Pembrolizumab in Advanced Hepatocellular Carcinoma as Second-line Treatment After Failure of Sorafenib

1. Be willing and able to provide written informed consent/assent for the trial. The subject may also provide consent for Biomedical Research. However, the subject may participate in the main trial without participating in Biomedical Research.
2. Have histologically or cytologically confirmed diagnosis of HCC (fibrolamellar and mixed hepatocellular/cholangiocarcinoma subtypes are not eligible) based on pathology report.
3. Have Barcelona Clinic Liver Cancer (BCLC) Stage C disease, or BCLC Stage B disease not amenable to locoregional therapy or refractory to locoregional therapy, and not amenable to a curative treatment approach.
4. Have a Child-Pugh class A liver score
5. Has experienced documented objective radiographic or clinical disease progression during first-line sorafenib therapy.
6. Have measurable disease based on RECIST1.1 as determined by investigator.
7. Be willing to provide fresh tissue for biomarker analysis, and, based on the adequacy of the tissue sample quality for assessment of biomarker status. Repeat samples may be required if adequate tissue is not provided. Newly obtained endoscopic biopsy specimens are preferred to archived samples and formalin-fixed, paraffin-embedded (FFPE) block specimens are preferred to slides.

Exclusion Criteria:

1. Is currently participating and receiving study therapy or has participated in a study of an investigational agent and received study therapy or used an investigational device within 4 weeks of the first dose of treatment.
2. Has received sorafenib within 14 days of first dose of study medication.
3. Has had esophageal or gastric variceal bleeding within the last 6 months. All subjects will be screened for esophageal varices, unless such screening has been performed in the past 12 months before first dose of treatment. If varices are present, they should be treated according to institutional standards before starting study treatment.
4. Had a solid organ transplant.
5. Has active autoimmune disease that has required systemic treatment in past 2 years (i.e., with use of disease-modifying agents, corticosteroids, or immunosuppressive drugs). Replacement therapy (e.g., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment.
6. Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to the first dose of trial treatment.
7. Has received locoregional therapy to liver (transcatheter chemoembolization [TACE], transcatheter embolization [TAE], radiation, radioembolization, or ablation) or major surgery to liver or other site within 4 weeks prior to the first dose of study drug. Minor surgery (e.g., simple excision, tooth extraction) must have occurred at least 7 days prior to the first dose of study treatment (Cycle 1, Day 1).