Surufatinib Combined With Serplulimab Plus Chemotherapy in the Treatment of Extensive-stage Small Cell Lung Cancer

"In dose escalation, Surufatinib will be administered orally (PO) once daily (QD) ,d1-21,q3w + Serplulimab 4.5 mg/kg ivgtt,d1,q3w+Etoposide 100mg/m2,d1-3,q3w + Carboplatin AUC=5,d1,q3w; 4-6 cycles in total.~At the indication-specific expansion portion of the study, patients will receive surufatinib RP2D,d1-21,q3w+Serplulimab 4.5 mg/kg ivgtt,d1,q3w+Etoposide 100mg/m2,d1-3,q3w + Carboplatin AUC=5,d1,q3w, 4-6 cycles in total. After the end of the first-line treatment, patients with CR, PR, and SD can continue to maintenance treatment with Surufatinib RP2D,d1-21,q3w＋Serplulimab 4.5 mg/kg ivgtt,d1,q3w until the disease progressed."