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Purpose: The aim of this study was to identify conserved pharmacodynamic and potential predictive biomarkers of response to anti-VEGF therapy using gene expression profiling in preclinical tumor models and in patients., Experimental Design: Surrogate markers of VEGF inhibition [VEGF-dependent genes or VEGF-dependent vasculature (VDV)] were identified by profiling gene expression changes induced in response to VEGF blockade in preclinical tumor models and in human biopsies from patients treated with anti-VEGF monoclonal antibodies. The potential value of VDV genes as candidate predictive biomarkers was tested by correlating high or low VDV gene expression levels in pretreatment clinical samples with the subsequent clinical efficacy of bevacizumab (anti-VEGF)-containing therapy., Results: We show that VDV genes, including direct and more distal VEGF downstream endothelial targets, enable detection of VEGF signaling inhibition in mouse tumor models and human tumor biopsies. Retrospective analyses of clinical trial data indicate that patients with higher VDV expression in pretreatment tumor samples exhibited improved clinical outcome when treated with bevacizumab-containing therapies., Conclusions: In this work, we identified surrogate markers (VDV genes) for in vivo VEGF signaling in tumors and showed clinical data supporting a correlation between pretreatment VEGF bioactivity and the subsequent efficacy of anti-VEGF therapy. We propose that VDV genes are candidate biomarkers with the potential to aid the selection of novel indications as well as patients likely to respond to anti-VEGF therapy. The data presented here define a diagnostic biomarker hypothesis based on translational research that warrants further evaluation in additional retrospective and prospective trials., (©2013 AACR.)

Purpose: To identify biomarkers and gene expression profile signatures to distinguish patients with partial response (PR) from those with stable disease (SD) and progressive disease (PD)., Experimental Design: Twenty patients with inflammatory breast cancer and one patient with locally advanced breast cancer received one cycle of bevacizumab followed by six cycles of bevacizumab plus docetaxel-doxorubicin before surgery. Baseline angiogenic/tumor markers were examined by immunohistochemistry and gene expression profiles were measured by Agilent Whole Human Genome arrays. All were assessed for clinical response., Results: Fourteen patients (67%, 95% confidence interval, 43-85.4%) had PR, five had SD, and two had PD. Expression of CD31 and platelet-derived growth factor receptor-beta (PDGFR-beta) in the tumor vasculature by immunohistochemistry was significantly associated with response (PR versus SD/PD; CD31 median, 33.5 versus 13.2; P = 0.0004; PDGFR-beta median, 5.9 versus 0.6; P = 0.01). Tumor VEGF-A showed a trend towards association with response (2.65 versus 0.25; P = 0.04). pVEGFR2(Y996), pVEGFR2(Y951), MVD, Ki67, apoptosis, grade, ER, HER-2/neu, and p53 were not associated with response. Twenty-six of 1,339 Gene Ontology (GO) classes at the gene transcriptional level were differentially expressed between patients with PR and SD/PD (P < 0.005). Representative significant GO classes include spindle (11 genes; P = 0.001), vascular endothelial growth factor receptor activity including PDGFR-beta (5 genes; P = 0.002), and cell motility including CD31 (80 genes; P = 0.005)., Conclusions: Baseline CD31, PDGFR-beta, and GO classes for vascular endothelial growth factor receptor activity and mitosis were significantly associated with response to bevacizumab followed by bevacizumab plus chemotherapy.

Phase 0 trials are designed primarily to evaluate the pharmacodynamic and/or pharmacokinetic properties of selected investigational agents before initiating more traditional phase I testing. One of the major objectives of phase 0 trials is to interrogate and refine a target or biomarker assay for drug effect in human samples implementing procedures developed and validated in preclinical models. Thus, close collaboration between laboratory scientists and clinical investigators is essential to the design and conduct of phase 0 trials. Given the relatively small number of patients and tissue samples, showing a significant drug effect in phase 0 trials requires precise and reproducible assay procedures and innovative statistical methodology. Furthermore, phase 0 trials involving limited exposure of a study agent administered at low doses and/or for a short period allow them to be initiated under the Food and Drug Administration exploratory investigational new drug guidance with less preclinical toxicity data than usually required for traditional first-in-human studies. Because of the very limited drug exposure, phase 0 trials offer no chance of therapeutic benefit, which can impede patient enrollment, particularly if invasive tumor biopsies are required. The challenges to accrual are not insurmountable, however, and well-designed and executed phase 0 trials are feasible and have great potential for improving the efficiency and success of subsequent trials, particularly those evaluating molecularly targeted agents.

Purpose: To evaluate safety and efficacy of trastuzumab with pertuzumab in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer who had progressive disease on trastuzumab-based therapy., Experimental Design: Patients with measurable HER2(+) metastatic breast cancer, < or = 3 trastuzumab-based regimens, and left ventricular ejection fraction (LVEF) > or = 55% received 8 or 6 mg/kg trastuzumab and 840 mg pertuzumab i.v. followed by 6 mg/kg trastuzumab and 420 mg pertuzumab every 3 weeks. Cardiac evaluation and tumor response were assessed every 3 and 6 weeks, respectively., Results: Eleven patients received 64 cycles of trastuzumab plus pertuzumab. A total of 92 echocardiograms and 8 cardiac magnetic resonance imaging studies were done. With the lower limit of normal LVEF 55%, left ventricular systolic dysfunction was observed in six patients, three grade 1, two grade 2, and one grade 3 according to the National Cancer Institute Common Terminology Criteria for Adverse Events. The objective response rate was 18%. Two patients had partial responses, three had stable disease, and six had progressive disease. The median time to progression was 6 weeks. In baseline tumors from formalin-fixed paraffin-embedded primary and/or metastatic tumor biopsies, pHER2-Y1248 trended toward an increase in patients with partial response compared with those with stable disease/progressive disease (P = 0.095)., Conclusion: Trastuzumab plus pertuzumab may have clinical benefit in selected patients who have previously been treated with trastuzumab. Cardiac toxicity, although asymptomatic in most cases, was associated with this treatment. Further evaluation of efficacy of this combination is required to define the overall risks and benefits.

Purpose: To delineate gene expression patterns and profile changes in metastatic tumor biopsies at baseline and 1 month after treatment with the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib in patients with metastatic breast cancer., Experimental Design: Patients were treated with 150 mg of oral erlotinib daily. Gene expression profiles were measured with Affymetrix U133A GeneChip and immunohistochemistry was used to validate microarray findings., Results: Estrogen receptor (ER) status by immunohistochemistry is nearly coincided with the two major expression clusters determined by expression of genes using unsupervised hierarchical clustering analysis. One of 10 patients had an EGFR-positive tumor detected by both microarray and immunohistochemistry. In this tumor, tissue inhibitor of metalloproteinases-3 and collagen type 1 alpha 2, which are the EGF-down-regulated growth repressors, were significantly increased by erlotinib. Gene changes in EGFR-negative tumors are those of G-protein-linked and cell surface receptor-linked signaling. Gene ontology comparison analysis pretreatment and posttreatment in EGFR-negative tumors revealed biological process categories that have more genes differentially expressed than expected by chance. Among 495 gene ontology categories, the significant differed gene ontology groups include G-protein-coupled receptor protein signaling (34 genes, P = 0.002) and cell surface receptor-linked signal transduction (74 genes, P = 0.007)., Conclusions: ER status reflects the major difference in gene expression pattern in metastatic breast cancer. Erlotinib had effects on genes of EGFR signaling pathway in the EGFR-positive tumor and on gene ontology biological process categories or genes that have function in signal transduction in EGFR-negative tumors.