Exposure-response analysis using time-to-event data for bevacizumab biosimilar SB8 and the reference bevacizumab

Purpose: This analysis aimed to characterize the exposure-response relationship of bevacizumab in non-small-cell lung cancer (NSCLC) and evaluate the efficacy of SB8, a bevacizumab biosimilar, and Avastin®, the reference bevacizumab sourced from the European Union (EU), based on the exposure reported in a comparative phase III efficacy and safety study (EudraCT, 2015-004026-34; NCT02754882). Materials and methods: The overall survival (OS) and progression-free survival (PFS) data from 224 patients with steady-state trough concentrations (Css,trough) were analyzed. A parametric time-to-event (TTE) model was developed using NONMEM®, and the effects of treatments (SB8 and bevacizumab-EU) and patient demographic and clinical covariates on OS and PFS were evaluated. Simulations of median OS and PFS by bevacizumab Css,trough were conducted, and concentrations required to achieve 50% and 90% of the maximum median TTE were computed. Results: A log-logistics model with Css,trough best described the OS and PFS data. Treatment was not a predictor of the hazard for OS or PFS. Simulations revealed steep exposure-response curves with a phase of rapid rise before saturating to a plateau. The median Css,trough values of SB8 and bevacizumab-EU reported from the clinical study were on the plateaus of the exposure-response curves. The concentrations required to achieve 50% and 90% of the maximum effect were 82.4 and 92.2 μg/mL, respectively, for OS and 79.7 and 89.1 μg/mL, respectively, for PFS. Conclusion: Simulations based on the constructed TTE models for OS and PFS have well described the exposure-response relationship of bevacizumab in advanced NSCLC. The analysis demonstrated comparable efficacy between SB8 and bevacizumab-EU in terms of OS and PFS based on their exposure levels.

Cyclophilin A: An Independent Prognostic Factor for Survival in Patients with Metastatic Colorectal Cancer Treated with Bevacizumab and Chemotherapy

Colorectal cancer (CRC) ranks as second most common cause of cancer-related deaths. The CRC management considerably improved in recent years, especially due to biological therapies such as bevacizumab. The lack of predictive or prognostic biomarkers remains one of the major disadvantages of using bevacizumab in the CRC management. We performed a prospective study to analyze the prognostic and predictive roles of three potential serum biomarkers (Cyclophilin A (CypA), copeptin and Tie2) investigated by ELISA in 56 patients with metastatic CRC undergoing bevacizumab and chemotherapy between May 2019 and September 2021 at baseline and after one and six months of therapy. We showed that low levels of CypA at baseline and after one month of treatment were associated with better overall survival (OS) (42 versus 24 months, p = 0.029 at baseline; 42 versus 25 months, p = 0.039 after one month). For copeptin and Tie2, Kaplan-Meier curves showed no correlation between these biomarkers and OS or progression-free survival. When adjusting for baseline and post-treatment factors, a multivariate Cox analysis showed that low values of CypA at baseline and after one month of treatment were independent prognostic factors for OS and correlated with a better prognosis in metastatic CRC patients.

Antiangiogenic Drug-Induced Proteinuria as a Prognostic Factor in Metastatic Colorectal Cancer

Treatment with bevacizumab is known to cause adverse events such as proteinuria and hypertension, amongst others. However, while bevacizumab-induced hypertension has been linked to increased overall survival (OS), data on proteinuria are controversial. We performed a retrospective analysis to observe the influence of adverse events developed during treatment with bevacizumab and chemotherapy on the OS in patients with metastatic colorectal cancer (mCRC). Kaplan–Meier and log-rank analyses were used to assess differences in OS, and hazard ratios (HR) were estimated using Cox models. Out of the 3497 mCRC patients admitted to our center between 2014 and 2019, 150 met the criteria for inclusion in our analysis. Out of these, 50.7% experienced proteinuria and had reached a longer OS (40 versus 25 months, p = 0.015) and progression-free survival (15 versus 12 months, p = 0.039). The following groups were identified as having a lower risk of death: patients with proteinuria (HR 0.589; 95% CI 0.402–0.863; p = 0.007), one metastatic site (HR 0.533; 95% CI 0.363–0.783; p = 0.001), and non-metastatic stage at diagnosis (HR 0.459; 95% CI 0.293–0.720; p = 0.001). Patients with anemia and diabetes had an increased risk of death. Proteinuria emerges as a useful prognostic factor in mCRC patients undergoing bevacizumab-based systemic therapy, and it could be easily integrated into the decision-making process, thus allowing physicians to further individualize systemic treatments.

