Inclusion Criteria:

- Unequivocal diagnosis of HCC

- unresectable disease not amenable to locoregional treatment.

- a 4-week washout period after sorafenib or any other systemic agent

- a 2-month washout period after internal or external radiation

- HCV chronic infection

- Child-Pugh stage A or B

- Measurable disease according to RECIST criteria

- ECOG < 2

- expected survival > 3 months

- Adequate liver, renal and blood functions

- ability to sign informed consent

Exclusion Criteria:

- previous treatment with an anti-CTL-4 agent

- serious infections or disease compromising general health status

- autoimmune disease that requires therapy

- treatment with immunosuppressors

- treatment with investigational agents

- other neoplasms except skin and bladder superficial tumors

- pregnancy or lactation

- SNC metastasis

- HIV infection

- relevant heart disease (NYHA class III or IV)