A Phase 1 Study of Y-3 in US Healthy Volunteers.

Inclusion Criteria:

1. Medically documented as healthy at the time of screening as determined by theirmedical history, medical assessment, physical examination, 12-lead electrocardiogram (ECG), and clinical laboratory tests, etc.

2. Within 18-45 years at the time of informed consent, inclusive.

3. Body weight ≥ 50 kg for male and ≥ 45 kg for female, body mass index (BMI) withinthe range of 19 - 28 kg/m2, inclusive.

4. Fully understand and provide a signed informed consent before performing anystudy-related procedures.

5. Comply with the study and follow-up procedures.

Exclusion Criteria:

1. Known allergy to Y-3 or any of its excipients.

2. Have disease history or current disease that may affect the safety evaluation of thesubject or the internal process of the study drug, that the investigator judged tobe of clinical significance, including the cardiovascular system, endocrine system,central nervous system, digestive system, respiratory system, hematological system,immunology, psychiatry, metabolic abnormalities, etc.

3. Clinically significant abnormal 12-lead electrocardiograms (ECG) and vital signsjudged by the investigator.

4. Clinically significant abnormal laboratory tests (hematology, serum chemistry,coagulation, urinalysis, etc.) and other screening tests judged by the investigator.

5. Test positive for hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV)antibody, syphilis antibody or human immunodeficiency virus (HIV) antibody.

6. Alcoholics or regular drinkers within 6 months prior to screening, that is, thosewho drink more than 14 units of alcohol per week (1 unit = 360 mL of beer or 45 mLof alcohol with 40% alcohol content or 150 mL of wine), or whose alcohol breath testresults are greater than 0.0 mg/100 mL, or who cannot abstain from alcohol duringthe study.

7. Smokers, that is, those who smoke more than 3 cigarettes per day within 3 monthsprior to screening, or those who cannot comply with the prohibition of smokingduring the study.

8. Current or former drug users, or positive urine screen for drugs of abuse atscreening.

9. Have special requirements for diet and cannot follow the unified diet.

10. Drink too much tea, coffee and/or caffeine-containing beverages (more than 8 cups, 1cup = 250 mL) every day within 3 months prior to screening, or who have consumed anydiet (food or beverage) rich in grapefruit, pitaya and mango within 14 days prior toscreening.

11. Have taken any prescription drug or over-the-counter drug, traditional Chinesemedicine or herbal medicine, health products within 14 days prior to screening, or 5half-lives, whichever is longer, before the first dose of study drug, or havereceived vaccine inoculation within 14 days prior to screening; or plan to inoculatevaccine during the study.

12. Participated in any other clinical trials within 3 months prior to screening.

13. Donation or loss of blood equal to or in excess of 200 mL within 3 months prior toscreening.

14. Female subjects who have unprotected intercourse within 14 days prior to screening,or pregnant or lactating women.

15. Male subjects (or their partners) or female subjects have baby plans during thewhole trial period and within 3 months after the end of the trial, or subjects areunwilling to take one or more non-drug contraceptive measures (such as completeabstinence, condoms, ligation, etc.) during the study.

16. Subjects voluntarily withdraw from the study due to personal reason, or subjects whothe investigator believes are not suitable for enrollment for other reasons.

17. Suicidal ideation, history of suicidal behavior, or history of psychiatriccomorbidities.