Overview

A total of 50 healthy subjects will be allocated to 5 groups in the SAD study. Each group includes 10 subjects (8 subjects will receive RZ-629 and 2 receive placebo). All subjects will check-in on the day before the administration (Day -1) and on Day 1. Each subject in fasted state will be randomly assigned to receive a single oral dose of RZ-629 or placebo. Subjects will remain in the clinical research unit (CRU) through the completion of the safety/tolerability evaluation. The safety review committee (SRC) will review all safety data and blinded summary of available PK data through the safety follow-up and decide to proceed to the next dose level.

Eligibility

Inclusion Criteria: 1. Sign the informed consent form (ICF) before the study, and fully understand the content, process and possible adverse reactions of the trial.

2. Healthy male or female subjects between the ages of 18 and 65 years, inclusive.

3. With a minimum body weight of 50 kg for males, and 45 kg for females, have a BMI of

18 to 32 kg/m2, inclusive.

4. Fasting plasma glucose is between 3.9 mmol/L (70.2 mg/dL) and 6.1 mmol/L (109.8

mg/dL) at screening.

5. In good health, with no clinically relevant acute or chronic medical conditions or

     severe diseases of the cardiovascular, gastrointestinal, hepatic, renal, endocrine,
     pulmonary, neurologic, psychiatric, respiratory, blood, immune or dermatological
     systems, as judged by the investigator.

6. With no clinically significant findings from vital signs measurements, physical

     examination, clinical laboratory evaluations and 12-lead ECG, as judged by the
     investigator.

7. Subjects must be willing to understand and comply with all research procedures and

restrictions and be able to communicate effectively with researchers.

Exclusion Criteria: 1. With a specific history of allergies or known to have multiple allergies.

2. Have experienced acute illnesses within 2 weeks prior to the first dose or are

taking concomitant medications.

3. With a history or current presence of dysphagia or diseases that may potentially

interfere with drug absorption or metabolism.

4. Subjects and their first-degree relatives with a history of diabetes before

screening.

5. With a history of hypoglycemia or with impaired awareness or cognition of

hypoglycemic symptoms within 3 months prior to screening.

6. History of previous corrected QT interval (QTc) prolongation or clinically abnormal

electrocardiogram (ECG) finding during screening.

7. Have undergone major surgery within the past 6 months, or those planning to undergo

surgery during the study period.

8. Have used any medications and dietary supplements within 2 weeks prior to the first

dose.

9. Within 48 h prior to the first dose, have consumed food or beverages containing

     caffeine, alcohol, or concentrated tea, or those who have consumed special diets
     and/or purine-rich diets or have other factors that may affect drug absorption,
     distribution, metabolism, or excretion.

10. Have received vaccinations within 4 weeks prior to the first dose or plan to receive

vaccinations during the trial.

11. Have participated in other clinical trials within 3 months prior to the first dose,

or those planning to participate in other trials during the study period.

12. Have donated blood and blood products (including plasma) within 3 months prior to

     the first dose or have experienced non-physiological blood loss of ≥ 400 mL within 6
     months.

13. Have consumed an average of more than 14 units of alcohol per week within the past

12 months prior to screening.

14. Have smoked more than 5 cigarettes per day within the past 3 months or cannot stop

using any tobacco products during the study.

15. With a history of drug abuse within the past 12 months or positive drug abuse at

screening.

16. With positive results for serology of infectious diseases at screening. 17. Cannot

tolerate venipuncture/indwelling needle or have a history of vasovagal syncope.

18. Subjects deemed unsuitable for participation in this trial by the investigator due

to other factors.

19. With chronic or acute gastrointestinal inflammation. 20. Abnormal liver function

     tests: ALT or AST > 2×ULN, or TBIL > 1.5×ULN. 21. Use of drugs that may affect
     glucose metabolism (e.g., systemic steroids, nonselective β-blockers, monoamine
     oxidase inhibitors) within 1 month prior to screening.