A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, Efficacy and Indications of RP903

Phase Ia is divided into two phases of dose escalation and dose extension: This part includes dose escalation and dose extension of RP903 single agent to investigate the safety, tolerability, maximum tolerated dose and pharmacokinetic (PK) characteristics of RP903 single agent. Phase Ib is the clinical indication expansion phase, and the primary purpose of this phase is to evaluate the initial safety and anti-tumor efficacy in a selected indication target population. After determining RP903 monotherapy RP2D in Phase Ia, SMC will select four advanced malignant tumors with PIK3CA mutations (cervical cancer, endometrial cancer, breast cancer, and ovarian cancer) as indications for clinical expansion studies based on phase Ia efficacy, safety, and pharmacokinetic (PK) data. The dose was determined according to the results of the dose escalation phase and the dose extension phase.