<h4>Objective</h4>This study evaluated the value of lipoprotein(a) (LPA) in lung adenocarcinoma (LUAD) patients receiving first-line chemoimmunotherapy and developed a model to predict progression-free survival (PFS) and grade 3/4 adverse events (G3/4 AEs).<h4>Methods</h4>A prospective cohort study was conducted on driver gene negative metastatic LUAD patients with PD-L1 TPS <50%, who received first-line chemoimmunotherapy. Here, CD274 is linked to lung adenocarcinoma.