Treatment-related mortality with bevacizumab in cancer patients: a meta-analysis

Targeting the tumor microenvironment: focus on angiogenesis

Tumorigenesis is a complex multistep process involving not only genetic and epigenetic changes in the tumor cell but also selective supportive conditions of the deregulated tumor microenvironment. One key compartment of the microenvironment is the vascular niche. The role of angiogenesis in solid tumors but also in hematologic malignancies is now well established. Research on angiogenesis in general, and vascular endothelial growth factor in particular, is a major focus in biomedicine and has led to the clinical approval of several antiangiogenic agents including thalidomide, bevacizumab, sorafenib, sunitinib, pazopanib, temesirolimus, and everolimus. Indeed, antiangiogenic agents have significantly changed treatment strategies in solid tumors (colorectal cancer, renal cell carcinoma, and breast cancer) and multiple myeloma. Here we illustrate important aspects in the interrelationship between tumor cells and the microenvironment leading to tumor progression, with focus on angiogenesis, and summarize derived targeted therapies.

Addition of bevacizumab to chemotherapy in advanced non-small cell lung cancer: a systematic review and meta-analysis

INTRODUCTION

Recently, studies have demonstrated that the addition of bevacizumab to chemotherapy could be associated with better outcomes in patients with advanced non-small cell lung cancer (NSCLC). However, the benefit seems to be dependent on the drugs used in the chemotherapy regimens. This systematic review evaluated the strength of data on efficacy of the addition of bevacizumab to chemotherapy in advanced NSCLC.

METHODS

PubMed, EMBASE, and Cochrane databases were searched. Eligible studies were randomized clinical trials (RCTs) that evaluated chemotherapy with or without bevacizumab in patients with advanced NSCLC. The outcomes included overall survival (OS), progression-free survival (PFS), response rate (RR), toxicities and treatment related mortality. Hazard ratios (HR) and odds ratios (OR) were used for the meta-analysis and were expressed with 95% confidence intervals (CI).

RESULTS

We included results reported from five RCTs, with a total of 2,252 patients included in the primary analysis, all of them using platinum-based chemotherapy regimens. Compared to chemotherapy alone, the addition of bevacizumab to chemotherapy resulted in a significant longer OS (HR 0.89; 95% CI 0.79 to 0.99; p = 0.04), longer PFS (HR 0.73; 95% CI 0.66 to 0.82; p<0.00001) and higher response rates (OR 2.34; 95% CI 1.89 to 2.89; p<0.00001). We found no heterogeneity between trials, in all comparisons. There was a slight increase in toxicities in bevacizumab group, as well as an increased rate of treatment-related mortality.

CONCLUSIONS

The addition of bevacizumab to chemotherapy in patients with advanced NSCLC prolongs OS, PFS and RR. Considering the toxicities added, and the small absolute benefits found, bevacizumab plus platinum-based chemotherapy can be considered an option in selected patients with advanced NSCLC. However, risks and benefits should be discussed with patients before decision making.

Management options in triple-negative breast cancer

Notorious for its poor prognosis and aggressive nature, triple-negative breast cancer (TNBC) is a heterogeneous disease entity. The nature of its biological specificity, which is similar to basal-like cancers, tumors arising in BRCA1 mutation carriers, and claudin-low cancers, is currently being explored in hopes of finding the targets for novel biologics and chemotherapeutic agents. In this review, we aim to give a broad overview of the disease's nomenclature and epidemiology, as well as the basic mechanisms of emerging targeted therapies and their performance in clinical trials to date.

Brain metastases from renal cell carcinoma. Should we change the current standard?

Renal cell carcinoma (RCC) is one of the most common sources of brain metastases, with an incidence that varies widely from 4% to 48% according to different studies. In addition, asymptomatic metastases occur in up to 33% of patients with metastatic RCC, further complicating the decision-making process in this poor prognosis population. The purpose of this review is to cover in depth the present state of knowledge on the diagnosis and management of patients with brain metastases from RCC, in order to assess whether the current standard should be challenged. The existing systems to predict response and survival will be reviewed, as well as the available therapeutic options regarding local treatment and systemic therapy, all within the context of updated data from clinical trials. In this regard, the role of novel targeted agents for the treatment of brain metastases from RCC, such as the multi-targeted receptor tyrosine kinase inhibitors sunitinib and sorafenib, will be updated and discussed.

