Ramucirumab (IMC-1121B): a novel attack on angiogenesis

Generation and characterization of a functional Nanobody against the vascular endothelial growth factor receptor-2; angiogenesis cell receptor

Vascular endothelial growth factor receptor-2 (VEGFR2) is an important tumor-associated receptor and blockade of the VEGF receptor signaling can lead to the inhibition of neovascularization and tumor metastasis. Nanobodies are the smallest intact antigen binding fragments derived from heavy chain-only antibodies occurring in camelids. Here, we describe the identification of a VEGFR2-specific Nanobody, named 3VGR19, from dromedaries immunized with a cell line expressing high levels of VEGFR2. We demonstrate by FACS, that 3VGR19 Nanobody specifically binds VEGFR2 on the surface of 293KDR and HUVECs cells. Furthermore, the 3VGR19 Nanobody potently inhibits formation of capillary-like structures. These data show the potential of Nanobodies for the blockade of VEGFR2 signaling and provide a basis for the development of novel cancer therapeutics.

Utility of vascular endothelial growth factor inhibitors in the treatment of ovarian cancer: from concept to application

Despite recent advances in the management of ovarian cancer, it remains the most lethal gynecologic malignancy. Vascular endothelial growth factor (VEGF) has been shown to play a pivotal role in the progression of ovarian cancer leading to the eventual development of malignant ascites. On this basis, agents rendering VEGF ineffective by neutralizing VEGF (bevacizumab), blocking its receptors (aflibercept), or interfering with the postreceptor signaling pathways (sunitinib) provide us with the rational treatment options. These agents are generally used in combination with the standard chemotherapeutic drugs. Here, we discuss the basis of and the logic behind the use of these agents in the treatment of epithelial ovarian cancer, as well as their evaluation in different preclinical and clinical studies.

An update on the current and emerging targeted agents in metastatic colorectal cancer

Over the past 8 to 10 years, significant advances have been made in the treatment of metastatic colorectal cancer (mCRC). In particular, the development of the targeted biologic agents bevacizumab, cetuximab, and panitumumab, and their integration with cytotoxic chemotherapy regimens has led to improvements in clinical efficacy. Despite these gains, the overall impact of current targeted agents in the treatment of mCRC has been relatively modest, and while 2-year survival has improved, no gains have been made, as of yet, in 5-year survival. Intense efforts continue to be focused on developing novel targeted agents with a different spectrum of activity. Presently, five novel targeted molecules are in phase III trials, including the antiangiogenesis agents aflibercept and ramucirumab, two novel receptor tyrosine kinase inhibitors, regorafenib and brivanib, and the Akt inhibitor perifosine. There are an additional 52 phase II trials investigating a wide range of other candidate molecules. The potential list of approved targeted agents in mCRC seems likely to increase over the next 5 to 10 years. To maximize their potential clinical impact, however, it will be critically important to introduce efficient molecular diagnostic methodologies into the drug development process for the identification and validation of predictive biomarkers for chemosensitivity. This article reviews the development of targeted agents for the treatment of mCRC, including the three molecules currently approved by the US Food and Drug Administration (FDA), as well as the main non-FDA-approved therapeutics currently undergoing phase II and III clinical testing.

Antiangiogenic agents in advanced gastrointestinal malignancies: past, present and a novel future

Advanced gastrointestinal (GI) malignancies are varied in presentation, prognosis, and treatment options. With the exception of resectable recurrent colorectal cancer, metastatic GI malignancies are incurable. Cytotoxic chemotherapies have been the mainstay of therapy for decades but limited extension of survival or clinical benefit has been achieved in non-colorectal GI cancers. There has been great interest in the incorporation of antiangiogenic strategies to improve outcomes for these patients. Clear benefits have been identified with bevacizumab and sorafenib in colorectal cancer and hepatocellular cancer, respectively; other GI tumor sites have lacked impressive results with antiangiogenic agents. In this review, we will present the benefits, or lack thereof, of clinically tested antiangiogenic compounds in GI malignancies and explore some potential new therapeutic anti-angiogenesis options for these diseases.

Antiangiogenic agents in advanced gastrointestinal malignancies: past, present and a novel future

Advanced gastrointestinal (GI) malignancies are varied in presentation, prognosis, and treatment options. With the exception of resectable recurrent colorectal cancer, metastatic GI malignancies are incurable. Cytotoxic chemotherapies have been the mainstay of therapy for decades but limited extension of survival or clinical benefit has been achieved in non-colorectal GI cancers. There has been great interest in the incorporation of antiangiogenic strategies to improve outcomes for these patients. Clear benefits have been identified with bevacizumab and sorafenib in colorectal cancer and hepatocellular cancer, respectively; other GI tumor sites have lacked impressive results with antiangiogenic agents. In this review, we will present the benefits, or lack thereof, of clinically tested antiangiogenic compounds in GI malignancies and explore some potential new therapeutic anti-angiogenesis options for these diseases.