GRK-008

Primary objective: To investigate the safety and tolerability of single and multiple oral administration of GRK-008 tablets in healthy subjects. Secondary objective: To evaluate the pharmacokinetic (PK) characteristics of single and multiple administration of GRK-008 tablets in healthy adult subjects, as well as the correlation between safety and PK exposure, and to provide a basis for dose selection for subsequent clinical studies. Exploratory objective: To explore the effects of GRK-008 on the corrected QT interval and other ECG parameters (heart rate, PR interval, RR interval, and QRS duration); to explore the metabolite profile of GRK-008 in human plasma.