Cancer immunotherapy has been largely adopted in oncology patient management in the last decade. The deep and long responses to immunotherapy have accelerated the approval of these drugs across multiple disease sites. However, these agents can also be toxic to patients, meaning, the patient will have to discontinue treatment and outcomes could be negatively affected. Recently, a combination of two immunotherapy drugs, ipilimumab and nivolumab (ipi/nivo), has been approved for the treatment of intermediate and poor-risk renal cell carcinoma (RCC) patients. This powerful combination provides survival benefit, however, it can also be highly toxic leading to discontinuation of this treatment.

There has been some evidence that these otherwise toxic drugs can be better tolerated by altering the composition of the patients gut bacteria to create a more diverse and healthy microbiome. The current study will involve Fecal Microbiota Transplantation (FMT) before the start of the immunotherapy combination, and during the first two cycles of ipilimumab treatment (the more toxic agent) as supportive therapy to prevent toxicity associated with the ipi/nivo combination.

The goal of this project is to study the safety of such FMT combination treatment and reduce occurrence of immune-related toxicities in patients, allowing them to continue their cancer treatments in the hopes of a better outcome. The investigators will also be looking at changes in the immune populations, microbiome profile of patients, response to treatment, and patient survival as secondary objectives.