Effects of combination anti-vascular endothelial growth factor receptor and anti-epidermal growth factor receptor therapies on the growth of gastric cancer in a nude mouse model

Gastric cancer presenting with ramucirumab-related gastrocolic fistula successfully managed by colonic stenting: a case report

We report a rare case of gastric cancer presenting with a gastrocolic fistula during ramucirumab and paclitaxel combination therapy that was successfully managed with colonic stenting. A 75-year-old man was admitted to our hospital with the chief complaint of melena. Esophagogastroduodenoscopy revealed a large ulcerated tumor in the lower stomach, judged by laparoscopy as unresectable (sT4bN1M0). After four cycles of first-line chemotherapy with S-1 plus oxaliplatin, the patient showed disease progression, and second-line therapy with ramucirumab and paclitaxel was started. At the end of the third cycle, the patient had gastric antral stenosis, which necessitated the placement of a gastroduodenal stent. When the patient complained of diarrhea 10 days later, esophagogastroduodenoscopy revealed a fistula between the greater curvature of the stomach and the transverse colon. The fistula was covered by double colonic stenting, with a covered metal stent placed within an uncovered metal stent, after which leakage from the stomach to the colon stopped.

Recent Trends and Advancements in the Diagnosis and Management of Gastric Cancer

Gastric cancer is an enigmatic malignancy that has recently been shown to be increasing in incidence globally. There has been recent progress in emerging technologies for the diagnosis and treatment of the disease. Improvements in non-invasive diagnostic techniques with serological tests and biomarkers have led to decreased use of invasive procedures such as endoscopy. A multidisciplinary approach is used to treat gastric cancer, with recent significant advancements in systemic therapies used in combination with cytotoxic chemotherapies. New therapeutic targets have been identified and clinical trials are taking place to assess their efficacy and safety. In this review, we provide an overview of the current and emerging treatment strategies and diagnostic techniques for gastric cancer.

Apatinib as a Third-Line Treatment for HER2-Positive Metastatic Gastric Cancer: A Multi-Center Single-Arm Cohort Study

PURPOSE

Treatment options are limited after the failure of first-and second-line treatments in patients with HER2⁺ metastatic gastric cancer (mGC). The present study aimed to explore the efficacy, safety, and prognostic factors of apatinib efficacy as a third-line therapy for patients with human epithelial growth factor receptor 2-positive (HER2⁺) mGC.

MATERIALS AND METHODS

A total of 59 HER2⁺ mGC patients who received apatinib as third-line therapy were retrospectively enrolled in this two-center, single-arm, cohort study; the clinical response, survival data, and adverse events were retrieved.

RESULTS

The median progression-free survival (PFS) was 5.2 months (95% confidence interval [CI], 3.9-6.5), and the median overall survival (OS) was 8.2 months (95% CI, 6.6-9.8) Furthermore, forward stepwise multivariate Cox regression analysis showed that a higher Eastern Cooperative Oncology Group performance status score and multiple metastases were independently correlated with decreased PFS and OS (both P<0.05). The main adverse events were leukopenia (45.8%), hypertension (44.1%), thrombocytopenia (39.0%), hand-foot syndrome (37.3%), and elevated transaminase (33.9%). Grade 3 adverse events mainly included hypertension (5.1%) and neutropenia (5.1%); grade 4 adverse events did not occur.

CONCLUSIONS

Apatinib is efficient and well tolerated in patients with HER2⁺ mGC as a third-line treatment, suggesting that it may be a candidate of choice for these patients.

Successes and failures of angiogenesis blockade in gastric and gastro-esophageal junction adenocarcinoma

Gastric and gastro-esophageal junction adenocarcinoma (GEA) remains a considerable major public health problem worldwide, being the fifth most common cancer with a fatality-to-case ratio that stands still at 70%. Angiogenesis, which is a well-established cancer hallmark, exerts a fundamental role in cancer initiation and progression and its targeting has been actively pursued as a promising therapeutic strategy in GEA. A wealth of clinical trials has been conducted, investigating anti-angiogenic agents including VEGF-directed monoclonal antibodies, small molecules tyrosine kinase inhibitors and VEGF-Trap agents both in the resectable and advanced setting, reporting controversial results. While phase III randomized trials testing the anti-VEGFR-2 antibody Ramucirumab and the selective VEGFR-2 tyrosine kinase inhibitor Apatinib demonstrated a significant survival benefit in later lines, the shift of angiogenesis inhibitors in the perioperative and first-line setting failed to improve patients’ outcome in GEAs. The molecular landscape of disease, together with novel combinatorial strategies and biomarker-selected approaches are under investigation as key elements to the success of angiogenesis blockade in GEA. In this article, we critically review the existing literature on the biological rationale and clinical development of antiangiogenic agents in GEA, discussing major achievements, limitations and future developments, aiming at fully realizing the potential of this therapeutic approach.

Molecularly Targeted Therapies for Gastric Cancer. State of the Art

Many phase III trials failed to demonstrate a survival benefit from the addition of molecular therapy to conventional chemotherapy for advanced and metastatic gastric cancer, and only three agents were approved by the FDA. We examined the efficacy and safety of novel drugs recently investigated. PubMed, Embase and Cochrane Library were searched for phase III randomized controlled trials published from January 2016 to December 2020. Patients in the experimental arm received molecular therapy with or without conventional chemotherapy, while those in the control arm had conventional chemotherapy alone. The primary outcomes were overall and progression-free survival. The secondary outcomes were the rate of tumor response, severe adverse effects, and quality of life. Eight studies with a total of 4223 enrolled patients were included. The overall and progression-free survival of molecular and conventional therapy were comparable. Most of these trials did not find a significant difference in tumor response rate and in the number of severe adverse effects and related deaths between the experimental and control arms. The survival benefits of molecular therapies available to date for advanced and metastatic gastric cancer are rather unclear, mostly due to inaccurate patient selection, particularly concerning oncogene amplification and copy number.

Efficacy and safety of first-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) combined with chemotherapy or antiangiogenic therapy as first-line treatment in patients with EGFR-mutant non-small cell lung cancer: A systematic review and meta-analysis

OBJECTIVE

We conducted a meta-analysis to synthesize the results of published randomized controlled trials conducted to evaluate the efficacy and safety of epidermal growth factor receptor - tyrosine kinase inhibitors (EGFR-TKIs) combined with chemotherapy or antiangiogenic therapy.

METHODS

PubMed, EMBASE, Cochrane Library and ClinicalTrials.gov databases were searched and literatures from international conferences were read to identify eligible studies. The primary endpoints were objective response rate (ORR) and progression free survival (PFS). The secondary endpoints were disease control rate (DCR), overall survival (OS) and treatment-emergent adverse events (TEAEs).

RESULTS

10 studies, all on first-generation EGFR-TKI combination therapy, involving 2367 patients were included. Combination therapy resulted in significant improvements in ORR (RR: 1.11, 95% CI: 1.06-1.17, P < 0.001), DCR (RR: 1.03, 95% CI: 1.01-1.05, P = 0.007), PFS (HR: 0.56, 95% CI: 0.51-0.62, P < 0.001), OS (HR: 0.74, 95% CI: 0.64-0.84, P = 0.002) over monotherapy. This improvement was more apparent in the EGFR-TKIs combination chemotherapy group, and indirect comparisons revealed that EGFR-TKIs combined with chemotherapy appeared to be superior to combined with antiangiogenic therapy in ORR (RR: 1.19, 95% CI: 1.07-1.32), DCR (RR: 1.04, 95% CI: 1.02-1.08), and OS (HR: 0.79, 95% CI: 0.66-0.96). Of additional concern is the increased incidence of TEAEs in combination therapy.