Expression of pro-angiogenic factors as potential biomarkers in experimental models of colon cancer

PURPOSE

RAS mutational status in colorectal cancer (CRC) represents a predictive biomarker of response to anti-EGFR therapy, but to date it cannot be considered an appropriate biomarker of response to anti-VEGF therapy. To elucidate the function of K-Ras in promoting angiogenesis, the effect of conditioned media from KRAS mutated and wild type colon cancer cell lines on HUVECs tubule formation ability and the correspondent production of pro-angiogenic factors have been evaluated by a specific ELISA assay.

METHODS

Ras-activated signaling pathways were compared by western blot analysis and RTq-PCR. In addition, VEGF, IL-8, bFGF and HIF-1α expression was determined in K-RAS silenced cells. Furthermore, we conducted an observational study in a cohort of RAS mutated metastatic CRC patients, treated with first-line bevacizumab-based regimens, evaluating VEGF-A and IL-8 plasma levels at baseline, and during treatment.

RESULTS

K-RAS promotes VEGF production by cancer cell lines. At the transcriptional level, this is reflected to a K-RAS dependent HIF-1α over-expression. Moreover, the HIF-1α, VEGF and FGF expression inhibition in KRAS knocked cells confirmed these results. Within the clinical part, no statistically significant correlation has been found between progression-free survival (PFS) and VEGF-A/IL-8 levels, but we cannot exclude that these biomarkers could be further investigated as predictive or prognostic biomarkers in this setting.

CONCLUSION

Our study confirmed the direct involvement of K-Ras in promoting angiogenesis into colon cancer cell lines.

Safety and Tolerability of Anti-Angiogenic Protein Kinase Inhibitors and Vascular-Disrupting Agents in Cancer: Focus on Gastrointestinal Malignancies

Angiogenesis is an essential process for tumor growth and metastasis. Inhibition of angiogenesis as an anticancer strategy has shown significant results in a plethora of tumors. Anti-angiogenic agents are currently part of many standard-of-care options for several metastatic gastrointestinal cancers. Bevacizumab, aflibercept, ramucirumab, and regorafenib have significantly improved both progression-free and overall survival in different lines of treatment in metastatic colorectal cancer. Second-line ramucirumab and third-line apatinib are effective anti-angiogenic treatments for patients with metastatic gastric cancer. Unfortunately, the anti-angiogenic strategy has major practical limitations: resistance inevitably develops through redundancy of signaling pathways and selection for subclonal populations adapted for hypoxic conditions. Anti-angiogenic agents may be more effective in combination therapies, with not only cytotoxics but also other emerging compounds in the anti-angiogenic class or in the separate class of the so-called vascular-disrupting agents. This review aims to provide an overview of the approved and "under development" anti-angiogenic compounds as well as the vascular-disrupting agents in the treatment of gastrointestinal cancers, focusing on the actual body of knowledge available on therapy challenges, pharmacodynamic and pharmacokinetic mechanisms, safety profiles, promising predictive biomarkers, and future perspectives.

The role of tumor angiogenesis as a therapeutic target in colorectal cancer

INTRODUCTION

Angiogenesis is a complex process regulated by several pro- and anti-angiogenic factors, thus the loss of its fine equilibrium plays a key role in colorectal cancer (CRC) development and progression. Therapeutic agents targeting VEGF/VEGFR signaling, the main regulator of this process, proved to be effective across different treatment lines in metastatic CRC (mCRC) and contributed greatly to improve patients' survival in recent years. Areas covered: This review aimed to summarize the actual body of knowledge available on the VEGF pathway in CRC, including currently available anti-angiogenic drugs and treatment challenges, mechanisms of resistance, promising predictive biomarkers and future perspectives. Expert commentary: Angiogenesis inhibition in subsequent lines of treatment is a valid strategy in the continuum of care of mCRC patients. In this scenario, the availability of multiple agents warrants to tailor therapy to an individualized approach. However, the validation of predictive biomarkers to aid therapeutic decisions remains an issue. Intrinsic and adaptive resistance to anti-angiogenic agents comprises distinct and intertwined processes, eventually leading to treatment failure and disease progression. The expanding knowledge on the mechanisms underlying the angiogenesis pathway, different potential treatment targets and mechanisms of tumor resistance, may lead to promising new perspectives in this field.

