Inclusion Criteria:

          -  Participant must have newly diagnosed histologically or cytologically confirmed,
             locally advanced or metastatic non-small cell lung cancer (NSCLC) that is treatment
             naive and not amenable to curative therapy including surgical resection or
             chemoradiation

          -  The tumor harbors exon 19 deletions (Exon 19del) or Exon 21 L858R substitution, as
             detected by an food and drug administration (FDA)-approved or other validated test in
             a clinical laboratory improvement amendments (CLIA) certified laboratory (sites in the
             United states [US]) or an accredited local laboratory (sites outside of the US) in
             accordance with site standard of care

          -  Mandatory submission of unstained tissue from tumor (in a quantity sufficient to allow
             for central analysis of EGFR mutation status and blood (for circulating tumor
             deoxyribonucleic acid [ctDNA], digital droplet polymerase chain reaction [ddPCR], and
             pharmacogenomic analysis)

          -  Any toxicities from prior anticancer therapy must have resolved to common terminology
             criteria for adverse events (CTCAE) Grade 1 or baseline level

          -  Participant must have at least 1 measurable lesion, according to response evaluation
             criteria in solid tumors (RECIST) v1.1 that has not been previously irradiated.
             Measurable lesions should not have been biopsied during screening, but if only 1
             non-irradiated measurable lesion exists, it may undergo a diagnostic biopsy and be
             acceptable as a target lesion, provided the baseline tumor assessment scans are
             performed at least 14 days after the biopsy

        Exclusion Criteria:

          -  Participant has received any prior systemic treatment for locally advanced or
             metastatic disease (adjuvant or neoadjuvant therapy for early stage disease is
             allowed, if administered more than 12 months prior to the development of locally
             advanced or metastatic disease)

          -  Participant has an active or past medical history of leptomeningeal disease

          -  Participant with untreated spinal cord compression. A participant that has been
             definitively treated with surgery or radiation and has a stable neurological status
             for at least 2 weeks prior to randomization is eligible provided they are off
             corticosteroid treatment or receiving low-dose corticosteroid treatment less than or
             equal to (<=) 10 milligrams per day (mg/day) prednisone or equivalent

          -  Participant has an active or past medical history of interstitial lung disease
             (ILD)/pneumonitis, including drug-induced or radiation ILD/pneumonitis

          -  Participant has known allergy, hypersensitivity, or intolerance to the excipients used
             in formulation of amivantamab, lazertinib, or osimertinib, or any contraindication to
             the use of osimertinib

          -  Participant has symptomatic brain metastases. A participant with asymptomatic or
             previously treated and stable brain metastases may participate in this study