Circulating protein biomarkers of pharmacodynamic activity of sunitinib in patients with metastatic renal cell carcinoma: modulation of VEGF and VEGF-related proteins.

BACKGROUND: Sunitinib malate (SUTENT) is an oral, multitargeted tyrosine kinase inhibitor, approved multinationally for the treatment of advanced RCC and of imatinib-resistant or - intolerant GIST. The purpose of this study was to explore potential biomarkers of sunitinib pharmacological activity via serial assessment of plasma levels of four soluble proteins from patients in a phase II study of advanced RCC: VEGF, soluble VEGFR-2 (sVEGFR-2), placenta growth factor (PlGF), and a novel soluble variant of VEGFR-3 (sVEGFR-3). METHODS: Sunitinib was administered at 50 mg/day on a 4/2 schedule (4 weeks on treatment, 2 weeks off treatment) to 63 patients with metastatic RCC after failure of first-line cytokine therapy. Predose plasma samples were collected on days 1 and 28 of each cycle and analyzed via ELISA. RESULTS: At the end of cycle 1, VEGF and PlGF levels increased >3-fold (relative to baseline) in 24/54 (44%) and 22/55 (40%) cases, respectively (P < 0.001). sVEGFR-2 levels decreased >or= 30% in 50/55 (91%) cases and >or= 20% in all cases (P < 0.001) during cycle 1, while sVEGFR-3 levels were decreased >or= 30% in 48 of 55 cases (87%), and >or= 20% in all but 2 cases. These levels tended to return to near-baseline after 2 weeks off treatment, indicating that these effects were dependent on drug exposure. Overall, significantly larger changes in VEGF, sVEGFR-2, and sVEGFR-3 levels were observed in patients exhibiting objective tumor response compared with those exhibiting stable disease or disease progression (P < 0.05 for each analyte; analysis not done for PlGF). CONCLUSION: Sunitinib treatment in advanced RCC patients leads to modulation of plasma levels of circulating proteins involved in VEGF signaling, including soluble forms of two VEGF receptors. This panel of proteins may be of value as biomarkers of the pharmacological and clinical activity of sunitinib in RCC, and of angiogenic processes in cancer and other diseases.

Altered metastatic behavior of human breast cancer cells after experimental manipulation of matrix metalloproteinase 8 gene expression.

Previous work in our laboratory led to the cloning, from the same parent tumor cell line (MDA-MB-435), of two human breast cancer cell lines (M-4A4 and NM-2C5) with opposite metastatic phenotypes. Additional investigations revealed that the nonmetastatic cell line NM-2C5 overexpressed the neutrophil collagenase, matrix metalloproteinase (MMP)-8, relative to its partner. Because other studies have implicated the MMP family in promoting tumor metastasis, we investigated the apparently paradoxical expression of MMP-8 in these cell lines. By genetic engineering, we inverted its relative levels of expression in the two partners and studied the effects on the behavior of the tumors that they generated in athymic mice. Knock-down of expression in NM-2C5 cells by transduction with a sequence encoding a specific ribozyme and overexpression of MMP-8 in M-4A4 cells by retroviral transduction both strikingly changed metastatic performance in opposite directions, indicating that this gene plays a role in the regulation of tumor metastasis.

The impact of a serum based proteomic mass spectrometry test on treatment recommendations in advanced non-small-cell lung cancer.

OBJECTIVE: To assess the impact of a serum-based proteomic test for non-small-cell lung cancer (NSCLC) on physician treatment recommendations. RESEARCH DESIGN AND METHODS: A multivariate, serum-based proteomic test (VeriStrat) is commercially available to assist physicians when determining treatment using epidermal growth factor receptor inhibitor (EGFRi) therapy, such as erlotinib (Tarceva), by stratifying patients into two categories: those with significantly better ('good') and those with significantly worse ('poor') outcomes following treatment with EGFRi therapy. All tests ordered from August 9, 2011 to November 26, 2012, were considered for this study. Pre- and post-test treatment recommendations were prospectively collected from ordering physicians on a voluntary basis. Only those tests that had both pre- and post-test treatment information were included in the analysis group. MAIN OUTCOME MEASURES: Proportional change and correlation of treatment recommendations before and after receipt of the test results. RESULTS: Over the duration of the study, 724 physicians ordered 2854 tests. The analysis group comprised the 226 physicians who provided pre- and post-test treatment information (n = 403 tests). Following receipt of the test results, 90.3% (95% CI: 86.4-93.3%) of patients who tested as 'good' received erlotinib recommendations versus 9.6% (95% CI: 4.5-17.4%, p < 0.0001) of patients who tested as 'poor'. Ninety percent of post-test treatment recommendations positively correlated with test results, with 40% showing a change from pre-test considerations. STUDY LIMITATIONS: Data based on physicians willing to submit recommendations and endpoint limited to therapy recommendations. CONCLUSIONS: Among test orderers, serum-based proteomic mass spectrometry testing significantly influenced therapy recommendations in NSCLC. Usage patterns should be monitored as use expands.