CONCLUSION

As a first-line treatment for patients with EGFR-mutated advanced non-small cell lung cancer (NSCLC), first-generation EGFR-TKIs combined with chemotherapy or antiangiogenic therapy was associated with significant improvement in ORR, DCR, PFS and OS compared with monotherapy.

Thyroid Hormone Enhances Angiogenesis and the Warburg Effect in Squamous Cell Carcinomas

Simple Summary

Cancer cells rewire their metabolism to promote growth, survival, proliferation, and long-term maintenance. Aerobic glycolysis is a prominent trait of many cancers; contextually, glutamine addiction, enhanced glucose uptake and aerobic glycolysis sustain the metabolic needs of rapidly proliferating cancer cells. Thyroid hormone (TH) is a positive regulator of tumor progression and metastatic conversion of squamous cell carcinoma (SCC). Accordingly, overexpression of the TH activating enzyme, D2, is associated with metastatic SCC. The aim of our study was to assess the ability of TH and its activating enzyme in promoting key tracts of cancer progression such as angiogenesis, response to hypoxia and metabolic adaptation. By performing in vivo and in vitro studies, we demonstrate that TH induces VEGF-A in cancer cells and fosters aerobic glycolysis inducing pro-glycolytic mediators, thus implying that TH signal attenuation represents a therapeutic tool to contrast tumor angiogenesis and tumor progression.

Abstract

Cancer angiogenesis is required to support energetic demand and metabolic stress, particularly during conditions of hypoxia. Coupled to neo-vasculogenesis, cancer cells rewire metabolic programs to sustain growth, survival and long-term maintenance. Thyroid hormone (TH) signaling regulates growth and differentiation in a variety of cell types and tissues, thus modulating hyper proliferative processes such as cancer. Herein, we report that TH coordinates a global program of metabolic reprogramming and induces angiogenesis through up-regulation of the VEGF-A gene, which results in the enhanced proliferation of tumor endothelial cells. In vivo conditional depletion of the TH activating enzyme in a mouse model of cutaneous squamous cell carcinoma (SCC) reduces the concentration of TH in the tumoral cells and results in impaired VEGF-A production and attenuated angiogenesis. In addition, we found that TH induces the expression of the glycolytic genes and fosters lactate production, which are key traits of the Warburg effect. Taken together, our results reveal a TH–VEGF-A–HIF1α regulatory axis leading to enhanced angiogenesis and glycolytic flux, which may represent a target for SCC therapy.

Analyzing Kinase Similarity in Small Molecule and Protein Structural Space to Explore the Limits of Multi-Target Screening

While selective inhibition is one of the key assets for a small molecule drug, many diseases can only be tackled by simultaneous inhibition of several proteins. An example where achieving selectivity is especially challenging are ligands targeting human kinases. This difficulty arises from the high structural conservation of the kinase ATP binding sites, the area targeted by most inhibitors. We investigated the possibility to identify novel small molecule ligands with pre-defined binding profiles for a series of kinase targets and anti-targets by in silico docking. The candidate ligands originating from these calculations were assayed to determine their experimental binding profiles. Compared to previous studies, the acquired hit rates were low in this specific setup, which aimed at not only selecting multi-target kinase ligands, but also designing out binding to anti-targets. Specifically, only a single profiled substance could be verified as a sub-micromolar, dual-specific EGFR/ErbB2 ligand that indeed avoided its selected anti-target BRAF. We subsequently re-analyzed our target choice and in silico strategy based on these findings, with a particular emphasis on the hit rates that can be expected from a given target combination. To that end, we supplemented the structure-based docking calculations with bioinformatic considerations of binding pocket sequence and structure similarity as well as ligand-centric comparisons of kinases. Taken together, our results provide a multi-faceted picture of how pocket space can determine the success of docking in multi-target drug discovery efforts.

[Research Progress of Small Molecule Anti-angiogenic Drugs in Non-small Cell Lung Cancer]

肺癌是世界上发病率最高的癌症之一，且尚无二线进展后的标准治疗方案，而肿瘤血管生成目前已被确定为恶性肿瘤的重要治疗靶点，小分子多靶点血管激酶抑制剂可通过抑制血管生成相关信号通路，抑制肿瘤血管的生成。目前已开展多项小分子抗血管生成药物治疗非小细胞肺癌的临床试验，且已有部分血管内皮生长因子受体酪氨酸激酶抑制剂（vascular endothelial growth factor receptor-tyrosine kinase inhibitors, VEGFR-TKIs）获批治疗晚期非小细胞肺癌，本文基于国内外多项小分子抗血管生成药物治疗非小细胞肺癌的发展现状，归纳了多个VEGFR-TKIs及成纤维细胞生长因子受体（fibroblast growth factor receptor, FGFR）-TKI单药或联合[包括分别与化疗、表皮生长因子受体（epidermal growth factor receptor, EGFR）-TKIs、免疫治疗、放疗等联合）]治疗非小细胞肺癌的疗效与安全性研究，同时探讨了VEGFR-TKIs可能存在的耐药机制及疗效预测指标等，并对未来抗血管治疗非小细胞肺癌的发展趋势以及存在的潜在问题进行展望，同时为肺癌后续的精准治疗及个体化治疗提供新的思路。

New advances in antiangiogenic combination therapeutic strategies for advanced non-small cell lung cancer

PURPOSE

Tumor growth relies on the sufficient blood supply and continuously requires new blood vessels to maintain, which lead to vascular abnormalities (Folkman, N Engl J Med 285:1182-1186, 1971). Antiangiogenic therapy has emerged with the goal of normalizing vasculature and tumor microenvironment (TME). Some antiangiogenic therapies combined with chemotherapy, targeted therapy or immunotherapy have been approved for clinical application. In this review, we summarize the recent advances of antiangiogenic combination therapeutic strategies in advanced NSCLC.

METHODS

References of this review are searched through PubMed and EMBASE and the abstracts of cancer conferences. The ClinicalTrials.gov database was used for relative trials.

RESULTS

Based on different mechanisms, antiangiogenic agents can be divided into monoclonal antibodies (mAbs), which mainly include bevacizumab and ramucirumab, and multi-target antiangiogenic tyrosine kinase inhibitors (TKIs) which include sunitinib, sorafenib, nintedanib, apatinib, anlotinib, fruquintinib, etc. In recent years, a number of large clinical studies have shown that antiangiogenic agents have conferred a significant overall survival (OS) benefit to patients with advanced non-small cell lung cancer (NSCLC). More and more evidences confirm that the combination of antiangiogenic agents with chemotherapy, targeted therapy and immunotherapy can improve the effect and prolong the survival of NSCLC patients. However, many problems about the application of antiangiogenic agents on advanced NSCLC patients still need to be explored. For example, the combination therapy of multi-target antiangiogenic agents is just beginning, and the biomarkers are not clear.

CONCLUSIONS

Antiangiogenic agents can achieve therapeutic benefit in advanced NSCLC patients and the combination of chemotherapy, targeted therapy or immunotherapy can lead to synergistic effect. However, exploring the best combination therapy and efficacy-related biomarkers needs further study.

The promising role of monoclonal antibodies for gastric cancer treatment

Gastric cancer (GC) is the second leading cause of cancer-related death world-wide. Despite improvements in prevention, early detection and various therapeutic options, the prognosis is still poor. GC is often diagnosed at an advanced stage with survivals less than 1 year. Chemotherapy as the mainstay of treatment in advanced stage is not of notable advantages, underlining the need for novel more effective therapeutic options. Based on current knowledge of molecular and cellular mechanisms, a number of novel biologic approaches such as monoclonal antibodies have been recently introduced for cancer treatment that mainly affect the immune system or target signaling pathways playing role in cancer and metastasis development. In this review, various monoclonal antibodies for GC therapy were explained.

