VEGF pathway genetic variants as biomarkers of treatment outcome with bevacizumab: an analysis of data from the AViTA and AVOREN randomised trials

Analysis of cell free DNA to predict outcome to bevacizumab therapy in colorectal cancer patients

To predict outcome to combination bevacizumab (BVZ) therapy, we employed cell-free DNA (cfDNA) to determine chromosomal instability (CIN), nucleosome footprints (NF) and methylation profiles in metastatic colorectal cancer (mCRC) patients. Low-coverage whole-genome sequencing (LC-WGS) was performed on matched tumor and plasma samples, collected from 74 mCRC patients from the AC-ANGIOPREDICT Phase II trial (NCT01822444), and analysed for CIN and NFs. A validation cohort of plasma samples from the University Medical Center Mannheim (UMM) was similarly profiled. 61 AC-ANGIOPREDICT plasma samples collected before and following BVZ treatment were selected for targeted methylation sequencing. Using cfDNA CIN profiles, AC-ANGIOPREDICT samples were subtyped with 92.3% accuracy into low and high CIN clusters, with good concordance observed between matched plasma and tumor. Improved survival was observed in CIN-high patients. Plasma-based CIN clustering was validated in the UMM cohort. Methylation profiling identified differences in CIN-low vs. CIN high (AUC = 0.87). Moreover, significant methylation score decreases following BVZ was associated with improved outcome (p = 0.013). Analysis of CIN, NFs and methylation profiles from cfDNA in plasma samples facilitates stratification into CIN clusters which inform patient response to treatment.

Machine Learning Application Identifies Germline Markers of Hypertension in Patients With Ovarian Cancer Treated With Carboplatin, Taxane, and Bevacizumab

Pharmacogenomics studies how genes influence a person's response to treatment. When complex phenotypes are influenced by multiple genetic variations with little effect, a single piece of genetic information is often insufficient to explain this variability. The application of machine learning (ML) in pharmacogenomics holds great potential - namely, it can be used to unravel complicated genetic relationships that could explain response to therapy. In this study, ML techniques were used to investigate the relationship between genetic variations affecting more than 60 candidate genes and carboplatin-induced, taxane-induced, and bevacizumab-induced toxicities in 171 patients with ovarian cancer enrolled in the MITO-16A/MaNGO-OV2A trial. Single-nucleotide variation (SNV, formerly SNP) profiles were examined using ML to find and prioritize those associated with drug-induced toxicities, specifically hypertension, hematological toxicity, nonhematological toxicity, and proteinuria. The Boruta algorithm was used in cross-validation to determine the significance of SNVs in predicting toxicities. Important SNVs were then used to train eXtreme gradient boosting models. During cross-validation, the models achieved reliable performance with a Matthews correlation coefficient ranging from 0.375 to 0.410. A total of 43 SNVs critical for predicting toxicity were identified. For each toxicity, key SNVs were used to create a polygenic toxicity risk score that effectively divided individuals into high-risk and low-risk categories. In particular, compared with low-risk individuals, high-risk patients were 28-fold more likely to develop hypertension. The proposed method provided insightful data to improve precision medicine for patients with ovarian cancer, which may be useful for reducing toxicities and improving toxicity management.

Unraveling the Synergy between Atezolizumab and Bevacizumab for the Treatment of Hepatocellular Carcinoma

Tyrosine kinase inhibitors (TKIs) with antiangiogenic properties, such as sorafenib, have been the standard choice to systemically treat hepatocellular carcinoma for over a decade. More recently, encouraging results were obtained using immune checkpoint inhibitors, although head-to-head comparisons with sorafenib in phase 3 trials could not demonstrate superiority in terms of overall survival. The IMbrave150 was a breakthrough study that resulted in atezolizumab/bevacizumab, a combination of an antiangiogenic and an immune checkpoint inhibitor, as a new standard of care for advanced HCC. This review discusses the mode of action, clinical efficacy, and biomarker research for both drug classes and for the combination therapy. Moreover, the synergy between atezolizumab and bevacizumab is highlighted, unraveling pathophysiological mechanisms underlying an enhanced anticancer immunity by changing the immunosuppressed to a more immunoreactive tumor microenvironment (TME). This is achieved by upregulation of antigen presentation, upregulation of T-cell proliferation, trafficking and infiltration, impairing recruitment, and proliferation of immunosuppressive cells in the TME. However, more insights are needed to identify biomarkers of response that may improve patient selection and outcome.

Predictive value of vascular endothelial growth factor polymorphisms for maintenance bevacizumab efficacy in metastatic colorectal cancer: an ancillary study of the PRODIGE 9 phase III trial

Background

Several studies have reported the impact of single nucleotide polymorphisms (SNPs) in vascular endothelial growth factor (VEGF) pathway genes on the efficacy of bevacizumab in metastatic colorectal cancer (mCRC), but results are still inconsistent. The PRODIGE 9 phase III study compared bevacizumab maintenance versus observation alone after induction chemotherapy with FOLFIRI plus bevacizumab.

Objective

We evaluated the impact of SNPs of VEGF-A, VEGF receptors (VEGFR-1, VEGFR-2), and hypoxia inducible factor-1α (HIF-1α) on tumor control duration (TCD), overall survival (OS), progression-free survival (PFS), and duration of first chemotherapy free-intervals (CFI).

Patients and methods

We included 314/491 patients from PRODIGE 9 with a DNA blood sample available. Nine SNPs were genotyped on germline DNA using real-time Polymerase Chain Reaction TaqMan TM (Thermo Fisher Scientific, Waltham, MA , USA 02451).

Results

In the bevacizumab arm, patients with the VEGFR-1 rs9582036 CC genotype (n = 14) had significantly longer TCD [22.4 months (95% confidence interval (CI): 14.75-not reached)] than patients with the AA or CA genotype [14.4 months (95% CI: 11.7-17.1)] (p = 0.036), whereas there was no significant difference in the observation arm. In the bevacizumab arm, no significant difference was found between the CC, and AA or CA genotype for OS [28.2 (95% CI: 18.1-42.8) versus 22.5 (95% CI: 18.6-24.6) months, p = 0.5], PFS [9.4 (95% CI: 7.2-11.3) versus 9.2 (95% CI: 8.71-10.1)], and duration of the first CFI [4.6 (95% CI: 1.6-13.3) versus 4.14 (95% CI: 0.5-29.0) months, p = 0.3].

Conclusion

Among mCRC patients treated with bevacizumab maintenance, those with the VEGFR-1 rs9582036 CC genotype experienced longer TCD. The presence of this genotype may thus predict a benefit of bevacizumab maintenance in mCRC.

The Association of Biochemical and Genetic Biomarkers in VEGF Pathway with Depression

VEGF is an important neurotrophic and vascular factor involved in mental disorders. The objective of this study was to verify the effect of genetic polymorphisms in the VEGF pathway on the risk for depression, symptom intensity, and suicide attempts. To examine the association between the VEGF pathway and depression, we genotyped polymorphisms and measured the plasma concentrations of VEGF, KDR, and FLT1 proteins. The participants were 160 patients with depression and 114 healthy controls. The questionnaires that assessed the clinical profile of the patients were the MINI-International Neuropsychiatric Interview, GRID-HAMD₂₁, CTQ, BSI, and the number of suicide attempts. Genotyping of participants was performed using the real-time PCR and protein measurements were performed using the enzyme-linked immunosorbent assay (ELISA). VEGF and its inhibitors were reduced in depression. Individuals with depression and displaying the homozygous AA of the rs699947 polymorphism had higher plasma concentrations of VEGF (p-value = 0.006) and were associated with a greater number of suicide attempts (p-value = 0.041). Individuals with depression that were homozygous for the G allele of the FLT1 polymorphism rs7993418 were associated with lower symptom severity (p-value = 0.040). Our results suggest that VEGF pathway polymorphisms are associated with the number of suicide attempts and the severity of depressive symptoms.

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.

Association of CTLA-4 and IL-4 polymorphisms in viral induced liver cancer

Background

Hepatocellular carcinoma (HCC) is one of the most prevalent types of cancer and is responsible for close to one million annual deaths globally. In Pakistan, HCC accounts for 10.7% of cancer incidence. Prior studies indicated an association between interleukin 4 (IL-4) and cytotoxic T lymphocyte protein 4 (CTLA-4) gene polymorphisms in many types of cancers, including HCC that are either hepatitis B virus (HBV)- or hepatitis C Virus (HCV)-induced. The association of IL-4 and CTLA-4 genetic polymorphisms with HCV-induced HCC is not yet determined in the Pakistani population. Therefore, this research is designed to investigate the implication of IL-4 and CTLA-4 gene polymorphisms by determining the association of IL-4 -590 C/T (rs2243250) and CTLA-4 + 49 A/G (rs231775) with HCC in Pakistan.

