Bevacizumab for the treatment of advanced non-small-cell lung cancer

Cost-effectiveness of Osimertinib vs Docetaxel-bevacizumab in Third-line Treatment in EGFR T790M Resistance Mutation Advanced Non-Small Cell Lung Cancer in China

PURPOSE

This study aimed to evaluate the cost-effectiveness of osimertinib vs docetaxel and bevacizumab in third-line treatment in EGFR T790M resistance mutation advanced non-small cell lung cancer in China from the perspective of the health care system.

METHODS

To explore modeling uncertainty, 2 different model methods (a Markov model and a partitioned survival [PS] model) were developed to simulate costs and health outcomes during a lifetime. Both models consisted of 3 health states: progression-free survival, postprogression survival, and death. Efficacy and safety data of osimertinib vs docetaxel and bevacizumab in patients who had acquired EGFR T790M resistance mutation were derived from a key head-to-head clinical trial. Cost and utility values were derived from local charges, the literature, the China Drug Bidding Database, and patients' health care documents. Two scenario analyses and sensitivity analyses were performed to explore the robustness of the results.

FINDINGS

In the Markov model, compared with docetaxel and bevacizumab, osimertinib yielded 0.69 additional quality-adjusted life-years (QALYs) at an additional cost (in US dollars) of $17,311 for an incremental cost-utility ratio (ICUR) of $25,463 per QALY. In the PS model, osimertinib yielded an additional 0.69 QALYs with an incremental cost of $17,827 for an ICUR of $25,951 per QALY. From the Markov model, the ICUR was $29,416 per QALY in scenario 1 and $25,543 per QALY in scenario 2. From the PS model, the ICUR was $30,264 per QALY and $25,947 per QALY for scenarios 1 and 2, respectively. In the probabilistic sensitivity analysis, osimertinib treatment had a 21%-63% probability of being cost-effective at a willingness-to-pay threshold of $9777 to $29,330 per QALY (1-3 times the gross domestic product per capita).

IMPLICATIONS

The findings from the present analysis suggest that osimertinib could be cost-effective vs docetaxel and bevacizumab in third-line treatment in EGFR T790M resistance mutation advanced non-small cell lung cancer in China.

Vascular Targeting to Increase the Efficiency of Immune Checkpoint Blockade in Cancer

Boosting natural immunity against malignant cells has had a major breakthrough in clinical cancer therapy. This is mainly due to the successful development of immune checkpoint blocking antibodies, which release a break on cytolytic anti-tumor-directed T-lymphocytes. However, immune checkpoint blockade is only effective for a proportion of cancer patients, and a major challenge in the field is to understand and overcome treatment resistance. Immune checkpoint blockade relies on successful trafficking of tumor-targeted T-lymphocytes from the secondary lymphoid organs, through the blood stream and into the tumor tissue. Resistance to therapy is often associated with a low density of T-lymphocytes residing within the tumor tissue prior to treatment. The recruitment of leukocytes to the tumor tissue relies on up-regulation of adhesion molecules and chemokines by the tumor vasculature, which is denoted as endothelial activation. Tumor vessels are often poorly activated due to constitutive pro-angiogenic signaling in the tumor microenvironment, and therefore constitute barriers to efficient leukocyte recruitment. An emerging possibility to enhance the efficiency of cancer immunotherapy is to combine pro-inflammatory drugs with anti-angiogenic therapy, which can enable tumor-targeted T-lymphocytes to access the tumor tissue by relieving endothelial anergy and increasing adhesion molecule expression. This would pave the way for efficient immune checkpoint blockade. Here, we review the current understanding of the biological basis of endothelial anergy within the tumor microenvironment, and discuss the challenges and opportunities of combining vascular targeting with immunotherapeutic drugs as suggested by data from key pre-clinical and clinical studies.

Monitoring antiangiogenesis of bevacizumab in zebrafish

Bevacizumab, which is a humanized anti-VEGF antibody, has been successfully applied in clinics since 2004. Bevacizumab in combination with chemotherapy showed high safety and has been applied to solid tumors. However, studies on the insight into the mechanism about the antiangiogenesis activity of bevacizumab were mostly done on mice models, and so there are no visual and intuitive models to observe the process of antiangiogenesis. Here, we first used a zebrafish model to investigate the angiogenesis suppressing behavior of bevacizumab. Our results showed that bevacizumab inhibited formation of zebrafish subintestinal veins, which mimics the process of tumor angiogenesis in vivo. Meanwhile, bevacizumab caused specific vasculature formation defects in subintestinal veins but not in the trunk. Our study also indicated that bevacizumab could inhibit zebrafish retinal angiogenesis with therapeutic potential.

