This study is expected to enroll 52-87 patients, including 30-60 patients for dose escalation, the enrollment will continue until about 12 patients in the dose group with response, as to determine RP2D (assuming the two dose groups will continue enrollment to 12 patients), additional 10-15 patients will be enrolled at the dose level of determined RP2D. The number of patients finally screened in the study will depend on the number of dose levels evaluated, occurrence of dose-limiting toxicity (DLT) in each dose group and the failure rate of screening.
The objective of this study is to evaluate the safety, tolerability and PK profile of HMPL-295S1 and determine MTD and/or RP2D in patients with advanced malignant solid tumor. It will be extended to enroll 10-15 patients at this dose after RP2D is determined, as to further evaluate the safety of RP2D and the preliminary efficacy of HMPL-295S1. In addition, an exploratory study on the pharmacokinetic biomarkers of HMPL-295S1 is planned in this study.