This is an open-label, two-cycle clinical study to evaluate the drug interaction between itraconazole or dextromethorphan and IBI351 in healthy subjects. A total of two cohorts of 12 healthy male subjects were planned to be enrolled in each cohort.

Inclusion Criteria:

1. Voluntarily sign the informed consent form before the trial, fully understand the content, process and possible adverse reactions of the trial, and be able to complete the study according to the requirements of the trial protocol.
2. Healthy male subjects aged 18 to 45 years (including both ends) at the time of signing informed consent.
3. Body weight is not less than 50 kg, and body mass index (BMI) is in the range of 19 ~ 26 kg/m2 (including both ends).
4. Physical examination, vital signs, routine laboratory tests (blood routine, blood biochemistry, urine routine, coagulation function), thyroid function, 12-lead electrocardiogram, chest CT, abdominal ultrasound (hepatobiliary, pancreatic, spleen and kidney), echocardiography (only applicable to Cohort 1 subjects) showed no abnormalities; or abnormal test results but judged as normal or clinically insignificant by the investigator.

Exclusion Criteria:

1. have taken any products containing alcohol or have a positive alcohol breath test (≥ 20 mg/100 ml) within 24 hours before taking study medication.
2. hepatitis B surface antigen HBsAg positive.
3. hepatitis C virus antibody positive.
4. positive AIDS antigen/antibody or Treponema pallidum antibody.