To Evaluate Efficacy and Safety of Serplulimab + Chemotherapy (Carboplatin- Etoposide) in US Patients With ES-SCLC

Voluntary participation in clinical studies. Male or female aged ≥ 18 years at the time of signing the ICF. Histologically or cytologically diagnosed with ES-SCLC (according to the Veterans Administration Lung Study Group staging system). No prior systemic therapy for ES-SCLC. At least one measurable lesion as assessed according to RECIST 1.1 within 4 weeks prior to randomization. Major organs are functioning well. Every effort should be made to provide tumor tissues for the determination of PD-L1 expression. An ECOG PS score of 0 or 1. An expected survival ≥ 12 weeks. Subjects with prior denosumab use that can and agree to switch to bisphosphonate therapy for bone metastases starting prior to randomization and throughout treatment. Participant must keep contraception.

Histologically or cytologically confirmed mixed SCLC. Known history of severe allergy to any monoclonal antibody. Known hypersensitivity to carboplatin or etoposide. Patients with myocardial infarction within half a year before the first dose of the study drug, poorly controlled arrhythmia. Pregnant or breastfeeding females. Patients with a known history of psychotropic drug abuse or drug addiction. Patients who have other factors that could lead to the early termination of this study based on the investigator's judgment.