Neoadjuvant Immune Checkpoint Inhibition and Novel IO Combinations in Early-stage Colon Cancer

Prior treatment

• No previous treatment with immune checkpoint inhibitors targeting CTLA-4, PD-1 or PD-L1
• No radiotherapy prior to or planned post-surgery radiotherapy
• No conditions requiring systemic treatment with either corticosteroids (10 mg daily prednisone or more and equivalents) or other immunosuppressive medications within 14 days of study drug administration
• No live vaccines in the 4 weeks prior to inclusion

Other illness

• No signs of obstruction or macroscopic bleeding or suspicion of perforation
• For patients with MSS tumors: no current use of NSAIDs or COX2-inhibitors at registration and no active peptic ulcer, gastrointestinal bleeding, unstable ischemic heart disease of thrombus etiology or significant established ischemic heart disease, peripheral arterial disease and/or cerebrovascular disease
• No history of allergy to study drug components, severe hypersensitivity reaction to any monoclonal antibody, allergy or severe hypersensitivity to NSAIDs or COX2-I (MSS tumors)
• No intercurrent illnesses, including but not limited to infections, unstable angina pectoris
• No positive test for hepatitis B virus surface antigen (HBsAg) or hepatitis C virus ribonucleic acid (HCV antibody) indicating acute or chronic infection
• No autoimmune disease

Other

• No signs of distant metastases
• Colonoscopy must be performed after registration to obtain study-specific biopsies. If biopsies are not possible, patients cannot be included in the study
• WHO performance status of 0 or 1

• Signed written informed consent
• Patients at least 18 years of age
• Non-metastatic adenocarcinoma of the colon (and rectosigmoid considered as nonrectal and not undergoing neoadjuvant treatment)
  • No signs of distant metastases on CT-scan and physical examination;
  • dMMR cohorts 3+6: \>cT3 and/or N+