Identification and Treatment Of Micrometastatic Disease in Stage III Colon Cancer

Required: PD-L1 (CD274) expression testing required

Tumor tissue required for PD-L1 biomarker analysis.

Allowed: MLH1 loss

Presence of deficient (d) DNA mismatch repair (dMMR) may be assessed by IHC for MMR protein expression (MLH1, MSH2, MSH6, PMS2) where loss of one or more proteins indicated dMMR.

Allowed: MSH2 loss

Presence of deficient (d) DNA mismatch repair (dMMR) may be assessed by IHC for MMR protein expression (MLH1, MSH2, MSH6, PMS2) where loss of one or more proteins indicated dMMR.

Allowed: MSH6 loss

Presence of deficient (d) DNA mismatch repair (dMMR) may be assessed by IHC for MMR protein expression (MLH1, MSH2, MSH6, PMS2) where loss of one or more proteins indicated dMMR.

Allowed: PMS2 loss

Presence of deficient (d) DNA mismatch repair (dMMR) may be assessed by IHC for MMR protein expression (MLH1, MSH2, MSH6, PMS2) where loss of one or more proteins indicated dMMR.

Allowed: BRAF V600E

Presence of BRAFV600E in tumor tissue previously determined by IMPACT at any time prior to Screening.

Allowed: HER2 (ERBB2) overexpression

HER2 overexpression/amplification as shown by NGS sequencing, IHC/FISH or Tumor with 3+ by IHC or 2+ by IHC and HER2/cep17 ratio >2 by FISH.

Allowed: HER2 (ERBB2) amplification

HER2 overexpression/amplification as shown by NGS sequencing, IHC/FISH or Tumor with 3+ by IHC or 2+ by IHC and HER2/cep17 ratio >2 by FISH.

Must have received: adjuvant chemotherapy (FOLFOX, CAPOX, 5FU analog) — adjuvant

Participants must have completed standard adjuvant chemotherapy per the discretion of the treating physician. Standard therapy includes FOLFOX, CAPOX, or therapy with 5FU analog alone will be permitted if it constitutes appropriate standard therapy in the opinion of the treating physician.

Cannot have received: neoadjuvant chemotherapy

Participants must not have received prior neoadjuvant chemotherapy.

Cannot have received: anticancer therapy (including chemotherapy, immunotherapy, or antineoplastic biologic therapy) (cetuximab, bevacizumab)

Exception: except standard of care adjuvant therapy

With the exception of standard of care adjuvant therapy, patient received anticancer therapy including chemotherapy, immunotherapy, or antineoplastic biologic therapy (e.g., cetuximab, bevacizumab etc.), within 30 days prior to start of study treatment.

Cannot have received: BRAF inhibitor (encorafenib, dabrafenib, vemurafenib)

Prior therapy with a BRAF inhibitor (e.g., encorafenib, dabrafenib, vemurafenib) and/or a MEK inhibitor (e.g., binimetinib, trametinib, cobimetinib).

Cannot have received: MEK inhibitor (binimetinib, trametinib, cobimetinib)

Prior therapy with a BRAF inhibitor (e.g., encorafenib, dabrafenib, vemurafenib) and/or a MEK inhibitor (e.g., binimetinib, trametinib, cobimetinib).

Cannot have received: monoclonal antibody

Has had a prior anti-cancer monoclonal antibody (mAb) within 4 weeks prior to study Day 1 or who has not recovered (i.e., ≤ Grade 1 or at baseline) from adverse events due to agents administered more than 4 weeks earlier.

Cannot have received: radiation therapy

Participants who have had radiotherapy ≤ 14 days prior to start of study treatment or who have not recovered from side effects of such procedure. Note: Palliative radiation therapy must be complete 7 days prior to the first dose of study treatment.

Cannot have received: major surgery

Participants who have undergone major surgery (e.g., in-patient procedures) ≤ 6 weeks prior to start of study treatment or who have not recovered from side effects of such procedure.