A Study to Evaluate INCA33890 in the Treatment of Circulating Tumor DNA-Positive Stage II/III Microsatellite Stable Colorectal Cancer After Curative Resection and Chemotherapy

Inclusion Criteria: * Received curative-intent (R0) resection of histologically confirmed Stage II or III colorectal adenocarcinoma. * Completed all neoadjuvant and/or adjuvant chemotherapy, including at least 3 months of fluoropyrimidine-based chemotherapy. * Has minimal residual disease (MRD), defined as ctDNA positive by the Signatera™ assay (whole exome sequencing \[WES\] or whole genome sequencing \[WGS\]) in a blood sample collected between: * 2 weeks and 12 months after completion of adjuvant chemotherapy or * 4 weeks and 12 months after curative resection following total neoadjuvant therapy. Note: If the participant received any investigational therapy for MRD, ctDNA positivity must be confirmed in a blood sample collected at least 4 weeks after completion of that investigational therapy and within the applicable 12-month window described above. * Has no clinical or radiographic evidence of disease confirmed by chest, abdominal, and pelvic PET-CT scan and by brain imaging (MRI or CT scan with contrast) within 4 weeks prior to C1D1 study drug administration. * ECOG performance status of 0 or 1. * Adequate organ function determined by laboratory results. Exclusion Criteria: * History of metastatic (Stage IV) colorectal adenocarcinoma, including oligometastatic disease or metastatic recurrence, even if all metastatic sites and the primary tumor were completely resected and the patient is currently without evidence of disease. * MSI-H/dMMR per historical data in the medical record. * History of other malignancy within 2 years. * Treatment with an anti-PD-(L)1 or anti-CTLA-4 for any indication within the last 3 years. * Active autoimmune disease that has required systemic treatment in the past 2 years. * Significant concurrent and/or uncontrolled medical condition. * History of organ transplant, including allogeneic stem cell transplantation. Other protocol-defined inclusion/exclusion criteria apply.