF expression. Enrichment analyses suggested that extracellular matrix-receptor interaction, growth factor binding, and the PI3K-Akt pathways were involved in VEGF expression. Four hub genes (COL6A1, SNRPG, COL3A1, and AHI1) associated with VEGF were identified. Among them, COL6A1 was regarded as the key gene associated with anti-VEGF therapy. Further, COL6A1 was upregulated in GBM compared to that in normal brain tissues. COL6A1 overexpression was associated with a poor prognosis. Conclusion: COL6A1 was identified as the key gene associated with anti-VEGF therapy and may provide novel insight into GBM targeted therapy.

Metabolite secretions of Lactobacillus plantarum YYC-3 may inhibit colon cancer cell metastasis by suppressing the VEGF-MMP2/9 signaling pathway

BACKGROUND

Colorectal cancer (CRC) is a major clinical challenge, and the gut microbiome plays important roles in the occurrence and metastasis of CRC. Lactobacillus and their metabolites are thought to be able to suppress the growth of CRC cells. However, the antimetastatic mechanism of Lactobacillus or their metabolites toward CRC cells is not clear. Therefore, the aim of this study was to assess the inhibitory mechanism of cell-free supernatants (CFSs) of L. rhamnosus GG, L. casei M3, and L. plantarum YYC-3 on metastasis of CRC cells.

RESULTS

YYC-3 CFS showed the highest inhibitory effect on CRC cell growth, invasion and migration, and inhibited MMP2, MMP9, and VEGFA gene and protein expression, and protein secretion. Furthermore, it suppressed the activities of MMPs by gelatin zymography. Moreover, the effective compounds in these CFSs were analyzed by Q Exactive Focus liquid chromatography-mass spectrometry.

CONCLUSIONS

Our results showed that metabolite secretions of YYC-3 may inhibited cell metastasis by downregulating the VEGF/MMPs signaling pathway. These data suggest that treatment of CRC cells with metabolites from L. plantarum YYC-3 may reduce colon cancer metastasis.

Ras Pathways on Prox1 and Lymphangiogenesis: Insights for Therapeutics

Over the past couple of decades, lymphatics research has accelerated and gained a much-needed recognition in pathophysiology. As the lymphatic system plays heavy roles in interstitial fluid drainage, immune surveillance and lipid absorption, the ablation or excessive growth of this vasculature could be associated with many complications, from lymphedema to metastasis. Despite their growing importance in cancer, few anti-lymphangiogenic therapies exist today, as they have yet to pass phase 3 clinical trials and acquire FDA approval. As such, many studies are being done to better define the signaling pathways that govern lymphangiogenesis, in hopes of developing new therapeutic approaches to inhibit or stimulate this process. This review will cover our current understanding of the Ras signaling pathways and their interactions with Prox1, the master transcriptional switch involved in specifying lymphatic endothelial cell fate and lymphangiogenesis, in hopes of providing insights to lymphangiogenesis-based therapies.

Carboplatin re-treatment in platinum-resistant epithelial ovarian cancer patients

PURPOSE

Treatment of multi-resistant epithelial ovarian cancer represents a clinical challenge with limited choices. Anti-angiogenic therapy has shown great potential in combination with frontline-therapy. Studies investigating heavily pre-treated patients are few. This study investigated the effect of re-treating patients with carboplatin combined with bevacizumab and cell-free DNA (cfDNA) as a potential predictor of outcome.

METHODS

This single-center study enrolled 73 multi-resistant ovarian cancer patients from 2008 to 2015. Patients were treated with a combination of bevacizumab (10 mg/kg) and carboplatin (AUC5) every 3 weeks. Baseline plasma samples were analyzed for cfDNA levels. Treatment response was evaluated based on the Response Evaluation Criteria in Solid Tumors (RECIST) criteria and CA125 blood values.

RESULTS

The response rate according to RECIST and/or CA125 was 57%. Median number of cycles was 6. The median progression-free survival and overall survival was 5.0 and 11.2 months, respectively. Eighteen patients developed allergic reactions to carboplatin. Patients were grouped into two cfDNA-groups according to median value. The cfDNA value was correlated to progression-free survival (PFS, p = 0.015), but not to overall survival (OS, p = 0.067) in the univariate analysis. In the multivariate analysis both PFS and OS were highly correlated to the levels of cfDNA (PFS, hazard ratio = 1.87, p = 0.012; OS, hazard ratio = 1.67, p = 0.037) with patients with high levels of cfDNA having poorest outcome.

CONCLUSION

Our results might provide guidance in cases with heavily pre-treated patients, where alternatives are limited. Carboplatin and bevacizumab treatment should be weighed against best supportive care, current non-platinum therapies and experimental treatment. cfDNA seems to offer prognostic insight.

VEGF in Signaling and Disease: Beyond Discovery and Development

The discovery of vascular endothelial-derived growth factor (VEGF) has revolutionized our understanding of vasculogenesis and angiogenesis during development and physiological homeostasis. Over a short span of two decades, our understanding of the molecular mechanisms by which VEGF coordinates neurovascular homeostasis has become more sophisticated. The central role of VEGF in the pathogenesis of diverse cancers and blinding eye diseases has also become evident. Elucidation of the molecular regulation of VEGF and the transformative development of multiple therapeutic pathways targeting VEGF directly or indirectly is a powerful case study of how fundamental research can guide innovation and translation. It is also an elegant example of how agnostic discovery and can transform our understanding of human disease. This review will highlight critical nodal points in VEGF biology, including recent developments in immunotherapy for cancer and multitarget approaches in neovascular eye disease.

