This trial is divided into three parts: 1) The first part: Four Chinese healthy subjects will be included in the pre-test group to evaluate the safety, tolerability and pharmacokinetics after taking SYHA1805 tablets; 2) The second part: To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamic characteristics, several single ascending doses of SYHA1805 tablets or matching placebo tablets will be randomly administered to 24 Chinese healthy subjects under fasting condition; 3) The third part :To evaluate the food effect on the pharmacokinetic characteristics, a single dose SYHA1805 tablets will be administered to 12 Chinese healthy subjects under fed or fasted condition.
This is a three-part Phase Ia study to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending doses of SYHA1805.