Cancer neovasculature-targeted near-infrared photoimmunotherapy (NIR-PIT) for gastric cancer: different mechanisms of phototoxicity compared to cell membrane-targeted NIR-PIT

BACKGROUND

Near-infrared photoimmunotherapy (NIR-PIT) constitutes a new class of molecular-targeted theranostics utilizing monoclonal antibody (mAb)-photosensitizer conjugates and NIR light. In this study, we developed a new type of NIR-PIT targeting vascular endothelial growth factor receptor 2 (VEGFR-2) expressed on vascular endothelium in an experimental gastric cancer model and evaluated the feasibility by comparing conventional NIR-PIT targeting cancer cell membrane in vitro and in vivo.

METHODS

HER2-positive human gastric cancer cells, NCI-N87, were used for the experiments. Anti-HER2 mAb, trastuzumab and anti-VEGFR-2 mAb, DC101 were conjugated to photosensitizer, IR700. Phototoxicity in response to NIR-PIT were investigated in vitro and in vivo. Microvessel densities, as an indicator of angiogenesis, were counted in harvested xenografts after NIR-PIT to elucidate the mechanism.

RESULTS

DC101-IR700 did not induce phototoxic effect in vitro because of the absence of expression of VEGFR-2 in NCI-N87 cancer cells. However, it induced an antitumor effect in NCI-N87 xenograft tumors accompanied with damage in tumor neovasculature as determined by decreasing tumor microvessel density, which represents a different mechanism than that of conventional NIR-PIT targeting antigens expressed on the tumor cell membrane.

CONCLUSION

We demonstrated a new approach of NIR-PIT utilizing a target on vascular endothelium, such as VEGFR-2, and this treatment might lead to the development of a new therapeutic strategy for human gastric cancer.

Tumor progression-dependent angiogenesis in gastric cancer and its potential application

Despite improvements in the early diagnosis, prognosis and therapeutic strategies for gastric cancer (GC), human GC remains one of the most frequently diagnosed malignant tumors in the world, and the survival rate of GC patients remains very poor. Thus, a suitable therapeutic strategy for GC is important for prolonging survival. Both tumor cells themselves and the tumor microenvironment play an important role in tumorigenesis, including angiogenesis, inflammation, immunosuppression and metastasis. Importantly, these cells contribute to gastric carcinogenesis by altering the angiogenic phenotype switch. The development, relapse and spreading of tumors depend on new vessels that provide the nutrition, growth factors and oxygen required for continuous tumor growth. Therefore, a state of tumor dormancy could be induced by blocking tumor-associated angiogenesis. Recently, several antiangiogenic agents have been identified, and their potential for the clinical management of GC has been tested. Here, we provide an up-to-date summary of angiogenesis and the angiogenic factors associated with tumor progression in GC. We also review antiangiogenic agents with a focus on the anti-vascular endothelial growth factor receptor (VEGFR)-mediated pathway for endothelial cell growth and their angiogenesis ability in GC. However, most antiangiogenic agents have reported no benefit to overall survival (OS) compared to chemotherapy alone in local or advanced GC. In phase III clinical trials, only ramucirumab (anti-VEGFR blocker) and apatinib (VEGFR-TKI blocker) have reported an improved median overall response rate and prolonged OS and progression-free survival outcomes as a 2nd-line agent combined with chemotherapy treatment in advanced GC. By providing insights into the molecular mechanisms of angiogenesis associated with tumor progression in GC, this review will hopefully aid the optimization of antiangiogenesis strategies for GC therapy in combination with chemotherapy and adjuvant treatment.

The Role of Angiogenesis Inhibitors in the Era of Immune Checkpoint Inhibitors and Targeted Therapy in Metastatic Non-Small Cell Lung Cancer

OPINION STATEMENT

The treatment of advanced non-small cell lung cancer (NSCLC) has evolved to include targeted therapy, immunotherapy as well as chemotherapy for selected patients in the first-line setting. Angiogenesis inhibitors have been used in combination with chemotherapy in the first-line and maintenance settings providing improved progression-free survival (PFS) and objective response rate (ORR), as well as overall survival (OS) in selected studies. Biologic rationale exists for combining anti-angiogenic agents with immunotherapy and targeted kinase inhibitors (TKIs). A recent study has demonstrated improved survival when anti-PD-L1 therapy was added to chemotherapy plus bevacizumab. Subgroup analysis of patients with mutations in the epidermal growth factor receptor (EGFR) gene and rearrangements in the anaplastic lymphoma kinase (ALK) gene also demonstrated benefit with combined anti-PD-L1, bevacizumab, and platinum chemotherapy. Further investigation into combination therapy is warranted in the EGFR- and ALK-positive population given this signal. Anti-angiogenics combined with EGFR-targeted treatment in the wild-type population have shown modest PFS benefit with no OS benefit, and their routine use has not been adopted. The combination of EGFR inhibitors plus vascular endothelial growth factor (VEGF) inhibitors in the EGFR mutation-positive population has demonstrated substantial improvements in response and PFS; however, given the higher toxicity and lack of survival benefit to date, combination therapy in this group should be used with caution. At the present time, use of bevacizumab can be recommended with atezolizumab and chemotherapy for the first-line treatment of non-squamous NSCLC patients. Data with other checkpoint inhibitors and anti-angiogenics are too early to make firm recommendations regarding their use.

Targeted therapies in pancreatic cancer: Promises and failures

Pancreatic ductal adenocarcinoma (PDAC) is an incidence rate nearly equal to its mortality rate. The poor prognosis of the disease can be explained by the absence of effective biomarkers for screening and early detection, together with the aggressive behavior and resistance to the currently available chemotherapy. The therapeutic failure can also be attributed to the inter-/intratumor genetic heterogeneity and the abundance of tumor stroma that occupies the majority of the tumor mass. Gemcitabine is used in the treatment of PDAC; however, the response rate is less than 12%. A recent phase III trial revealed that the combination of oxaliplatin, irinotecan, fluorouracil, and leucovorin could be an option for the treatment of metastatic PDAC patients with good performance status, although these approaches can result in high toxicity level. Further investigations are required to develop innovative anticancer agents that either improve gemcitabine activity, within novel combinatorial approaches or acts with a better efficacy than gemcitabine. The aim of the current review is to give an overview of preclinical and clinical studies targeting key dysregulated signaling pathways in PDAC.

Advances in molecular, genetic and immune signatures of gastric cancer: Are we ready to apply them in our patients' decision making?

In the last few years we have witnessed a vast expansion of our knowledge regarding the molecular and genetic profile of gastric cancer. The molecular subtypes described have shed light on the pathogenesis of the disease, thus prompting the development of new therapeutic strategies and favoring a more individualized approach for treatment. Most of the clinical trials for so called targeted therapies could be considered, at best, partially successful. In addition, checkpoint inhibitors have recently been added to our armamentarium in later stages of the disease, and combinations with chemotherapy and targeted agents are currently under development. In view of the rapid advances of molecular oncology, a new challenge for the clinical oncologist arises: The appropriate patient selection for each new therapy, which can be made possible only through the implementation of predictive biomarkers in our therapy decision making.

