Biologic Therapy for Refractory Immune Checkpoint Inhibitor Colitis

Immune checkpoint inhibitors (ICI) are treatments for several cancer types. Pathogenesis of ICI-induced colitis is not yet clearly explained as it can be disguised as another form such as inflammatory bowel disease or IBD. Recent studies revealed that ICI-induced colitis is a unique form of colitis wherein the synergy of regulatory T cells with the gut microbiome is involved. Diagnosis of colitis can be done via endoscopic lesions and histopathological methods. A patient with colitis can be compared with someone who has IBD. Initial treatment is a corticosteroid. Cooperation between gastroenterologists and oncologists is required to understand further the complete diagnosis and management of different behaviors of ICI-induced colitis. Although immunotherapy provides breakthroughs in treating cancer, adverse effects cannot be prevented and have to be carefully addressed. This study aimed to discuss different biologic therapeutic perspectives in treating refractory immune checkpoint inhibitor-induced colitis. This review provided guidelines, challenges, and suggested protocols for drug immunosuppression.