• Histologically or cytologically confirmed diagnosis of squamous non-small cell lung cancer (NSCLC) \[Stage IV: M1a, M1b, M1c, American Joint Committee on Cancer Staging Manual, version 8\]

• Measurable disease per Response Evaluation Criteria in Solid Tumours (RECIST) 1.1 as assessed by the local site investigator/radiology

• Has life expectancy ≥3 months

• Has Eastern Cooperative Oncology Group Performance Status (ECOG PS) score of 0 or 1 assessed within 7 days prior to allocation

• Archival tumor tissue sample or newly obtained core, incisional, or excisional biopsy of a tumor lesion not previously irradiated has been provided

• Human immunodeficiency virus (HIV)-infected participants must have well controlled HIV on antiretroviral therapy (ART)

• Participants who are hepatitis B surface antigen (HBsAg)-positive are eligible if they have received hepatitis B virus (HBV) antiviral therapy for at least 4 weeks and have undetectable HBV viral load before allocation

• Participants with history of hepatitis C virus (HCV) infection are eligible if HCV viral load is undetectable at screening

• Participants who have adverse events (AEs) due to previous anticancer therapies must have recovered to Grade ≤1 or baseline (participants with endocrine-related AEs who are adequately treated with hormone replacement are eligible). Note: Participants with Grade =2 neuropathy are eligible

• Has adequate organ function

• For Maintenance only (prior to randomization): is without disease progression of their NSCLC, as determined by BICR using RECIST 1.1 after completion of study-specified Induction with an evaluable scan at Week 12 or most recent scan before randomization

• For Maintenance only (prior to randomization): has ECOG PS of 0 or 1 as assessed at the Prerandomization Visit

• For Maintenance only (prior to randomization): all AEs (with the exception of alopecia, Grade 2 fatigue, and Grade ≤2 endocrine-related AEs requiring treatment or hormone replacement) have recovered