CLINICAL TRIAL / NCT05855200

Inclusion Criteria: - Has untreated pathologically confirmed colon adenocarcinoma - Has resectable colon adenocarcinoma defined as clinically T4N0 or Stage III - Has radiologically evaluable disease - Has a tumor demonstrating the presence of either dMMR status or MSI-H Exclusion Criteria: - Has distant metastatic disease. - Has received prior medical therapy (chemotherapy, immunotherapy, biologic, or targeted therapy), radiation therapy or surgery for management of colon cancer - Has a tumor that, in the investigator's judgment is causing symptomatic bowel obstruction or otherwise requires urgent/emergent surgery - Has undergone any major surgical procedure, open biopsy, or experienced significant traumatic injury within 28 days prior to randomization - Has any history of interstitial lung disease or pneumonitis - Has cirrhosis or current unstable liver or biliary disease per investigator assessment defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminemia, esophageal/gastric varices, or persistent jaundice - Has a history of allogenic stem cell transplantation or organ transplantation - Is receiving any other anticancer or experimental therapy. No other experimental therapies (including but not limited to chemotherapy, radiation, hormonal treatment, antibody therapy, immunotherapy, gene therapy, vaccine therapy, or other experimental drugs) of any kind are permitted while the participant is receiving study intervention - Is pregnant, breastfeeding, or expecting to conceive children within the projected duration of the study - Has a history of severe allergic and/or anaphylactic reactions to chimeric, human or humanized antibodies, fusion proteins, or known allergies to dostarlimab, or its excipients, or any components of FOLFOX or CAPEOX