This is a global, multicenter, double-blind, placebo-controlled, randomized adaptive Phase 2/3 study to evaluate the clinical activity and safety of EIK1001 administered IV in combination with pembrolizumab and histologically appropriate chemotherapy (pemetrexed plus either carboplatin or cisplatin) to participants with Stage 4 non-squamous or (carboplatin plus either paclitaxel or nab-paclitaxel) for participants with squamous NSCLC who have not received prior systemic therapy. The study is conducted in 2 phases (Phase 2 and Phase 3) and analyzed in 3 parts (dose optimization, dose expansion and confirmatory hypothesis testing).