BEBT-260

The main purpose of the Phase Ia dose escalation phase is to evaluate the tolerability and safety of BEBT-260 in patients with advanced solid tumors with p53 overexpression; to explore the pharmacokinetic characteristics of BEBT-260 in patients with advanced solid tumors with p53 overexpression. Secondary objectives: to explore the preliminary efficacy of BEBT-260 in patients with advanced solid tumors with p53 overexpression; to explore biomarkers related to pharmacodynamics and safety. The main purpose of the Phase Ib dose expansion phase is to evaluate the safety and tolerability of BEBT-260 monotherapy or combined with low-dose gemcitabine (LDG) in the treatment of patients with advanced solid tumors with p53 overexpression; to recommend the dose (RP2D) for the Phase II clinical trial of BEBT-260 monotherapy or combined with LDG in the treatment of patients with advanced solid tumors with p53 overexpression. Secondary objectives: To explore the pharmacokinetic characteristics of BEBT-260 as a single agent or in combination with LDG in the treatment of patients with advanced solid tumors with overexpression of p53; to evaluate the preliminary efficacy of BEBT-260 as a single agent or in combination with LDG in the treatment of patients with advanced solid tumors with overexpression of p53; to explore biomarkers related to the pharmacodynamics and safety of BEBT-260 as a single agent or in combination with LDG.