PRIMARY OBJECTIVES:~I. Establish the safety of durvalumab and tremelimumab following radioembolization with selective internal radiation (SIR)-Spheres in patients with microsatellite stable (MSS) metastatic colorectal cancer to the liver.~II. Determine the hepatic response rate of SIR-Spheres followed by durvalumab and tremelimumab in patients with MSS metastatic colorectal cancer to the liver.~SECONDARY OBJECTIVES:~I. Estimate the progression free survival (PFS) and overall survival (OS) of the overall treated population.~II. Describe the overall response rate of the treated population. III. Describe the extra-hepatic response in the treated population (abscopal responses).~TERTIARY OBJECTIVES:~I. Describe intra-tumor immune alterations following SIR-Spheres, and following durvalumab plus tremelimumab in comparison to baseline through serial hepatic metastases biopsies.~II. Describe the immune alterations in the blood following SIR-Spheres and following durvalumab plus tremelimumab.~OUTLINE:~Patients receive durvalumab intravenously (IV) over 60 minutes and tremelimumab IV over 60 minutes on day 1. Treatment repeats every 4 weeks for up to 4 courses in the absence of disease progression or unacceptable toxicity. Beginning at week 17, patients receive durvalumab IV over 60 minutes on day 1. Treatment repeats every 4 weeks for up to 9 courses in the absence of disease progression or unacceptable toxicity.~After completion of study treatment, patients are followed up periodically.
This pilot clinical trial studies the side effects and how well durvalumab and tremelimumab work in treating patients with microsatellite stable colorectal cancer that has spread to the liver. Monoclonal antibodies, such as durvalumab and tremelimumab, may interfere with the ability of tumor cells to grow and spread.