Nivolumab and Ipilimumab in Mucinous Colorectal and Appendiceal Tumors

Treatment will consist of nivolumab 480mg every 4 weeks and ipilimumab 1mg/kg every 8 weeks (within a 56-day cycle, (Nivolumab administered on days 1 and 29, and Ipilimumab administered on day 1 of each cycle). Imaging assessments will be conducted every 8 weeks (+/-2 weeks) for the first 24 weeks then every 8-12 weeks (+/-2 weeks). If progression is noted on imaging in the setting of clinical stability, subjects may remain on study and have confirmatory imaging in 4-8 weeks per iRECIST criteria