Evaluation of tamoxifen and simvastatin as the combination therapy for the treatment of hormonal dependent breast cancer cells

Tamoxifen (TAM) is a nonsteroidal antiestrogen drug, used in the prevention and treatment of all stages of hormone-responsive breast cancer. Simvastatin (SIM), a lipid-lowering agent, has been shown to inhibit cancer cell growth. The study aimed at investigating the impact of using SIM with TAM in estrogen receptor-positive (ER+) breast cancer cell line, T47D, as well as in mice-bearing Ehrlich solid tumor. The cell line was treated with different concentrations of TAM or/and SIM for 72 h. The effects of treatment on cytotoxicity, oxidative stress markers, apoptosis, angiogenesis, and metastasis were investigated. Our results showed that the combination treatment decreased the oxidative stress markers, glucose uptake, VEGF, and MMP 2 &9 in the cell line compared to TAM- treated cells. Drug interaction of TAM and SIM was synergistic in T47D by increasing the apoptotic makers Bax/BCL-2 ratio and caspase 3 activity. Additionally, in vivo, the combination regimen resulted in a non-significant decrease in the tumor volume compared to TAM treated group. Moreover, the combined treatment decreased the protein expression of TNF-α, NF-kB compared to control. In conclusion, our results suggest that SIM may serve as a promising treatment with TAM for improving the efficacy against estrogen receptor-positive (ER+) breast cancer.

Potential Influence of Endothelial Adsorption on the Delayed Time to Maximum Concentration of Biopharmaceuticals

Background and objectives

Maximum plasma concentration of biopharmaceuticals sometimes occurs long after completion of intravenous infusion. The objective of this research was to study the hypothetical adsorption of biopharmaceuticals to endothelium and infusion material, which may theoretically explain this phenomenon.

Methods

Infusion procedures were mimicked in an artificial vessel covered with a confluent monolayer of endothelial cells. Three monoclonal antibodies (MAbs) and C1 inhibitor were studied.

Results

Adsorption of MAbs to endothelium was observed followed by release when the vessel was subsequently perfused with buffer. Adsorption to infusion material also occurred to various degrees and in a seemingly random fashion, with a loss of up to 15% during a single flush of the line, but release from the line was not seen.

Conclusions

Our results indicate that adsorption of biopharmaceuticals to endothelium can occur. This observation can explain the increase in plasma concentration after completion of intravenous administration.

Bevacizumab biosimilars: scientific justification for extrapolation of indications

The first biosimilar of bevacizumab was approved by the US FDA; other potential biosimilars of bevacizumab are in late-stage clinical development. Their availability offers opportunity for increased patient access across a number of oncologic indications. The regulatory pathway for biosimilar approval relies on the totality of evidence that includes a comprehensive analytical assessment, and a clinical comparability study in a relevant disease patient population. Extrapolation of indications for a biosimilar to other eligible indications held by the originator, in the absence of direct clinical comparison, frequently forms part of the regulatory judgment. Herein, we consider the evidence required to demonstrate biosimilarity for bevacizumab biosimilars, with particular focus on the rationale for extrapolation across oncologic indications.

Molecular Pharmacology of VEGF-A Isoforms: Binding and Signalling at VEGFR2

Vascular endothelial growth factor-A (VEGF-A) is a key mediator of angiogenesis, signalling via the class IV tyrosine kinase receptor family of VEGF Receptors (VEGFRs). Although VEGF-A ligands bind to both VEGFR1 and VEGFR2, they primarily signal via VEGFR2 leading to endothelial cell proliferation, survival, migration and vascular permeability. Distinct VEGF-A isoforms result from alternative splicing of the Vegfa gene at exon 8, resulting in VEGFxxxa or VEGFxxxb isoforms. Alternative splicing events at exons 5⁻7, in addition to recently identified posttranslational read-through events, produce VEGF-A isoforms that differ in their bioavailability and interaction with the co-receptor Neuropilin-1. This review explores the molecular pharmacology of VEGF-A isoforms at VEGFR2 in respect to ligand binding and downstream signalling. To understand how VEGF-A isoforms have distinct signalling despite similar affinities for VEGFR2, this review re-evaluates the typical classification of these isoforms relative to the prototypical, “pro-angiogenic” VEGF165a. We also examine the molecular mechanisms underpinning the regulation of VEGF-A isoform signalling and the importance of interactions with other membrane and extracellular matrix proteins. As approved therapeutics targeting the VEGF-A/VEGFR signalling axis largely lack long-term efficacy, understanding these isoform-specific mechanisms could aid future drug discovery efforts targeting VEGF receptor pharmacology.

Potential lymphangiogenesis therapies: Learning from current antiangiogenesis therapies-A review

In recent years, lymphangiogenesis, the process of lymphatic vessel formation from existing lymph vessels, has been demonstrated to have a significant role in diverse pathologies, including cancer metastasis, organ graft rejection, and lymphedema. Our understanding of the mechanisms of lymphangiogenesis has advanced on the heels of studies demonstrating vascular endothelial growth factor C as a central pro-lymphangiogenic regulator and others identifying multiple lymphatic endothelial biomarkers. Despite these breakthroughs and a growing appreciation of the signaling events that govern the lymphangiogenic process, there are no FDA-approved drugs that target lymphangiogenesis. In this review, we reflect on the lessons available from the development of antiangiogenic therapies (26 FDA-approved drugs to date), review current lymphangiogenesis research including nanotechnology in therapeutic drug delivery and imaging, and discuss molecules in the lymphangiogenic pathway that are promising therapeutic targets.