Methods

Different bioinformatics tools were employed to determine the pathogenicity of these polymorphisms. Samples were collected from HCV-induced HCC patients, followed by DNA extraction and ARMS-PCR analysis.

Results

The SNP analysis results indicated a positive association of IL-4 -590C/T and CTLA-4 + 49A/G gene polymorphisms with HCV-induced HCC in Pakistan. The CTLA-4 polymorphism might enhance therapeutic efficiency of HCC chemotherapy medicines. The IL-4 polymorphism might introduce new transcription factor binding site in IL-4 promoter region.

Conclusion

This study delineated risk factor alleles in CTLA-4 and IL-4 genes associated with HCV-mediated HCC among Pakistani patients that may have application to serve as genetic markers for pre- and early diagnosis and prognosis of HCC in HCV patients.

Phase IB study of ziv-aflibercept plus pembrolizumab in patients with advanced solid tumors

BACKGROUND

The combination of antiangiogenic agents with immune checkpoint inhibitors could potentially overcome immune suppression driven by tumor angiogenesis. We report results from a phase IB study of ziv-aflibercept plus pembrolizumab in patients with advanced solid tumors.

METHODS

This is a multicenter phase IB dose-escalation study of the combination of ziv-aflibercept (at 2-4 mg/kg) plus pembrolizumab (at 2 mg/kg) administered intravenously every 2 weeks with expansion cohorts in programmed cell death protein 1 (PD-1)/programmed death-ligand 1(PD-L1)-naïve melanoma, renal cell carcinoma (RCC), microsatellite stable colorectal cancer (CRC), and ovarian cancer. The primary objective was to determine maximum tolerated dose (MTD) and recommended dose of the combination. Secondary endpoints included overall response rate (ORR) and overall survival (OS). Exploratory objectives included correlation of clinical efficacy with tumor and peripheral immune population densities.

RESULTS

Overall, 33 patients were enrolled during dose escalation (n=3) and dose expansion (n=30). No dose-limiting toxicities were reported in the initial dose level. Ziv-aflibercept 4 mg/kg plus pembrolizumab 2 mg/kg every 2 weeks was established as the MTD. Grade ≥3 adverse events occurred in 19/33 patients (58%), the most common being hypertension (36%) and proteinuria (18%). ORR in the dose-expansion cohort was 16.7% (5/30, 90% CI 7% to 32%). Complete responses occurred in melanoma (n=2); partial responses occurred in RCC (n=1), mesothelioma (n=1), and melanoma (n=1). Median OS was as follows: melanoma, not reached (NR); RCC, 15.7 months (90% CI 2.5 to 15.7); CRC, 3.3 months (90% CI 0.6 to 3.4); ovarian, 12.5 months (90% CI 3.8 to 13.6); other solid tumors, NR. Activated tumor-infiltrating CD8 T cells at baseline (CD8+PD1+), high CD40L expression, and increased peripheral memory CD8 T cells correlated with clinical response.

CONCLUSION

The combination of ziv-aflibercept and pembrolizumab demonstrated an acceptable safety profile with antitumor activity in solid tumors. The combination is currently being studied in sarcoma and anti-PD-1-resistant melanoma.

TRIAL REGISTRATION NUMBER

NCT02298959.

c-MET/VEGFR-2 co-localisation impacts on survival following bevacizumab therapy in epithelial ovarian cancer: an exploratory biomarker study of the phase 3 ICON7 trial

INTRODUCTION

Bevacizumab improves survival outcomes in women diagnosed with epithelial ovarian cancer (EOC). Pre-clinical data showed that the c-MET/VEGFR-2 heterocomplex negates VEGF inhibition through activation of c-MET signalling, leading to a more invasive and metastatic phenotype. We evaluated the clinical significance of c-MET and VEGFR-2 co-localisation and its association with VEGF pathway-related single nucleotide polymorphisms (SNPs) in women participating in the phase 3 trial, ICON7 (ClinicalTrials.gov identifier: NCT00262847).

MATERIALS AND METHODS

Patients had FIGO stage I-IIA grade 3/poorly differentiated or clear cell carcinoma or stage IIB-IV epithelial ovarian, primary peritoneal or fallopian tube cancer. Immunofluorescence staining for co-localised c-MET and VEGFR-2 on tissue microarrays and genotyping of germline DNA from peripheral blood leukocytes for VEGFA and VEGFR-2 SNPs was performed. The significance of these biomarkers was assessed against survival.

RESULTS

Tissue microarrays from 178 women underwent immunofluorescence staining. Multivariable analysis showed that greater c-MET/VEGFR-2 co-localisation predicted worse OS in patients treated with bevacizumab after adjusting for FIGO stage and debulking surgery outcome (hazard ratio [HR] 1.034, 95% confidence interval [95%CI] 1.010-1.059). Women in the c-MET/VEGFR-2HIGH group treated with bevacizumab demonstrated significantly reduced OS (39.3 versus > 60 months; HR 2.00, 95%CI 1.08-3.72). Germline DNA from 449 women underwent genotyping. In the bevacizumab group, those women with the VEGFR-2 rs2305945 G/G variant had a trend towards shorter PFS compared with G/T or T/T variants (18.3 versus 23.0 months; HR 0.74, 95%CI 0.53-1.03).

CONCLUSIONS

In bevacizumab-treated women diagnosed with EOC, high c-MET/VEGFR-2 co-localisation on tumour tissue and the VEGFR-2 rs2305945 G/G variant, which may be biologically related, were associated with worse survival outcomes.

VEGF-A, VEGFR1 and VEGFR2 single nucleotide polymorphisms and outcomes from the AGITG MAX trial of capecitabine, bevacizumab and mitomycin C in metastatic colorectal cancer

The phase III MAX clinical trial randomised patients with metastatic colorectal cancer (mCRC) to receive first-line capecitabine chemotherapy alone or in combination with the anti-VEGF-A antibody bevacizumab (± mitomycin C). We utilised this cohort to examine whether single nucleotide polymorphisms (SNPs) in VEGF-A, VEGFR1, and VEGFR2 are predictive of efficacy outcomes with bevacizumab or the development of hypertension. Genomic DNA extracted from archival FFPE tissue for 325 patients (69% of the MAX trial population) was used to genotype 16 candidate SNPs in VEGF-A, VEGFR1, and VEGFR2, which were analysed for associations with efficacy outcomes and hypertension. The VEGF-A rs25648 ‘CC’ genotype was prognostic for improved PFS (HR 0.65, 95% CI 0.49 to 0.85; P = 0.002) and OS (HR 0.70, 95% CI 0.52 to 0.94; P = 0.019). The VEGF-A rs699947 ‘AA’ genotype was prognostic for shorter PFS (HR 1.32, 95% CI 1.002 to 1.74; P = 0.048). None of the analysed SNPs were predictive of bevacizumab efficacy outcomes. VEGFR2 rs11133360 ‘TT’ was associated with a lower risk of grade ≥ 3 hypertension (P = 0.028). SNPs in VEGF-A, VEGFR1 and VEGFR2 did not predict bevacizumab benefit. However, VEGF-A rs25648 and rs699947 were identified as novel prognostic biomarkers and VEGFR2 rs11133360 was associated with less grade ≥ 3 hypertension.

Prospective Exploratory Analysis of Angiogenic Biomarkers in Peripheral Blood in Advanced NSCLC Patients Treated With Bevacizumab Plus Chemotherapy: The ANGIOMET Study

Finding angiogenic prognostic markers in advanced non-small-cell lung cancer is still an unmet medical need. We explored a set of genetic variants in the VEGF-pathway as potential biomarkers to predict clinical outcomes of patients with non-small-cell lung cancer treated with chemotherapy plus bevacizumab. We prospectively analyzed the relationship between VEGF-pathway components with both pathological and prognostic variables in response to chemotherapy plus bevacizumab in 168 patients with non-squamous non-small-cell lung cancer. Circulating levels of VEGF and VEGFR2 and expression of specific endothelial surface markers and single-nucleotide polymorphisms in VEGF-pathway genes were analyzed. The primary clinical endpoint was progression-free survival. Secondary endpoints included overall survival and objective tumor response. VEGFR-1 rs9582036 variants AA/AC were associated with increased progression-free survival (p = 0.012 and p = 0.035, respectively), and with improved overall survival (p = 0.019) with respect to CC allele. Patients with VEGF-A rs3025039 harboring allele TT had also reduced mortality risk (p = 0.049) compared with the CC allele. The VEGF-A rs833061 variant was found to be related with response to treatment, with 61.1% of patients harboring the CC allele achieving partial treatment response. High pre-treatment circulating levels of VEGF-A were associated with shorter progression-free survival (p = 0.036). In conclusion, in this prospective study, genetic variants in VEGFR-1 and VEGF-A and plasma levels of VEGF-A were associated with clinical benefit, progression-free survival, or overall survival in a cohort of advanced non-squamous non-small-cell lung cancer patients receiving chemotherapy plus antiangiogenic therapy.