Problems involved in the clinical trials for non-small cell lung carcinoma

Along with changes in smoking habits, non-small cell lung carcinoma (NSCLC) has come to account for about 90% of all cases of lung cancer. For the treatment of NSCLC, cytocidal antineoplastic drugs such as pemetrexed and molecular-targeted drugs such as gefitinib, erlotinib, and bevacizumab have been approved globally and used as a part of the standard treatment. The importance of better patient selection based on the optimum indication of these drugs is attracting much attention. Additionally, timing for the use of these drugs also seems to be an important issue. The present review presents a critical discussion about the following issues based on the results of clinical studies: (1) whether or not the assessment of the EGFR mutation status in NSCLC patients is indispensable; (2) whether gefitinib and erlotinib have different effects; (3) the need to sub-classify NSCLC by histologic type; (4) significance of maintenance therapy for NSCLC; and (5) whether platinum-doublet chemotherapy plus bevacizumab is a standard treatment for non-squamous cell carcinoma.

Safety of bevacizumab in patients with metastatic breast cancer

Five randomized phase III trials - AVF2119g, E2100, AVADO, RIBBON-1, and RIBBON-2 - have reported data on the efficacy and safety of bevacizumab, combined with a variety of chemotherapy agents and in various settings, in patients with metastatic breast cancer (MBC). The E2100 trial demonstrated a significant improvement in progression-free survival according to the independent review facility, from 5.8 to 11.3 months when bevacizumab was combined with paclitaxel (p < 0.0001) as first-line therapy in patients with HER2-nonamplified MBC; subsequent trials of bevacizumab as first-line (AVADO, RIBBON-1) and second-line (RIBBON-2) therapy for patients with HER2-nonamplified MBC have also met their primary end point of prolonging progression-free survival (PFS). Accumulating safety data for bevacizumab in MBC show that it is generally well tolerated and associated with predictable adverse events, including hypertension and proteinuria. The majority of adverse events are mild and manageable, but bevacizumab is also associated with some severe toxicities. The management of bevacizumab-related adverse events in MBC has improved with increased experience. This review summarizes bevacizumab efficacy in MBC and focuses on bevacizumab-related toxicities as reported in 5 phase III clinical trials. Current adverse event management strategies, based on guidelines and experience from these trials, are outlined.

Antiangiogenic therapy for patients with recurrent and newly diagnosed malignant gliomas

Malignant gliomas have a poor prognosis despite advances in diagnosis and therapy. Although postoperative temozolomide and radiotherapy improve overall survival in glioblastoma patients, most patients experience a recurrence. The prognosis of recurrent malignant gliomas is dismal, and more effective therapeutic strategies are clearly needed. Antiangiogenesis is currently considered an attractive targeting therapy for malignant gliomas due to its important role in tumor growth. Clinical trials using bevacizumab have been performed for recurrent glioblastoma, and these studies have shown promising response rates along with progression-free survival. Based on the encouraging results, bevacizumab was approved by the FDA for the treatment of recurrent glioblastoma. In addition, bevacizumab has shown to be effective for recurrent anaplastic gliomas. Large phase III studies are currently ongoing to demonstrate the efficacy and safety of the addition of bevacizumab to temozolomide and radiotherapy for newly diagnosed glioblastoma. In contrast, several other antiangiogenic drugs have also been used in clinical trials. However, previous studies have not shown whether antiangiogenesis improves the overall survival of malignant gliomas. Specific severe side effects, difficult assessment of response, and lack of rational predictive markers are challenging problems. Further studies are warranted to establish the optimized antiangiogenesis therapy for malignant gliomas.

