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

Inclusion Criteria: Aged 18 years-75 years Histological transformation from EGFR-mutated NSCLC to SCLC after treatment No systemic therapy or immunotherapy targeting T-SCLC, anti-PD-1/L1 or CTLA-4 should have been administered after the histologic transformation( immunotherapy prior to transformation is acceptable, but the last line of therapy prior to transformation cannot include immunotherapy) ECOG PS 0 or 1 At least one measurable target lesion based on Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1) criteria identified within the four weeks leading up to the initial treatment dose Expected life expectancy of 12 weeks or more Adequate organ function Exclusion Criteria: Pathological reports post the histologic transformation not provided Active central nervous system (CNS) metastases and/or carcinomatous meningitis identified during the screening phase (Exceptions will be made for patients with asymptomatic brain metastases or those who have had stable brain metastases for at least 2 months after treatment) Other active malignancies either concurrently or within the past five years Received Curative radiation therapy within the three months leading up to the first treatment dose