Effect of tumor microenvironment on tumor VEGF during anti-VEGF treatment: systems biology predictions

BACKGROUND

Vascular endothelial growth factor (VEGF) is known to be a potent promoter of angiogenesis under both physiological and pathological conditions. Given its role in regulating tumor vascularization, VEGF has been targeted in various cancer treatments, and anti-VEGF therapy has been used clinically for treatment of several types of cancer. Systems biology approaches, particularly computational models, provide insight into the complexity of tumor angiogenesis. These models complement experimental studies and aid in the development of effective therapies targeting angiogenesis.

METHODS

We developed an experiment-based, molecular-detailed compartment model of VEGF kinetics and transport to investigate the distribution of two major VEGF isoforms (VEGF121 and VEGF165) in the body. The model is applied to predict the dynamics of tumor VEGF and, importantly, to gain insight into how tumor VEGF responds to an intravenous injection of an anti-VEGF agent.

RESULTS

The model predicts that free VEGF in the tumor interstitium is seven to 13 times higher than plasma VEGF and is predominantly in the form of VEGF121 (>70%), predictions that are validated by experimental data. The model also predicts that tumor VEGF can increase or decrease with anti-VEGF treatment depending on tumor microenvironment, pointing to the importance of personalized medicine.

CONCLUSIONS

This computational study suggests that the rate of VEGF secretion by tumor cells may serve as a biomarker to predict the patient population that is likely to respond to anti-VEGF treatment. Thus, the model predictions have important clinical relevance and may aid clinicians and clinical researchers seeking interpretation of pharmacokinetic and pharmacodynamic observations and optimization of anti-VEGF therapies.

Targeted therapies in colorectal cancer-an integrative view by PPPM

In developed countries, colorectal cancer (CRC) is the third most common malignancy, but it is the second most frequent cause of cancer-related death. Clinicians are still faced with numerous challenges in the treatment of this disease, and future approaches which target the molecular features of the disorder will be critical for success in this disease setting. Genetic analyses of many solid tumours have shown that up to 100 protein-encoding genes are mutated. Within CRC, numerous genetic alterations have been identified in a number of pathways. Therefore, understanding the molecular pathology of CRC may present information on potential routes for treatment and may also provide valuable prognostic information. This will be particularly pertinent for molecularly targeted treatments, such as anti-vascular endothelial growth factor therapies and anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapy. KRAS and BRAF mutations have been shown to predict response to anti-EGFR therapy. As EGFR can also signal via the phosphatidylinositol 3-kinase (PI3K) kinase pathway, there is considerable interest in the potential roles of members of this pathway (such as PI3K and PTEN) in predicting treatment response. Therefore, a combined approach of new techniques that allow identification of these biomarkers alongside interdisciplinary approaches to the treatment of advanced CRC will aid in the treatment decision-making process and may also serve to guide future therapeutic approaches.

Predictive impact of circulating vascular endothelial growth factor in four phase III trials evaluating bevacizumab

PURPOSE

We evaluated the prognostic and predictive use of circulating VEGF-A levels in phase III trials of bevacizumab in colorectal cancer, lung cancer, and renal cell carcinoma.

METHODS

Baseline plasma samples from 1,816 patients were analyzed for VEGF-A using an ELISA, which recognizes the major isoforms with equivalent sensitivity. HR and 95% confidence intervals (CI) for study end points were estimated using Cox regression analysis. A subset of matched archival tumor samples was analyzed for VEGF-A expression using in situ hybridization.

RESULTS

Higher VEGF-A levels showed trends toward adverse prognostic significance in the control arms of multiple trials, reaching statistical significance for overall survival (OS) in AVF2107 (highest vs. lowest 50%: HR = 1.76; 95% CI, 1.28-2.41), AVAiL (HR = 1.52; 95% CI, 1.16-2.00), and AVOREN (HR = 1.67; 95% CI, 1.18-2.36). In predictive analyses, the HRs for progression-free survival were similar across low and high VEGF-A subgroups and favored bevacizumab-containing treatment. In the low VEGF-A subgroups, HRs (95% CIs) were 0.61 (0.43-0.87) in AVF2107, 0.71 (0.43-1.16) in E4599, 0.74 (0.59-0.94) in AVAiL (low-dose), 0.89 (0.70-1.13) in AVAiL (high-dose), and 0.56 (0.40-0.78) in AVOREN. Analyses of OS data have shown similar results. No correlation between primary tumor VEGF-A expression and plasma VEGF-A levels was observed.

