XCCS605B

The main purpose of single-drug or combination-drug escalation is to evaluate the safety and tolerability of XCCS605B alone or in combination with toripalimab in the treatment of patients with advanced solid tumors, explore the maximum tolerated dose of XCCS605B alone or in combination with toripalimab, and determine the recommended dose (RP2D) for Phase II. Secondary purpose: to evaluate the PK characteristics of XCCS605B alone or in combination with toripalimab in the treatment of patients with advanced solid tumors; to observe the preliminary efficacy of XCCS605B alone or in combination with toripalimab in the treatment of patients with advanced solid tumors. Exploratory purpose: to explore biomarkers related to the efficacy of XCCS605B alone or in combination with toripalimab. The main purpose of combination-drug expansion is to evaluate the efficacy of XCCS605B combined with toripalimab in the treatment of patients with advanced solid tumors such as squamous cell carcinoma of the external genitalia (such as anal canal cancer, penile cancer, vulvar cancer, etc.), small cell lung cancer, esophageal squamous cell carcinoma, and head and neck squamous cell carcinoma. Secondary objectives: To evaluate the safety of XCCS605B combined with toripalimab in the treatment of patients with advanced solid tumors such as squamous cell carcinoma of the genitalia (such as anal canal cancer, penile cancer, vulvar cancer, etc.), small cell lung cancer, esophageal squamous cell carcinoma, head and neck squamous cell carcinoma, etc.; To evaluate the PK characteristics of XCCS605B combined with toripalimab in the treatment of patients with advanced solid tumors such as squamous cell carcinoma of the genitalia (such as anal canal cancer, penile cancer, vulvar cancer, etc.), small cell lung cancer, esophageal squamous cell carcinoma, head and neck squamous cell carcinoma, etc. Exploratory objectives: To explore biomarkers associated with the efficacy of XCCS605B combined with toripalimab.