696P - A Multi-Center Phase II Study and Predictive Biomarker Analysis of Combined Cetuximab and Modified Folfiri as Second-Line Treatment in Patients with Metastatic Gastric Cancer

Abstract

ABSTRACT Background This study was conducted to explore potential biomarkers for predicting clinical outcome of cetuximab in combination with modified FOLFIRI (mFOLFIRI) and to analyze safety of this regimen as a second-line treatment in metastatic gastric cancer patients. Methods A total of 61 patients received an initial intravenous (IV) dose of cetuximab (400 mg/m2) and weekly doses (250 mg/m2) thereafter. On day 2 of each 14-day period, patients received IV irinotecan (180 mg/m2), leucovorin (200 mg/m2), and an IV bolus dose of 5-FU (400 mg/m2) followed by a continuous infusion of 5-FU (2400 mg/m2) for 46 hours. The primary endpoint was time-to-progression (TTP). Findings The response rate (RR) was 33.3% among 54 evaluable patients. In the intention-to-treat (ITT) analysis, median TTP was 4.6 months (95% confidential interval [CI]: 3.6-5.6 months) and median overall survival (OS) was 8.6 months (95% CI: 7.3-9.9 months). It was demonstrated that plasma vascular endothelial growth factor (VEGF) levels could be a predictive factor for the treatment prognosis. In patients with low (≤12.6 pg/ml) and high (>12.6 pg/ml) baseline plasma VEGF levels, RR values were 55.0% and 5.3%, respectively (P = 0.001); median TTP values were 6.9 months and 2.8 months, respectively (P = 0.0005); and median OS values were 12 months and 5 months, respectively (P Interpretation Low baseline plasma VEGF levels were identified as a potential predictive biomarker of prognosis. Combination therapy comprising cetuximab and mFOLFIRI was well tolerated, which would be potentially used as a second-line treatment for patients with advanced gastric cancer. Funding This study was supported by Fudan University Shanghai Cancer Center; Merck KGaA Darmstadt, Germany, and National “Eleventh Five-year plan” new drug discovery major projects of P. R. China. Disclosure All authors have declared no conflicts of interest.