It is not an absolute contraindication! It depends on how active the Crohns is; what therapy he is on for the Crohns. Patients on auto immune disorders treated with IO have about a 30% chance of a flare.  In RCC, prior to the availability of CPI, monotherapy with sequential TKI's was the stand...

Traditionally, clinical trials demonstrating the efficacy of checkpoint inhibitors have excluded patients with autoimmune conditions. Retrospective studies show that these agents can be used. In one retrospective study, six patients with IBD received ipilimumab, two of the six patients had enterocol...

Agree with the responses below that it is never an absolute contraindication. Assess how active and severe is the autoimmune condition, talk to the rheumatologist/gastroenterologist, etc early, keep them updated regularly and reach out to get updates on their dz activity, monitor the patient closely...