Beyond Bevacizumab: Antiangiogenic Agents

Development and validation of a nomogram for evaluating the prognosis of immunotherapy plus antiangiogenic therapy in non-small cell lung cancer

Background

With the combination therapy of PD-1/PD-L1 antibody and antiangiogenic drugs used widely in clinic, a novel method to estimate the prognosis of patients is needed. We aimed to develop a nomogram to examine prognosis of anti-PD-1/PD-L1 antibody plus bevacizumab in non-small cell lung cancer (NSCLC) patients.

Methods

We developed a nomogram using the cohort involving 204 NSCLC patients who treated with immunotherapy and anti-angiogenesis therapy. The nomogram was validated under the same conditions in another cohort with 69 patients. Prognostic factors were analyzed by Cox regression analysis. The nomogram was internally validated using bootstrap resampling and then externally validated. Performance was assessed using concordance index, calibration curve and decision curve analysis. Clinical utility was evaluated using receiver operation characteristic curve.

Results

Pleural metastasis (P = 0.001, HR = 2.980, 95%CI 1.521–5.837), ANC (P < 0.001, HR = 5.139, 95%CI 2.081–12.691), ALC (P = 0.010, HR = 0.331, 95%CI 0.142–0.771), B cells (P = 0.005, HR = 0.329, 95%CI 0.151–0.714), Treg cells (P = 0.002, HR = 2.934, 95%CI 1.478–5.826) were independent prognostic factors. The calibration curves showed good consistency and the C-index of nomogram were 0.808, 0.741 in training and external validation cohort, respectively. The area under the curve (AUC) in receiver operation characteristic curves (ROC) are 0.833 (P < 0.001) and 0.908 (P < 0.001), respectively.

Conclusion

We build an accurate and convenient nomogram to predict long-time overall survival (OS) of NSCLC patients treated with PD-1/PD-L1 antibody and antiangiogenic drugs and validated this nomogram. The nomogram might be helpful to clinicians to estimate long-time OS of NSCLC patients treated with PD-1/PD-L1 antibody and antiangiogenic drugs.

Boosting Antitumor Drug Efficacy with Chemically Engineered Multidomain Proteins

A facile chemical approach integrating supramolecular chemistry, site-selective protein chemistry, and molecular biology is described to engineer synthetic multidomain protein therapeutics that sensitize cancer cells selectively to significantly enhance antitumor efficacy of existing chemotherapeutics. The desired bioactive entities are assembled via supramolecular interactions at the nanoscale into structurally ordered multiprotein complexes comprising a) multiple copies of the chemically modified cyclic peptide hormone somatostatin for selective targeting and internalization into human A549 lung cancer cells expressing SST-2 receptors and b) a new cysteine mutant of the C3bot1 (C3) enzyme from Clostridium botulinum, a Rho protein inhibitor that affects and influences intracellular Rho-mediated processes like endothelial cell migration and blood vessel formation. The multidomain protein complex, SST3-Avi-C3, retargets C3 enzyme into non-small cell lung A549 cancer cells and exhibits exceptional tumor inhibition at a concentration ≈100-fold lower than the clinically approved antibody bevacizumab (Avastin) in vivo. Notably, SST3-Avi-C3 increases tumor sensitivity to a conventional chemotherapeutic (doxorubicin) in vivo. These findings show that the integrated approach holds vast promise to expand the current repertoire of multidomain protein complexes and can pave the way to important new developments in the area of targeted and combination cancer therapy.

Functional evaluation of therapeutic response of HCC827 lung cancer to bevacizumab and erlotinib targeted therapy using dynamic contrast-enhanced and diffusion-weighted MRI

This study aimed to investigate the therapeutic responses of lung cancer mice models with adenocarcinoma HCC827 (gefitinib sensitive) and HCC827R (gefitinib resistant) to the epidermal growth factor receptor-tyrosine kinase inhibitor erlotinib alone and in combination with the anti-angiogenesis agent bevacizumab using dynamic contrast enhanced (DCE) and diffusion-weighted MRI. In the HCC827 model, temporal changes in DCE-MRI derived parameters (K^trans, k_ep, and iAUC₉₀) and apparent diffusion coefficient (ADC) were significantly correlated with tumor size. K^trans and iAUC₉₀ significantly decreased at week 2 in the groups receiving erlotinib alone and in combination with bevacizumab, whereas k_ep decreased at week 1 and 2 in both treatment groups. In addition, there was a significant difference in iAUC₉₀ between the treatment groups at week 1. Compared to the control group of HCC827, there was a significant reduction in microvessel density and increased tumor apoptosis in the two treatment group. ADC value increased in the erlotinib alone group at week 1 and week 2, and in the erlotinib combined with bevacizumab group at week 2. Enlarged areas of central tumor necrosis were associated with a higher ADC value. However, progressive enlargement of the tumors but no significant differences in DCE parameters or ADC were noted in the HCC827R model. These results showed that both erlotinib alone and in combination with bevacizumab could effectively inhibit tumor growth in the gefitinib-sensitive lung cancer mice model, and that this was associated with decreased vascular perfusion, increased ADC percentage, decreased microvessel density, and increased tumor apoptosis with a two-week treatment cycle.

