Single-dose and Multiple-dose X842 Phase 1 Study

A total of 7 dose groups will be set for the ascending dose: 5.6 mg, 12.5 mg, 25 mg, 50 mg, 100 mg, 150 mg, 225 mg. In the 5.6 mg dose group, 4 subjects will receive X842; in the 12.5 mg, 25 mg, 50 mg, 100 mg, 150 mg, 225 mg dose groups, 8 subjects in each group will receive X842. Each subject can only receive a certain dose level and cannot enter in multiple dose groups repeatedly.

Two dose groups will be set, including the groups receiving the recommended phase II dose and a higher dose; Eight subjects will be enrolled in each group, with half male and half female, who will receive X842 once daily for 5 consecutive days. Each subject can only receive a certain dose level and cannot enter in multiple dose groups repeatedly.

Twelve subjects (appropriate ratio of male to female) screened for eligibility will be randomized into Group A and B. The 6 subjects in Group A will take the study drug (X842) in fasted condition and subject in Group B will take the study drug in fed condition in the 1st cycle. In the 2nd Cycle, subjects in Group A will take the study drug in fed condition, and subjects in Group B will take the study drug in fasted condition. The interval between the two cycles is at least 7 days.