A Study designed to evaluate the efficacy and safety of tiragolumab plus atezolizumab compared with placebo plus atezolizumab administered in participants with PD-L1 ≥ 1% TC Stage IIB, IIIA, or select IIIB (T3N2 only) NSCLC following resection and adjuvant platinum-based chemotherapy

Prior treatment

• Any history of prior NSCLC within the last 5 years
• Previous NSCLC must have been treated with surgery only
• Prior treatment with systemic therapy (e.g., chemotherapy or immunotherapy) for the treatment of NSCLC, with the exception of adjuvant platinum-based chemotherapy as outlined in the inclusion criteria

Other illness

• Any evidence of residual disease or disease recurrence following surgical resection of NSCLC, or during or following adjuvant chemotherapy

Lab values

• NSCLC with a mutation in the EGFR gene or an ALK fusion oncogene

• Eastern Cooperative Oncology Group performance status of 0 or 1
• Histological or cytological diagnosis of Stage IIB, IIIA, and select IIIB (T3N2) NSCLC of either non-squamous or squamous histology
• Participants must have had complete resection of NSCLC (no residual tumor and all surgical margins negative for invasive carcinoma)
• At a minimum, mediastinal lymph node systematic sampling will have occurred, though complete mediastinal lymph node dissection (MLND) is preferred
• Participants must have received between one to four cycles (four preferred) of adjuvant histology-based platinum doublet chemotherapy: cisplatin (preferred) or carboplatin, with pemetrexed (non-squamous), gemcitabine, docetaxel, vinorelbine, etoposide, or paclitaxel
• Participants must have recovered adequately from surgery and from adjuvant chemotherapy (no Grade > 2 unresolved toxicity)