The Anti-VEGF(R) Drug Discovery Legacy: Improving Attrition Rates by Breaking the Vicious Cycle of Angiogenesis in Cancer

Resistance to anti-vascular endothelial growth factor (VEGF) molecules causes lack of response and disease recurrence. Acquired resistance develops as a result of genetic/epigenetic changes conferring to the cancer cells a drug resistant phenotype. In addition to tumor cells, tumor endothelial cells also undergo epigenetic modifications involved in resistance to anti-angiogenic therapies. The association of multiple anti-angiogenic molecules or a combination of anti-angiogenic drugs with other treatment regimens have been indicated as alternative therapeutic strategies to overcome resistance to anti-angiogenic therapies. Alternative mechanisms of tumor vasculature, including intussusceptive microvascular growth (IMG), vasculogenic mimicry, and vascular co-option, are involved in resistance to anti-angiogenic therapies. The crosstalk between angiogenesis and immune cells explains the efficacy of combining anti-angiogenic drugs with immune check-point inhibitors. Collectively, in order to increase clinical benefits and overcome resistance to anti-angiogenesis therapies, pan-omics profiling is key.

Rational Treatment of Metastatic Colorectal Cancer: A Reverse Tale of Men, Mice, and Culture Dishes

Stratification of colorectal cancer into subgroups with different response to therapy was initially guided by descriptive associations between specific biomarkers and treatment outcome. Recently, preclinical models based on propagatable patient-derived tumor samples have yielded an improved understanding of disease biology, which has facilitated the functional validation of correlative information and the discovery of novel response determinants, therapeutic targets, and mechanisms of tumor adaptation and drug resistance. We review the contribution of patient-derived models to advancing colorectal cancer characterization, discuss their influence on clinical decision-making, and highlight emerging challenges in the interpretation and clinical transferability of results obtainable with such approaches. SIGNIFICANCE: Association studies in patients with colorectal cancer have led to the identification of response biomarkers, some of which have been implemented as companion diagnostics for therapeutic decisions. By enabling biological investigation in a clinically relevant experimental context, patient-derived colorectal cancer models have proved useful to examine the causal role of such biomarkers in dictating drug sensitivity and are providing fresh knowledge on new actionable targets, dynamics of tumor evolution and adaptation, and mechanisms of drug resistance.

Biomarkers Associated with Regorafenib First-Line Treatment Benefits in Metastatic Colorectal Cancer Patients: REFRAME Molecular Study

Simple Summary

Biomarkers able to predict response and toxicity upon regorafenib therapy for colorectal cancer (CRC) are critical for treatment choice, particularly relevant in fragile patients. Here, we validated for the first time 18 distinct microRNAs (miRNAs) detected in serum and primary tumor samples, three germline single-nucleotide polymorphisms (SNPs) in vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor (VEGFR) genes, and low levels of Notch 1 expression in the primary tumor as predictive biomarkers of different features. Specifically, these markers were associated with a favorable response to treatment, disease stage, and relapse, as well as the appearance of asthenia. Therefore, these markers can be potentially useful biomarkers for patient stratification and for providing a more personalized and effective therapeutic strategy in fragile patients, while limiting the appearance of adverse effects.

Abstract

First-line treatment with regorafenib in frail metastatic colorectal cancer (mCRC) patients has shown some benefit. To accurately identify such patients before treatment, we studied blood biomarkers and primary tumor molecules. We unveiled serum microRNAs (miRNAs), single-nucleotide polymorphisms (SNPs) in angiogenic-related genes, and Notch 1 expression as biomarkers associated with response or toxicity. MicroRNA array profiling and genotyping of selected SNPs were performed in the blood of fragile mCRC patients treated with regorafenib. Notch 1 and CRC-associated miRNA expression was also analyzed in tumors. High levels of miR-185-5p in serum, rs7993418 in the vascular endothelial growth factor receptor 1 (VEGFR1) gene, and Notch 1 expression in biopsies were associated with a favorable response to treatment. Serum levels of miR-126-3p and miR-152-3p and tumor expression of miR-92a-1-5p were associated with treatment toxicity, particularly interesting in patients exhibiting comorbidities, and high levels of miR-362-3p were associated with asthenia. Additionally, several miRNAs were associated with the presence of metastasis, local recurrence, and peritoneal metastasis. Besides, miRNAs determined in primary tumors were associated with tumor-node-metastasis (TNM) staging. The rs2305948 and rs699947 SNPs in VEGFR2 and VEGFA, respectively, were markers of poor prognosis correlating with locoregional relapse, a higher N stage, and metastatic shedding. In conclusion, VEGF and VEGFR SNPs, miRNAs, and Notch 1 levels are potential useful biomarkers for the management of advanced CRC under regorafenib treatment.

Bevacizumab as First-line Treatment for HER2-negative Advanced Breast Cancer: Paclitaxel plus Bevacizumab Versus Other Chemotherapy

BACKGROUND

The efficacy of paclitaxel and bevacizumab (PB) compared with other chemotherapies in patients with human epidermal growth factor receptor 2-negative (HER2^-) advanced breast cancer is unclear.

PATIENTS AND METHODS

We retrospectively investigated 301 patients with HER2^- ABC who received first-line chemotherapy from January 2011 to December 2016.

RESULTS

We included 114 patients who received PB and 187 patients who received other chemotherapies. After propensity score matching, the PB group showed a significantly superior overall response rate (77.8% vs. 38.9%, p<0.0001) and median time to treatment failure (7.3 vs. 5.9 months, p=0.035). In subgroup analyses, PB improved the median overall survival of patients with pleural lesions or pulmonary lymphangiopathy (not reached vs. 18.9 months, p=0.037), and of patients with three or more metastatic sites without liver metastases, (48.0 vs. 27.3 months, p=0.015).

CONCLUSION

Compared with conventional chemotherapy, PB improved the overall response rate and time to treatment failure in patients with HER2^- advanced breast cancer and improved overall survival in some patient subgroups.

Decorin expression is associated with predictive diffusion MR phenotypes of anti-VEGF efficacy in glioblastoma

Previous data suggest that apparent diffusion coefficient (ADC) imaging phenotypes predict survival response to anti-VEGF monotherapy in glioblastoma. However, the mechanism by which imaging may predict clinical response is unknown. We hypothesize that decorin (DCN), a proteoglycan implicated in the modulation of the extracellular microenvironment and sequestration of pro-angiogenic signaling, may connect ADC phenotypes to survival benefit to anti-VEGF therapy. Patients undergoing resection for glioblastoma as well as patients included in The Cancer Genome Atlas (TCGA) and IVY Glioblastoma Atlas Project (IVY GAP) databases had pre-operative imaging analyzed to calculate pre-operative ADC_L values, the average ADC in the lower distribution using a double Gaussian mixed model. ADC_L values were correlated to available RNA expression from these databases as well as from RNA sequencing from patient derived mouse orthotopic xenograft samples. Targeted biopsies were selected based on ADC values and prospectively collected during resection. Surgical specimens were used to evaluate for DCN RNA and protein expression by ADC value. The IVY Glioblastoma Atlas Project Database was used to evaluate DCN localization and relationship with VEGF pathway via in situ hybridization maps and RNA sequencing data. In a cohort of 35 patients with pre-operative ADC imaging and surgical specimens, DCN RNA expression levels were significantly larger in high ADC_L tumors (41.6 vs. 1.5; P = 0.0081). In a cohort of 17 patients with prospectively targeted biopsies there was a positive linear correlation between ADC_L levels and DCN protein expression between tumors (Pearson R² = 0.3977; P = 0.0066) and when evaluating different targets within the same tumor (Pearson R² = 0.3068; P = 0.0139). In situ hybridization data localized DCN expression to areas of microvascular proliferation and immunohistochemical studies localized DCN protein expression to the tunica adventitia of blood vessels within the tumor. DCN expression positively correlated with VEGFR1 & 2 expression and localized to similar areas of tumor. Increased ADC_L on diffusion MR imaging is associated with high DCN expression as well as increased survival with anti-VEGF therapy in glioblastoma. DCN may play an important role linking the imaging features on diffusion MR and anti-VEGF treatment efficacy. DCN may serve as a target for further investigation and modulation of anti-angiogenic therapy in GBM.