CONCLUSIONS

In this comprehensive evaluation, pretreatment total circulating VEGF-A was prognostic for outcome in metastatic colorectal, lung, and renal cell cancers, but it was not predictive for bevacizumab-based treatment benefit.

Patients with metastatic breast cancer using bevacizumab as a treatment: is there still a role for it?

OPINION STATEMENT

Over the last few decades, the angiogenesis mechanism has increasingly been studied and implicated in cancer pathophysiology. At present, it is known that angiogenesis plays a relevant role in tumor growth, and more importantly many new molecules exists can potentially interfere with this process. Bevacizumab, a humanized monoclonal antibody targeting the vascular endothelial growth factor A (VEGF-A) now commonly used in the treatment of colorectal, renal cell, and brain cancer, is the first anti-angiogenesis drug delivered in combination with chemotherapy that has consistently shown clinical efficacy in the treatment of breast cancer. Since the ECOG 2100 trial has shown that bevacizumab added to paclitaxel as a first-line treatment for advanced breast cancer nearly doubled the time to progression and tumor response rate, its approval was granted almost worldwide. However, other phase III trials revealed a smaller absolute improvement in progression-free survival (PFS) and response rates, and no trials yet have demonstrated survival enhancement which led to a great controversy and debate over the use of bevacizumab. The discrepancy between PFS and overall survival also raises the question of whether or not bevacizumab has been applied sub-optimally in some of the studies, if a predictive biomarker(s) exists to select the group of patients whom would receive the greatest benefit and what is the appropriate clinical end-point for approval and funding of new targeted agents. In this article we will review the bevacizumab mechanism of action and the clinical trials that assessed its benefit in the treatment of metastatic breast cancer (MBC).

Overcoming resistance to antiangiogenic therapies

The concept of targeting new blood vessel formation, or angiogenesis, in tumors is an important advancement in cancer therapy, resulting, in part, from the development of such biologic agents as bevacizumab, a monoclonal antibody directed against vascular endothelial growth factor (VEGF)-A. The rationale for antiangiogenic therapy is based on the hypothesis that if tumors are limited in their capacity to obtain a new blood supply, so too is their capacity for growth and metastasis. Additional evidence suggests that pruning and/or "normalization" of irregular tumor vasculature and reduction of hypoxia may facilitate greater access of cytotoxic chemotherapy (CT) to the tumor. Indeed, for metastatic colorectal cancer, bevacizumab in combination with established CT regimens has efficacy superior to that of CT alone. Despite ~2-month longer progression-free and overall survival times than with CT alone, patients still progress, possibly because of alternative angiogenic "escape" pathways that emerge independent of VEGF-A, or are driven by hypoxic stress on the tumor. Other VEGF family members may contribute to resistance, and many factors that contribute to the regulation of tumor angiogenesis function as part of a complex network, existing in different concentrations and spatiotemporal gradients and producing a wide range of biologic responses. Integrating these concepts into the design and evaluation of new antiangiogenic therapies may help overcome resistance mechanisms and allow for greater efficacy over longer treatment periods.

Bevacizumab in combination with chemotherapy as first-line therapy in advanced gastric cancer: a biomarker evaluation from the AVAGAST randomized phase III trial

PURPOSE

The AVAGAST study showed that adding bevacizumab to chemotherapy in patients with advanced gastric cancer improves progression-free survival and tumor response rate but not overall survival. To examine the hypothesis that angiogenic markers may have predictive value for bevacizumab efficacy in gastric cancer, AVAGAST included a prospective, mandatory biomarker program.

PATIENTS AND METHODS

Patients with previously untreated, locally advanced or metastatic gastric cancer were randomly assigned to bevacizumab (n = 387) or placebo (n = 387) in combination with chemotherapy. Blood and tumor tissue samples were collected at baseline. Prespecified biomarkers included plasma vascular endothelial growth factor-A (VEGF-A), protein expression of neuropilin-1, and VEGF receptors-1 and -2 (VEGFR-1 and VEGFR-2). Correlations between biomarkers and clinical outcomes were assessed by using a Cox proportional hazards model.