Phase Ib trial combining capecitabine, erlotinib and bevacizumab in pancreatic adenocarcinoma - REBECA trial

Background Purpose of this phase Ib trial was to establish the maximum tolerable dose (MTD) of capecitabine and to escalate the dosages of erlotinib and bevacizumab to determine the recommended phase II dose (RP2D) in patients with advanced/metastatic pancreatic adenocarcinoma not pretreated for metastatic disease. Methods Starting doses were capecitabine 500 mg/m² bid orally continuously, erlotinib 100 mg orally daily, and bevacizumab 5 mg/kg intravenously q 2 weeks. Dose escalation was performed according to a 3 + 3 design for capecitabine until MTD, for erlotinib and bevacizumab until the maximum doses registered by applying a substance-related, toxicity-based scheme accompanied by pharmacokinetic analysis. Circulating tumor cells (CTCs) were determined pretherapeutically by immunohistochemical identification after enrichment with immunomagnetic separation. Results Thirty patients were evaluable at six dose levels. 900 mg/m² bid were determined as MTD for capecitabine based on dose-limiting toxicities: cutaneous in two patients and vascular in another. The most severe (Grade (G)3/4) drug-related treatment-emergent adverse events (toxicities) belonged to the categories gastrointestinal, vascular, cutaneous, cardiovascular, metabolic/nutritional or hematological. G3 toxicities occurred in 14 (47%), G3 + G4 in a single (3%) patient. 2 out of 28 patients (7%) exerted partial response, 17 (61%) stable disease. Pharmacokinetic evaluation revealed lack of drug-drug interaction between capecitabine and erlotinib and their metabolites. Presence of CTCs was associated with shorter progression-free survival (p = 0.009). Conclusions The study met the primary objective. RP2D was capecitabine 800 mg/m² bid continuously, erlotinib 150 mg daily, and bevacizumab 10 mg/kg q 2 weeks. The regimen could be applied safely, but demonstrated limited efficacy.

Strong radioprotective FGF1 signaling down-regulates proliferative and metastatic capabilities of the angiosarcoma cell line, ISOS-1, through the dual inhibition of EGFR and VEGFR pathways

•

Angiosarcoma is associated with a poor prognosis and is treated with radiotherapy.

•

Highly stable FGF1 mutants exhibit stronger mitogenic activity than wild-type FGF1 and are candidates for radioprotectors.

•

They were examined as strong signaling agonists to clarify the effects of FGF1 on the murine angiosarcoma cell line ISOS-1.

•

Strong FGF1 signaling reduced the proliferative, invasive, and migration capabilities of ISOS-1cells.

•

Their malignancy was reduced through the dual inhibition of EGFR and VEGFR pathways by strong FGF1 signaling.

Background and purpose

Angiosarcoma is associated with a poor prognosis and is treated with radiotherapy. Although FGF1 is a potential radioprotector, the influence of FGF1 on the malignancy of angiosarcoma remains unknown.

Materials and methods

Highly stable FGF1 mutants, which exhibit stronger mitogenic activity than wild-type FGF1, were examined as strong radioprotectors and signaling agonists to clarify the effects of FGF1 on the murine angiosarcoma cell line ISOS-1.

Results

FGF1 mutants reduced colony formation by and the in vitro invasion and migration of ISOS-1 cells, in addition to an increase in radiosensitivity to X-rays. In contrast, an FGFR inhibitor blocked the inhibitory effects of FGF1 mutants on colony formation, invasion, and migration. siRNA targeting the Fgfr1 gene showed that strong FGFR1 signaling reduced colony formation by ISOS-1 cells. However, the FGF1 mutant reduced the activation of VEGFRs and EGFRs in ISOS-1 cells more strongly than wild-type FGF1. Moreover, the inhibition of VEGFRs and EGFRs synergistically reduced colony formation by and invasion and migration of ISOS-1 cells.

Conclusion

These results suggest that strong FGF1 signaling exerts not only radioprotective effects, but also inhibitory effects on proliferative and metastatic capacities of angiosarcoma through the dual inhibition of EGFR and VEGFR pathways.

Development and Clinical Indications of Cetuximab

Cetuximab is a chimeric immunoglobulin G1 monoclonal antibody that targets the extracellular domain of the epidermal growth factor receptor (EGFR) with high specificity and affinity. It competitively inhibits endogenous ligand binding and thereby inhibits subsequent EGFR activation. The EGFR signaling pathways regulate cell differentiation, proliferation, migration, angiogenesis and apoptosis, all of which become deregulated in cancer cells. EGFR is an important target for cancer therapy and many studies have demonstrated that cetuximab is active in several types of cancer, particularly colorectal and head and neck cancer. Cetuximab enhances the effects of many standard cytotoxic agents, including irinotecan, and in combination with chemotherapy it can elicit antitumor responses in tumors that previously failed to respond to that chemotherapy. Cetuximab also enhances radiation-induced apoptosis. On the basis of a pivotal European randomized study (the BOND study) and of 2 clinical studies conducted in the USA, cetuximab has been approved in combination with irinotecan for patients affected by EGFR-expressing metastatic colon cancer after failure with irinotecan. There have only been a few small phase II trials on first-line treatment in metastatic colorectal cancer, but the results suggest promising activity of cetuximab together with irinotecan or oxaliplatin. There is some evidence that additive efficacy can be achieved using EGFR inhibitors in combination with vascular endothelial growth factor receptor inhibitors such as bevacizumab. A correlation between response and the main toxicity (acne-like skin reaction) has been observed but is unclear. EGFR status as a specific marker for EGFR inhibitors is controversial. At the moment, EGFR expression does not appear to be a predictive factor for response to EGFR inhibitors.

Epidermal Growth Factor Receptor and c-erbB-2 Contents in Unresectable (UICC R1 or R2) Gastric Cancer

Background

Epidermal growth factor receptor (EGFR) and c-erbB-2 are membrane receptors expressed in a variety of solid human cancers and directly correlated with poor prognosis. The objective of this work was to evaluate the EGFR and c-erbB-2 levels in non-resectable gastric carcinomas, their possible relationship with a variety of clinicopathological tumor parameters, and their prognostic significance.

Methods

This was a prospective analysis of 65 patients with unresectable gastric carcinomas (UICC R1 or R2), who underwent palliative surgery and were followed up for a median period of 13 months. Membranous EGFR levels were examined by radioligand binding assays and cytosolic c-erbB-2 levels by means of an immunoenzymatic assay.

Results

There was a wide variability in EGFR (80.3-2910 fmol/mg of protein) and c-erbB-2 (0.4-10071 NHU/mg of protein) levels in neoplastic tissues from patients with unresectable gastric carcinomas. Median c-erbB2 was significantly higher in tumors of the intestinal type than in tumors of the diffuse type (p=0.035) and in R2 than in R1 tumors (p=0.016). Statistical analysis showed that there was no relationship between tumor c-erbB-2 or EGFR content and any other patient or tumor characteristics. However, high levels of EGFR were significantly associated with a shorter overall survival (p=0.01).

Conclusion

Our data suggest a role of both transmembrane proteins in the progression of gastric cancer. EGFR and c-erbB-2 contents in unresectable gastric cancer could be utilized as appropriate biological markers for selecting candidates for treatment based on EGFR and/or c-erbB-2 inhibition.

Angiogenesis and Anti-Angiogenic Therapy in Gastric Cancer

Gastric cancer is one of the most frequent malignancies worldwide. Despite improvements in diagnosis and therapy, the overall prognosis remains poor. In the last decade, several anti-angiogenic drugs for cancer treatment have been approved and lately also introduced to gastric cancer treatment. While the initial trials focused only on unresectable or metastatic cancer, anti-angiogenic treatment is now also investigated in the perioperative and neoadjuvant setting. In this review, an overview of the role of angiogenesis and angiogenic factors in gastric cancer as well as anti-angiogenic treatment of gastric cancer is provided. Findings from in vitro and animal studies are summarized and put in a context with translational data on angiogenesis in gastric cancer. The most important angiogenic factors and their effect in gastric cancer are highlighted and clinical trials including anti-angiogenic drugs are discussed. Finally, an outlook of biomarkers for predicting response to anti-angiogenic treatment is presented, the ongoing trials on this topic are discussed and current challenges of anti-angiogenic therapy are outlined.

