Background: Sorafenib is the standard first line treatment for advanced HCC and showed a median time to progression (TTP) of 5.5 months and an overall response rate (ORR) of 2% in the phase III SHARP trial. FOLFOX has shown modest activity in HCC with a progression free survival (PFS) of 2.9 months and ORR of 8% in a phase III trial. In this single-arm, multicenter phase 2 and biomarker study, sorafenib plus FOLFOX was evaluated in the first line treatment of advanced HCC. Methods: Patients with histologically proven advanced HCC, Child Pugh A liver function, and no prior systemic therapies received sorafenib 400mg orally twice daily during a 2-week lead-in, followed by concurrent modified FOLFOX (5-FUCI 1200mg/m2/day for 46 hours and LV 400mg/m2 bolus, Oxaliplatin 85mg/m2) on day 1 and 15 of each 28-day cycle. The primary endpoint was TTP, calculated from date of study entry to date of radiological or clinical disease progression. Serial plasma anti-angiogenic and anti-inflammatory biomarkers were evaluated. Results: The study enrolled 40 patients with advanced HCC: median age, 65 years; male 85%; Child Pugh A5, 70%; BCLC stage C, 95%; HCC etiology, HCV 40%, HBV 13%, alcohol 13%. Grade 3/4 adverse events were notable for AST (23%), ALT (15%), bilirubin (10%), diarrhea (10%), anemia (10%), hypertension (5%), hand-foot syndrome (5%), and thrombocytopenia (5%). Dose reductions for sorafenib and FOLFOX were done in 73% and 65% of patients, respectively. The median TTP was 8.8 months (95%CI, 6.5-11.2). The ORR was 18%, and the stable disease rate was 55%. Among 36 patients with a baseline AFP ≥ 5 ng/mL, 10 (28%) had a ≥ 50% drop in AFP. Low baseline plasma levels of sVEGFR1, VEGF-C, and bFGF and high levels of s-cMET and IL-12 tended to associate with longer TTP (p < 0.10). Decreased s-cMET at day 15 and decreased s-cMET and IL-2 at day 43 were associated with longer TTP (p < 0.05). Conclusions: Sorafenib+FOLFOX demonstrated encouraging clinical efficacy with moderate toxicity in the first line treatment of advanced HCC. Initial biomarker evaluation suggested a correlation between TTP and baseline angiogenic markers as well as changes in IL-2 and s-cMET. Complete biomarker analysis will be presented at the meeting. Clinical trial information: NCT01775501