Immunotherapy with immune checkpoint-inhibitors is standard treatment for patients with melanoma. However, in about 15% of patients treated with Ipilimumab a grade 3-4 colitis will occur. In programmed cell death protein 1 (PD1) inhibitors colitis is also seen as adverse event, although less prominent. We want to find a good predictive biomarker to select patients that are prone to colitis.So far no test is available that might be predictive whether a patient will develop a grade 3-4 colitis.
The study will consists of four parts: 1.) to identify a genetic profile associated with ipilimumab-induced colitis, 2.) to identify predictive (serum or fecal) biomarkers for ipilimumab-induced colitis, 3.) to study the tissue of ipilimumab-induced colitis and 4) to study the role of the gut microbiome in the development of colitis. Patients are able to participate in one, or more parts of the study.