Anticancer potentiality of lignan rich fraction of six Flaxseed cultivars

The objective of our study is to highlight the therapeutic effect and mechanism of action by which purified Flaxseed hydrolysate (PFH) which is a lignan rich fraction exerts its anticancer activity on a human breast cancer cell line (T47D) and in mice bearing tumor. HPLC analysis of PFH of six flaxseed cultivars had shown that PFH of the cultivar Giza 9 (PFH-G9) contains the highest concentration of SDG (81.64 mg/g). The in vitro cytotoxic potentiality of PFH’s of six flaxseed cultivars was screened against a panel of human cancer cell lines. PFH -G9 showed the most significant cytotoxic activity against ER-receptor positive breast cell lines MCF7 and T47D with IC₅₀ 13.8 and 15.8 µg/ml, respectively. Moreover, PFH-G9 reduced the expression of the metastasis marker, 1-α, metalloproteinases and vascular endothelial growth factor (VEGF), one of the most potent stimulators of angiogenesis, while it increased the caspase-3 dependent apoptosis. Our study also showed that dietary intake of 10% of Giza 9 Flaxseeds (FS), fixed oil (FSO) or Flax meal (FSM) twice daily for 3 weeks in mice-bearing solid Ehrlich ascites carcinoma (EAC) resulted in reducing the tumor volume, the expression of estrogen, insulin growth factor, progesterone, VEGF and MMP-2, but enhanced expression of caspase-3.

The prophylactic and therapeutic effects of Momordica charantia methanol extract through controlling different hallmarks of the hepatocarcinogenesis

Inspite of the wide facilities for controlling cancer growth, there are little drugs to inhibit its metastasis or prevent its angiogenesis. Discovering such natural or synthetic multi-targeted agent that might strike different targets is considered as a vital goal for tumor controlling. In a previous study, the chemoprotective effect of methanol extract of Momordicacharantia (MEMC) on albino western rats bearing hepatocarcinogenesis was evaluated. The mechanism by which MEMC exert its anticancer properties was unknown. Therefore, we aimed in this study to investigate the possible role of MEMC as anti-proliferative, anti-angiogenic and anti-metastatic agent to exert its chemoprotective effect. The study was conducted on sixty albino western rats divided into six groups, 10 rats each. Diethylnitrosamine (DENA) was injected intraperitoneally (i.p.) at a dose of 200 mg/kg body weight once, 2 weeks later rats were received carbon tetrachloride (CCl₄₎ subcutaneously (3 ml/kg/week) continued for 10 weeks. MEMC was orally produced to rats (40 mg/kg) alone, as well as before, at the same time and after DENA injection. Cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), caspase-3,-8 (Casp-3,-8), histone deacetylase (HDAC) and matrixmetalloproteinases-2,-9 (MMP-2,-9) were evaluated. MEMC treatment significantly decreased Cox-2, VEGF, HDAC and MMP-2,-9 and increased Casp-3,-8 as compared to DENAgroup,which demonstrated that the anticancer effect of MEMC may be through the inhibition of angiogenesis, proliferation and metastasis and the activation of apoptosis. The improvement in before-treated group was more pronounced than that in after- and simultaneous-treated groups, indicating thatMEMC may act as a prophylactic agent more than being a therapeutic agent.

Proper oral hygiene protocols decreased inflammation of gingivitis in a patient during chemotherapy with bevacizumab: a case report

The case is a woman who had a diagnosis of ovarian cancer and endometrial cancer. After surgical therapy, platinum-based adjuvant treatment was performed, followed by additional bevacizumab administration. Because considerable gingivitis appeared, a proper approach for oral hygiene was performed. As a result, the symptom was reduced considerably.

Anti-angiogenic agents for the treatment of solid tumors: Potential pathways, therapy and current strategies - A review

Recent strategies for the treatment of cancer, other than just tumor cell killing have been under intensive development, such as anti-angiogenic therapeutic approach. Angiogenesis inhibition is an important strategy for the treatment of solid tumors, which basically depends on cutting off the blood supply to tumor micro-regions, resulting in pan-hypoxia and pan-necrosis within solid tumor tissues. The differential activation of angiogenesis between normal and tumor tissues makes this process an attractive strategic target for anti-tumor drug discovery. The principles of anti-angiogenic treatment for solid tumors were originally proposed in 1972, and ever since, it has become a putative target for therapies directed against solid tumors. In the early twenty first century, the FDA approved anti-angiogenic drugs, such as bevacizumab and sorafenib for the treatment of several solid tumors. Over the past two decades, researches have continued to improve the performance of anti-angiogenic drugs, describe their drug interaction potential, and uncover possible reasons for potential treatment resistance. Herein, we present an update to the pre-clinical and clinical situations of anti-angiogenic agents and discuss the most recent trends in this field.

Topical versus subconjunctival anti-vascular endothelial growth factor therapy (Bevacizumab, Ranibizumab and Aflibercept) for treatment of corneal neovascularization

In order to evaluate the effect of topical and subconjunctival anti-vascular endothelial growth factor (anti-VEGF) therapy, Ranibizumab, Bevacizumab and Aflibercept as a therapy for corneal neovascularization (NV) treatment, the aim of this study was to review all data related to some of anti-VEGF as a promising therapies for corneal NV treatment. Corneal NV is a dangerous condition leading to a marked reduction in vision due to angiogenesis of abnormal vessels that block light. During the recent years, we have recognized new drug proliferation for corneal NV treatment. Recently, anti-VEGF therapies are one of the most important drugs used for corneal NV treatment. Several growth factors are involved in angiogenesis. The most important growth factor in corneal angiogenesis is VEGF. VEGF can be considered as key mediators in corneal angiogenesis. It is upregulated during corneal NV. In fact, anti-VEGF therapies have shown efficacy in attenuation of corneal NV in both animal models and clinical trials. A promising therapeutic success has been achieved using antibodies directed against VEGF. Bevacizumab has demonstrated efficacy and efficiency in the treatment of different neo-vascular ocular diseases and it has partially reduced corneal NV through different routes of administrations: topical, subconjunctival, and intraocular application. A similar efficacy to bevacizumab profiles in the treatment of neo-vascular age-related macular degeneration was induced by ranibizumab. Moreover, at worse levels of initial visual acuity of diabetic macular edema, aflibercept was more effective at improving vision. Anti-VEGF agents (Bevacizumab, Ranibizumab and Aflibercept) seem to have a higher efficiency and efficacy for corneal NV treatment. Both subconjunctival therapy and topical therapy of bevacizumab prohibit corneal NV, while early treatment with subconjunctival administration of ranibizumab may successfully reduce corneal NV. Therefore, establishment of safe doses is highly important before these drugs can be involved in the clinical setting. Further investigations and studies are highly warranted to adjust the dose and route of administration for the antibodies directed against VEGF to be the key therapeutic agents in the corneal NV treatment.