A case of ramucirumab-related gastrointestinal perforation in gastric cancer with small bowel metastasis

Background

Ramucirumab is a monoclonal antibody targeting vascular endothelial growth factor receptor 2 (VEGFR-2). Ramucirumab either alone or in combination with paclitaxel (PTX) has been found to be safe and effective for patients with previously treated advanced gastric cancer. One of the serious adverse events associated with ramucirumab is gastrointestinal (GI) perforation.

Case presentation

We report the case of a 67-year-old man who developed a ramucirumab-related GI perforation while undergoing treatment for gastric cancer with small bowel metastasis. He underwent laparoscopic total gastrectomy following neoadjuvant chemotherapy in January 2015 and was diagnosed with hepatic and bone recurrence in October 2015. Ramucirumab in combination with PTX was administered for one and half months after first-line chemotherapy failure. He presented with abdominal pain 7 days after the last ramucirumab dose, and emergency exploratory surgery revealed a small intestinal perforation. Pathological findings indicated that it occurred in a zone containing a small intestinal tumor, which was found to be metastasis of the gastric cancer. He had no postoperative complications, but chemotherapy was not reintroduced and he died 3 months later.

Conclusion

We present a recent case of ramucirumab-related gastrointestinal perforation in gastric cancer with small bowel metastasis. This case is rare, but important to consider.

Angiogenesis inhibitors in early development for gastric cancer

INTRODUCTION

Angiogenesis, or the generation of new blood vessels from pre-existent ones is a critical process for tumor growth and progression. Hence, the development of angiogenesis inhibitors with therapeutic potential has been a central focus for researchers. Most angiogenesis inhibitors target the Vascular Endothelial Growth Factor (VEGF) pathway, however a number of tyrosine kinase inhibitors (TKIs), immunomodulatory drugs (IMiDs) and inhibitors of the mammalian Target-Of-Rapamycin (mTOR) pathway also display antiangiogenic activity. Areas covered: Here we review the effectiveness of a variety of compounds with antiangiogenic properties in preclinical and clinical settings in gastric cancer (GC). Expert opinion: In coming years angiogenesis will remain as a therapeutic target in GC. To date, ramucirumab a monoclonal antibody that targets VEGFR2 is the most successful antiangiogenic tested in clinical studies, and it is now well established as a second-line therapy in GC. The arrival of precision medicine and the success of immune checkpoint inhibitors will increase the number of clinical trials using targeted agents like ramucirumab in combination with immune checkpoint inhibitors. A hypothetical working model that combines ramucirumab with immunotherapy is presented. Also, the impact of nanotechnology and a molecular subtype classification of GC are discussed.

Genetics of Gastric Cancer

Gastric cancer represents a major cause of cancer mortality worldwide despite a declining incidence. New molecular classification schemes developed from genomic and molecular analyses of gastric cancer have provided a framework for understanding this heterogenous disease, and early findings suggest these classifications will be relevant for designing and implementing new targeted therapies. The success of targeted therapy and immunotherapy in breast cancer and melanoma, respectively, has not been duplicated in gastric cancer, but trastuzumab and ramucirumab have demonstrated efficacy in select populations. New markers that predict therapeutic response are needed to improve patient selection for both targeted and immunotherapies.

A multi-center phase II study and biomarker analysis of combined cetuximab and modified FOLFIRI as second-line treatment in patients with metastatic gastric cancer

BACKGROUND

To evaluate the efficacy of cetuximab combined with modified FOLFIRI (mFOLFIRI) as a second-line treatment in metastatic gastric cancer patients and to identify potential biomarkers of clinical outcomes.

METHODS

All 61 patients received an initial intravenous (IV) dose of cetuximab (400 mg/m²) and weekly doses (250 mg/m²) thereafter, starting on day 1. On day 2 of each 14-day period, patients received IV irinotecan (180 mg/m²), leucovorin (200 mg/m²), and an IV bolus dose of 5-FU (400 mg/m²) followed by a continuous infusion of 5-FU (2400 mg/m²) for 46 h. The primary endpoint was time-to-progression (TTP).

RESULTS

The response rate (RR) was 33.3% among 54 evaluable patients. In the intention-to-treat analysis, median TTP was 4.6 months (95% confidential interval [CI]: 3.6-5.6 months) and median overall survival (OS) was 8.6 months (95% CI: 7.3-9.9 months). In univariate analyses, plasma vascular endothelial growth factor (VEGF) levels were correlated with clinical outcome. In patients with low (≤12.6 pg/ml) and high (>12.6 pg/ml) baseline plasma VEGF levels, RR values were 55.0% and 5.3%, respectively (P = 0.001); median TTP values were 6.9 months and 2.8 months, respectively (P = 0.0005); and median OS values were 12 months and 5 months, respectively (P <0.0001). None of these patients exhibited KRAS, BRAF, or PIK3CA mutations.

CONCLUSIONS

Combination therapy comprising cetuximab and mFOLFIRI was well tolerated and active as a second-line treatment for patients with metastatic gastric cancer. Patients with low baseline plasma VEGF levels were associated with better clinical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov. NCT00699881 . Registered 17 June 2008 (retrospectively registered).

Challenges in molecular targeted therapy for gastric cancer: considerations for efficacy and safety

INTRODUCTION

The Cancer Genome Atlas Research Network recently proposed a molecular classification for gastric cancer (GC) into four subtypes based on comprehensive evaluation. While the mechanisms of molecular targeted therapies in GC were confirmed by multiple clinical studies, only a limited number of therapeutics for GC have been approved to date. Areas covered: In this systematic review of the available literature, we discuss the completed and ongoing clinical trials of molecular targeted therapies in patients with GC, with a focus on their efficacy and safety profiles. Expert opinion: Results of recent studies clearly demonstrated that trastuzumab and ramucirumab, monoclonal antibodies (mAbs) against human epidermal growth factor receptor 2 (HER2) and vascular endothelial growth factor (VEGF), respectively, improved overall survival (OS) in GC with manageable safety profiles. Careful surveillance of ongoing clinical trials and timely profiling and monitoring of genetic signatures are imperative to establish a strong foundation for precision medicine in GC.

Targeted therapies for gastric cancer: failures and hopes from clinical trials

Gastric cancer is the third leading cause of cancer mortality worldwide. As surgery is the only curative treatment strategy and conventional chemotherapy has shown limited efficacy -with a median overall survival of 10 months- new treatments are urgently needed. Trastuzumab and Ramucirumab (targeting HER2 and VEGFR2, respectively) are the only targeted therapies approved so far. Indeed, most Phase III clinical trials evaluating molecular drugs in gastric cancer failed. This review will retrace the relevant clinical trials with molecular therapies performed in gastric cancer patients, discussing the possible reasons for their failure and indicating new perspective for a real improvement of the treatment of this disease.

The safety and efficacy of ramucirumab in combination with paclitaxel for the treatment of advanced gastric or gastro-esophageal junction adenocarcinoma

INTRODUCTION

Gastric cancer (GC) is a health problem. Platinum and fluoropyrimidine-based combinations have been established as first-line drugs used worldwide. However, there are no other options for treatment if first-line therapy fails. Therefore, second-line treatment options are needed. Targeted therapies have optimized the results of chemotherapy, specifically trastuzumab as a first-line and ramucirumab in second-line.

AREAS COVERED

Vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) are involved in the pathogenesis of GC. Clinical studies have evaluated VEGFR-2 blocked in second line. Two phase III trials using ramucirumab alone or associated to paclitaxel have demonstrated that second-line therapy could improve the survival of patients with GC. Expert commentary: VEGF-2 receptor blockade is effective at treating GC. The combination of paclitaxel with ramucirumab can be used to establish an angiogenic blockade in second-line therapy. The magnitude of the treatment effect suggests that this combination should be used as the current standard.