Pharmacogenomics, Pharmacokinetics and Circulating Proteins as Biomarkers for Bevacizumab Treatment Optimization in Patients with Cancer: A Review

Bevacizumab is a monoclonal antibody that targets VEGF-A and inhibits tumor angiogenesis. Bevacizumab is approved for the treatment of various cancer, including metastatic colorectal cancer (mCRC), ovarian cancer, lung cancer, and others. Thus, it is widely used in oncology, but contrary to other therapeutic classes, there is still a lack of validating predictive factors for treatment outcomes with these agents. In recent years, the research for factors predictive of anti-VEGF treatments and especially bevacizumab response has been one of the most competitive translational research fields. Herein, we review and present the available literature of the clinical use of biomarkers, pharmacogenomics (PG), and therapeutic drug monitoring (TDM) approaches that can be used for the optimization of bevacizumab use in the era of precision medicine.

Combination of variations in inflammation- and endoplasmic reticulum-associated genes as putative biomarker for bevacizumab response in KRAS wild-type colorectal cancer

Chemotherapy combined with the angiogenesis inhibitor bevacizumab (BVZ) is approved as a first-line treatment in metastatic colorectal cancer (mCRC). Limited clinical benefit underpins the need for improved understanding of resistance mechanisms and the elucidation of novel predictive biomarkers. We assessed germline single-nucleotide polymorphisms (SNPs) in 180 mCRC patients (Angiopredict [APD] cohort) treated with combined BVZ + chemotherapy and investigated previously reported predictive SNPs. We further employed a machine learning approach to identify novel associations. In the APD cohort IL8 rs4073 any A carriers, compared to TT carriers, were associated with worse progression-free survival (PFS) (HR = 1.51, 95% CI:1.03-2.22, p-value = 0.037) and TBK1 rs7486100 TT carriers, compared to any A carriers, were associated with worse PFS in KRAS wild-type (wt) patients (HR = 1.94, 95% CI:1.04-3.61, p-value = 0.037), replicating previous findings. Machine learning identified novel associations in genes encoding the inflammasome protein NLRP1 and the ER protein Sarcalumenin (SRL). A negative association between PFS and carriers of any A at NLRP1 rs12150220 and AA for SRL rs13334970 in APD KRAS wild-type patients (HR = 4.44, 95% CI:1.23-16.13, p-value = 0.005), which validated in two independent clinical cohorts involving BVZ, MAVERICC and TRIBE. Our findings highlight a key role for inflammation and ER signalling underpinning BVZ + chemotherapy responsiveness.

[18F]Fluciclatide PET as a biomarker of response to combination therapy of pazopanib and paclitaxel in platinum-resistant/refractory ovarian cancer

BACKGROUND

Angiogenesis is a driver of platinum resistance in ovarian cancer. We assessed the effect of combination pazopanib and paclitaxel followed by maintenance pazopanib in patients with platinum-resistant/refractory ovarian cancer. Integrins αvβ3 and αvβ5 are both upregulated in tumor-associated vasculature. [18F]Fluciclatide is a novel PET tracer that has high affinity for integrins αvβ3/5, and was used to assess the anti-angiogenic effect of pazopanib.

PATIENTS AND METHODS

We conducted an open-label, phase Ib study in patients with platinum-resistant/refractory ovarian cancer. Patients received 1 week of single-agent pazopanib (800 mg daily) followed by combination therapy with weekly paclitaxel (80 mg/m2). Following completion of 18 weeks of combination therapy, patients continued with single-agent pazopanib until disease progression. Dynamic [18F]fluciclatide-PET imaging was conducted at baseline and after 1 week of pazopanib. Response (RECIST 1.1), toxicities, and survival outcomes were recorded. Circulating markers of angiogenesis were assessed with therapy.

RESULTS

Fourteen patients were included in the intention-to-treat analysis. Complete and partial responses were seen in seven patients (54%). Median progression-free survival (PFS) was 10.63 months, and overall survival (OS) was 18.5 months. Baseline [18F]fluciclatide uptake was predictive of long PFS. Elevated baseline circulating angiopoietin and fibroblast growth factor (FGF) were predictive of greater reduction in SUV60,mean following pazopanib. Kinetic modeling of PET data indicated a reduction in K1 and Ki following pazopanib indicating reduced radioligand delivery and retention.

CONCLUSIONS

Combination therapy followed by maintenance pazopanib is effective and tolerable in platinum-resistant/refractory ovarian cancer. [18F]Fluciclatide-PET uptake parameters predict clinical outcome with pazopanib therapy indicating an anti-angiogenic response.

Genetic biomarkers in the VEGF pathway predicting response to anti-VEGF therapy in age-related macular degeneration

Objective

Age-related macular degeneration (ARMD) is a leading cause of visual impairment. Intravitreal injections of anti-vascular endothelial growth factor (VEGF) are the standard treatment for wet ARMD. There is however, variability in patient responses, suggesting patient-specific factors influencing drug efficacy. We tested whether single nucleotide polymorphisms (SNPs) in genes encoding VEGF pathway members contribute to therapy response.

Methods and analysis

A retrospective cohort of 281 European wet ARMD patients treated with anti-VEGF was genotyped for 138 tagging SNPs in the VEGF pathway. Per patient, we collected best corrected visual acuity at baseline, after three loading injections and at 12 months. We also registered the injection number and changes in retinal morphology after three loading injections (central foveal thickness (CFT), intraretinal cysts and serous neuroepithelium detachment). Changes in CFT after 3 months were our primary outcome measure. Association of SNPs to response was assessed by binomial logistic regression. Replication was attempted by associating visual acuity changes to genotypes in an independent Japanese cohort.

Results

Association with treatment response was detected for seven SNPs, including in FLT4 (rs55667289: OR=0.746, 95% CI 0.63 to 0.88, p=0.0005) and KDR (rs7691507: OR=1.056, 95% CI 1.02 to 1.10, p=0.005; and rs2305945: OR=0.963, 95% CI 0.93 to 1.00, p=0.0472). Only association with rs55667289 in FLT4 survived multiple testing correction. This SNP was unavailable for testing in the replication cohort. Of six SNPs tested for replication, one was significant although not after multiple testing correction.

Conclusion

Identifying genetic variants that define treatment response can help to develop individualised therapeutic approaches for wet ARMD patients and may point towards new targets in non-responders.

Therapeutic Targeting of the Colorectal Tumor Stroma

Colorectal tumors have been classified based on histologic factors, genetic factors, and consensus molecular subtypes, all of which affect the tumor microenvironment. Elements of the tumor microenvironment serve as therapeutic targets and might be used as prognostic factors. For example, immune checkpoint inhibitors are used to treat tumors with microsatellite instability, and anti-angiogenic agents may be used in combination with other drugs to slow or inhibit tumor growth. We review the features of the colorectal tumor stroma that are associated with patient outcomes and discuss potential therapeutic agents that target these features.

Role of VEGFR-1 in melanoma acquired resistance to the BRAF inhibitor vemurafenib

The vascular endothelial growth factor receptor‐1 (VEGFR‐1) is a tyrosine kinase receptor frequently expressed in melanoma. Its activation by VEGF‐A or placental growth factor (PlGF) promotes tumour cell survival, migration and invasiveness. Moreover, VEGFR‐1 stimulation contributes to pathological angiogenesis and induces recruitment of tumour‐associated macrophages. Since melanoma acquired resistance to BRAF inhibitors (BRAFi) has been associated with activation of pro‐angiogenic pathways, we have investigated VEGFR‐1 involvement in vemurafenib resistance. Results indicate that human melanoma cells rendered resistant to vemurafenib secrete greater amounts of VEGF‐A and express higher VEGFR‐1 levels compared with their BRAFi‐sensitive counterparts. Transient VEGFR‐1 silencing in susceptible melanoma cells delays resistance development, whereas in resistant cells it increases sensitivity to the BRAFi. Consistently, enforced VEGFR‐1 expression, by stable gene transfection in receptor‐negative melanoma cells, markedly reduces sensitivity to vemurafenib. Moreover, melanoma cells expressing VEGFR‐1 are more invasive than VEGFR‐1 deficient cells and receptor blockade by a specific monoclonal antibody (D16F7 mAb) reduces extracellular matrix invasion triggered by VEGF‐A and PlGF. These data suggest that VEGFR‐1 up‐regulation might contribute to melanoma progression and spreading after acquisition of a drug‐resistant phenotype. Thus, VEGFR‐1 inhibition with D16F7 mAb might be a suitable adjunct therapy for VEGFR‐1 positive tumours with acquired resistance to vemurafenib.

