Safety and Efficacy Evaluation of Serplulimab Plus Chemo in SCLC Transformed From EGFR-mutated NSCLC After Treatment

Participants with EGFR-mutant NSCLC who were transformed into SCLC after treatment and did not undergo systemic anticancer therapy after transformation will be divided into three cohorts. We plan to enroll 36 patients in the first cohort, and 18 patients in the second cohort. Participants in cohort 1 and cohort 2 will undertake a combination chemotherapy regimen, comprised of serplulimab (300mg), etoposide (100 mg/m2), and carboplatin (AUC 5 mg/mL/min, up to 750mg). These agents will be administered intravenously in 3-week intervals over a span of 4 to 6 cycles. Participants in cohort 3 will be treated with the clinical routine treatment recommended by the investigator.