RESULTS

Plasma was available from 712 patients (92%), and tumor samples were available from 727 patients (94%). Baseline plasma VEGF-A levels and tumor neuropilin-1 expression were identified as potential predictors of bevacizumab efficacy. Patients with high baseline plasma VEGF-A levels showed a trend toward improved overall survival (hazard ratio [HR], 0.72; 95% CI, 0.57 to 0.93) versus patients with low VEGF-A levels (HR, 1.01; 95% CI, 0.77 to 1.31; interaction P = .07). Patients with low baseline expression of neuropilin-1 also showed a trend toward improved overall survival (HR, 0.75; 95% CI, 0.59 to 0.97) versus patients with high neuropilin-1 expression (HR, 1.07; 95% CI, 0.81 to 1.40; interaction P = .06). For both biomarkers, subgroup analyses demonstrated significance only in patients from non-Asian regions.

CONCLUSION

Plasma VEGF-A and tumor neuropilin-1 are strong biomarker candidates for predicting clinical outcome in patients with advanced gastric cancer treated with bevacizumab.

Turning promise into progress for antiangiogenic agents in epithelial ovarian cancer

Despite efforts to improve chemotherapeutic efficacy in epithelial ovarian cancer, outcome for patients with advanced disease has remained unchanged since the introduction of standard carboplatin and paclitaxel. Interest has therefore shifted toward molecularly targeted therapies that interfere with important features of ovarian carcinogenesis, such as angiogenesis. Several angiogenesis inhibitors, targeting vascular endothelial growth factor (VEGF) ligands (bevacizumab, VEGF-Trap) or their receptors (VEGFR-targeted tyrosine kinase inhibitors) have been clinically evaluated. These agents demonstrated efficacy in phase II clinical trials. Results from phase III trials, in which bevacizumab was added to standard frontline chemotherapy, show a modest effect. Although the initial expectations for angiogenesis inhibitors have been tempered, further research is warranted to define their precise place in the treatment of ovarian cancer. This review summarizes the performed and ongoing studies with regard to angiogenesis inhibitors in ovarian cancer, and the available data on biomarkers for response prediction. Preclinical studies evaluating alternative angiogenesis inhibitors will also be discussed.

Bevacizumab in non-small-cell lung cancer: a review

Current targeted strategies for cancer focus on the blockade of growth factor receptors and the inhibition of angiogenesis. The VEGF pathway has become an attractive target in multiple malignancies, including lung cancer. Bevacizumab, a monoclonal antibody against VEGF, increased survival in non-small-cell lung cancer (NSCLC) patients when added to standard carboplatin/paclitaxel chemotherapy. The pivotal Phase III study (ECOG 4599) in NSCLC showed longer overall survival: 12.3 versus 10.3 months and a higher median progression-free survival of 6.2 versus 4.5 months when chemotherapy was associated with bevacizumab. Benefits were confirmed in terms of progression-free survival in the European Phase III study (AVAiL). Subsequently, bevacizumab gained US FDA and European Medicines Agengy approval as a first-line therapy for advanced NSCLC. Bevacizumab's safety profile is well established: most adverse events are mild to moderate and can be managed using standard interventions. This article presents an overview of the current data on bevacizumab for NSCLC.

Prognostic significance of angiogenesis and angiogenic growth factors in nonsmall cell lung cancer

Currently, nonsmall-cell lung cancer (NSCLC) is the leading cause of cancer-related death in the United States. Angiogenesis, the formation of new vasculature, is a complex and tightly regulated process that promotes metastasis and disease progression in lung cancer and other malignancies. Developmental antiangiogenic agents have shown activity in NSCLC, and bevacizumab, an antiangiogenic monoclonal antibody, is approved for the treatment of patients with advanced disease. However, predictive biomarkers are needed to guide the administration of antiangiogenic agents. It is possible that angiogenic molecules could accurately predict patient response to targeted antiangiogenic therapies, which would allow individualized and perhaps more effective treatment. Angiogenic signaling molecules may also have value as prognostic indicators, which may be useful for the management of NSCLC. Here the author provides an overview of angiogenic molecules currently being investigated as prognostic biomarkers in NSCLC and discusses their potential to guide treatment choices.