Genetic interaction between placental growth factor and vascular endothelial growth factor A in psoriasis

Background

Expression of vascular endothelial growth factor A (VEGFA) is increased in chronic inflammatory skin diseases, including psoriasis, and loci for two VEGFA single nucleotide polymorphisms are associated with early‐onset psoriasis (presenting before the age of 40 years). Studies have suggested that expression of placenta growth factor (PGF) is also upregulated in cutaneous inflammation and that VEGFA‐mediated angiogenesis may be dependent on the simultaneous presence of PGF within the skin.

Aim

To elucidate the biological importance of PGF in psoriasis.

Methods

We investigated whether two commonly occurring PGF polymorphisms were associated with early‐onset psoriasis and the genetic interaction between VEGFA and PGF in psoriasis.

Results

We observed a significant (P = 0.04) association between rs2268614 TT and rs2268615 AA genotypes of PGF and early‐onset psoriasis. In addition, genetic complement, comprising the PGF rs2268615 AA genotype and the VEGFA −460 (rs833061) T allele, was significantly associated with the development of early‐onset psoriasis (P < 0.03). We identified that the VEGFA genotype influences PGF expression (P = 0.001) and that mean plasma levels of PGF are lower in patients with severe psoriasis compared with those with mild–moderate disease (P = 0.04).

Conclusion

Our observed genetic interaction between PGF and VEGFA appears relevant to psoriasis, a disease with an angiogenic basis, and may influence development of an antiangiogenic approach to treatment.

Pharmacogenomic analyses of sunitinib in patients with pancreatic neuroendocrine tumors

Aim: Evaluate associations between clinical outcomes and SNPs in patients with well-differentiated pancreatic neuroendocrine tumors receiving sunitinib. Patients & methods: Kaplan–Meier and Cox proportional hazards models were used to analyze the association between SNPs and survival outcomes using data from a sunitinib Phase IV (genotyped, n = 56) study. Fisher’s exact test was used to analyze objective response rate and genotype associations. Results: After multiplicity adjustment, progression-free and overall survivals were not significantly correlated with SNPs; however, a higher objective response rate was significantly associated with IL1B rs16944 G/A versus G/G (46.4 vs 4.5%; p = 0.001). Conclusion: IL1B SNPs may predict treatment response in patients with pancreatic neuroendocrine tumors. VEGF pathway SNPs are potentially associated with survival outcomes.

Ramucirumab: the long and winding road toward being an option for mCRC treatment

INTRODUCTION

Colorectal cancer (CRC) is one of the main causes of cancer-related morbidity and mortality worldwide. Mortality is most often attributable to metastatic disease. Despite the progress achieved so far, life expectancy continues to be limited in most patients. Ramucirumab, a most recent antiangiogenic drug, is vying in the race to metastatic CRC (mCRC) treatment since its approval by the Food and Drug Administration (FDA), based on the results of the RAISE study.

AREAS COVERED

This article reviews the role of ramucirumab in mCRC, including clinical indication, safety issues, and future perspectives.

EXPERT OPINION

The use of Ramucirumab in clinical practice is still limited, probably due to economic burden and the lack of specific biomarkers. Future efforts will be addressed to improve our knowledge in the use of this drug and better guide us in patients' care.

Evaluation of soluble carbonic anhydrase IX as predictive marker for efficacy of bevacizumab: A biomarker analysis from the geparquinto phase III neoadjuvant breast cancer trial

We analyzed the predictive potential of pretreatment soluble carbonic anhydrase IX levels (sCAIX) for the efficacy of bevacizumab in the phase III neoadjuvant GeparQuinto trial. sCAIX was determined by enzyme-linked immunosorbent assay (ELISA). Correlations between sCAIX and pathological complete response (pCR), disease-free and overall survival (DFS, OS) were assessed with logistic and Cox proportional hazard regression models using bootstrapping for robust estimates and internal validation. 1,160 HER2-negative patient sera were analyzed, of whom 577 received bevacizumab. Patients with low pretreatment sCAIX had decreased pCR rates (12.1 vs. 20.1%, p = 0.012) and poorer DFS (adjusted 5-year DFS 71.4 vs. 80.5 months, p = 0.010) compared to patients with high sCAIX when treated with neoadjuvant chemotherapy (NCT). For patients with low sCAIX, pCR rates significantly improved upon addition of bevacizumab to NCT (12.1 vs. 20.4%; p = 0.017), which was not the case in patients with high sCAIX (20.1% for NCT vs. 17.0% for NCT-B, p = 0.913). When analyzing DFS we found that bevacizumab improved 5-year DFS for patients with low sCAIX numerically but not significantly (71.4 vs. 78.5 months; log rank 0.234). In contrast, addition of bevacizumab worsened 5-year DFS for patients with high sCAIX (81 vs. 73.6 months, log-rank 0.025). By assessing sCAIX levels we identified a patient cohort in breast cancer that is potentially undertreated with NCT alone. Bevacizumab improved pCR rates in this group, suggesting sCAIX is a predictive biomarker for bevacizumab with regards to treatment response. Our data also show that bevacizumab is not beneficial in patients with high sCAIX.

Bevacizumab in the neoadjuvant treatment of human epidermal growth factor receptor 2-negative breast cancer: A meta-analysis of randomized controlled trials

Several randomized clinical trials have suggested the effectiveness of bevacizumab (Bev) in early and advanced breast cancer; however, due to the increased toxicity and lack of a clear long-term survival benefit, there is currently no defined role for Bev in breast cancer in the USA, while it has been approved in Europe. We herein sought to conduct a meta-analysis of large randomized trials comparing the efficacy and long-term outcome of neoadjuvant chemotherapy with Bev compared with chemotherapy without Bev in human epidermal factor receptor 2 (HER2)-negative breast cancer. A search was conducted through PubMed and Ovid Medline databases. Among the 279 articles identified, 5 met the eligibility criteria and were included in the present analysis. A total of 2,268 patients treated with Bev and 2,278 treated without Bev were analyzed. Pathological complete response (pCR) was obtained in 35% of patients treated with Bev and in 26% of those treated without Bev. A statistically significant increase (26%) in the incidence of pCR was observed in the Bev-treated group. However, patients treated with Bev exhibited no significant difference in the risk of disease recurrence or death. To the best of our knowledge, this is the first meta-analysis addressing the long-term outcomes of Bev in combination with chemotherapy in the neoadjuvant treatment of HER2-negative breast cancer. The results confirmed the significant benefit of Bev combined with chemotherapy compared with chemotherapy alone on breast cancer response, in both triple-negative and hormone receptor-positive cases. However, this benefit does not translate into a long-term disease-free or definitive overall survival advantage. Optimizing patient selection is desirable for maximizing the long-term benefits of Bev, while reducing cost and treatment-related adverse effects. Future efforts directed toward the discovery of predictive markers would be crucial for identifying the subset(s) of breast cancer patients who are most likely to benefit from Bev therapy.

Regulation of Blood and Lymphatic Vessels by Immune Cells in Tumors and Metastasis

Research over the last decades has provided strong evidence for the pivotal role of the tumor-associated blood and lymphatic vasculature in supporting immunoevasion and in subverting T cell-mediated immunosurveillance. Conversely, tumor blood and lymphatic vessel growth is in part regulated by the immune system, with infiltrating innate as well as adaptive immune cells providing both immunosuppressive and various angiogenic signals. Thus, tumor angiogenesis and escape of immunosurveillance are two cancer hallmarks that are tightly linked and interregulated by cell constituents from compartments secreting both chemokines and cytokines. In this review, we discuss the implication and regulation of innate and adaptive immune cells in regulating blood and lymphatic angiogenesis in tumor progression and metastases. Moreover, we also highlight novel therapeutic approaches that target the tumor vasculature as well as the immune compartment to sustain and improve therapeutic efficacy in cancer.

Predictive genomic markers of response to VEGF targeted therapy in metastatic renal cell carcinoma

Background

First-line treatment for metastatic renal cell carcinoma (mRCC) is rapidly changing. It currently includes VEGF targeted therapies (TT), multi-target tyrosine kinase inhibitors (TKIs), mTOR inhibitors, and immunotherapy. To optimize outcomes for individual patients, genomic markers of response to therapy are needed. Here, we aim to identify tumor-based genomic markers of response to VEGF TT to optimize treatment selection.

