RecruitingPhase 2Drug trialA Study of Simmitinib Plus Irinotecan in Advanced Esophageal Squamous Cell CarcinomaTo evaluate the safety and efficacy of simmitinib plus irinotecan liposome in the treatment of advanced esophageal squamous cell carcinoma, and to evaluate the PK of the drug and the correlation between biomarkers and clinical efficacy of simmitinib plus irinotecan liposome.