Pemetrexed 500 milligrams per square meter (mg/m^2), administered by IV infusion, Q3W on Day 1 of each 21-day cycle.
Carboplatin at dose of area under the concentration-time curve (AUC) of 5, administered by IV infusion, Q3W on Day 1 of each 21-day cycle for 4 cycles.
Cisplatin 75 mg/m^2, administered by IV infusion, Q3W on Day 1 of each 21-day cycle for 4 cycles.
Tiragolumab at a fixed dose of 600 milligrams (mg), administered by intravenous (IV) infusion, every 3 weeks (Q3W) on Day 1 of each 21-day cycle.
Atezolizumab at a fixed dose of 1200 mg, administered by IV infusion, Q3W on Day 1 of each 21-day cycle.
Tiragolumab Matching Placebo
Droga
Matching placebo, administered by IV infusion, Q3W on Day 1 of each 21-day cycle.
Pembrolizumab at a fixed dose of 200 mg, administered by IV infusion, Q3W, on Day 1 of each 21-day cycle.