Methods

From an institutional database, primary tumor tissue was obtained from 79 patients with clear cell mRCC, and targeted sequencing was performed. Clinical outcomes were obtained retrospectively. Progression-free survival (PFS) on first-line VEGF TT was correlated to genomic alterations (GAs) using Kaplan-Meier methodology and Cox proportional hazard models. A composite model of significant GAs predicting PFS in the first-line setting was developed.

Results

Absence of VHL mutation was associated with inferior PFS on first-line VEGF TT. A trend for inferior PFS was observed with GAs in TP53 and FLT1 C/C variant. A composite model of these 3 GAs was associated with inferior PFS in a dose-dependent manner.

Conclusion

In mRCC, a composite model of TP53 mutation, wild type VHL, and FLT1 C/C variant strongly predicted PFS on first-line VEGF TT in a dose-dependent manner. These findings require external validation.

Copy number load predicts outcome of metastatic colorectal cancer patients receiving bevacizumab combination therapy

Increased copy number alterations (CNAs) indicative of chromosomal instability (CIN) have been associated with poor cancer outcome. Here, we study CNAs as potential biomarkers of bevacizumab (BVZ) response in metastatic colorectal cancer (mCRC). We cluster 409 mCRCs in three subclusters characterized by different degrees of CIN. Tumors belonging to intermediate-to-high instability clusters have improved outcome following chemotherapy plus BVZ versus chemotherapy alone. In contrast, low instability tumors, which amongst others consist of POLE-mutated and microsatellite-instable tumors, derive no further benefit from BVZ. This is confirmed in 81 mCRC tumors from the phase 2 MoMa study involving BVZ. CNA clusters overlap with CRC consensus molecular subtypes (CMS); CMS2/4 xenografts correspond to intermediate-to-high instability clusters and respond to FOLFOX chemotherapy plus mouse avastin (B20), while CMS1/3 xenografts match with low instability clusters and fail to respond. Overall, we identify copy number load as a novel potential predictive biomarker of BVZ combination therapy.

Increased copy number alterations, indicative of chromosomal instability, is associated with poor cancer outcome. Here, metastatic colorectal cancer patients displaying intermediate-high CIN associate with improved outcome following chemotherapy and bevacizumab treatment, suggesting CIN as a predictive biomarker.

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.

Pharmacodynamic and Pharmacokinetic Markers For Anti-angiogenic Cancer Therapy: Implications for Dosing and Selection of Patients

Angiogenesis is integral to tumour growth and invasion, and is a key target for cancer therapeutics. However, for many of the licensed indications, only a modest clinical benefit has been observed for both monoclonal antibody and small-molecule tyrosine kinase inhibitor anti-angiogenic therapy. Pre-clinical and clinical studies have attempted to evaluate circulating, imaging, genomic, pharmacokinetic, and pharmacodynamic markers that may aid both the selection of patients for treatment and define dosing. Correct dosing is likely to be critical in the context of vascular normalization to allow better delivery of concomitant anti-cancer therapy and novel imaging techniques hold much promise in the early evaluation of pharmacodynamic response to improve efficacy.

Exome Sequencing of Plasma DNA Portrays the Mutation Landscape of Colorectal Cancer and Discovers Mutated VEGFR2 Receptors as Modulators of Antiangiogenic Therapies

Purpose: Despite the wide use of antiangiogenic drugs in the clinical setting, predictive biomarkers of response to these drugs are still unknown.Experimental Design: We applied whole-exome sequencing of matched germline and basal plasma cell-free DNA samples (WES-cfDNA) on a RAS/BRAF/PIK3CA wild-type metastatic colorectal cancer patient with primary resistance to standard treatment regimens, including inhibitors to the VEGF:VEGFR2 pathway. We performed extensive functional experiments, including ectopic expression of VEGFR2 mutants in different cell lines, kinase and drug sensitivity assays, and cell- and patient-derived xenografts.Results: WES-cfDNA yielded a 77% concordance rate with tumor exome sequencing and enabled the identification of the KDR/VEGFR2 L840F clonal, somatic mutation as the cause of therapy refractoriness in our patient. In addition, we found that 1% to 3% of samples from cancer sequencing projects harbor KDR somatic mutations located in protein residues frequently mutated in other cancer-relevant kinases, such as EGFR, ABL1, and ALK. Our in vitro and in vivo functional assays confirmed that L840F causes strong resistance to antiangiogenic drugs, whereas the KDR hot-spot mutant R1032Q confers sensitivity to strong VEGFR2 inhibitors. Moreover, we showed that the D717V, G800D, G800R, L840F, G843D, S925F, R1022Q, R1032Q, and S1100F VEGFR2 mutants promote tumor growth in mice.Conclusions: Our study supports WES-cfDNA as a powerful platform for portraying the somatic mutation landscape of cancer and discovery of new resistance mechanisms to cancer therapies. Importantly, we discovered that VEGFR2 is somatically mutated across tumor types and that VEGFR2 mutants can be oncogenic and control sensitivity/resistance to antiangiogenic drugs. Clin Cancer Res; 24(15); 3550-9. ©2018 AACR.

Antitumor activity of a novel anti-vascular endothelial growth factor receptor-1 monoclonal antibody that does not interfere with ligand binding

Vascular endothelial growth factor receptor-1 (VEGFR-1) is a tyrosine kinase transmembrane receptor that has also a soluble isoform containing most of the extracellular ligand binding domain (sVEGFR-1). VEGF-A binds to both VEGFR-2 and VEGFR-1, whereas placenta growth factor (PlGF) interacts exclusively with VEGFR-1. In this study we generated an anti-VEGFR-1 mAb (D16F7) by immunizing BALB/C mice with a peptide that we had previously reported to inhibit angiogenesis and endothelial cell migration induced by PlGF. D16F7 did not affect binding of VEGF-A or PlGF to VEGFR-1, thus allowing sVEGFR-1 to act as decoy receptor for these growth factors, but it hampered receptor homodimerization and activation. D16F7 inhibited both the chemotactic response of human endothelial, myelomonocytic and melanoma cells to VEGFR-1 ligands and vasculogenic mimicry by tumor cells. Moreover, D16F7 exerted in vivo antiangiogenic effects in a matrigel plug assay. Importantly, D16F7 inhibited tumor growth and was well tolerated by B6D2F1 mice injected with syngeneic B16F10 melanoma cells. The antitumor effect was associated with melanoma cell apoptosis, vascular abnormalities and decrease of both monocyte/macrophage infiltration and myeloid progenitor mobilization. For all the above, D16F7 may be exploited in the therapy of metastatic melanoma and other tumors or pathological conditions involving VEGFR-1 activation.

Therapy for Cancer: Strategy of Combining Anti-Angiogenic and Target Therapies

The concept that blood supply is required and necessary for cancer growth and spreading is intuitive and was firstly formalized by Judah Folkman in 1971, when he demonstrated that cancer cells release molecules able to promote the proliferation of endothelial cells and the formation of new vessels. This seminal result has initiated one of the most fascinating story of the medicine, which is offering a window of opportunity for cancer treatment based on the use of molecules inhibiting tumor angiogenesis and in particular vascular-endothelial growth factor (VEGF), which is the master gene in vasculature formation and is the commonest target of anti-angiogenic regimens. However, the clinical results are far from the remarkable successes obtained in pre-clinical models. The reasons of this discrepancy have been partially understood and well addressed in many reviews (Bergers and Hanahan, 2008; Bottsford-Miller et al., 2012; El-Kenawi and El-Remessy, 2013; Wang et al., 2015; Jayson et al., 2016). At present anti-angiogenic regimens are not used as single treatments but associated with standard chemotherapies. Based on emerging knowledge of the biology of VEGF, here we sustain the hypothesis of the efficacy of a dual approach based on targeting pro-angiogenic pathways and other druggable targets such as mutated oncogenes or the immune system.

Vandetanib plus gemcitabine versus placebo plus gemcitabine in locally advanced or metastatic pancreatic carcinoma (ViP): a prospective, randomised, double-blind, multicentre phase 2 trial

BACKGROUND

Erlotinib is an EGFR tyrosine kinase inhibitor that has shown a significant but only marginally improved median overall survival when combined with gemcitabine in patients with locally advanced and metastatic pancreatic cancer. Vandetanib is a novel tyrosine kinase inhibitor of VEGFR2, RET, and EGFR, all of which are in involved in the pathogenesis of pancreatic cancer. We investigated the clinical efficacy of vandetanib when used in combination with gemcitabine in patients with advanced pancreatic cancer.