Ranibizumab in monotherapy and combined with photodynamic therapy for retinal angiomatous proliferation

Purpose

To compare the effects of intravitreal ranibizumab in monotherapy (group A) and combined with photodynamic therapy (PDT) with verteporfin (group B) in retinal angiomatous proliferation (RAP) treatment.

Methods

This was a multicentric, prospective, randomized clinical study conducted with parallel groups. The study eye in both groups received ranibizumab on days 1, 30, and 60 (loading dose); group B received PDT additionally on day 1. Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity (VA) testing and optical coherence tomography were performed monthly, and fluorescein angiography and indocyanine green angiography were performed quarterly. Retreatment criteria were leakage in fluorescein angiography or indocyanine green angiography, mean foveal thickness increase ≥100 µm, or VA decrease ≥5 letters.

Results

Twenty patients were recruited (ten patients in each group). Six eyes had previous treatment (three eyes in group A and three eyes in group B), so only 14 eyes were naïve. At 12-month follow-up, mean VA improved +1.5 letters in group A and +5.6 letters in group B (analysis of variance test; P>0.05). Two patients (20%) in both groups gained ≥15 letters (chi-square test; P>0.05). Mean changes in greatest linear dimension and in foveal thickness were not statistically significant between groups of treatment (analysis of variance test; P>0.05). Mean retreatments per patient were 1.8 (group A) and 0.9 (group B) (Mann–Whitney U-test; P>0.05). One patient died due to underlying disease not related to study medication.

Conclusion

Intravitreal ranibizumab administered in monotherapy or combined with PDT was efficacious in terms of VA stabilization in patients with RAP.

The Combination of α-Tocopheryl Succinate and Sodium Selenite on Breast Cancer: A Merit or a Demerit?

α-Tocopheryl succinate (α-TOS), a mitochondria-targeting agent, induces apoptosis in malignant cells in vitro and in vivo. Selenite is a nutritional supplement that has been shown to stimulate apoptosis in cancer cells. This study was designed to investigate the cytotoxic effect of combined treatment of α-TOS and sodium selenite (SSe) in vitro and in vivo and to explore their effect on apoptosis and autophagy in breast cancer. The type of interaction between α-TOS and SSe was evaluated and levels of oxidative stress and apoptotic and autophagic markers were determined. SSe alone showed varying degrees of cytotoxicity on all the tested cell lines. Its combination with α-TOS was antagonistic in vitro in MCF7 and in vivo in mice bearing Ehrlich tumor compared to α-TOS-treated one. Combination of TOS with 2 μM of SSe increased the level of glutathione without changes in antiapoptotic markers Bcl-2 and Mcl-1 at 16 and 48 hrs. SSe decreased caspase 3 activity and protein level of caspases 7 and 9, while it increased autophagic markers beclin-1 and LC3B protein levels of MCF7 cells treated with α-TOS. In conclusion, SSe antagonizes α-TOS-induced apoptosis via inhibition of oxidative stress and promoting prosurvival machinery of autophagy.

Ten years of anti-vascular endothelial growth factor therapy

The targeting of vascular endothelial growth factor A (VEGFA), a crucial regulator of both normal and pathological angiogenesis, has revealed innovative therapeutic approaches in oncology and ophthalmology. The first VEGFA inhibitor, bevacizumab, was approved by the US Food and Drug Administration in 2004 for the first-line treatment of metastatic colorectal cancer, and the first VEGFA inhibitors in ophthalmology, pegaptanib and ranibizumab, were approved in 2004 and 2006, respectively. To mark this tenth anniversary of anti-VEGFA therapy, we discuss the discovery of VEGFA, the successes and challenges in the development of VEGFA inhibitors and the impact of these agents on the treatment of cancers and ophthalmic diseases.

Anti-angiogenic alternatives to VEGF blockade

Angiogenesis is a major requirement for tumour formation and development. Anti-angiogenic treatments aim to starve the tumour of nutrients and oxygen and also guard against metastasis. The main anti-angiogenic agents to date have focused on blocking the pro-angiogenic vascular endothelial growth factors (VEGFs). While this approach has seen some success and has provided a proof of principle that such anti-angiogenic agents can be used as treatment, the overall outcome of VEGF blockade has been somewhat disappointing. There is a current need for new strategies in inhibiting tumour angiogenesis; this article will review current and historical examples in blocking various membrane receptors and components of the extracellular matrix important in angiogenesis. Targeting these newly discovered pro-angiogenic proteins could provide novel strategies for cancer therapy.

Targeting glycolysis by 3-bromopyruvate improves tamoxifen cytotoxicity of breast cancer cell lines

Background

Tamoxifen is the standard endocrine therapy for ER+ breast cancer; however, many women still relapse after long-term therapy. 3-Bromopyruvate, a glycolytic inhibitor, has shown high selective anti-tumor activity in vitro, and in vivo. The aim of this study was to evaluate the possible augmentation of the effect of tamoxifen via reprograming cancer cell metabolism using 3-bromopyruvate.

Methods

An in vitro screening of antitumor activity as well as the apoptotic, anti-metastatic, and anti-angiogenic potentials of the combination therapy were carried out using different techniques on breast cancer cell lines MCF7and T47D. In addition the antitumor effect of the combined therapy was done on mice bearing tumor.

Results

Our results showed modulation in apoptosis, angiogenesis and metastatic potential by either drug alone; however, their combination has surpassed that of the individual one. Combination regimen enhanced activated caspases-3, 7 and 9, as well as oxidative stress, signified by increased malondialdehyde and decreased glutathione level. Additionally, the angiogenesis and metastasis markers, including hypoxia inducing factor-1α, vascular endothelia growth factor, and metaloproteinases-2 and 9 were decreased after using the combination regimen. These results were further confirmed by the in vivo study, which depicted a decrease in the tumor volume and angiogenesis and an increase in oxidative stress as well.

