S0941: a phase 2 SWOG study of sorafenib and erlotinib in patients with advanced gallbladder carcinoma or cholangiocarcinoma

Background: Gallbladder cancers and cholangiocarcinomas make up a heterogenous group of tumours with a poor prognosis in advanced stages. On the basis of evidence of dysregulation of the epidermal growth factor receptor, vascular endothelial growth factor and mitogen-activated protein kinase pathways in biliary cancers, we performed a phase 2 trial of sorafenib and erlotinib in patients with advanced biliary cancers. Methods: Eligible patients were previously untreated in the advanced setting with adequate hepatic and bone marrow function. Sorafenib and erlotinib were administered continuously at 400mg BID and 100mg daily, respectively. Results: Thirty-four eligible patients were recruited. The study was terminated after the first stage of accrual owing to failure to meet the predetermined number of patients who were alive and progression free at 4 months. There were two unconfirmed partial responses (6%, 95% CI: 1-20%), with a median progression-free survival of 2 months (95% CI: 2-3), and median overall survival of 6 months (95% CI: 3-8 months). Grade 3 and 4 adverse events included hypertension, AST/ALT increase, bilirubin increase, diarrhoea, hypokalaemia, hypophosphatemia and rash. Conclusions: Despite compelling preclinical rationale, the combination of sorafenib and erlotinib does not have promising clinical activity in an unselected population of patients with biliary cancers. Improved patient selection based on tumour biology and molecular markers is critical for future evaluation of targeted therapies in this disease.