The purpose of this study is to assess the efficacy of adding lazertinib to amivantamab, carboplatin, and pemetrexed (LACP/ACP-L dosing strategies) and amivantamab, carboplatin and pemetrexed (ACP) compared with carboplatin and pemetrexed (CP) in participants with locally advanced or metastatic epidermal growth factor receptor (EGFR) Exon 19del or Exon 21 L858R substitution non-small cell lung cancer (NSCLC) after osimertinib failure. The purpose of the extension cohort is to further describe the safety and efficacy for the ACP-L dosing schedule versus ACP with additional data. After completion of the primary analysis, the study may eventually transition to an open-label extension (OLE) or long-term extension (LTE) phase during which participants will have the option to continue their assigned treatment.