Conclusion

3-bromopyruvate could be a valuable compound when added with tamoxifen in breast cancer treatment.

Bevacizumab in combination with fluoropyrimidine-irinotecan- or fluoropyrimidine-oxaliplatin-based chemotherapy for first-line and maintenance treatment of metastatic colorectal cancer

Despite a slight decrease in mortality rates, recent advances in screening methods, diagnosis and overall improved therapeutic options, colorectal cancer (CRC) remains among the leading causes of cancer-related death worldwide. The major cause is the mortality related to metastatic status of CRC. Increasing clinical evidence derived from randomized trials strongly suggests that the efficacy of standard cytotoxic agents, including various combinations of 5-fluoouracil (5-FU)/leucovorin (LV), capecitabine, irinotecan and oxaliplatin, may be significantly augmented with concomitant administration of molecular agents targeting the vascular endothelial growth factor (VEGF) signaling pathways, such as bevacizumab. Herein, we critically discuss the current data on the efficacy and safety profile of bevacizumab in combination with fluoropyrimidine-based chemotherapy for first-line and maintenance treatment of metastatic CRC and briefly comment on existing controversies and future perspectives.

Combination of imatinib and clotrimazole enhances cell growth inhibition in T47D breast cancer cells

Imatinib mesylate (IM), a tyrosine kinase inhibitor, is used as targeted cancer therapy. However, mono-targeting by IM does not always achieve full tumor eradication and thus it is recommended to combine IM with other anticancer agents. Clotrimazole (CLT) is an antifungal azole derivative with promising anticancer effects due to inhibiting the activity of glycolytic enzymes. The present study aimed to evaluate the effect of combining CLT with IM on breast cancer cell line in an attempt to establish effective new combination. T47D human breast cancer cell line was treated with different concentrations of IM and/or CLT for 48 h. IM-CLT interaction was determined by isobologram equation and combination index. Cell viability was confirmed by measuring LDH activity. As indicators of glycolysis inhibition, the expression of hexokinase-2 (HK-2) and 6-phosphofructo-1-kinase (PFK-1) plus the activity of intracellular lactate dehydrogenase (LDH) and pyruvate kinase (PK) were determined. In addition, glucose consumption and adenosine triphosphate (ATP) production were measured. Moreover, nitric oxide (NO), vascular endothelial growth factor (VEGF) and hypoxia inducible factor-α (HIF-α) were also determined as they are modulators for glycolysis. This study demonstrated that IM or CLT synergistically inhibited cell growth in T47D as shown by combination and dose reduction indices. The combination of 15 μM IM and 20 μM CLT significantly decreased glucose consumption, activity of both PK and intracellular LDH, while increased leaked LDH, VEGF and NO in the medium compared to each drug alone. Furthermore the combination decreased gene expression of HK-2, PFK-1 and ATP content compared to the control. In conclusion, the synergistic effect of CLT on IM cytotoxicity in T47D cell line maybe mediated through inhibition of glycolysis and increasing both NO and VEGF. Further studies are required to confirm the efficiency and safety of this combination.

Immunotherapeutic approaches for cancer therapy: An updated review

In spite of specific immune effector mechanisms raised against tumor cells, there are mechanisms employed by the tumor cells to keep them away from immune recognition and elimination; some of these mechanisms have been identified, while others are still poorly understood. Manipulation or augmentation of specific antitumor immune responses are now the preferred approaches for treatment of malignancies, and traditional therapeutic approaches are being replaced by the use of agents which potentiate immune effector mechanisms, broadly called "immunotherapy". Cancer immunotherapy is generally classified into two main classes including active and passive methods. Interventions to augment the immune system of the patient, for example, vaccination or adjuvant therapy, actively promote antitumor effector mechanisms to improve cancer elimination. On the other hand, administration of specific monoclonal antibodies (mAbs) against different tumor antigens and adoptive transfer of genetically-modified specific T cells are currently the most rapidly developing approaches for cancer targeted therapy. In this review, we will discuss the different modalities for active and passive immunotherapy for cancer.

VEGF-releasing suture material for enhancement of vascularization: development, in vitro and in vivo study

As it has been demonstrated that bioactive substances can be delivered locally using coated surgical suture materials, the authors developed a vascular endothelial growth factor (VEGF)-releasing suture material that should promote vascularization and potentially wound healing. In this context, the study focused on the characterization of the developed suture material and the verification of its biological activity, as well as establishing a coating process that allows reproducible and stable coating of a commercially available polydioxanone suture material with poly(l-lactide) (PLLA) and 0.1μg and 1.0μg VEGF. The in vitro VEGF release kinetics was studied using a Sandwich ELISA. The biological activity of the released VEGF was investigated in vitro using human umbilical vein endothelial cells. The potential of the VEGF-releasing suture material was also studied in vivo 5days after implantation in the hind limb of Wistar rats, when the histological findings were analyzed. The essential results, enhanced cell viability in vitro as well as significantly increased vascularization in vivo, were achieved using PLLA/1.0μg VEGF-coated suture material. Furthermore, ELISA measurements revealed a high reproducibility of the VEGF release behavior. Based on the results achieved regarding the dose-effect relationship of VEGF, the stability during its processing and the release behavior, it can be predicted that a bioactive suture material would be successful in later in vivo studies. Therefore, this knowledge could be the basis for future studies, where bioactive substances with different modes of action are combined for targeted, overall enhancement of wound healing.

Addition of bevacizumab enhances antitumor activity of erlotinib against non-small cell lung cancer xenografts depending on VEGF expression

PURPOSE

Erlotinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), and bevacizumab, an anti-vascular endothelial growth factor (VEGF) agent, are promising therapies for advanced non-small cell lung cancer (NSCLC). Our study was aimed to determine whether there were conditions under which the addition of bevacizumab would enhance the antitumor activity of erlotinib against NSCLC tumors in vitro and in vivo.