Antagonist antibodies to vascular endothelial growth factor receptor 2 (VEGFR-2) as anti-angiogenic agents

Interaction of numerous signaling pathways in endothelial and mesangial cells results in exquisite control of the process of physiological angiogenesis, with a central role played by vascular endothelial growth factor receptor 2 (VEGFR-2) and its cognate ligands. However, deregulated angiogenesis participates in numerous pathological processes. Excessive activation of VEGFR-2 has been found to mediate tissue-damaging vascular changes as well as the induction of blood vessel expansion to support the growth of solid tumors. Consequently, therapeutic intervention aimed at inhibiting the VEGFR-2 pathway has become a mainstay of treatment in cancer and retinal diseases. In this review, we introduce the concepts of physiological and pathological angiogenesis, the crucial role played by the VEGFR-2 pathway in these processes, and the various inhibitors of its activity that have entered the clinical practice. We primarily focus on the development of ramucirumab, the antagonist monoclonal antibody (mAb) that inhibits VEGFR-2 and has recently been approved for use in patients with gastric, colorectal, and lung cancers. We examine in-depth the pre-clinical studies using DC101, the mAb to mouse VEGFR-2, which provided a conceptual foundation for the role of VEGFR-2 in physiological and pathological angiogenesis. Finally, we discuss further clinical development of ramucirumab and the future of targeting the VEGF pathway for the treatment of cancer.

Preclinical and clinical studies on afatinib in monotherapy and in combination regimens: Potential impact in colorectal cancer

Targeting the epidermal growth factor receptor (EGFR) with monoclonal antibodies (mAbs) or tyrosine kinase inhibitors (TKI) has been an interesting therapeutic strategy because aberrant activation of this receptor plays an important role in the tumorgenesis of many cancer types, including colorectal cancer (CRC). After the initial promising results of EGFR-targeted therapies, therapeutic resistance is a major clinical problem. In order to overcome resistance to these EGFR-targeted therapies, new treatment options are necessary. In contrast to first generation EGFR inhibitors, afatinib (BIBW2992) is a second-generation irreversible ErbB family blocker that inhibits EGFR as well as HER2 and HER4. Consequently, treatment with afatinib may result in a distinct and more pronounced therapeutic benefit. Preclinical studies have reported promising results for afatinib in monotherapy as well as in combination with other drugs in CRC model systems. Furthermore, clinical studies examining afatinib as single agent and in combination therapy demonstrated manageable safety profile. Nevertheless, only limited antitumor activity has been observed in CRC patients. Although several combination treatments with afatinib have already been investigated, no optimal combination has been identified for CRC patients yet. As molecular tumor characteristics have gained increased importance in the choice of treatment, additional studies with biomarker-driven patient recruitment are required to further explore afatinib efficacy in CRC.

Monoclonal antibodies for treating gastric cancer: promises and pitfalls

INTRODUCTION

Gastric cancer (GC) presents dismal prognosis when diagnosed at advanced stages, standard chemotherapy having shown little efficacy. Introduction of biotherapies interfering with novel targets and signaling pathways is currently an emerging strategy.

AREAS COVERED

Only two monoclonal antibodies (trastuzumab and ramucirumab) have been approved, mostly in association with cytotoxics. Conversely, testing other promising biotherapies (panitumumab, cetuximab, bevacizumab, rilotumumab) have yielded conflicting results, since encouraging early clinical trials have failed to be confirmed in larger phase-III studies. Empirical and underpowered strategies when designing combinational studies, lack of comprehensive knowledge of pharmacokinetics/pharmacodynamics (PK/PD) relationships, and underestimation of the large inter-patient variability in drug exposure levels with monoclonal antibodies, could explain the failures in developing biotherapies in gastric cancer. This review covers the achievements and limits of monoclonal antibodies in gastric cancer and proposes clues to overcome current failures.

EXPERT OPINION

Trastuzumab efficacy could be improved thanks to its combination with triplet chemotherapy or with another anti-HER2 agents or in continuation during second-line chemotherapy. Concerning ramucirumab, further studies are necessary to prove its interest in first line treatment of advanced GC, to use the optimal dose in each patient-given the large inter-patients variability, and to find predictive biomarkers of efficacy.

Current targeted therapies in the treatment of advanced colorectal cancer: a review

Treatment strategies for metastatic colorectal cancer (mCRC) patients have undergone dramatic changes in the past decade and despite improved patient outcomes, there still exist areas for continued development. The introduction of targeted agents has provided clinicians with additional treatment options in mCRC, however, results have been mixed at best. These novel therapies were designed to interfere with specific molecules involved in the cellular carcinogenesis pathway and ultimately deliver a more focused treatment. Currently, their use in mCRC has been limited primarily as an adjunct to conventional chemotherapy regimens. This review explores the relevant cell-signaling networks in colorectal cancer, provides focus on the current targeted agent armamentarium approved for use in mCRC and explores the usefulness of predictive mCRC biomarkers.

BEVERLY: Rationale and Design of a Randomized Open-Label Phase III Trial Comparing Bevacizumab Plus Erlotinib Versus Erlotinib Alone as First-Line Treatment of Patients With EGFR-Mutated Advanced Nonsquamous Non-Small-Cell Lung Cancer

BACKGROUND

About 20% of advanced non-small-cell lung cancer (NSCLC) cases harbor somatic mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene. In these patients, the standard first-line treatments are the EGFR-tyrosine kinase inhibitors, such as gefitinib, erlotinib, or afatinib. Most of these patients develop resistance and relapse within about 1 year of initiation of an EGFR-tyrosine kinase inhibitor. Consequently, it is important to develop new combination strategies to delay this resistance. Preclinical data have showed that EGFR and vascular endothelial growth factor (VEGF) share a common downstream pathway, suggesting the important role of VEGF in the resistance to EGFR blockade. The combination of erlotinib and bevacizumab, an anti-VEGF agent, showed very interesting clinical results.

PATIENTS AND METHODS

The bevacizumab plus erlotinib study (BEVERLY) is a randomized, open-label, phase III trial investigating first-line erlotinib plus bevacizumab versus erlotinib in patients with advanced NSCLC harboring activating EGFR mutations. The co-primary endpoints are investigator-assessed progression-free survival (PFS) and blinded, independent centrally reviewed PFS. The secondary endpoints include overall survival, quality of life, objective response rate, and safety. A total of 200 patients will be randomized 1:1 to receive oral erlotinib (150 mg daily) plus bevacizumab (15 mg/kg, intravenously, on day 1 of every 21-day cycle) or erlotinib alone, until objective disease progression or unacceptable toxicity or the patient's or physician's motivated decision to stop the treatment.

CONCLUSION

If the primary endpoint of PFS is met, the erlotinib plus bevacizumab combination will be confirmed as the best first-line treatment for patients with advanced NSCLC harboring activating EGFR mutations.

Phase II trial of gefitinib in combination with bevacizumab as first-line therapy for advanced non-small cell lung cancer with activating EGFR gene mutations: the Okayama Lung Cancer Study Group Trial 1001

PURPOSE

Whether bevacizumab enhances the effect of the epidermal growth factor receptor (EGFR) inhibitor gefitinib on EGFR mutant non-small cell lung cancers (NSCLCs) remains unknown. We conducted a phase II trial to investigate the efficacy and safety of gefitinib when combined with bevacizumab as first-line therapy in patients with advanced NSCLC harboring EGFR gene mutations.

