Publications (5)29.75 Total impact
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Article: Mechanism-related circulating proteins as biomarkers for clinical outcome in patients with unresectable hepatocellular carcinoma receiving sunitinib.
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ABSTRACT: Several proteins that promote angiogenesis are overexpressed in hepatocellular carcinoma (HCC) and have been implicated in disease pathogenesis. Sunitinib has antiangiogenic activity and is an oral multitargeted inhibitor of vascular endothelial growth factor receptors (VEGFRs)-1, -2, and -3, platelet-derived growth factor receptors (PDGFRs)-α and -β, stem-cell factor receptor (KIT), and other tyrosine kinases. In a phase II study of sunitinib in advanced HCC, we evaluated the plasma pharmacodynamics of five proteins related to the mechanism of action of sunitinib and explored potential correlations with clinical outcome. Patients with advanced HCC received a starting dose of sunitinib 50 mg/day administered orally for 4 weeks on treatment, followed by 2 weeks off treatment. Plasma samples from 37 patients were obtained at baseline and during treatment and were analyzed for vascular endothelial growth factor (VEGF)-A, VEGF-C, soluble VEGFR-2 (sVEGFR-2), soluble VEGFR-3 (sVEGFR-3), and soluble KIT (sKIT). At the end of the first sunitinib treatment cycle, plasma VEGF-A levels were significantly increased relative to baseline, while levels of plasma VEGF-C, sVEGFR-2, sVEGFR-3, and sKIT were significantly decreased. Changes from baseline in VEGF-A, sVEGFR-2, and sVEGFR-3, but not VEGF-C or sKIT, were partially or completely reversed during the first 2-week off-treatment period. High levels of VEGF-C at baseline were significantly associated with Response Evaluation Criteria in Solid Tumors (RECIST)-defined disease control, prolonged time to tumor progression (TTP), and prolonged overall survival (OS). Baseline VEGF-C levels were an independent predictor of TTP by multivariate analysis. Changes from baseline in VEGF-A and sKIT at cycle 1 day 14 or cycle 2 day 28, and change in VEGF-C at the end of the first off-treatment period, were significantly associated with both TTP and OS, while change in sVEGFR-2 at cycle 1 day 28 was an independent predictor of OS. Baseline plasma VEGF-C levels predicted disease control (based on RECIST) and were positively associated with both TTP and OS in this exploratory analysis, suggesting that this VEGF family member may have utility in predicting clinical outcome in patients with HCC who receive sunitinib. ClinicalTrials.gov: NCT00247676.Journal of Translational Medicine 07/2011; 9:120. · 3.41 Impact Factor -
Article: Changes in tumor density in patients with advanced hepatocellular carcinoma treated with sunitinib.
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ABSTRACT: Response Evaluation Criteria in Solid Tumors (RECIST) may underestimate the efficacy of targeted therapies. In hepatocellular carcinoma (HCC) studies with sunitinib, RECIST-defined response rates are low, although hypodensity on computed tomography (CT) scans occurs more frequently. This exploratory analysis investigated tumor density as a surrogate endpoint of sunitinib activity in a phase II HCC study. Patients received sunitinib 50 mg/d (4 weeks on/2 weeks off). Tumor size and density were assessed on CT scans by using RECIST and Choi criteria, the latter of which classify a partial response as a 15% or more reduction in tumor density or a 10% or more reduction in tumor size. The overall percentage volume of tumor necrosis was calculated with volumetric reconstruction. Tumor perfusion parameters were assessed by using perfusion CT scans with specific acquisition. Among the 26 evaluable patients, 1 achieved a partial response and 22 had tumor stabilization by RECIST. In analysis of tumor density, 17 of 26 patients (65.4%) were responders by Choi criteria. Volumetric assessment showed major tumor necrosis (≥30% of tumor volume) in 10 of 21 patients (47.6%). Among four patients evaluated, tumor blood flow was reduced by 58.8% and blood volume by 68.4% after 4 weeks of treatment. The median time to progression (TTP) was 6.4 months. Patients with responses by Choi criteria had a significantly longer TTP (7.5 months) compared with nonresponders (4.8 months; HR = 0.33, two-sided P = 0.0182). Tumor density assessment suggested that radiologic endpoints in addition to RECIST may be considered to capture sunitinib activity in HCC.Clinical Cancer Research 04/2011; 17(13):4504-12. · 7.74 Impact Factor -
Article: Safety and efficacy of sunitinib in patients with advanced hepatocellular carcinoma: an open-label, multicentre, phase II study.