Tumor Vessel Development and Expansion in Ewing's Sarcoma: A Review of the Vasculogenesis Process and Clinical Trials with Vascular-Targeting Agents

Ewing's sarcoma accounts for a disproportionately high portion of the overall pediatric mortality rate compared to its rare incidence in the pediatric population. Little progress has been made since the introduction of traditional chemotherapies, and understanding the biology of the tumor is critical for developing new therapies. Ewing's sarcomas rely on a functional vascular supply, which is formed by a combination of angiogenesis and vasculogenesis. Recent insights into the molecular regulation of bone marrow (BM) cell participation in vascular development have identified VEGF, SDF-1α, and DLL4 as critical players in the vasculogenesis process. Clinical trials using vascular targeting agents, specifically targeting VEGF or DLL4, are underway.

Convection-enhanced delivery of 131I-chTNT-1/B mAB for treatment of high-grade adult gliomas

INTRODUCTION

Despite treatment advances for malignant gliomas in adults, prognosis remains poor, largely due to the infiltrative and heterogeneous biology of these tumors. Response to adjuvant therapy is not always uniform and the blood-brain barrier prevents the majority of chemotherapeutics from adequately reaching primary tumor sites. These obstacles necessitate development of novel delivery methods and agents.

AREAS COVERED

(131)I-chTNT-1/B mAB (Cotara) is a genetically engineered chimeric monoclonal antibody that binds to the DNA-histone H1 complex. It carries (131)I, which delivers sufficient energy to kill adjacent tumor cells. Through convection-enhanced delivery (CED) it provides radioimmunotherapy directly to the resection cavity. We review the pharmacology and clinical experience with (131)I-chTNT-1/B mAB, detailing results of completed Phase I and II trials.

EXPERT OPINION

Novel agents and therapeutic modalities, such as (131)I-chTNT-1/B mAB, are of interest for treatment of malignant glioma, for which the prognosis continues to be dismal. (131)I-chTNT-1/B mAB targets tumor cells and radioisotope labeling allows radiation delivery to the tumor with sharp fall-off. Data from Phase I and II trials of CED delivery of (131)I-chTNT-1/B mAB shows it is well tolerated. Phase II trial data suggests it could be promising therapeutically, though conclusions about efficacy require further trials and clinical experience. The compound is currently in a Phase II trial for dose confirmation in patients with malignant gliomas.

[Indications and current development of new targeted therapies in pediatric oncology]

Progresses performed in pediatric oncology during the last 30 years allowed to obtain about 70 to 80% healing rates. These progresses are the result of the optimization of the cytotoxic chemotherapies protocols used at standard and high doses, as well as the improvement of the local treatment. Most of the new anticancer treatments currently in developmental stage are based on targeted therapies, acting against numerous tumor cell abnormalities, like growth factors et their receptors, cell proliferation-inducing factors, molecules involved in DNA repair, cell death inducers, tumor invasion and angiogenesis. They are widely used in adult patients since 10 years and they are being more and more employed in children with cancer. The aim of this article is to review the main indications of these new targeted drugs in pediatric oncology and the new developments of these drugs.

Magnitude of risks and benefits of the addition of bevacizumab to chemotherapy for advanced breast cancer patients: Meta-regression analysis of randomized trials

BACKGROUND

Although the addition of bevacizumab significantly improves the efficacy of chemotherapy for advanced breast cancer, regulatory concerns still exist with regard to the magnitude of the benefits and the overall safety profile.

METHODS

A literature-based meta-analysis to quantify the magnitude of benefit and safety of adding bevacizumab to chemotherapy for advanced breast cancer patients was conducted. Meta-regression and sensitivity analyses were also performed to identify additional predictors of outcome and to assess the influence of trial design.

RESULTS

Five trials (3,841 patients) were gathered. A significant interaction according to treatment line was found for progression-free survival (PFS, p = 0.027); PFS was significantly improved for 1(st) line (Hazard Ratio, HR 0.68, p < 0.0001), with a 1-yr absolute difference (AD) of 8.4% (number needed to treat, NNT 12). A non-significant trend was found in overall survival (OS), and in PFS for 2(nd) line. Responses were improved with the addition of bevacizumab, without interaction between 1(st) line (Relative Risk, RR 1.46, p < 0.0001) and 2(nd) line (RR 1.58, p = 0.05). The most important toxicity was hypertension, accounting for a significant AD of 4.5% against bevacizumab (number needed to harm, NNH 22). Other significant, although less clinically meaningful, adverse events were proteinuria, neurotoxicity, febrile neutropenia, and bleeding. At the meta-regression analysis for 1(st)-line, more than 3 metastatic sites (p = 0.032), no adjuvant chemotherapy (p = 0.00013), negative hormonal receptor status (p = 0.009), and prior anthracyclines-exposure (p = 0.019), did significantly affect PFS.