METHODS

In this trial, 42 patients with a performance status of 0 to 2 received gefitinib (250 mg/d) and bevacizumab (15 mg/kg, every 3 weeks). The primary end point of this study was the 1-year progression-free survival (PFS) rate. We assumed that a 1-year PFS rate of 55% would indicate potential usefulness and that a 1-year PFS rate of 40% would constitute the lower limit of interest.

RESULTS

Forty-two patients were enrolled in the study with a median age of 73 (range 42-86) years. Activating EGFR gene mutations included exon 19 deletion (57%) and L858R point mutations in exon 21 (38%). The objective response rate was 73.8% and included two complete responses. The 1-year PFS rate and median PFS time were 56.7% (95% confidence interval [CI] 39.9-70.5) and 14.4 months (95% CI 10.1-19.2), respectively. The median PFS differed significantly between EGFR exon 19 deletion and the L858R point mutation (18.0 versus 9.4 months, respectively; p = 0.006). The median overall survival had not yet been reached. Severe adverse events included grade 3 skin rash (15%), hypertension (17%), aspartate transaminase/alanine aminotransferase elevation (17%), proteinuria (7%), intracranial hemorrhage (2%), and grade 4 perforation of the digestive tract (2%). There were no treatment-related deaths.

CONCLUSION

Gefitinib in combination with bevacizumab as first-line therapy seems to be a favorable and well-tolerated treatment for patients with advanced NSCLC with activating EGFR gene mutations, especially those with EGFR exon 19 deletion mutations, although the primary end point was not met because the lower limit of the CI was less than 40%.

A novel bispecific diabody targeting both vascular endothelial growth factor receptor 2 and epidermal growth factor receptor for enhanced antitumor activity

Epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor 2 (VEGFR2) are receptor tyrosine kinases known to play critical roles in the development and progression of tumors. Based on the cross-talk between EGFR and VEGFR2 signal pathways, we designed and produced a bispecific diabody (bDAb) targeting both EGFR and VEGFR2 simultaneously. The bispecific molecule (EK-02) demonstrated that it could bind to HUVEC (VEGFR2 high-expressing) and A431 (EGFR overexpressing) cells. Additionally, similar to the parental antibodies, it was able to inhibit proliferation and migration, and induced apoptosis in these cells (HUVECs and A431), demonstrating that it had retained the functional properties of its parental antibodies. Furthermore, the efficacy of EK-02 was evaluated using the human colon adenocarcinoma cell line HT29 (VEGFR2 and EGFR coexpressing). In vitro assay showed that EK-02 could bind to HT29 cells, restrain cell growth and migration, and induce apoptosis with enhanced efficacy compared to both parental antibodies. Further, it inhibited the neovascularization and tumor formation on an HT29 cell bearing chicken chorioallantoic membrane (CAM) tumor model in vivo. In conclusion, these data suggest that the novel bDAb (EK-02) has antiangiogenesis and antitumor capacity both in vitro and in vivo, and can possibly be used as cotargeted therapy for the treatment of EGFR and VEGFR2 overexpressing tumors. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:294-302, 2016.

Adaptive responses to antibody based therapy

Receptor tyrosine kinases (RTKs) represent a large class of protein kinases that span the cellular membrane. There are 58 human RTKs identified which are grouped into 20 distinct families based upon their ligand binding, sequence homology and structure. They are controlled by ligand binding which activates intrinsic tyrosine-kinase activity. This activity leads to the phosphorylation of distinct tyrosines on the cytoplasmic tail, leading to the activation of cell signaling cascades. These signaling cascades ultimately regulate cellular proliferation, apoptosis, migration, survival and homeostasis of the cell. The vast majority of RTKs have been directly tied to the etiology and progression of cancer. Thus, using antibodies to target RTKs as a cancer therapeutic strategy has been intensely pursued. Although antibodies against the epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) have shown promise in the clinical arena, the development of both intrinsic and acquired resistance to antibody-based therapies is now well appreciated. In this review we provide an overview of the RTK family, the biology of EGFR and HER2, as well as an in-depth review of the adaptive responses undertaken by cells in response to antibody based therapies directed against these receptors. A greater understanding of these mechanisms and their relevance in human models will lead to molecular insights in overcoming and circumventing resistance to antibody based therapy.

Angiogenesis inhibitors in gastric and gastroesophageal junction cancer

Despite significant improvements in systemic chemotherapy during the past two decades, the prognosis of patients with advanced gastric and gastroesophageal junction adenocarcinoma remains poor. Because of molecular heterogeneity, it is essential to classify tumors based on the underlying oncogenic pathways and to develop targeted therapies acting on individual tumors. Unfortunately, although a number of molecular targets have been studied, very few of these agents can be used in a clinical setting. In this review, we summarize the available data on anti-angiogenic agents in advanced/metastatic gastric cancer.

Monoclonal antibodies-based treatment in gastric cancer: current status and future perspectives

Gastric cancer (GC) is the second leading cause of cancer-related death, and despite having improved treatment modalities over the last decade, for most patients, only modest improvements have been seen in overall survival. Recent progress in understanding the molecular biology of GC and the related signaling pathways offers, from the clinical point of view, promising advances for selected groups of patients. In the past, targeted therapies have significantly impacted the treatment strategy of several common solid tumors such as breast, colorectal, and lung cancers. Unfortunately, translational and clinical research shows fewer encouraging targeted treatments with regards to the GC. To date, only two monoclonal antibodies (mAb), named trastuzumab and ramucirumab, are approved for the treatment of advanced GC, suggesting that in GC, maybe more than in other cancers, effective targeted therapy requires patient selection based on precise predictive molecular biomarkers. The aim of this review is to summarize the available data on the clinical advantages offered by the use of mAbs in the treatment of advanced/metastatic GC. Future perspective is also discussed.

Antitumor activity of the multikinase inhibitor regorafenib in patient-derived xenograft models of gastric cancer

Background

Unresectable gastric cancer is associated with poor outcomes, with few treatment options available after failure of cytotoxic chemotherapy. Clinical trials of targeted therapies have generally shown no survival benefit in gastric cancer, with the exceptions of the antibodies ramucirumab (anti-VEGFR2) and trastuzumab (anti-HER2/neu). Given the efficacy of the multikinase inhibitor regorafenib in other gastrointestinal tumors, we investigated its potential in gastric cancer.

Methods

The antitumor activity of oral regorafenib was assessed in eight murine patient-derived gastric cancer xenograft models. Dose–response experiments assessed the efficacy and tolerability of oral regorafenib 5, 10, and 15 mg/kg/day in two models, with 10 mg/kg/day selected for further investigation in all eight models. Tumor weight and volume was monitored during treatment; tumor cell proliferation, angiogenesis, apoptosis, and intracellular signaling were assessed using immunohistochemistry and Western blotting of total tumor lysates at the end of treatment.

Results

Regorafenib showed dose-dependent inhibition of tumor growth and was well tolerated, with no significant decreases in bodyweight or evident toxicity. Regorafenib 10 mg/kg/day significantly inhibited tumor growth in all eight models (72 to 96 %; all p < 0.01), resulting in reduced tumor weight versus vehicle controls. Regorafenib reduced tumor angiogenesis 3- to 11-fold versus controls in all models (all p < 0.05), reduced tumor proliferation 2- to 5-fold in six of the eight models (all p < 0.05), and induced apoptosis in seven models.

Conclusion

Regorafenib was effective in patient-derived models of gastric cancer of different histological subtypes, with inhibition of tumor growth, angiogenesis, and tumor-cell proliferation observed in almost all models. These findings are consistent with the observed activity of regorafenib in preclinical models of other gastrointestinal tumors, and support further clinical investigation in gastric cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0243-5) contains supplementary material, which is available to authorized users.

