Efficacy, Safety, and Biomarkers of Single-Agent Bevacizumab Therapy in Patients with Advanced Hepatocellular Carcinoma

Abstract

Hepatocellular carcinoma (HCC) is a highly vascularized tumor in which neoangiogenesis contributes to growth and metastasis. We assessed the safety, efficacy, and potential biomarkers of activity of bevacizumab in patients with advanced HCC. In this phase II trial, eligible patients received bevacizumab, 5 mg/kg or 10 mg/kg every 2 weeks. The disease-control rate at 16 weeks (16W-DCR) was the primary endpoint. Circulating endothelial cells (CECs) and plasma cytokines and angiogenic factors (CAFs) were measured at baseline and throughout treatment. The 16W-DCR was 42% (95% confidence interval, 27%-57%). Six of the 43 patients who received bevacizumab achieved a partial response (objective response rate [ORR], 14%). Grade 3-4 asthenia, hemorrhage, and aminotransferase elevation occurred in five (12%), three (7%), and three (7%) patients, respectively. During treatment, placental growth factor markedly increased, whereas vascular endothelial growth factor (VEGF)-A dramatically decreased (p < .0001); soluble VEGF receptor-2 (p < .0001) and CECs (p = .03) transiently increased on day 3. High and increased CEC counts at day 15 were associated with the ORR (p = .04) and the 16W-DCR (p = .02), respectively. Lower interleukin (IL)-8 levels at baseline (p = .01) and throughout treatment (p ≤ .04) were associated with the 16W-DCR. High baseline IL-8 and IL-6 levels predicted shorter progression-free and overall survival times (p ≤ .04). Bevacizumab is active and well tolerated in patients with advanced HCC. The clinical value of CECs, IL-6, and IL-8 warrants further investigation.