Inclusion criteria - Male or female patients e" 18 years - Histological diagnosis of HCC, whether new or recurrent following a prior curative therapeutic management. - Barcelona Clinical Liver Cancer(BCLC) stage Category A - Patients with HCC amenable for EP as assessed by multidisciplinary board corresponding to the following extension: o Uninodular HCC >3cm and <5cm o Multinodular HCC diameter <5 cm and 3 nodular max - At least one uni-dimensional measurable lesion by computed tomography (CT) scan or magnetic resonance imaging (MRI) according to modified RECIST for HCC - Liver function status Child-Pugh Class A - Eastern Cooperative Oncology Group (ECOG) Performance Status d" 2 - Adequate bone marrow, liver and renal function as assessed by the following laboratory tests: o Hemoglobin > 8.5 g/dL o Absolute neutrophil count e" 1500/mm3 o Platelet count e" 60,000/ mm3 o Total bilirubin d" 2 mg/dL o Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) d" 5 x upper limit of normal (ULN) o Serum creatinine d" 1.5 x ULN o Lipase d" 2 x ULN o Prothrombine time-international normalized ratio (PT-INR) < 2.3 x ULN and PTT < 1.5 x ULN o Glomerular Filtration Rate (GFR) e" 30 mL/min/1.73 m2 "NIVOLEP" protocol, version2.2 du 27/02/2019 30/60 - Life expectancy e" 3 months - Women of childbearing potential (WOCBP) need to accept one effective method of contraception until 5 months after the last nivolumab infusion - Patients who are sexually active with WOCBP partners need to accept one effective method of contraception until 7 months after the nivolumab infusion and men must agree to use adequate contraception - Patients affiliated to a Social Security System - Written informed consent signed

5.2 Exclusion criteria - Patients with contraindications to EP - Patients with contraindication to contrast medium intravenous injection either gadolinium or iodinate - Prior liver transplantation or candidates for liver transplantation - - - Prior systemic treatment for HCC, in particular agents targeting T-cell costimulation or checkpoint pathways (including those targeting PD-1, PD-L1 or PD-L2, CD137, or cytotoxic T-lymphocyte antigen [CTLA-4]). - Patients with autoimmune disease and patients requiring chronic systemic treatment with corticosteroids (>10 mg daily prednisone equivalent) or other immunosuppressive medications. - Patients with large esophageal varices at risk of bleeding that are not being treated with conventional medical intervention - Past or concurrent history of neoplasm other than HCC, except for in situ carcinoma of the cervix uteri and/or non-melanoma skin cancer and superficial bladder tumors. Any cancer curatively treated > 3 years prior to study entry is permitted - Known history or symptomatic metastatic brain or meningeal tumors - Major surgical procedure or significant traumatic injury within 28 days before enrolment - Congestive heart failure New York Heart Association (NYHA) e" class 2 - Unstable angina or myocardial infarction within the past 6 months before enrolment - Cardiac arrhythmias requiring anti-arrhythmic therapy - Grade 3 (severe) hypertension e"180 and/or e"110 mmHG (systolic and diastolic, according to National Heart Foundation 2016) - Patients with phaeochromocytoma - Refractory ascites according to EASL guidelines definition (ascites that cannot be mobilized or the early recurrence of which cannot be prevented because of a lack of response to sodium restriction and diuretic treatment) - Persistent proteinuria of NCI-CTCAE version 4.0 e" Grade 3 - Ongoing infection > Grade 2 according to NCI-CTCAE version 4.0. Hepatitis B is allowed if no active replication is present (below 100 IU/mL). Hepatitis C is allowed if no antiviral treatment is required - Clinically significant bleeding NCI-CTCAE version 4.0 e" Grade 3 within 30 days before enrolment - Arterial or venous thrombotic or embolic events such as cerebrovascular accident, deep vein thrombosis or pulmonary embolism within 6 months before enrolment - Any psychological, familial, sociological, geographical or illness or medical condition that could jeopardize the safety of the patient and/or his compliance with the study protocol and follow-up procedure - Known history of human immunodeficiency virus (HIV) infection - Seizure disorder requiring medication - Non-healing wound, ulcer or bone fracture - Known hypersensitivity to the study drug or excipients in the formulation "NIVOLEP" protocol, version2.2 du 27/02/2019 31/60 - Any malabsorption condition - Breast feeding - Pregnancy - Patient unable to swallow oral medication