Background: The multikinase inhibitor SOR prolongs survival in patients with HCC not amenable to curative therapies. In HCC preclinical models, the combination of SOR with an inhibitor of the mammalian target of rapamycin (mTOR) pathway is synergistic, though single-agent mTOR inhibition did not improve survival in HCC patients after failure of SOR in a phase III trial. We previously completed a phase I study of the mTOR inhibitor TEM combined with SOR in 25 HCC patients which identified the maximum tolerated dose as TEM 10 mg IV weekly and SOR 200 mg PO BID. This two-center, phase II study was developed to examine the efficacy of the combination and to explore candidate biomarkers. The study was approved and funded by the National Comprehensive Cancer Network (NCCN) Oncology Research Program from general research support, with activation October 2012. Methods: The study is registered on ClinicalTrials.gov (NCT01687673). Design: Single-arm, one stage phase II trial. Primary endpoint: Time to progression (TTP) by RECIST 1.1. Other endpoints: Progression-free survival, response rate, overall survival, proportion with alpha fetoprotein decline ≥ 50%, toxicity, hepatitis B virus reactivation rate, and exploratory biomarkers including mTOR pathway protein expression in tumor, circulating tumor cells, and blood and tumor micro-RNA profiles. Sample size: 25 evaluable patients are required to detect a difference between the null hypothesis of median TTP < 3 months versus alternate hypothesis of median TTP ≥ 6 months (a clinically-meaningful outcome in advanced HCC), with 1-sided significance level of 10% and power 88% under the exact test. Main eligibility criteria: HCC not amenable to curative therapies, histologically-confirmed, ≥ 1 untreated, radiographically-measurable site of disease. No prior systemic therapy. ECOG ≤ 1. Child-Pugh score ≤ 7 with bilirubin ≤ 2 mg/dL. Treatment and procedures: TEM 10 mg IVweekly plus SOR 200 mg PO BID in 28-day cycles, with collection of archival tumor samples and blood samples at baseline, on treatment, and at progression. Accrual:Sixteen of 25 planned evaluable patients have enrolled. An interim analysis for safety after 30% enrollment met pre-specified target to continue. Clinical trial information: NCT01687673