4032 Background: Gemcitabine-platinum chemotherapy (CTx) regimens are widely accepted as first-line standard of care for patients (pts) with advanced biliary cancers (ABC). EGFR overexpression has been observed in ABC, suggesting that the combination with anti-EGFR monoclonal antibodies may be appropriate. Methods: Patients with ABC, WHO performance status (PS) 0-1, and without prior palliative CTx were eligible for this international, open-label, two-stage, non-comparative, randomized phase II trial. Patients received GEMOX (gemcitabine, 1 g/m² [10 mg/m²/min] at day [D]1 + oxaliplatin, 100 mg/m² at D2, arm A) or GEMOX + cetuximab (500 mg/m² at D1 or 2, arm B), every 2 weeks. The primary endpoint was crude 4-month progression-free survival (PFS) rate (H0, <40%; H1, ≥60%; planned sample size, 100 pts, increased to 150 pts by amendment to allow subgroup analyses). Secondary endpoints were objective response rate (ORR), disease control rate (DCR), PFS, overall survival (OS), and toxicity (NCI-CTC v3.0). Exploratory endpoints included early metabolic response as assessed by PET at 1 month, and tumor KRAS mutational analysis. Results: From Oct. 2007 to Dec. 2009, we enrolled 150 pts (median age, 62 years; male, 57%; metastatic, 79%; cholangiocarcinoma, 84%; median follow-up, 30 months) (Table). Conclusions: GEMOX-cetuximab regimen was well tolerated and met its primary endpoint (4-month PFS ≥60%). However, median PFS and OS were similar in both arms. Exploratory analyses (e.g., KRAS tumor status) are underway to identify pt subgroups deriving benefit from the addition of cetuximab to CTx. [Table: see text]