DCLAK11, a multi-tyrosine kinase inhibitor, exhibits potent antitumor and antiangiogenic activity in vitro

AIM

To investigate the molecular targets of DCLAK11, a novel compound discovered from a series of substituted pyridin-3-amine derivatives, and to characterize its anti-tumor properties in vitro.

METHODS

Kinase inhibition was measured by an ELISA assay. Cell viability was assessed with an SRB or a CCK8 assay. The alterations induced by kinase signaling proteins in cancer cells were detected by Western blot. Apoptosis was determined by an Annexin V-PI assay. The following assays were used to evaluate the impact on angiogenesis: wound-healing, Transwell, tube formation and microvessel outgrowth from rat aortic rings.

RESULTS

DCLAK11 was a multi-targeted kinase inhibitor that primarily inhibited the EGFR, HER2, and VEGFR2 tyrosine kinases with IC50 value of 6.5, 18, and 31 nmol/L, respectively. DCLAK11 potently inhibited the proliferation of EGFR- and HER2-driven cancer cells: its IC50 value was 12 and 22 nmol/L, respectively, in HCC827 and HCC4006 cells with EGFR exon deletions, and 19 and 81 nmol/L, respectively, in NCI-N87 and BT474 cells with HER2 amplification. Consistently, DCLAK11 blocked the EGFR and HER2 signaling in cancer cells with either an EGFR or a HER2 aberration. Furthermore, DCLAK11 effectively induced EGFR/HER2-driven cell apoptosis. Moreover, DCLAK11 exhibited anti-angiogenic activity, as shown by its inhibitory effect on the proliferation, migration and tube formation of human umbilical vascular endothelial cells and the microvessel outgrowth of rat aortic rings.

CONCLUSIONS

DCLAK11 is a multi-targeted kinase inhibitor with remarkable potency against tyrosine kinases EGFR, HER2 and VEGFR2, which confirms its potent anti-cancer activity in EGFR- and HER2-addicted cancers and its anti-angiogenic activity.

Critical evaluation of ramucirumab in the treatment of advanced gastric and gastroesophageal cancers

Gastric (GC) and gastroesophageal junction (GEJ) cancers are two global health problems with a relatively high mortality, particularly in the advanced stage. Inhibition of angiogenesis is now contemplated as a classic treatment preference for myriad tumor types encompassing renal cell carcinoma, non-small cell lung cancer, colorectal cancer, glioblastoma, and ovarian cancer, among others. Bevacizumab and ramucirumab have been widely investigated in GC and GEJ cancer, with some controversy about their therapeutic role. Ramucirumab is a monoclonal antibody for vascular endothelial growth factor receptor-2, with demonstrated activity both as a monotherapy and as a part of combination strategy in the management of advanced GC/GEJ cancer. In this review article, we present a critical evaluation of the preclinical and clinical data underlying the use of this drug in this indication. Moreover, we provide a spotlight on the future perspectives in systemic therapy for advanced GC/GEJ cancer.

Targeted therapy in gastric cancer

Gastric cancer is often diagnosed at an advanced stage. Although chemotherapy prolongs survival and improves quality of life, the survival of gastric cancer patients with advanced disease is short. Thanks to recent insights into the molecular pathways involved in gastric carcinogenesis, new targeted treatment options have become available for gastric cancer patients. Trastuzumab, an antibody targeted to HER-2, was shown to improve survival of advanced gastric cancer patients harboring HER-2 overexpression due to gene amplification in their tumor cells, and is currently also explored in adjuvant and neoadjuvant settings. Another agent with promising results in clinical trials is ramucirumab, an antibody targeting VEGFR-2. No clear survival benefit, however, were experienced with agents targeting EGFR (cetuximab, panitumumab), VEGF-A (bevacizumab), or mTOR (everolimus). Drugs targeting c-MET/HGF are currently under investigation in biomarker-selected cohorts, with promising results in early clinical trials. This review will summarize the current status of targeted treatment options in gastric cancer.

Erlotinib and bevacizumab versus cisplatin, gemcitabine and bevacizumab in unselected nonsquamous nonsmall cell lung cancer

Erlotinib with bevacizumab showed promising activity in recurrent nonsquamous (NS) nonsmall cell lung cancer (NSCLC). The INNOVATIONS study was designed to assess in first-line treatment of unselected cisplatin-eligible patients this combination compared to cisplatin, gemcitabine and bevacizumab. Stage IIIB/IV patients with NS-NSCLC were randomised on erlotinib (150 mg daily) and bevacizumab (15 mg·kg(-1) on day 1, every 3 weeks) (EB) until progression, or cisplatin (80 mg·m(-2) on day 1, every 3 weeks) and gemcitabine (1250 mg·m(-2) on days 1 and 8, every 3 weeks) up to six cycles and bevacizumab (15 mg·kg(-1) on day 1, every 3 weeks) (PGB) until progression. 224 patients were randomised (EB n=111, PGB n=113). The response rate (12% versus 36%; p<0.0001), progression-free survival (median 3.5 versus 6.9 months; hazard ratio (HR) 1.85, 95% CI 1.39-2.45; p<0.0001) and overall survival (median 12.6 versus 17.8 months; HR 1.41, 95% CI 1.01-1.97; p=0.04) clearly favoured PGB. In patients with epidermal growth factor receptor mutations (n=32), response rate, progression-free survival and overall survival were not superior with EB. Platinum-based combination chemotherapy remains the standard of care in first-line treatment of unselected NS-NSCLC. Molecular targeted approaches strongly mandate appropriate testing and patient selection.

Vascular endothelial growth factor a inhibition in gastric cancer

Angiogenesis is a vital process in the progression and metastasis of solids tumors including gastric adenocarcinoma. Tumors induce angiogenesis by secreting proangiogenic molecules such as vascular endothelial growth factor A (VEGF-A), and VEGF-A inhibition has become a common therapeutic strategy for many cancers. Several drugs targeting the VEGF-A pathway have been approved for clinical use in selected solid tumors, and several anti-VEGF-A strategies have been examined for gastric cancer. Phase II studies suggested that bevacizumab, an anti-VEGF antibody, can increase the efficacy of chemotherapy for advanced gastric cancer, but two international phase III trials failed to show an overall survival benefit. Two more recent international phase III trials have examined ramucirumab, an antibody targeting the primary receptor for VEGF-A, as second-line therapy for advanced gastric cancer and found a survival benefit both as single agent therapy and when combined with chemotherapy. Finally, correlative science studies suggest that the VEGF-A pathway may have varying importance in gastric cancer progression depending on ethnicity or race. This article will review the preclinical and clinical studies on the role of the VEGF-A pathway inhibition in gastric cancer.

Anti-angiogenic therapies for advanced esophago-gastric cancer

Neo-vascularization is a vital process for tumor growth and development which involves the interaction between tumor cells and stromal endothelial cells through several growth factors and membranous receptors which ultimately activate pro-angiogenic intracellular signaling pathways. Inhibition of angiogenesis has become a standard treatment option for several tumor types including colorectal cancer, glioblastoma and ovarian cancer. In gastric cancer, the therapeutic role of anti-angiogenic agents is more controversial. Bevacizumab and ramucirumab, two monoclonal antibodies, which target vascular endothelial growth factor-A and vascular endothelial growth factor receptor-2, respectively, have been demonstrated antitumor activity in patients with tumors of the stomach or esophagogastric junction. However, especially for bevacizumab, this antitumor activity has not consistently translated into a survival advantage over standard treatment in randomized trials. In this article, we provide an overview of the role of angiogenesis in gastric cancer and discuss the results of clinical trials that investigated safety and effectiveness of antiangiogenic therapies in this disease. A review of the literature has been done using PubMed, ClinicalTrials.gov website and the ASCO Annual Meeting Library.