Targeting angiogenesis in esophagogastric adenocarcinoma

The possibility of targeting tumor angiogenesis was postulated almost 40 years ago. The vascular endothelial growth factor (VEGF) family and its receptors have since been characterized and extensively studied. VEGF overexpression is a common finding in solid tumors, including esophagogastric cancer, and frequently correlates with poor prognosis. Monoclonal antibodies, soluble receptors, and small-molecule tyrosine kinase inhibitors have been developed to inhibit tumor angiogenesis, and antiangiogenic therapy is now a component of standard treatment for advanced renal cell, hepatocellular, colorectal, breast, and non-small cell lung carcinomas. The small-molecule tyrosine kinase inhibitors sunitinib and sorafenib have been evaluated in phase II studies in esophagogastric cancer but appear to have only modest activity. Similarly, despite promising efficacy signals from phase II studies, the addition of the anti-VEGF-A monoclonal antibody bevacizumab to cisplatin plus capecitabine failed to result in a longer overall survival duration than with the chemotherapy doublet plus placebo. The response rate and progression-free survival interval were significantly greater with bevacizumab, confirming some efficacy in advanced gastric cancer, but with inadequate benefit to justify the high cost of treatment. Evaluation of bevacizumab in the neoadjuvant and perioperative settings continues, hypothesizing that a higher response rate will translate into longer survival in patients with operable disease. Despite extensive research, the discovery of a reliable predictive biomarker for antiangiogenic therapy continues to elude the scientific and oncology communities, and mechanisms of primary and acquired resistance are incompletely understood. We are therefore currently unable to personalize antiangiogenic therapy for established indications, or use molecular selection for clinical trials evaluating novel indications.

Dose-finding study and pharmacogenomic analysis of fixed-rate infusion of gemcitabine, irinotecan and bevacizumab in pretreated metastatic colorectal cancer patients

BACKGROUND

To determine the dose-limiting toxicity (DLT), maximum tolerated dose, recommended dose (RD) and preliminary evidence of activity of escalating doses of irinotecan (CPT-11) fixed-dose-rate infusional gemcitabine (FDR-GMB) and bevacizumab in pretreated metastatic colorectal cancer (mCRC) patients. Pharmacogenomic analysis was performed to investigate the association between VEGF single-nucleotide polymorphisms and clinical outcome.

PATIENTS AND METHODS

A total of 89 mCRC patients were recruited in a two-step study design; 28 were included in the dose-finding study and 59 in the pharmacogenomic analysis. The FDR-GMB of 1000 mg m⁻², bevacizumab 5 mg kg⁻¹ and CPT-11 doses ranging from 100 to 160 mg m⁻² were explored. The VEGF protein serum levels were quantified by EIA. Allelic discrimination was performed to genotype polymorphisms in the VEGF gene.

RESULTS

CPT-11 RD was 150 mg m⁻². Diarrhoea and neutropenia were the DLT. After a median follow-up of 42 months, the median time to progression (TTP) and overall survival were 5.2 and 19.9 months, respectively. VEGF levels were significantly correlated with VEGF-2578AA and VEGF-460CC genotypes, and a trend was observed with VEGF+405GG genotype. The presence of any of these genotypes correlated with a longer median TTP (8.8 vs 4.5 months, P=0.04).

CONCLUSION

The triplet combination tested in this study is effective and well tolerated. A possible predictive role for VEGF gene polymorphisms and baseline VEGF circulating levels is suggested.

Parameters for individualizing systemic therapy in non-small cell lung cancer

Rational drug design based on molecular targets is starting to revolutionize cancer care. To maximize its potential for patients, a concomitant leveraging of molecular knowledge for selection of patients to future and current therapeutic options is paramount. The terms "individualized", "personalized", or "precision therapy" are currently used to describe these efforts. Here, we summarize current knowledge for selection of systemic targeted and cytotoxic therapy for patients with non-small-cell lung cancer. Based on this knowledge, we present a potential decision algorithm to best select patients for currently available therapies, which include the treatment options single-agent erlotinib or gefitinib, the ALK inhibitor crizotinib, double agent gemcitabine and platinum, double agent platinum and pemetrexed, and as a default option a taxane combined with a non-platinum drug, for instance a vinca alkaloid. The addition of bevacizumab to double-agent chemotherapy is also discussed. Currently available data on predictive biomarkers are largely based on subgroup or companion biomarker analyses of patient cohorts or clinical trials. Current and emerging markers must be incorporated prospectively into the design of clinical trials that test novel and established agents to better understand their clinical utility and to refine selection parameters and marker interactions. Future development will lead to increasing complexity in clinical decision making with substantial anticipated benefits to patients including increased therapeutic efficacy, reduced toxicity, and better quality of life.