CONCLUSIONS

Although with heterogeneity, the addition of bevacizumab to 1st-line chemotherapy significantly improves PFS, and overall activity. Hypertension should be weighted with the overall benefit on the individual basis.

Vascular endothelial growth factors and receptors: anti-angiogenic therapy in the treatment of cancer

Vascular endothelial growth factors (VEGFs) are critical regulators of vascular and lymphatic function during development, in health and in disease. There are five mammalian VEGF ligands and three VEGF receptor tyrosine kinases. In addition, several VEGF co-receptors that lack intrinsic catalytic activity, but that indirectly modulate the responsiveness to VEGF contribute to the final biological effect. This review describes the molecular features of VEGFs, VEGFRs and co-receptors with focus on their role in the treatment of cancer.

Molecular targeted approaches for treatment of pancreatic cancer

Human pancreatic cancer remains a highly malignant disease with almost similar incidence and mortality despite extensive research. Many targeted therapies are under development. However, clinical investigation showed that single targeted therapies and most combined therapies were not able to improve the prognosis of this disease, even though some of these therapies had excellent anti-tumor effects in pre-clinical models. Cross-talk between cell proliferation signaling pathways may be an important phenomenon in pancreatic cancer, which may result in cancer cell survival even though some pathways are blocked by targeted therapy. Pancreatic cancer may possess different characteristics and targets in different stages of pathogenesis, maintenance and metastasis. Sensitivity to therapy may also vary for cancer cells at different stages. The unique pancreatic cancer structure with abundant stroma creates a tumor microenvironment with hypoxia and low blood perfusion rate, which prevents drug delivery to cancer cells. In this review, the most commonly investigated targeted therapies in pancreatic cancer treatment are discussed. However, how to combine these targeted therapies and/or combine them with chemotherapy to improve the survival rate of pancreatic cancer is still a challenge. Genomic and proteomic studies using pancreatic cancer samples obtained from either biopsy or surgery are recommended to individualize tumor characters and to perform drug sensitivity study in order to design a tailored therapy with minimal side effects. These studies may help to further investigate tumor pathogenesis, maintenance and metastasis to create cellular expression profiles at different stages. Integration of the information obtained needs to be performed from multiple levels and dimensions in order to develop a successful targeted therapy.

Cardiac troponin T and advanced glycation end-products in hemodialysis patients

BACKGROUND

Cardiac troponin T (cTnT) is used as a biomarker of myocardial damage for the diagnosis of acute myocardial infarction and acute coronary syndrome. The aim was to investigate the association between advanced glycation end products (AGEs) and cTnT in hemodialysis (HD) patients.

METHODS

The plasma level of cTnT in 224 HD patients was measured using the electrochemiluminescence immunoassay. The plasma levels of N(epsilon)-(carboxymethyl)lysine (CML) and pentosidine were measured using an enzyme-linked immunosorbent assay.

RESULTS

The cTnT-positive group (>0.1 ng/ml) showed significantly high plasma levels of calcium, CML and pentosidine as compared with the cTnT-negative group. In multiple logistic regression analysis, the prevalence of patients with high plasma calcium (>median) was increased in the cTnT-positive group as compared with the cTnT-negative group (OR: 5.08, 95% CI: 1.62-15.92, p < 0.01). The prevalence of high plasma CML (>median) was increased in the cTnT-positive group (OR: 4.45, 95% CI: 1.41-14.03, p < 0.05). Further, the prevalence of high plasma pentosidine (>median) was also increased in the cTnT-positive group (OR: 4.94, 95% CI: 1.55-15.70, p < 0.01).

CONCLUSION

In addition to calcium, AGEs such as CML and pentosidine were associated with cTnT, a marker of myocardial damage, in HD patients.