Sacituzumab Tirumotecan in Combination With Anlotinib in Previously Treated Patients With Extensive-Stage Small Cell Lung Cancer (ES-SCLC)

Inclusion Criteria: * 1.Voluntary participation with written informed consent obtained prior to any study-specific procedures. * 2.Age ≥ 18 years and ≤ 75 years, regardless of sex. * 3.Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. * 4.Life expectancy of at least 3 months. * 5.Histologically or cytologically confirmed small cell lung cancer (SCLC) based on pathology and immunohistochemistry/immunophenotyping results; disease staged as extensive-stage SCLC (ES-SCLC) according to the Veterans Administration Lung Study Group (VALG) staging system. * 6.Disease progression (at the time of enrollment) after at least two cycles of platinum-based systemic therapy with or without PD-1/L1 inhibitors; no more than two prior lines of therapy. Note: Adjuvant therapy is considered one prior line if disease progression occurs during treatment or within 6 months of the last adjuvant dose. * 7.At least one measurable lesion as defined by RECIST version 1.1. Lesions previously treated with local therapy may be considered target lesions only if progression has been clearly documented at that site post-treatment. Brain lesions as sole target lesions are not acceptable. * 8.Adequate bone marrow function without transfusion or growth factor support within 14 days prior to screening: Absolute neutrophil count (ANC) ≥ 1.5 × 10⁹/L; Platelet count ≥ 100 × 10⁹/L; Hemoglobin ≥ 90 g/L. * 9.Adequate hepatic function: Total bilirubin (TBIL) ≤ 1.5 × upper limit of normal (ULN), o…