HW071021

This study will evaluate the safety, tolerability, pharmacokinetics and preliminary efficacy of HW071021 tablets as a monotherapy for advanced solid tumors. Primary objective: To evaluate the safety and tolerability of HW071021 tablets as a monotherapy in patients with advanced solid tumors. Secondary objectives: To evaluate the human PK characteristics of oral administration of HW071021 tablets; To evaluate the dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) that may occur after oral administration of HW071021 tablets at a preset dose (Phase I only); To determine the Phase II recommended dose (RP2D) of HW071021 tablets as a monotherapy in patients with advanced solid tumors; To evaluate the effects of different doses of HW071021 tablets on the QT/QTc interval of subjects (Phase I only); To preliminarily evaluate the efficacy of HW071021 tablets as a monotherapy for advanced solid tumors. Exploratory objective: To explore the population that benefits best from HW071021 tablets.