Incidence and risk of thromboembolism associated with bevacizumab in patients with non-small cell lung carcinoma

Background

Bevacizumab, a recombinant humanized monoclonal antibody against vascular endothelial growth factor (VEGF), is effective for the treatment of advanced non-small cell lung cancer (NSCLC). However, severe adverse events (AEs) have been reported in NSCLC patients treated with bevacizumab. Currently, the contribution of Bevacizumab to thromboembolism is still controversial. We conducted a study to determine the overall risk and incidence of thromboembolism with bevacizumab in NSCLC patients.

Methods

Electronic databases such as the PubMed, Web of Science and Cochrane Library were searched for related trials. Statistical analyses were conducted to calculate the overall incidence rates, odds ratios (ORs), and 95% confidence intervals (CIs) by using either random-effect or fixed-effect models depending on the heterogeneity. We also used trial sequence analysis (TSA) to verify the pooled result.

Results

A total of 3,555 subjects from nine studies were included. The overall incidence of thromboembolism events in NSCLC patients treated with bevacizumab was 4.8% (95% CI: 1.9-7.7%). Without bevacizumab, this incidence was 2.9% (95% CI: 0.6-5.1%). Bevacizumab use was associated with a significantly increased risk in thromboembolism events (OR =1.74; 95% CI: 1.15-2.62; P=0.008). Subgroup analysis based on the doses showed that bevacizumab administered at 15 mg/kg (OR =1.81; 95% CI: 1.14-2.86; P=0.012), but not 7.5 mg/kg (OR =1.32; 95% CI: 0.78-2.24; P=0.296), increased the risk of thromboembolism.

Conclusions

Bevacizumab is associated with a significantly increased risk of thromboembolism development in NSCLC patients. It may have dose-toxicity relationship and low dose of bevacizumab may be a better choice for NSCLC patients, with equal efficacy and low hazard of thromboembolism events.

Genetically Engineered Vaccinia Viruses As Agents for Cancer Treatment, Imaging, and Transgene Delivery

Despite advances in technology, the formidable challenge of treating cancer, especially if advanced, still remains with no significant improvement in survival rates, even with the most common forms of cancer. Oncolytic viral therapies have shown great promise for the treatment of various cancers, with the possible advantages of stronger treatment efficacy compared to conventional therapy due to higher tumor selectivity, and less toxicity. They are able to preferentially and selectively propagate in cancer cells, consequently destroying tumor tissue mainly via cell lysis, while leaving non-cancerous tissues unharmed. Several wild-type and genetically engineered vaccinia virus (VACV) strains have been tested in both preclinical and clinical trials with promising results. Greater understanding and advancements in molecular biology have enabled the generation of genetically engineered oncolytic viruses for safer and more efficacious treatment, including arming VACVs with cytokines and immunostimulatory molecules, anti-angiogenic agents, and enzyme prodrug therapy, in addition to combining VACVs with conventional external and systemic radiotherapy, chemotherapy, immunotherapy, and other virus strains. Furthermore, novel oncolytic vaccinia virus strains have been generated that express reporter genes for the tracking and imaging of viral therapy and monitoring of therapeutic response. Further study is needed to unlock VACVs’ full potential as part of the future of cancer therapy.

Vascular heterogeneity and targeting: the role of YKL-40 in glioblastoma vascularization

Malignant glioblastomas (GBM) are highly malignant brain tumors that have extensive and aberrant tumor vasculature, including multiple types of vessels. This review focuses on recent discoveries that the angiogenic factor YKL-40 (CHI3L1) acts on glioblastoma-stem like cells (GSCs) to drive the formation of two major forms of tumor vascularization: angiogenesis and vasculogenic mimicry (VM). GSCs possess multipotent cells able to transdifferentiate into vascular pericytes or smooth muscle cells (PC/SMCs) that either coordinate with endothelial cells (ECs) to facilitate angiogenesis or assemble in the absence of ECs to form blood-perfused channels via VM. GBMs express high levels of YKL-40 that drives the divergent signaling cascades to mediate the formation of these distinct microvascular circulations. Although a variety of anti-tumor agents that target angiogenesis have demonstrated transient benefits for patients, they often fail to restrict tumor growth, which underscores the need for additional therapeutic tools. We propose that targeting YKL-40 may compliment conventional anti-angiogenic therapies to provide a substantial clinical benefit to patients with GBM and several other types of solid tumors.