METHODS

MTS was for NSCLC cell (PC9, 11-18, H1975, H157, H460 and A549) growth assay in vitro. ELISA was for VEGF protein assay in cells and tumor tissues. Mouse xenograft models were established with H157, H460 and A549 with primary resistance to erlotinib and treated with erlotinib plus bevacizumab or each agent alone. Erlotinib concentrations in tumors were determined by high-performance liquid chromatography.

RESULTS

Bevacizumab alone did not inhibit NSCLC cell growth in vitro. In primarily erlotinib-resistant NSCLC cells, the levels of VEGF protein were highest in H157 cell followed in order by H460 and A549 cells. In vivo, bevacizumab alone significantly inhibited tumor growth only in xenograft models with high (H157) and/or moderate (H460) levels of VEGF protein. A combination of erlotinib and bevacizumab partially reversed resistance to erlotinib in H157 xenografts (high VEGF level) with increasing intratumoral erlotinib concentrations, but not in H460 (moderate) or A549 (low) xenografts.

CONCLUSIONS

These results support that combined with anti-VEGF therapy could enhance antitumor activity of anti-EGFR therapy and/or partially reverse resistance to EGFR TKI, by increasing EGFR TKI concentration in specific tumors that express high levels of VEGF protein.

Thirty-minutes infusion rate is safe enough for bevacizumab; no need for initial prolong infusion

Bevacizumab (Bev) is a vascular endothelial growth factor-A monoclonal antibody that targets tumor angiogenesis. The transfusion rate of Bev is 90 min in the first dose, 60 min in the second and than from the third dose it is 30 min if no hypersensitivity reaction occurs in the first two doses. The purpose of this study determines whether these initial prolonged infusions are really necessary or not. Between 2007 and 2009, we were using the standard schedule for Bev infusions. In July 2009, we reviewed our medical reports, nursing orders and adverse drug reaction forms to identify the Bev used patients and possible hypersensitivity reactions (HSRs). Depending on that information between August 2009 and July 2014, we started to make Bev infusions in 30 min from the first dose of the therapy. In this study, we documented the findings of these 30-min infusion used patients. From August 2009 to July 2014, we treated 145 patients with 1,145 Bev infusions each one in 30 min. Out of 145 patients, 12 of them received only single dosage of Bev infusion treatment. Bev doses were 5 mg/kg for 87 patients, 7.5 mg/kg for 64 patients, 10 mg/kg for four patients and 15 mg/kg for only one patient. No HSRs were reported during these transfusions. Initial prolonged infusion times are unnecessary for Bev. Thirty-minute infusion rates can be used safely for all courses.

Potent anti-angiogenesis and anti-tumor activity of a novel human anti-VEGF antibody, MIL60

Angiogenesis is crucial for tumor development, growth and metastasis. Vascular endothelial growth factor (VEGF) has been implicated in promoting solid tumor growth and metastasis via stimulating tumor-associated angiogenesis, and blocking the activity of VEGF can starve tumors. Avastin, which is a humanized anti-VEGF antibody, has been successfully applied in clinics since 2004. However, the price of Avastin is extremely high for Chinese people. Here, we report a novel human anti-VEGF neutralizing antibody, MIL60, which shows an affinity comparable to that of Avastin (the KD value of MIL60 was 44.5 pM, while that of Avastin was 42.7 pM). MIL60 displays favorable actions in inhibiting VEGF-triggered endothelial cell proliferation (the IC50 value of MIL60 was 31±6.4 ng/ml and that of Avastin was 47±8.1 ng/ml), migration (8 µg/ml or 0.8 µg/ml MIL60 versus the control: P<0.05) and tube formation (2 µg/ml or 0.2 µg/ml MIL60 versus the control: P<0.05) via the VEGFR2 signaling pathway. Moreover, MIL60 was shown to inhibit tumor growth and angiogenesis in vivo in xenograft models of human colon carcinoma and ovarian cancer using immunotherapy and immunohistochemistry analysis (MIL60 versus N.S.: P=0.0007; Avastin versus N.S.: P=0.00046). These data suggest that MIL60 is a potential therapeutic, anti-angiogenic agent. Our work provides a novel anti-VEGF antibody, which can be considered an anti-tumor antibody candidate and a new option for patients with various cancers.

[A perspective: role of targeted therapy in colon cancer]

Colorectal cancer is the third most common malignant disease in incidence according to a report in 2009 from Korea. The 5-fluorouracil (5-FU) remains to be a major chemotherapeutic agents. But, over the last 10-15 years, the treatment pattern for metastatic colorectal cancer changed significantly. Irinotecan and oxaliplatin are cytotoxic drugs, or bevacizumab and cetuximab are monoclonal antibodies against molecular targets. The introduction of novel agents targeting specific molecular features of cancer cells promises more options and marked improvements in efficacy for the treatment of metastatic colon cancer. Bevacizumab has been shown to extend survival in colorectal cancer when used in combination with irinotecan and 5-FU-based chemotherapy, and the addition of cetuximab to irinotecan and 5-FU-based chemotherapy eliminates irinotecan resistance. Better understanding of the tumor biology and the molecular pathway and mechanisms of tumorigenesis has led to the discovery of novel agents with improved outcomes.

Oncogene and non-oncogene addiction in inflammation-associated cancers

Many cancers originate in tissues that are chronically inflamed, and the inflammatory microenvironment is considered to promote the progression of malignancy, including initiation, growth, angiogenesis, invasion and metastasis. The molecular mechanism of inflammation-induced progression of cancers has been widely discussed. Oncogene and non-oncogene addiction have been proposed as two distinct but complementary theories to explain the initiation and development of cancers. Furthermore, they also play a role in cancer-associated inflammation. A solid understanding of oncogene and non-oncogene addiction in cancer-associated inflammatory microenvironments will help to exploit cancer drug targets for cancer prevention and clinical treatment.

