A Study of Benmelstobart, Anlotinib, Chemotherapy and Thoracic Radiotherapy for People With Extensive-stage Small Cell Lung Cancer

This is a single-center, single-arm, exploratory clinical study conducted at Shanghai Pulmonary Hospital, Tongji University. It aims to evaluate the efficacy and safety of first-line treatment with benmelstobart plus anlotinib and chemotherapy (carboplatin/cisplatin plus etoposide), followed by sequential thoracic radiotherapy, in patients with previously untreated extensive-stage small cell lung cancer (ES-SCLC). Eligible participants will be adults aged 18-75 years with histologically or cytologically confirmed ES-SCLC, measurable lesions per RECIST 1.1, ECOG performance status 0-1, and adequate organ function. Patients will receive 4 cycles of induction therapy (benmelstobart, anlotinib, platinum-etoposide chemotherapy). Those without disease progression will receive consolidative thoracic radiotherapy, followed by maintenance therapy with benmelstobart plus anlotinib until disease progression or unacceptable toxicity. The primary endpoint is objective response rate (ORR) assessed by investigators. Secondary endpoints include progression-free survival (PFS), overall survival (OS), disease control rate (DCR), duration of response (DOR), and safety parameters including adverse events graded by CTCAE 5.0. A total of 33 subjects will be enrolled. This study uses a non-randomized, open-label design without a control group.