The purpose of this study is to compare anti-tumor activity of amivantamab in addition to pembrolizumab and carboplatin versus pembrolizumab, 5-fluorouracil (FU), and platinum therapy (carboplatin or cisplatin) in participants with refractory/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). HNSCC is a type of cancer that develops in the head and neck regions, including the outer tissue layer of the mouth and throat. This study will focus on participants with HNSCC who are treatment-naive (have not received prior treatment) in the R/M setting.

The purpose of this study is to compare how long the participants are disease-free (progression-free survival) and and the length of time until a participant dies (overall survival), when treated with amivantamab and chemotherapy with 5-fluorouracil, leucovorin calcium (folinic acid) or levoleucovorin, and irinotecan hydrochloride (FOLFIRI) versus either cetuximab or bevacizumab and FOLFIRI given to participants with Kirsten rat sarcoma viral oncogene/ neuroblastoma RAS viral oncogene homolog (KRAS/ NRAS) and v-raf murine sarcoma viral oncogene homolog B (BRAF) wild-type recurrent, unresectable or metastatic colorectal cancer who have previously received chemotherapy.