The whole study includes 2 parts. Both the SAD study and MAD study are randomized, double-blinded, and placebo-controlled studies, conducted in healthy subjects, to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics profiles of CS0159. The SAD part also involves a pilot food effect (FE) study, designed to assess the food effect on single-dose PK profile in healthy subjects.

A total of 48 healthy subjects will be allocated to 1 of 6 cohorts (cohort A1~A6) in the SAD study, each cohort including 8 subjects (6 subjects will receive investigational new drug (IND) product and 2 receive placebo). Each subject in fasted state will be randomly assigned to receive a single oral dose of CS0159 or placebo.To ensure the safety for all SAD cohorts (including A3 in both treatment periods).

The MAD study will enroll 32 healthy subjects, allocated to 1 of 4 cohorts (cohort B1~B4) and each cohort including 8 participants (6 subjects will receive IND products and 2 receive placebo). Subjects will be randomly assigned to orally receive the IND product or placebo.

Inclusion Criteria:

1. Healthy male and non-pregnant female volunteers
2. In good health, determined by having no clinically significant findings from medical history, physical examination, 12-lead ECG, vital signs measurements, and clinical laboratory evaluations

Exclusion Criteria:

1. Subjects with special dietary requirements and cannot follow a uniform diet.
2. Pregnant or nursing females or females who have pregnancy plans during the trial or within 3 months after the trial.
3. Any subject with SARS-CoV-2 infection, based on a positive polymerase chain reaction for SARS-CoV-2.
4. History or evidence of clinically significant disorder, condition, or disease that, in the opinion of the investigator, would pose a risk to subject safety or interfere with the study evaluations, procedures, or completion.