Incorporation of Antiangiogenic Therapy Into the Non-Small-Cell Lung Cancer Paradigm

Although molecular targeted agents have improved the treatment of lung cancer, their use has largely been restricted to limited subsets of the overall population that carry specific mutations. Angiogenesis, the formation of new blood vessels from existing networks, is an attractive, more general process for the development of targeted anticancer therapies, because it is critical for the growth of solid tumors, including non-small-cell lung cancer. Growing tissues require a vascular supply within a few millimeters. Therefore, solid tumors create a proangiogenic microenvironment to facilitate the development of new tumor-associated blood vessels, thus providing an adequate vascular supply for continued tumor growth. Antiangiogenic agents can specifically target the vascular endothelial growth factor (VEGF) signaling pathways, broadly inhibit multiple tyrosine kinases, or interfere with other angiogenic processes, such as disruption of existing tumor vasculature. The present report provides an overview of antiangiogenic therapy for non-small-cell lung cancer, including both currently approved antiangiogenic therapies (bevacizumab [anti-VEGF] and ramucirumab [anti-VEGF receptor 2] monoclonal antibodies), and a variety of promising novel agents in development. Although recent data have demonstrated promising efficacy for some novel agents, the overall development of antiangiogenic therapy has been hampered by redundancy in signaling pathways and the highly heterogeneous nature of tumors. An improved understanding of the molecular basis of angiogenesis will guide the development of new antiangiogenic therapies and the identification of biomarkers to predict which patients with lung cancer are most likely to benefit from antiangiogenic therapy.

Bioengineering Models for Breast Cancer Research

Despite substantial advances in early diagnosis, breast cancer (BC) still remains a clinical challenge. Most BC models use complex in vivo models and two-dimensional monolayer cultures that do not fully mimic the tumor microenvironment. The integration of cancer biology and engineering can lead to the development of novel in vitro approaches to study BC behavior and quantitatively assess different features of the tumor microenvironment that may influence cell behavior. In this review, we present tissue engineering approaches to model BC in vitro. Recent advances in the use of three-dimensional cell culture models to study various aspects of BC disease in vitro are described. The emerging area of studying BC dormancy using these models is also reviewed.

Quinazoline derivatives as anticancer drugs: a patent review (2011 - present)

INTRODUCTION

Quinazoline is one of the most studied moieties in medicinal chemistry due to the wide range of biological properties such as the anticancer, antibacterial, anti-inflammatory, antimalarial and antihypertensive activities. During the past decades, several patents and articles have been published in international peer-reviewed literature regarding the discovery and development of original and promising quinazoline derivatives for cancer treatment. Although quinazolines are well known to inhibit EGFR, there is also a large panel of other therapeutic protein targets.

AREAS COVERED

This review summarized the new patents and articles published about quinazoline derivatives as anticancer drugs since 2011.

EXPERT OPINION

Since 2011, a lot of quinazoline compounds have shown EGFR inhibition. Unlike the first-generation EGFR inhibitors, they inhibit both wild-type and mutated EGFR. In recent years, a number of studies on quinazoline synthesis have been reported and used by several medicinal chemistry groups for better and easier development of new derivatives. Therefore, several patents have been approved for the use of quinazoline compounds as inhibitors of other kinases, histone deacetylase, Nox and some metabolic pathways. Because of the large number of proteins targeted, some high structural diversity is observed in patented quinazoline compounds. Due to the vast applications of quinazoline derivatives, development of novel quinazoline compounds as anticancer drugs remains a promising field.

Enhanced anti-angiogenic effect of E7820 in combination with erlotinib in epidermal growth factor receptor-tyrosine kinase inhibitor-resistant non-small-cell lung cancer xenograft models