Vasoactive intestinal peptide increases VEGF expression to promote proliferation of brain vascular endothelial cells via the cAMP/PKA pathway after ischemic insult in vitro

Vasoactive intestinal peptide (VIP) enhances angiogenesis in rats with focal cerebral ischemia. In the present study, we investigated the molecular mechanism of the proangiogenic action of VIP using an in vitro ischemic model, in which rat brain microvascular endothelial cells (RBMECs) are subjected to oxygen and glucose deprivation (OGD). Western blotting and immunocytochemistry were carried out to examine the expression of VIP receptors and vascular endothelial growth factor (VEGF) in cultured RBMECs. The cell proliferation was assessed by the MTT assay. Cyclic adenosine monophosphate (cAMP) and VEGF levels were measured by using the enzyme-linked immunosorbent assay. The cultured RBMECs expressed VPAC1, VPAC2 and PAC1 receptors. Treatment with VIP significantly promoted the proliferation of RBMECs and increased OGD-induced expression of VEGF, and this effect was antagonized by the VPAC receptor antagonist VIP6-28 and VEGF antibody. VIP significantly increased contents of cAMP in RBMECs and VEGF in the culture medium. The VIP-induced VEGF production was blocked by H89, a protein kinase A (PKA) inhibitor. These data suggest that treatment with VIP promotes VEGF-mediated endothelial cell proliferation after ischemic insult in vitro, and this effect appears to be initiated by the VPAC receptors leading to activation of the cAMP/PKA pathway.

Tumor angiogenesis and anti-angiogenic therapy in malignant gliomas revisited

The cellular and molecular mechanisms of tumor angiogenesis and its prospects for anti-angiogenic cancer therapy are major issues in almost all current concepts of both cancer biology and targeted cancer therapy. Currently, (1) sprouting angiogenesis, (2) vascular co-option, (3) vascular intussusception, (4) vasculogenic mimicry, (5) bone marrow-derived vasculogenesis, (6) cancer stem-like cell-derived vasculogenesis and (7) myeloid cell-driven angiogenesis are all considered to contribute to tumor angiogenesis. Many of these processes have been described in developmental angiogenesis; however, the relative contribution and relevance of these in human brain cancer remain unclear. Preclinical tumor models support a role for sprouting angiogenesis, vascular co-option and myeloid cell-derived angiogenesis in glioma vascularization, whereas a role for the other four mechanisms remains controversial and rather enigmatic. The anti-angiogenesis drug Avastin (Bevacizumab), which targets VEGF, has become one of the most popular cancer drugs in the world. Anti-angiogenic therapy may lead to vascular normalization and as such facilitate conventional cytotoxic chemotherapy. However, preclinical and clinical studies suggest that anti-VEGF therapy using bevacizumab may also lead to a pro-migratory phenotype in therapy resistant glioblastomas and thus actively promote tumor invasion and recurrent tumor growth. This review focusses on (1) mechanisms of tumor angiogenesis in human malignant glioma that are of particular relevance for targeted therapy and (2) controversial issues in tumor angiogenesis such as cancer stem-like cell-derived vasculogenesis and bone-marrow-derived vasculogenesis.

Anti-VEGF therapy for the treatment of glaucoma: a focus on ranibizumab and bevacizumab

INTRODUCTION

Anti-VEGF therapy has been widely used in the treatment of ocular neovascular diseases. Because of their anti-angiogenic and anti-fibrotic properties, anti-VEGF antibodies such as bevacizumab and ranibizumab have emerged as an adjunctive treatment modality in glaucoma to improve success of conventional treatments.

AREAS COVERED

Ranibizumab is an anti-VEGF-A antigen binding fragment currently indicated in neovascular age-related macular degeneration as well as macular edema following retinal vein occlusion. Several off-label uses include the treatment of neovascular glaucoma to regress/suppress iris and iridocorneal angle neovascularization and the modulation of wound healing after glaucoma filtration surgery. Bevacizumab is a full-length anti-VEGF antibody, which is also being used in aforementioned eye conditions off-label. An overview of these anti-VEGF antibodies and the results of preclinical and clinical studies regarding their use in the treatment of glaucoma are presented.

EXPERT OPINION

Early studies on the utility of both bevacizumab and ranibizumab in neovascular glaucoma and filtration surgery reported promising results. However, a large-scale randomized clinical trial as well as comparative studies between the two anti-VEGF antibodies are currently lacking. A single dose of ranibizumab costs approximately 40 times as much as a single dose of bevacizumab. Clinicians should take this into account, in addition to their differences in the efficacy and safety, when treating patients.

Clinical trials and future potential of targeted therapy for ovarian cancer

Ovarian cancer is the leading cause of death in women with gynecological cancer. Most patients are diagnosed at an advanced stage with a poor prognosis. Currently, surgical tumor debulking followed by chemotherapy based on platinum and taxane is the standard treatment for advanced disease. However, these patients remain at great risk for recurrence and developing drug resistance. Therefore, new treatment strategies are needed to improve outcomes for patients with advanced and recurrent ovarian cancer. Several agents targeted at particular molecules have been developed for ovarian cancer and are now entering clinical trials. The functional targets of these agents are aberrations in tumor tissues including angiogenesis, the human epidermal growth factor receptor family, poly(ADP-ribose) polymerase (PARP), mammalian target of rapamycin (mTOR) signaling pathway, and α-folate receptor (α-FR). The anti-angiogenic compound bevacizumab has been reported as the most effective targeted agent. Bevacizumab plus chemotherapy prolonged progression-free survival (PFS) both for advanced and platinum-sensitive recurrent ovarian cancer, but did not increase overall survival. A PARP inhibitor, olaparib, applied as maintenance treatment also improved PFS in platinum-sensitive relapsed ovarian cancer. Furthermore, mTOR inhibitors and a monoclonal antibody to α-FR, farletuzumab, are attractive treatment strategies either alone or combined with chemotherapy. Understanding the tumor molecular biology and identifying predictive biomarkers are essential steps in selecting the best treatment strategies. This article reviews available clinical data on the most promising targeted agents for ovarian cancer.

