PRIMARY OBJECTIVE:~I. To determine if the microbiome alpha-diversity is predictive of response (Response Evaluation Criteria in Solid Tumors [RECIST] version [v] 1.1) at a 12-week computed tomography (CT) scan or toxicity.~SECONDARY OBJECTIVE:~I. To determine the recruitment and compliance rates for longitudinal biospecimen collection, including stool, in melanoma patients.~EXPLORATORY OBJECTIVE:~I. To determine if individual microbes or their changes in relative abundance are predictive of response or toxicity.~OUTLINE:~Patients complete a Food Frequency Questionnaire (FFQ) at baseline, undergo collection of stool samples at baseline, within 2 days of starting corticosteroid treatment (if applicable), when asked for a control sample, and at 12 weeks, and undergo collection of blood samples and computed tomography (CT) at baseline and 12 weeks.
This pilot trial studies the effect of the microbiome on immune checkpoint inhibitors response in patients with melanoma by collecting stool and blood samples. Gut microbiome plays a critical role in response to immune checkpoint inhibitors. Studying the change in an individual's microbiome due to corticosteroid use may help researchers to determine whether an individual's microbiome can predict their response and toxicity to immune checkpoint inhibitors.