Efficacy and safety of gemcitabine, oxaliplatin, and bevacizumab in advanced biliary-tract cancers and correlation of changes in 18-fluorodeoxyglucose PET with clinical outcome: a phase 2 study

Background Previous phase 2 studies have shown antitumour activity with gemcitabine and oxaliplatin (GEMOX) in patients with advanced biliary-tract cancers (BTCs). In this phase 2 study, we assessed the efficacy and safety of combined bevacizumab with GEMOX (GEMOX-B) in patients with advanced BTCs, and investigated how changes in 18-fluorodeoxyglucose ([F-18]FDG)-PET correlate with clinical outcome. Methods Patients with advanced measurable BTCs were given the following treatment on days 1 and 15 of a 28-day cycle: bevacizumab 10 mg/kg, followed by gemcitabine 1000 mg/m(2) (10 mg/m(2) per min) and oxaliplatin 85 mg/m(2) (2-h infusion). [F-18]FDG-PET scans were obtained at baseline and after completion of the second cycle. The primary endpoint was progression-free survival (PFS). Efficacy and safety analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00361231. Findings 35 patients were enrolled and evaluable for efficacy and toxicity. Median PFS was 7.0 months (95% CI 5.3-10.3), and PFS at 6 months was 63% (47-79), which was below the targeted rate of 70%. Grade 3-4 toxic effects included neutropenia (n=7), raised alanine aminotransferase concentrations (n=5), peripheral neuropathy (n=5), and hypertension (n=5). [F-18]FDG-PET scans showed a significant decrease in maximum standardised uptake value (SUVmax) after two cycles of treatment (5-72 [SD 2.01] at baseline; 3.73 [SD 1.88] after two cycles; p<0.0001). These changes were more pronounced in patients with partial response or stable disease than those with progressive disease (24 patients, -2.80 [SD 1.95] vs five patients, 1.41 [SD 3.13]; p=0.009). Change in SUVmax was a significant predictor of PFS (HR 1.35, 1.14-1.60, p=0.0006) and overall survival (1.25, 1.05-1.50, p=0.01). Interpretation GEMOX-B showed antitumour activity with tolerable safety in patients with advanced BTCs. Decreases in SUVmax on [F-18]FDG-PET scans after treatment were associated with disease control and increases in PFS and overall survival.