Novel targeted agents for the treatment of advanced breast cancer

The discovery of the molecular processes involved in cancer development has led to the design of an array of targeted agents. These agents, directed to specific proteins in the machinery of cancer cells, interfere with vital cascades involved in cell invasion, metastasis, apoptosis, cell-cycle control and angiogenesis. In breast cancer, the main pathways studied and targeted by drugs are the HER2 pathway, EGFR, VEGF, PI3K/Akt/mammalian target of rapamycin (PI3K-M-Tor), IGF/IGFR, poly(ADP ribose) polymerase 1, HDAC and many others. In this review, we present the most promising studies of these new targeted therapies and novel combination of targeted therapies with cytotoxic agents for the treatment of breast cancer patients.

Osteonecrosis and the Jaws and Bevacizumab Therapy: A Case Report

Bevacizumab is a humanized recombinant monoclonal antibody that blocks Vascular Endothelial Growth Factor (VEGF). Recently, its use has been related with osteneocrosis of the jaws (ONJ), a disease showing a histological pattern similar to bisphosphonate-related ONJ. The aim of this study is to describe an ONJ case-report following bevacizumab chemotherapy without bisphosphonate therapy. We monitored ONJ development associated with the use of bevacizumab in a 47-year-old male with primitive adenocarcinoma of the parotid gland. Our results could suggest a possible correlation between the eruption of the lower third molar tooth and ONJ development following bevacizumab therapy. Clinicians should be aware of the potential risk of bevacizumab-related ONJ complication; moreover, since there are no effective therapeutic protocols for ONJ treatment, it is very important that patients develop good oral hygiene habits and undergo regular dental status evaluation by dentists.

Cisplatin plus paclitaxel and maintenance of bevacizumab on tumour progression, dissemination, and survival of ovarian carcinoma xenograft models

Background:

Bevacizumab is being incorporated as first-line therapy with standard-of-care chemotherapy on epithelial ovarian carcinoma (EOC). We investigated bevacizumab combined with chemotherapy on tumour progression and mouse survival in EOC xenograft models.

Methods:

Bevacizumab was administered concomitantly with cisplatin plus paclitaxel (DDP+PTX), continued after induction (maintenance) or started after chemotherapy. The effect on tumour progression was monitored by bioluminescence imaging (BLI) (1A9-luc xenograft). Tumour dissemination into the peritoneal organs and ascites formation (HOC22 xenograft) was evaluated by histological analysis at the end of treatment (interim) and at euthanasia (survival). The effects on overall survival (OS) were investigated in both EOC models.

Results:

Bevacizumab with PTX+DDP delayed tumour progression in mice bearing EOC xenografts. OS was significantly extended, with complete responses, by bevacizumab continued after stopping chemotherapy in the HOC22 xenograft. Bevacizumab alone inhibited ascites formation, with only limited effect on tumour burden, but combined with PTX+DDP reduced ascites and metastases. Bevacizumab started after induction with PTX+DDP and maintained was equally effective on tumour progression and survival on 1A9-luc xenograft.

Conclusion:

Bevacizumab combined with chemotherapy not only affected tumour progression, but when administered as maintenance regimen significantly prolonged survival, reducing ascites, and tumour dissemination. We believe our findings are consistent with the clinical results and shed light on the potential effects of this kind of treatment on tumour progression.

Angiogenesis inhibition for the improvement of photodynamic therapy: the revival of a promising idea

Photodynamic therapy (PDT) is a minimally invasive form of treatment, which is clinically approved for the treatment of angiogenic disorders, including certain forms of cancer and neovascular eye diseases. Although the concept of PDT has existed for a long time now, it has never made a solid entrance into the clinical management of cancer. This is likely due to secondary tissue reactions, such as inflammation and neoangiogenesis. The recent development of clinically effective angiogenesis inhibitors has lead to the initiation of research on the combination of PDT with such angiostatic targeted therapies. Preclinical studies in this research field have shown promising results, causing a revival in the field of PDT. This review reports on the current research efforts on PDT and vascular targeted combination therapies. Different combination strategies with angiogenesis inhibition and vascular targeting approaches are discussed. In addition, the concept of increasing PDT selectivity by targeted delivery of photosensitizers is presented. Furthermore, the current insights on sequencing the therapy arms of such combinations will be discussed in light of vascular normalization induced by angiogenesis inhibition.

Bevacizumab and ovarian cancer

PURPOSE OF REVIEW

Vascular endothelial growth factor (VEGF), one of the major pathways involved in tumor angiogenesis, is often overexpressed in epithelial ovarian cancer (EOC), and therefore an attractive target for therapy. This review aims to evaluate the rationale for targeting angiogenic pathways by the usage of the anti-VEGF agent bevacizumab in EOC.

RECENT FINDINGS

Bevacizumab monotherapy has been shown to be effective in the treatment of EOC with response rate of 16-21% in phase II trials. In phase III trials, patients with advanced EOC who received combination chemotherapy (paclitaxel + carboplatin) plus bevacizumab with maintenance bevacizumab had significantly longer progression-free survival than those who received chemotherapy alone, but did not prolong overall survival. The most common grade 3/4 adverse events of bevacizumab monotherapy include hypertension and proteinuria, while heavily pretreated patients were at increased risk of bowel perforation. The addition of bevacizumab to the standard chemotherapy in patients with advanced EOC may not be cost-effective.

SUMMARY

Bevacizumab has significant activity and is the most promising drug in EOC. However, understanding of its unique adverse events and identification of predictive biomarkers of bevacizumab response are necessary in order to select patients most likely to benefit from this therapy.