Early Vedolizumab as First-Line for Immune-Related Colitis Therapy Trial

Inclusion Criteria: * In order to participate in the study, a patient must meet all the following inclusion criteria: * Age ≥18 years. * Treatment with an ICI for cancer within the past 8 weeks. * Confirmed endoscopic/histologic diagnosis of ICI colitis. * Grade 2-3 diarrhea by Common Terminology Criteria for Adverse Events. * Willing and able to comply with the requirements of the protocol. * Ability to understand and the willingness to sign a written informed consent document. * Exclusion Criteria * Prior history of inflammatory colitis requiring treatment with greater than prednisone 10 mg daily or equivalent or any immunosuppressive medication. * Current or recent use of immunosuppressive biologic medication (for any reason including ICI colitis) within 4 weeks. * Concurrent immune-related adverse event requiring systemic steroids or systemic immunosuppression within 2 weeks. * Colonic perforation or abscess. * Partial or complete bowel obstruction within the last 3 months, signs/symptoms of bowel obstruction, or known radiologic evidence of impending obstruction. * Active Clostridium difficile or other colonic infection. * Concurrent hepatitis B or C infection. * History of untreated tuberculosis and/or positive quantiferon/Tspot test without previous tuberculosis prophylaxis, or untreated active infection with mycobacterium tuberculosis. * Active or known prior infection with nontuberculous mycobacteria (NTM). * Unable or unwilling to undergo a colonoscopy/flexible sig…