A Phase II Platform Study to Evaluate Treatment With Cemiplimab Monotherapy or Cemiplimab Plus Fianlimab or Other Novel Combinations in Patients With Colorectal Cancer With Minimal Residual Disease Following Definitive Surgery and Chemotherapy (EMPIRE)

Inclusion Criteria: * The patient must have consented to participate and, prior to beginning specific study procedures, must have signed and dated appropriate Institutional Review Board (IRB) -approved consent forms that conform to federal and institutional guidelines for study treatment. * Patients must be greater than or equal to18 years old. * The ECOG performance status must be 0-1. * Patients must have confirmed histologic and pathologic stage II/III colon, stage II/III rectal, or oligometastatic stage IV colorectal adenocarcinoma (per AJCC 8th edition). * There must be documentation by CT scan with contrast that the patient has no definitive evidence of metastatic disease including assessment of chest, abdomen, and pelvis at the time of study enrollment * All patients must have had a complete (R0) resection of their primary tumor and oligometastatic disease if present AND at least 3 months of a standard systemic chemotherapy regimen (e.g., FOLFOX or CAPOX or fluoropyrimidine monotherapy). This includes either adjuvant chemotherapy for colon cancer or perioperative (adjuvant or neoadjuvant) chemotherapy for rectal cancer or oligometastatic colon or rectal cancer. Chemoradiotherapy for rectal cancer (as a component of curative treatment) is acceptable. NOTE: Patients who achieve a clinical complete response and opt for a non-operative approach to their primary tumor management are not eligible. * Patients must be ctDNA-positive by an assay run in any CLIA-certified la…