Antiangiogenic mechanisms and factors in breast cancer treatment

Breast cancer is known to metastasize in its latter stages of existence. The different angiogenic mechanisms and factors that allow for its progression are reviewed in this article. Understanding these mechanisms and factors will allow researchers to design drugs to inhibit angiogenic behaviors and control the rate of tumor growth.

Expression of anti-VEGF antibody together with anti-EGFR or anti-FAP enhances tumor regression as a result of vaccinia virotherapy

The tumor microenvironment plays an important role in tumor growth and progression. Here we demonstrate that vaccinia virus-mediated, constitutively expressed intratumoral antibodies against vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), and fibroblast activation protein (FAP) significantly improved tumor regression and oncolytic virotherapy through suppression of angiogenesis, cell proliferation, and stromagenesis in virus-colonized tumors. In contrast to the tumor growth inhibition by the three tumor growth-inhibiting antibodies individually, when two of the three antibodies were expressed simultaneously by single vaccinia virus strains tumor regression was further enhanced. These findings strongly indicate that interference with the two tumor growth-stimulating mechanisms did in fact result in enhanced therapeutic efficacy in tumor xenograft models and may lead to an effective therapy in patients with cancer.

Assessment methods for angiogenesis and current approaches for its quantification

Angiogenesis is a physiological process which describes the development of new blood vessels from the existing vessels. It is a common and the most important process in the formation and development of blood vessels, so it is supportive in the healing of wounds and granulation of tissues. The different assays for the evaluation of angiogenesis have been described with distinct advantages and some limitations. In order to develop angiogenic and antiangiogenic techniques, continuous efforts have been resulted to give animal models for more quantitative analysis of angiogenesis. Most of the studies on angiogenic inducers and inhibitors rely on various models, both in vitro, in vivo and in ova, as indicators of efficacy. The angiogenesis assays are very much helpful to test efficacy of both pro- and anti- angiogenic agents. The development of non-invasive procedures for quantification of angiogenesis will facilitate this process significantly. The main objective of this review article is to focus on the novel and existing methods of angiogenesis and their quantification techniques. These findings will be helpful to establish the most convenient methods for the detection, quantification of angiogenesis and to develop a novel, well tolerated and cost effective anti-angiogenic treatment in the near future.

The efficacy of bevacizumab compared with other targeted drugs for patients with advanced NSCLC: a meta-analysis from 30 randomized controlled clinical trials

Background

The extent of the benefit of bevacizumab combined with chemotherapy in the treatment of advanced non-small-cell lung cancer (NSCLC) is still unclear. We performed this meta-analysis to compare the efficacy of bevacizumab with other commonly used targeted drugs for different patients with advanced NSCLC.

Methods

We searched PubMed, Cochrane Library, EMBASE and abstracts from the proceedings of the American Society of Clinical Oncology (ASCO), and identified 30 randomized controlled clinical trials published within 1999 to 2011 for meta-analysis.

Results

The outcomes of treatment efficacy included response rate, PFS and OS. Comparing bevacizumab (15 mg/kg) with chemotherapy to standard chemotherapy alone, for chemotherapy-naïve patients, the pooled OR of response rate was 2.741(95%CI: 2.046, 3.672), the pooled HR for disease progression was 0.645 (95%CI: 0.561, 0.743), and the pooled HR for death was 0.790 (95%CI: 0.674, 0.926), respectively. In addition, the adjusted HR for previously-treated patients was 0.680 (95%CI: 0.492, 0.942) comparing bevacizumab combined with chemotherapy to standard chemotherapy alone.

Conclusions

Bevacizumab accompanied by chemotherapy was found to significantly improve patients' response rate, progression free survival (PFS), and overall survival (OS) among chemotherapy-naïve patients compared to other targeted drugs in the treatment of non-small cell lung carcinoma (NSCLC).

