A Global Phase III Study of Rilvegostomig or Pembrolizumab Plus Chemotherapy for First-Line Treatment of Locally Advanced or Metastatic Squamous Non-small Cell Lung Cancer (NSCLC)

Inclusion Criteria: * Histologically or cytologically documented squamous NSCLC. * Stage III B/C or IV mNSCLC (based on the American Joint Committee on Cancer Edition 8) not amenable to curative treatment. * Absence of documented tumor genomic mutation results from tests conducted as part of standard local practice in any actionable driver oncogenes for which there are locally approved and available targeted 1L therapies. * Provision of acceptable tumor sample to confirm tumor PD-L1 expression TC ≥ 1%. * At least one lesion not previously irradiated that qualifies as a RECIST 1.1 TL at baseline and can be accurately measured at baseline as ≥ 10 mm in the longest diameter (except lymph nodes, which must have short axis ≥ 15 mm) with CT or MRI and is suitable for accurate repeated measurements. * Adequate organ and bone marrow function. Exclusion Criteria: * Presence of small cell and neuroendocrine histology components. * Brain metastases unless asymptomatic, stable, and not requiring steroids or anticonvulsants for at least 7 days prior to randomization. A minimum of 2 weeks must have elapsed between the end of local therapy (brain radiotherapy or surgery) and randomization. Participants must have recovered from the acute toxic effect of radiotherapy (eg, dizziness and signs of increased intracranial pressure) or surgery prior to randomization. * Any prior systemic, non-curative therapy received for NSCLC. * Any prior treatment with an anti-PD-1 or anti-PD-L1 agent. * Any prior exposure to an anti-TIGIT therapy or any other anticancer therapy targeting immune-regulatory receptors or mechanisms. * History of another primary malignancy except for malignancy treated with curative intent with no known active disease ≥ 2 years before the first dose of study intervention and of low potential risk for recurrence. * Active or prior documented autoimmune or inflammatory disorders requiring chronic systemic treatment with the use of disease-modifying agents or other immunosuppressive drugs. * Active primary immunodeficiency/active infectious disease(s). * Active tuberculosis infection.