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ABSTRACT: Hepatocellular carcinoma (HCC) tumour spread is partly dependent on neoangiogenesis. In this open-label, multicentre, phase II trial done in Europe and Asia, sunitinib, a multitargeted tyrosine-kinase inhibitor with anti-angiogenic properties, was assessed in patients with advanced unresectable HCC. Between February and July, 2006, eligible patients were enrolled and treated with repeated cycles of oral sunitinib (50 mg/day for 4 weeks, followed by 2 weeks off treatment). The primary endpoint of this Simon two-stage phase II trial was objective response rate according to Response Evaluation Criteria in Solid Tumours (RECIST) criteria, with an expected response rate of 15%. This trial is registered with ClinicalTrials.gov, number NCT00247676. Of 37 patients enrolled, one (2.7%) patient experienced a confirmed partial response, giving an overall objective response rate of 2.7% (95% CI 0.1-14.2); on the basis of this, the trial did not proceed to the second stage. 13 (35%) of 37 patients achieved stable disease for over 3 months. Commonly observed grade 3 and 4 adverse events included thrombocytopenia (14 of 37; 37.8%), neutropenia (nine of 37; 24.3%), asthenia (five of 37; 13.5%), hand-foot syndrome (four of 37; 10.8%), and anaemia (four of 37; 10.8%). There were four deaths among the 37 patients (10.8%) that were possibly related to treatment. Sunitinib showed pronounced toxicities at a dose of 50 mg/day in patients with unresectable HCC. The response rate was low, and the study did not meet the primary endpoint based on RECIST criteria. Pfizer Oncology.The lancet oncology 09/2009; 10(8):794-800. · 14.47 Impact Factor -
Article: A new method for the comparison of survival distributions.
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ABSTRACT: The assessment of overall homogeneity of time-to-event curves is a key element in survival analysis in biomedical research. The currently commonly used testing methods, e.g. log-rank test, Wilcoxon test, and Kolmogorov-Smirnov test, may have a significant loss of statistical testing power under certain circumstances. In this paper we propose a new testing method that is robust for the comparison of the overall homogeneity of survival curves based on the absolute difference of the area under the survival curves using normal approximation by Greenwood's formula. Monte Carlo simulations are conducted to investigate the performance of the new testing method compared against the log-rank, Wilcoxon, and Kolmogorov-Smirnov tests under a variety of circumstances. The proposed new method has robust performance with greater power to detect the overall differences than the log-rank, Wilcoxon, and Kolmogorov-Smirnov tests in many scenarios in the simulations. Furthermore, the applicability of the new testing approach is illustrated in a real data example from a kidney dialysis trial.Pharmaceutical Statistics 04/2009; 9(1):67-76. · 2.07 Impact Factor -
Article: A two-stage phase II trial design utilizing both primary and secondary endpoints.
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ABSTRACT: Phase II trials in oncology drug development are usually conducted to perform the initial assessment of treatment activity. The common designs in this setting, for example, Simon 2-stage designs, are often developed based on testing whether a parameter of interest, usually a proportion (e.g. response rate), is less than a certain level or not. These designs usually consider only one parameter. However, sometimes we may encounter situations where we need to consider not a single parameter, but multiple parameters. This paper presents a two-stage design in which both primary and secondary endpoints are utilized in the decision rules. The family-wise Type 1 error rate and statistical power of the proposed design are investigated under a variety of situations by means of Monte-Carlo simulations.Pharmaceutical Statistics 7(2):88-92. · 2.07 Impact Factor
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2009
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Wyeth
New Johnsonville, TN, USA
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