METHODS

The Vandetanib in Pancreatic Cancer (ViP) trial was a phase 2 double-blind, multicentre, randomised placebo-controlled trial in previously untreated adult patients (aged ≥18 years) diagnosed with locally advanced or metastatic carcinoma of the pancreas confirmed by cytology or histology. Patients had to have an Eastern Cooperative Oncology Group (ECOG) score of 0-2 and a documented life expectancy of at least 3 months. Patients were randomly assigned 1:1 to receive vandetanib plus gemcitabine (vandetanib group) or placebo plus gemcitabine (placebo group) according to pre-generated sequences produced on the principle of randomly permuted blocks with variable block sizes of two and four. Patients were stratified at randomisation by disease stage and ECOG performance status. All patients received gemcitabine 1000 mg/m2 as a 30-min intravenous infusion, weekly, for 7 weeks followed by a 1-week break, followed by a cycle of 3 weeks of treatment with a 1-week break, until disease progression, and either oral vandetanib 300 mg per day once daily or matching placebo. Patients and investigators were masked to treatment assignment. The primary outcome measure was overall survival (defined as the difference in time between randomisation and death from any cause or the censor date) in the intention-to-treat population. This trial has been completed and the final results are reported. The study is registered at EudraCT, number 2007-004299-38, and ISRCTN, number ISRCTN96397434.

FINDINGS

Patients were screened and enrolled between Oct 24, 2011, and Oct 7, 2013. Of 381 patients screened, 142 eligible patients were randomly assigned to treatment (72 to the vandetanib group and 70 to the placebo group). At database lock on July 15, 2015, at a median follow-up of 24·9 months (IQR 24·3 to not attainable), 131 patients had died: 70 (97%) of 72 in the vandetanib group and 61 (87%) of 70 in the placebo group. The median overall survival was 8·83 months (95% CI 7·11-11·58) in the vandetanib group and 8·95 months (6·55-11·74) in the placebo group (hazard ratio 1·21, 80·8% CI 0·95-1·53; log rank χ21df 1·1, p=0·303). The most common grade 3-4 adverse events were neutropenia (35 [49%] of 72 patients in the vandetanib group vs 22 [31%] of 70 in the placebo group), thrombocytopenia (20 [28%] vs 16 [23%]), hypertension (nine [13%] vs 11 [16%]), leucopenia (12 [17%] vs 13 [19%]), and fatigue (17 [24%] vs 15 [21%]). No treatment-related deaths occurred during the study.

INTERPRETATION

The addition of vandetanib to gemcitabine monotherapy did not improve overall survival in advanced pancreatic cancer. Tyrosine kinase inhibitors might still have potential in the treatment of pancreatic cancer but further development requires the identification of biomarkers to specifically identify responsive cancer subtypes.

FUNDING

Cancer Research UK and AstraZeneca.

Biology and therapeutic implications of VEGF-A splice isoforms and single-nucleotide polymorphisms in colorectal cancer

Tumor growth, dissemination and metastasis are dependent on angiogenesis. The predominant vascular endothelial growth factor (VEGF) isoform that plays a major role in angiogenesis is VEGF-A. Indeed, VEGF-A is implicated in promoting angiogenesis of numerous solid malignancies, including colorectal cancer (CRC). A large body of preclinical and clinical evidence indicates that the expression of specific VEGF-A isoforms represents a predominant pro-angiogenic factor, which is associated with formation of metastases and poor prognosis in CRC patients. Different isoforms of human VEGF-A have been identified, all of which arise from alternative splicing of the primary transcript of a single gene. Notably, it has been recently demonstrated that expression of type 3 isoform pattern is significantly correlated with venous involvement in CRC as well as in progression to metastatic colorectal cancer (mCRC), although it remains unclear what proportion of CRC tumors express these isoforms. This review highlights the importance of investigating the genetic and the epigenetic variations in VEGF-A pathways in CRC, the functions of different VEGF-A isoforms and their potential application as prognostic markers and/or therapeutic targets. Better understanding of the mechanisms controlling angiogenesis in liver metastases is necessary to address the limitations of current anti-angiogenic therapies.

The Effect of FLT1 Variant on Long-Term Cardiovascular Outcomes: Validation of a Locus Identified in a Previous Genome-Wide Association Study

Background

Data on genetic variants that can predict follow-up cardiovascular events are highly limited, particularly for Asians. The aim of this study was to validate the effects of two variants in FLT1 and 9p21 on long-term cardiovascular outcomes in high-risk Korean patients.

Methods

We examined the prognostic values of the rs9508025 and rs1333049 variants that were found to be associated with coronary artery disease (CAD) risk in a previous Korean genome-wide association study. A total of 2693 patients (mean age: 55.2 years; male: 55.2%) with CAD or its risk factors at baseline were enrolled and followed for major adverse cardiac events (MACE).

Results

During the mean follow-up of 8.8 years, 15.4% of the patients experienced MACE. Kaplan-Meier curves showed that MACE-free survival was different according to the genotype of rs9508025 (log rank p = 0.02), whereas rs1333049 genotype did not correlate with the prognosis. Multivariate Cox proportional hazard analysis showed that C-allele of rs9508025 was significantly associated with a high rate of MACE, while rs1333049 was not. Further analyses demonstrated that the association of the rs9508025 variant with MACE was mainly due to its relation to coronary revascularization, which was also associated with the rs1333049 variant. In an additional analysis, rs9508025 was found to be an independent determinant of the outcome only in the subgroup with history of CAD.

Conclusions

rs9508025 in FLT1 was significantly associated with long-term cardiovascular events, particularly in patients with prior CAD. The association of rs1333049 in 9p21 was not significant.

A functional bioassay to determine the activity of anti-VEGF antibody therapy in blood of patients with cancer

Background:

Only a small proportion of patients respond to anti-VEGF therapy, pressing the need for a reliable biomarker that can identify patients who will benefit. We studied the biological activity of anti-VEGF antibodies in patients' blood during anti-VEGF therapy by using the Ba/F3-VEGFR2 cell line, which is dependent on VEGF for its growth.

Methods:

Serum samples from 22 patients with cancer before and during treatment with bevacizumab were tested for their effect on proliferation of Ba/F3-VEGFR2 cells. Vascular endothelial growth factor as well as bevacizumab concentrations in serum samples from these patients were determined by enzyme linked immunosorbent assay (ELISA).

Results:

The hVEGF-driven cell proliferation was effectively blocked by bevacizumab (IC₅₀ 3.7 μg ml⁻¹; 95% CI 1.7–8.3 μg ml⁻¹). Cell proliferation was significantly reduced when patients' serum during treatment with bevacizumab was added (22–103% inhibition compared with pre-treatment). Although bevacizumab levels were not related, on-treatment serum VEGF levels were correlated with Ba/F3-VEGFR2 cell proliferation.

Conclusions:

We found that the neutralising effect of anti-VEGF antibody therapy on the biological activity of circulating VEGF can be accurately determined with a Ba/F3-VEGFR2 bioassay. The value of this bioassay to predict clinical benefit of anti-VEGF antibody therapy needs further clinical evaluation in a larger randomised cohort.

Validation of VEGFR1 rs9582036 as predictive biomarker in metastatic clear-cell renal cell carcinoma patients treated with sunitinib

OBJECTIVES

To validate vascular endothelial growth factor receptor-1 (VEGFR1) single nucleotide polymorphism (SNP) rs9582036 as a potential predictive biomarker in metastatic clear-cell renal cell carcinoma (m-ccRCC) patients treated with sunitinib.

MATERIALS AND METHODS

m-ccRCC patients receiving sunitinib as first-line targeted therapy were included. We assessed response rate (RR), progression-free survival (PFS), overall survival (OS), and clinical and biochemical parameters associated with outcome. We genotyped five VEGFR1 SNPs: rs9582036, rs7993418, rs9554320, rs9554316 and rs9513070. Association with outcome was studied by univariate analysis and by multivariate Cox regression. Additionally, we updated survival data of our discovery cohort as described previously.

RESULTS

Sixty-nine patients were included in the validation cohort. rs9582036 CC-carriers had a poorer PFS (8 vs 12 months, P = 0.02) and OS (11 vs 27 months, P = 0.003) compared to AC/AA-carriers. rs7993418 CC-carriers had a poorer OS (8 vs 24 months, P = 0.004) compared to TC/TT-carriers. rs9554320 AA-carriers had a poorer RR (0% vs 53%, P = 0.009), PFS (5 vs 12 months, P = 0.003) and OS (10 vs 25 months, P = 0.004) compared to AC/CC-carriers. When pooling patients from the discovery cohort, as described previously (n = 88), and the validation cohort, in the total series of 157 patients, rs9582036 CC-carriers had a poorer RR (8% vs 49%, P = 0.004), PFS (8 vs 14 months, P = 0.003) and OS (13 vs 30 months, P = 0.0004) compared to AC/AA-carriers. Unfavorable prognostic markers at start of sunitinib were well balanced between rs9582036 CC- and AC/AA-carriers.

