A Study to Assess Intravenous ABBV-1480 Combined With Chemotherapy Versus Pembrolizumab Combined With Chemotherapy for the First Line Treatment of Locally Advanced/Metastatic Non-Small Cell Lung Cancer in Adult Participants

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, accounting for 80%-85% of lung cancers cases. Squamous carcinoma accounts for 20-30% of all NSCLC cases. The purpose of this study is to determine if ABBV-1480 plus chemotherapy works better than pembrolizumab plus chemotherapy in adult participants with NSCLC. ABBV-1480 is an investigational drug being developed for the treatment of NSCLC. Participants will be randomized into 2 groups. One group will receive ABBV-1480 with platinum based chemotherapy. Another group will receive standard of care (SOC) pembrolizumab with platinum based chemotherapy. Up to approximately 940 adult participants with locally advanced (Stage IIIB/C) or metastatic (Stage IV) sqNSCLC, will be enrolled in the study in approximately 250 sites globally. In this Phase 3 study one of two groups will receive doses of Intravenous (IV) ABBV-1480 + Carboplatin \& Paclitaxel/ Nab-paclitaxel and other group will receive Intravenous (IV) Pembrolizumab + Carboplatin \& Paclitaxel/ Nab-paclitaxel. There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at an approved institution (hospital or clinic). The effect of the treatment will be frequently checked by medical assessments, blood tests, questionnaires and side effects.