A Study of Amivantamab Monotherapy and in Addition to Standard-of-Care Chemotherapy in Participants With Advanced or Metastatic Colorectal Cancer

Inclusion Criteria: * Participant must have been previously diagnosed with histologically or cytologically confirmed unresectable or metastatic adenocarcinoma of the colon or rectum * Participant must have tumor previously characterized as having wild-type Kirsten rat sarcoma viral oncogene (KRAS), neuroblastoma RAS viral oncogene homolog (NRAS), v-raf murine sarcoma viral oncogene homolog B (BRAF), and without evidence of Erb-b2 receptor tyrosine kinase 2/human epidermal growth factor receptor 2 (ERBB2/HER2) amplification. Additional cohort-specific requirements: * Phase (Ph) 2 (Cohorts A, B, and C) Amivantamab monotherapy: Participant must have received at least 2 but not more than 3 prior lines of systemic therapy in the metastatic setting. Participant must have been diagnosed with left-sided colorectal cancer (CRC) (Cohort A and B) and right-sided (Cohort C)and have received or been intolerant to standard of care (SoC) fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy and an anti-vascular endothelial growth factor (VEGF) treatment. Participant must be anti-EGFR treatment naive in Cohort A, an anti-epidermal growth factor receptor (EGFR) treatment Cohort B, with or without an anti-EGFR treatment in Cohort C * Ph 1b Dose Confirmation Cohorts (Ph1b-D and Ph1b-E), Ph2 (Cohorts D and E) Amivantamab+mFOLFOX6/FOLFIRI: Participant must been diagnosed with CRC and have received no more than 1 prior line of systemic therapy in the metastatic setting. Cohort P…