CONCLUSION

VEGFR1 rs9582036 is a candidate predictive biomarker in m-ccRCC-patients treated with sunitinib.

Antiangiogenic therapy in oncology: current status and future directions

Angiogenesis, the formation of new blood vessels from pre-existing vessels, has been validated as a target in several tumour types through randomised trials, incorporating vascular endothelial growth factor (VEGF) pathway inhibitors into the therapeutic armoury. Although some tumours such as renal cell carcinoma, ovarian and cervical cancers, and pancreatic neuroendocrine tumours are sensitive to these drugs, others such as prostate cancer, pancreatic adenocarcinoma, and melanoma are resistant. Even when drugs have yielded significant results, improvements in progression-free survival, and, in some cases, overall survival, are modest. Thus, a crucial issue in development of these drugs is the search for predictive biomarkers-tests that predict which patients will, and will not, benefit before initiation of therapy. Development of biomarkers is important because of the need to balance efficacy, toxicity, and cost. Novel combinations of these drugs with other antiangiogenics or other classes of drugs are being developed, and the appreciation that these drugs have immunomodulatory and other modes of action will lead to combination regimens that capitalise on these newly understood mechanisms.

International Experts Panel Meeting of the Italian Association of Thoracic Oncology on Antiangiogenetic Drugs for Non-Small Cell Lung Cancer: Realities and Hopes

Angiogenesis, one of the hallmarks of cancer, occurs when new blood vessels feed malignant cells, providing oxygen and nutrients, promoting tumor growth, and allowing tumor cells to escape into the circulation, thus leading to metastases. To date, a series of antiangiogenic drugs (either monoclonal antibodies or small molecules) have been approved by regulatory agencies for the treatment of advanced non-small cell lung cancer, and they are currently available for both first- and second-line therapy. The overall benefit of these drugs seems modest (although clearly significant), especially when administered as a single agent, and there is no clear consensus with regard to which patients should be candidates to receive these drugs across the different disease settings. From the biological perspective, angiogenesis represents a difficult and complex process to explore, given the interference with other key pathways and the dynamic evolution during the disease's history. Indeed, this process is complicated by the presence of multiple targets to hit, polymorphisms, hypoxia-dependent modifications, and epigenetics. These difficulties do not allow capture of which specific key pathways can be identified as biomarkers of efficacy so as to maximize to overall benefit of such drugs. An International Experts Panel Meeting was inspired by the absence of clear recommendations to address which patients should receive antiangiogenic drugs in the context of advanced non-small cell lung cancer so as to support decisions for clinical practice on a daily basis and determine priorities for future research. After a literature review and panelists consensus, a series of recommendations were defined to support decisions for the daily clinical practice and to indicate a potential road map for translational research.

Predictive and prognostic biomarkers of targeted agents and modern immunotherapy in renal cell carcinoma

In the past decade, several agents targeting angiogenesis and signal transduction pathways have replaced the use of cytokines as standard of care treatment for metastatic renal cell carcinoma (RCC) after showing improved clinical benefit and survival. Currently, several novel immunotherapy agents targeting the programmed cell death-1 (PD-1) and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) pathways are being tested in metastatic RCC and are bound to revolutionise the management of this disease. However, the success of both antiangiogenic drugs and new immunotherapy agents still depends on our ability to select patients most likely to respond to treatment. This article will review the current available evidence on prognostic and predictive biomarkers of response to signal transduction pathways-targeted agents and modern immunotherapy in metastatic RCC.

Functional FLT1 Genetic Variation is a Prognostic Factor for Recurrence in Stage I-III Non-Small-Cell Lung Cancer

BACKGROUND

We propose that single-nucleotide polymorphisms (SNPs) in genes of the vascular endothelial growth factor pathway of angiogenesis will associate with survival in non-small-cell lung cancer (NSCLC) patients.

METHODS

Fifty-three SNPs in vascular endothelial growth factor-pathway genes were genotyped in 150 European stage I-III NSCLC patients and tested for associations with patient survival. Replication was performed in an independent cohort of 142 European stage I-III patients. Reporter gene assays were used to assess the effects of SNPs on transcriptional activity.

RESULTS

In the initial cohort, five SNPs associated (q < 0.05) with relapse-free survival (RFS). The minor alleles of intronic FLT1 SNPs, rs7996030 and rs9582036, associated with reduced RFS (hazard ratio [HR] = 1.67 [95% confidence interval, CI, 1.22-2.29] and HR = 1.51 [95% CI, 1.14-2.01], respectively) and reduced transcriptional activity. The minor alleles of intronic KRAS SNPs, rs12813551 and rs10505980, associated with increased RFS (HR = 0.64 [0.46-0.87] and HR = 0.64 [0.47-0.87], respectively), and the minor allelic variant of rs12813551 also reduced transcriptional activity. Lastly, the minor allele of the intronic KRAS SNP rs10842513 associated with reduced RFS (HR = 1.65 [95% CI, 1.16-2.37]). Analysis of the functional variants suggests they are located in transcriptional enhancer elements. The negative effect of rs9582036 on RFS was confirmed in the replication cohort (HR = 1.69 [0.99-2.89], p = 0.028), and the association was significant in pooled analysis of both cohorts (HR = 1.67 [1.21-2.30], p = 0.0001).

CONCLUSIONS

The functional FLT1 variant rs9582036 is a prognostic determinant of recurrence in stage I-III NSCLC. Its predictive value should be tested in the adjuvant setting of stage I-III NSCLC.

A personalized paradigm in the treatment of platinum-resistant ovarian cancer - A cost utility analysis of genomic-based versus cytotoxic therapy

OBJECTIVE

To assess the cost-effectiveness of a strategy employing genomic-based tumor testing to guide therapy for platinum-resistant ovarian cancer.

METHODS

A decision model was created to compare standard of care (SOC) cytotoxic chemotherapy to a genomic-based treatment strategy. The genomic arm included tumor testing with treatment directed at targets identified. Overall survival was assumed to be similar between strategies; quality of life (QOL) was assumed superior during targeted therapy compared to chemotherapy. Pertinent uncertainties (cost of targeted therapy and genomic testing, response to targeted therapy, probability of a tumor having a targetable alteration, and impact on QOL) were evaluated in a series of one-and two-way sensitivity analyses.

RESULTS

The genomic testing strategy was more expensive ($90,271 vs. $74,926) per patient than SOC. The incremental cost-effectiveness ratio (ICER) of the genomic strategy was $479,303 per quality-adjusted life year saved (QALY). Model results were insensitive to the cost of genomic testing, differences in QOL, and the probability of identifying a targetable alteration. However, the model was sensitive to the cost of targeted therapy. For example, when the cost of targeted therapy was reduced to 56% of its current cost (or $6400/cycle), the genomic strategy became more cost-effective with an ICER of $96,612/QALY.

CONCLUSIONS

Genomic-based tumor testing and targeted therapy in patients with platinum-resistant ovarian cancer is not cost-effective compared with SOC. However, reducing the cost of targeted therapy (independently, or in combination with reducing the cost of the genomic test) provides opportunities for improved value in cancer care.

Markers of Response to Antiangiogenic Therapies in Colorectal Cancer: Where Are We Now and What Should Be Next?

Despite advances in the treatment of colorectal cancer (CRC), it remains the second most common cause of cancer-related death in the Western world. Angiogenesis is a complex process that involves the formation of new blood vessels from preexisting vessels. It is essential for promoting cancer survival, growth, and dissemination. The inhibition of angiogenesis has been shown to prevent tumor progression experimentally, and several chemotherapeutic targets of tumor angiogenesis have been identified. These include anti-vascular endothelial growth factor (VEGF) treatments, such as bevacizumab (a VEGF-specific binding antibody) and anti-VEGF receptor tyrosine kinase inhibitors, although antiangiogenic therapy has been shown to be effective in the treatment of several cancers, including CRC. However, it is also associated with its own side effects and financial costs. Therefore, the identification of biomarkers that are able to identify patients who are more likely to benefit from antiangiogenic treatment is very important. This article intends to be a concise summary of the potential biomarkers that can predict or prognosticate the benefit of antiangiogenic treatments in CRC, and also what we can expect in the near future.