This is a Phase II, single-arm, open-label clinical study to evaluate the efficacy and safety of Sacituzumab Tirumotecan (SKB264) combined with Anlotinib in patients with extensive-stage small cell lung cancer (ES-SCLC). The study is designed for patients who have experienced disease progression or treatment failure after prior first-line therapy with a PD-(L)1 inhibitor combined with platinum-based doublet chemotherapy. The primary hypothesis is that this combination therapy will improve the objective response rate compared to historical controls.