Therapeutic Applications of Programmed Death Ligand 1 Inhibitors in Small Cell Lung Cancer

Background: Small cell lung cancer (SCLC) is an aggressive cancer with rapid progression, limited treatment success, and high relapse rates. Chemotherapy and radiation are standard treatments but often result in chemoresistance. PD-L1 inhibitors have gained attention for their role in enhancing tumor immunity. Methods: This review summarizes clinical trials involving PD-L1 inhibitors, such as atezolizumab, durvalumab, pembrolizumab, and nivolumab, in SCLC treatment. Key trials include IMpower133, CASPIAN, KEYNOTE-604, and CheckMate 331, focusing on survival outcomes and treatment efficacy. Results: Studies such as IMpower133 and CASPIAN demonstrate improved overall survival when PD-L1 inhibitors were added to platinum-based chemotherapy. However, outcomes in trials such as KEYNOTE-604 and CheckMate 331 varied, showing the need for refined patient selection. Adverse events (AEs) associated with these treatments were also noted. PD-L1 inhibitors offer promise in SCLC treatment, but efficacy varies across trials and patient groups. Future research should focus on better patient selection and overcoming resistance mechanisms. Addressing immune-related AEs is essential for optimizing treatment strategies.