Glioblastoma-derived tumor cells induce vasculogenic mimicry through Flk-1 protein activation

Glioblastoma (GBM) is extremely aggressive and essentially incurable. Its malignancy is characterized by vigorous microvascular proliferations. Recent evidence has shown that tumor cells display the ability to drive blood-perfused vasculogenic mimicry (VM), an alternative microvascular circulation independent of endothelial cell angiogenesis. However, molecular mechanisms underlying this vascular pathogenesis are poorly understood. Here, we found that vascular channels of VM in GBM were composed of mural-like tumor cells that strongly express VEGF receptor 2 (Flk-1). To explore a potential role of Flk-1 in the vasculogenesis, we investigated two glioblastoma cell lines U87 and GSDC, both of which express Flk-1 and exhibit a vascular phenotype on Matrigel. Treatment of both cell lines with either Flk-1 gene knockdown or Flk-1 kinase inhibitor SU1498 abrogated Flk-1 activity and impaired vascular function. Furthermore, inhibition of Flk-1 activity suppressed intracellular signaling cascades, including focal adhesion kinase and mitogen-activated protein kinase ERK1/2. In contrast, blockade of VEGF activity by the neutralizing antibody Bevacizumab failed to recapitulate the impact of SU1498, suggesting that Flk-1-mediated VM is independent of VEGF. Xenotransplantation of SCID/Beige mice with U87 cells and GSDCs gave rise to tumors harboring robust mural cell-associated vascular channels. Flk-1 shRNA restrained VM in tumors and subsequently inhibited tumor development. Collectively, all the data demonstrate a central role of Flk-1 in the formation of VM in GBM. This study has shed light on molecular mechanisms mediating tumor aggressiveness and also provided a therapeutic target for patient treatment.

Osteonecrosis and the Jaws and Bevacizumab Therapy: A Case Report

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

Recent advances in anti-angiogenic therapy of cancer

Since angiogenesis is critical for tumor growth and metastasis, anti-angiogenic treatment is a highly promising therapeutic approach. Thus, for over last couple of decades, there has been a robust activity aimed towards the discovery of angiogenesis inhibitors. More than forty anti-angiogenic drugs are being tested in clinical trials all over the world. This review discusses agents that have approved by the FDA and are currently in use for treating patients either as single-agents or in combination with other chemotherapeutic agents.

A phase II first-line study of gemcitabine, carboplatin, and bevacizumab in advanced stage nonsquamous non-small cell lung cancer

BACKGROUND

Bevacizumab improves responses and progression-free survival when added to first-line paclitaxel/carboplatin or cisplatin/gemcitabine for patients with advanced nonsquamous non-small cell lung cancer. This study was designed to evaluate toxicities and efficacy of gemcitabine/carboplatin/bevacizumab.

METHODS

Patients with untreated advanced nonsquamous non-small cell lung cancer, with no evidence of brain metastases and not on anticoagulation were eligible. Patients received gemcitabine 1000 mg/m on days 1 and 8; carboplatin area under the curve 5 day 1; and bevacizumab 15 mg/kg day 1 every 3 weeks for up to six cycles. Bevacizumab was then continued every 3 weeks until disease progression or unacceptable toxicity.

RESULTS

From July 2006 to December 2008, 48 patients were enrolled: 23 (48%) men, 25 (52%) women, and 19 (40%) never smokers. One patient never received therapy and is not included in the analysis. Median cycle number was 8 (1-42) with 37 patients (78.7%) completing ≥4 cycles of three drugs. Dose reductions occurred in 34 (72.3%) patients. Grade 3/4 toxicities included neutropenia (47%/15%), thrombocytopenia (11%/15%), anemia (6%/0%), dyspnea (6%/2%), bacterial pneumonia (4%/0%), and hypertension (4%/2%). No neutropenic fevers occurred. One patient died of hemoptysis. Grade 3 bleeding occurred in three other patients. There were seven (14.9%) partial responses. Median time to first event (progression/death/toxicity requiring discontinuation) was 6.4 months (95% confidence interval: 4.8-7.9 months). The median overall survival (OS) was 12.8 months (95% confidence interval: 10.0-16.5). The OS is 57% at 1 year and 10% at 2 years.

CONCLUSIONS

Although perhaps skewed by a high proportion of nonsmokers and women, treatment with gemcitabine/carboplatin/bevacizumab has an acceptable toxicity profile with promising median OS despite a low response rate.

