Sotorasib and Panitumumab Versus Investigator's Choice for Participants With Kirsten Rat Sarcoma (KRAS) p.G12C Mutation

Inclusion Criteria: * Participant has provided informed consent/assent prior to initiation of any study specific activities/procedures. * Age ≥18 years. * Pathologically documented metastatic colorectal adenocarcinoma with Kirsten rat sarcoma (KRAS) p.G12C mutation as determined by prospective central testing, using the analytically validated Qiagen Therascreen KRAS RGQ polymerase chain reaction Kit in CRC as an investigational device demonstrating a KRAS p.G12C mutation is present. Local testing and documentation of KRAS p.G12C mutation should have been previously performed as part of standard of care. * Participants will have received at least 1 prior line of therapy for metastatic disease. Participants must have received and progressed or experienced disease recurrence on or after fluoropyrimidine, irinotecan, and oxaliplatin given for metastatic disease unless the participant, in the opinion of the investigator, is not a candidate for fluoropyrimidine, irinotecan, or oxaliplatin, in which case, the participant may be eligible after investigator discussion with Amgen medical monitor provided participant has received at least one prior line of therapy for metastatic disease and provided trifluridine and tipiracil or regorafenib is deemed the appropriate next line of therapy for the participant. * Measurable disease per Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 criteria. Lesions previously radiated are not considered measurable unless they have progressed af…