Most non-small-cell lung cancers (NSCLCs) harboring activating mutations in the epidermal growth factor receptor (EGFR) are initially responsive to EGFR tyrosine kinase inhibitors (EGFR-TKIs); however, they invariably develop resistance to these drugs. E7820 is an angiogenesis inhibitor that decreases integrin-α2 expression and is currently undergoing clinical trials. We investigated whether E7820 in combination with erlotinib, an EGFR-TKI, could overcome EGFR-TKI-resistance in the NSCLC cell lines A549 (KRAS; G12S), H1975 (EGFR; L858R/T790M), and H1650 (PTEN; loss, EGFR; exon 19 deletion), which are resistant to erlotinib. Immunohistochemical analysis was carried out in xenografted tumors to investigate anti-angiogenesis activity and endothelial cell apoptosis levels by endothelial cell marker CD31 and TUNEL staining, respectively. Treatment with E7820 (50 mg/kg) with erlotinib (60 mg/kg) showed a synergistic antitumor effect in three xenograft models. Immunohistochemical analysis indicated that combined treatment with E7820 and erlotinib significantly decreased microvessel density and increased apoptosis of tumor-associated endothelial cells compared with use of only one of the agents. This combination increased apoptosis in HUVECs through activation of both intrinsic and extrinsic apoptosis pathways in vitro. The combination of E7820 with erlotinib is an alternative strategy to overcome erlotinib resistance in NSCLC by enhancement of the anti-angiogenic activity of E7820.

IFNγ-responsiveness of endothelial cells leads to efficient angiostasis in tumours involving down-regulation of Dll4

Although IFNγ is regarded as a key cytokine in angiostatic response, our poor understanding of its effective cellular target drastically limits its clinical trials against angiogenesis-related disorders. Here, we investigated the effect of IFNγ on endothelial cells (ECs) and possible molecular mechanisms in angiostasis. By employing Tie2(IFNγR) mice, in which IFNγR expression was reconstituted under the control of Tie2 promoter in IFNγR-deficient mice, we found that the response of ECs to IFNγ was highly effective in inhibiting blood supply and retarding tumour growth. Interestingly, the expression of IFNγR on Tie2(-) cells did not inhibit, but promoted tumour growth in control wild-type mice. Mechanism studies showed that IFNγ reacting on ECs down-regulated the delta-like ligand 4 (Dll4)/Notch signalling pathway. Accordingly, overexpression of Dll4 in human ECs diminished the effect of IFNγ on ECs. This study demonstrates that the action of IFNγ on ECs, but not other cells, is highly effective for tumour angiostasis, which involves down-regulating Dll4. It provides insights for EC-targeted angiostatic therapy in treating angiogenesis-associated disorders in the clinic.

Targeting multiple angiogenic pathways simultaneously: experience with nintedanib in non-small-cell lung cancer

ABSTRACT: 

Angiogenesis plays a major role in the growth and progression of non-small-cell lung cancer (NSCLC), and there is increasing interest in the development of therapies that block this particular aspect of tumorigenesis. Bevacizumab was the first US FDA-approved inhibitor of angiogenesis after demonstrating improved progression-free survival and overall survival in combination with chemotherapy in treating NSCLC. However, the benefit of bevacizumab is only modest and transient as the tumors inevitably develop resistance to this particular treatment. Therefore, new therapies are being developed that attempt to inhibit angiogenesis through several different pathways. One promising new drug, nintedanib, is an oral triple angiokinase inhibitor that acts by blocking not only VEGFR, but also FGFR and PDGFR, which are involved in the development of resistance to bevacizumab. This article discusses the rationale for this approach and summarizes the clinical trial data on nintedanib, including the two most recent Phase III trials.

Patient-derived xenografts, the cancer stem cell paradigm, and cancer pathobiology in the 21st century

Cancer is a heterogeneous disease manifest in many forms. Tumor histopathology can differ significantly among patients and cellular heterogeneity within tumors is common. A primary goal of cancer biologists is to better understand tumorigenesis and cancer progression; however, the complex nature of tumors has posed a substantial challenge to unlocking cancer's secrets. The cancer stem cell (CSC) paradigm for the pathobiology of solid tumors appropriately acknowledges phenotypic and functional tumor cell heterogeneity observed in solid tumors and accounts for the disconnect between drug approval based on response and the general inability of approved therapies to meaningfully impact survival due to their failure to eradicate these most important of cellular targets. First proposed to exist decades ago, CSC have only recently begun to be precisely identified due to technical advancements that facilitate identification, isolation, and interrogation of distinct tumor cell subpopulations with differing ability to form and perpetuate tumors. Precise identification of CSC populations and the complete hierarchy of cells within solid tumors will facilitate more accurate characterization of patient subtypes and ultimately contribute to more personalized and effective therapies. Rapid advancement in the understanding of tumor biology as it exists in patients requires cooperation among institutions, surgeons, pathologists, cancer biologists and patients alike, primarily because this translational research is best done with patient-derived tissue grown in the xenograft setting as patient-derived xenografts. This review calls for a broader change in the approaches taken to study cancer pathobiology, highlights what implications the CSC paradigm has for pathologists and cancer biologists alike, and calls for greater collaboration between institutions, physicians and scientists in order to more rapidly advance our collective understanding of cancer.