CD133+ circulating haematopoietic progenitor cells predict for response to sorafenib plus erlotinib in non-small cell lung cancer patients

BACKGROUND

Blood-based biomarkers may be particularly useful for patient selection and prediction of treatment response for angiogenesis inhibitors. Circulating endothelial cells (CECs) and haematopoietic progenitor cells (HPCs) might have a role in tumour angiogenesis and in tumour growth. Measurement of CECs and HPCs in the blood of patients could be a simple, non-invasive way to monitor or predict responses to treatment.

METHODS

(VEGFR2(+)) CECs(,) (CD133(+)) HPCs, plasma vascular endothelial growth factor (VEGF) and erythropoietin were measured in blood from 25 non-small cell lung cancer (NSCLC) patients before and during treatment with sorafenib plus erlotinib (SO/ER). In order to assess the drug specificity of changes in CECs and HPCs, 18 patients treated with bevacizumab plus erlotinib (BV/ER) and 10 patients with erlotinib (ER) monotherapy were studied. Response was measured in all patient groups by Response Evaluation Criteria in Solid Tumors (RECIST).

RESULTS

At day 7, SO/ER-treated patients showed a three-fold increase in CECs (P<0.0001) comparable to BV/ER-treated patients (P<0.01), and the CECs did not change with erlotinib treatment (P=0.8). At day 7, CD133(+)/HPCs decreased with SO/ER treatment (P<0.0001). HPC numbers did not change with either BV/ER or erlotinib. In SO/ER-treated patients pre-treatment CD133(+)/HPCs were significantly lower in responders (P=0.01) and pre-treatment CD133(+)/HPC numbers lower than the median correlated with a longer time-to-progression (TTP) (P=0.037).

CONCLUSION

Pre-treatment CD133(+)/HPCs are a promising candidate biomarker to further explore for use in selecting NSCLC patients who might benefit from SO/ER treatment.

Immunotherapy in the landscape of new targeted treatments for non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. Active immunotherapies and molecules targeting tyrosine kinase receptors both offer new avenues for the treatment of NSCLC. Furthermore, their combinations or their administration along with standard treatments enlarges the potential for clinical benefit. Moreover, the discovery of biomarkers predicting the response to these new therapies should allow a better selection of patients susceptible to optimally benefit from these treatments. In this paper, we review the most promising active immunotherapies, antibodies and small molecules in the context of NSCLC management, focusing on compounds in phase III clinical development.

Anti-VEGF single-chain antibody GLAF-1 encoded by oncolytic vaccinia virus significantly enhances antitumor therapy

We previously reported that the replication-competent vaccinia virus (VACV) GLV-1h68 shows remarkable oncolytic activity and efficacy in different animal models as a single treatment modality and also in combination with chemotherapy [Yu YA, et al. (2009) Mol Cancer Ther 8:141-151]. Here, we report the construction of 3 VACV strains encoding GLAF-1, a previously undescribed engineered single-chain antibody (scAb). This unique scAb is transcribed from 3 vaccinia promoters (synthetic early, early/late, and late) and directed against both human and murine VEGFs. The expression of GLAF-1 was demonstrated in cell cultures. Also, the replication efficiency of all GLAF-1-expressing VACV strains in cell culture was similar to that of the parental GLV-1h68 virus. Successful tumor-specific delivery and continued production of functional scAb derived from individual VACV strains were obtained in tumor xenografts following a single intravenous injection of the virus. The VACV strains expressing the scAb exhibited significantly enhanced therapeutic efficacy in comparison to treatment of human tumor xenografts with the parental virus GLV-1h68. This enhanced efficacy was comparable to the concomitant treatment of tumors with a one-time i.v. injection of GLV-1h68 and multiple i.p. injections of Avastin. Taken together, the VACV-mediated delivery and production of immunotherapeutic anti-VEGF scAb in colonized tumors may open the way for a unique therapy concept: tumor-specific, locally amplified drug therapy in humans.

Off-label use of bevacizumab for the treatment of age-related macular degeneration: what is the evidence?

