To describe the U.S. Food and Drug Administration (FDA) review and approval of sorafenib (Nexavar; Bayer Pharmaceuticals Corp., Montville, NJ, and Onyx Pharmaceuticals Corp., Emeryville, CA), an oral kinase inhibitor, for the treatment of patients with unresectable hepatocellular carcinoma (HCC).The FDA independently analyzed an international, double-blind, placebo-controlled trial comparing the effect of best supportive care plus sorafenib or matching placebo on overall survival. Eligible patients had unresectable, biopsy-proven HCC and had not received prior systemic therapy.Among the 602 randomized patients (placebo, 303; sorafenib, 299), baseline characteristics were well balanced, and 97% were Child-Pugh score A. HCC was "advanced" in 70% overall, as defined by extrahepatic metastases or by tumor radiographically visible in venous structures outside the liver. Underlying liver diseases included hepatitis B (18%), hepatitis C (28%), and alcohol-related (26%). The trial was stopped following a prespecified second interim analysis showing a statistically significant survival advantage for sorafenib [median, 10.7 vs 7.9 months; hazard ratio, 0.69 (95% confidence interval, (0.55, 0.87)), p = 0.00058]. Adverse events in sorafenib-treated patients included diarrhea in 55% (grade 3, 10%), hand-foot syndrome in 21% (grade 3, 8%), rash in 19% (grade 3, 1%), and cardiac ischemia or infarction in 2.7% (versus 1.3% for placebo). On sorafenib, treatment-emergent hypertension occurred in 9% of patients (placebo, 4%) and was grade 3 in 4% (placebo, 1%); elevated serum lipase occurred in 40% (placebo, 37%); hypophosphatemia occurred in 35% (placebo, 11%).Sorafenib is the first systemic therapy to demonstrate a survival benefit in a randomized trial for unresectable HCC and has received FDA approval for this indication.