Stereotactic Body Radiotherapy (SBRT) Followed by Immunotherapy in Liver Cancer

1.1 Primary Objective \& Hypothesis Determine the safety and tolerability of SBRT followed by nivolumab or ipilimumab with nivolumab for hepatocellular carcinoma by establishing the rates of toxicity that occur within 6 months from start of SBRT. Hypothesis: SBRT followed by nivolumab or nivolumab and ipilimumab will have similar toxicity to historical controls of SBRT or nivolumab monotherapy. 1.2 Secondary Objectives and Hypotheses Estimate the investigator determined best overall response rate. Hypothesis: Combining radiation and nivolumab or nivolumab and ipilimumab will improve the best overall response rate compared to historical controls with SBRT or nivolumab alone. Estimate the rates of long-term adverse events (after 6 months) from the end of SBRT. Hypothesis: Long-term toxicity from SBRT with nivolumab or nivolumab and ipilimumab will be comparable to that observed with nivolumab monotherapy. Summarize the distant disease control, progression-free survival, and overall survival. Hypothesis: Disease control and survival will be comparable to (or better than) that observed with nivolumab monotherapy. Summarize the local control of the SBRT treated lesion. Hypothesis: Combining SBRT and nivolumab or nivolumab and ipilimumab will have similar (or better) local control rates as observed in SBRT only series. 1.3 Exploratory Objectives Explore changes in inflammatory biomarkers (including, but not limited to CD8/Treg ratio, total CD4 counts, total lymphocyte count) in pretreatment and on-treatment serially collected peripheral blood samples. Hypothesis: Changes in inflammatory biomarkers after radiation therapy may correlate with a more favorable response to immunotherapy. Explore changes in the tumor microenvironment induced by radiation on pre and post treatment biopsies. Hypothesis: Changes in the tumor microenvironment after radiation therapy will be observed that may correlate with a more favorable response to immunotherapy.