The study aims to enroll and obtain samples of investigational interest from 200 patients over a 36-month recruitment period. Blood and/ or stool samples will be taken at baseline, in context of irAE development / during CPI treatment and during follow-up. Skin samples may also be taken upon development of organspeciifc irAEs.~Further assessments at baseline or during the course of or following treatment will be conducted in accordance with standard institutional practice and will be clinically driven. Clinical data, samples and results from archival, current or prospective diagnostic or therapeutic procedures will be used for research purposes within EXACT.~IrAE clinical monitoring will be conducted in accordance with standard institutional practice and will be clinically driven.
A prospective observational cohort study of patients undergoing CPI therapy in which translational research is the fundamental aspect of the study.