There is an active and controversial debate about the role of intravitreal bevacizumab versus approved drugs in the treatment of neovascular age-related macular degeneration (AMD). Because bevacizumab was available prior to the launch of ranibizumab, off-label use of the former became widespread and the cancer drug bevacizumab is the most commonly used medication in ophthalmology nowadays. This review considers every publication identified in MEDLINE using the keywords 'bevacizumab' and 'Avastin' between 1 June 2005 and 31 July 2008. The search identified 511 papers that were evaluated. In 33 studies, there was consistent and clear evidence for the efficacy of bevacizumab in neovascular AMD. However, the highest grade studies (three prospective, randomized, controlled trials) did not attain better than grade 2b level of evidence, and objective evaluation of the benefit of bevacizumab relative to representative controls was therefore not possible. Certainly, the available evidence is inferior to that obtained from the approval studies of ranibizumab and this should influence treatment selection and guidance of patients. These considerations indicate that important quality criteria need to be included in future studies to ensure more meaningful conclusions can be drawn. These include clearly defined inclusion criteria, information about the recruitment procedure (including data on withdrawals, excluded patients, concealed treatment allocation, use of intention-to-treat analyses and blinded assessment procedures). Although preclinical studies have almost exclusively found bevacizumab to be safe, the design utilized in clinical case series cannot rule out a possible increase in adverse events, which already show a high spontaneous incidence in elderly AMD patients. The superior evidence level for ranibizumab and the limited safety data for bevacizumab must be taken into consideration when evaluating the costs that a healthcare system is willing to spend. However, the superior grade of evidence for ranibizumab should not be confused with the (still missing) evidence for superior efficacy. The results of ongoing randomized, controlled, comparative trials will provide further data on the efficacy and cost effectiveness of bevacizumab and ranibizumab in the treatment of AMD. In the meantime, patients should be informed about the alternatives, the price differences and the restricted liability issue when off-label use of bevacizumab is offered.

The function of vascular endothelial growth factor

Vascular endothelial growth factor (VEGF) is considered the master regulator of angiogenesis during growth and development, as well as in disease states such as cancer, diabetes, and macular degeneration. This review details our current understanding of VEGF signaling and discusses the benefits and unexpected side effects of promising anti-angiogenic therapeutics that are currently being used to inhibit neovacularization in tumors.

Multidisciplinary approach to esophageal and gastric cancer

The incidence of esophageal and gastric malignancies has increased over the last decade. Historically, surgery has been considered the best treatment for these cancers. However, long-term survival after surgery is fair at best, because of the tendency of disease to recur locally and distantly. Presently, the management of these cancers involves surgery, chemotherapy, and radiation therapy. This article discusses various treatment strategies that employ these modalities either alone or in combination, in an attempt to improve survival rates for patients who have gastroesophageal malignancies.

Chemotherapy for advanced stage non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is a common, often fatal malignancy, and is most frequently diagnosed in the advanced stage. Systemic chemotherapy for advanced (Stage IIIB and IV), inoperable NSCLC has evolved over the course of the last few decades. Survival advantage was first noted with platinum chemotherapy, with ultimate development of platinum-containing doublet combinations, which have now become standard of care in the treatment of advanced NSCLC. Over the course of the last few years, multiple nonplatinum combinations have also been demonstrated to be efficacious, and the addition of bevacizumab to existing doublet regimens has improved outcomes in this population of patients. Maintenance regimens for advanced stage NSCLC are currently under extensive investigation. Clinical trials have also recently demonstrated increased efficacy for agents such as docetaxel and pemetrexed in the second line setting for refractory disease.

The tumour microenvironment: a novel target for cancer therapy

Cancer therapy is in the midst of a major paradigm shift. Traditionally, cancer treatments have focused on tumour cells. However, studies over the past few decades have demonstrated that cancer is a vastly complex entity with multiple components affecting a tumour's growth, invasion and metastasis. These components, collectively termed the 'tumour microenvironment', include endothelial cells, pericytes, fibroblasts, inflammatory cells, leucocytes and elements of the extracellular matrix (ECM). Biological agents that target components of the tumour microenvironment may provide an interesting alternative to traditional tumour cell-directed therapy. Because of the complexity of the tumour milieu, the most beneficial therapy will likely involve the combination of one or more agents directed at this new target. This review highlights recent preclinical and clinical studies involving agents that target tumour vasculature, leucocytes, pericytes, cancer-associated fibroblasts and ECM components. We pay particular attention to combination therapies targeting multiple components of the tumour microenvironment, and aim to demonstrate that this strategy holds promise for the future of cancer treatment.