Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of Recombinant Anfibatide Injection in Healthy Volunteers

• Recombinant Anfibatide Injection (Drug): Recombinant Anfibatide Injection is a polypeptide antithrombotic agent. Administered as a single intravenous bolus injection over approximately 5 minutes.
• Placebo (Other): Matching placebo injection

Primary outcomes

• Incidence and Severity of Treatment-Emergent Adverse Events (TEAEs) [From dosing through Day 8 follow-up visit]: Safety and tolerability assessed by the incidence, severity, and relationship of adverse events, graded per NCI CTCAE v6.0, including abnormal laboratory values, vital signs, ECG, and physical examination findings.

Secondary outcomes

• Time to Maximum Observed Concentration (Tmax) of Recombinant Anfibatide [Pre-dose through 48 hours post-dose]: Time from dosing to reach the peak concentration of recombinant anfibatide, measured at scheduled time points.
• Area Under the Concentration-time Curve From Time Zero to the Last Quantifiable Concentration (AUC0-t) [Pre-dose through 48 hours post-dose]: Area under the concentration-time curve of recombinant anfibatide from time zero to the last quantifiable concentration, based on scheduled post-dose measurements.
• Maximum Observed Concentration (Cmax) of Recombinant Anfibatide [Pre-dose through 48 hours post-dose]: Peak concentration of recombinant anfibatide following single intravenous administration, measured at scheduled time points.
• Platelet Aggregation Inhibition Rate (Ristocetin-induced) [Pre-dose through 48 hours post-dose]: Inhibition rate of ristocetin-induced platelet aggregation measured at scheduled time points after single dose administration.
• Glycoprotein Ib (GP-Ib) Receptor Binding Rate [Pre-dose through 48 hours post-dose]: GP-Ib receptor binding rate measured at scheduled time points after single dose administration.
• Number of Participants With Positive Anti-drug Antibody (ADA) [Pre-dose and Day 8 post-dose]: Number of participants who tested positive for anti-drug antibody after single dose administration.
• Number of Participants With Positive Neutralizing Antibody (Nab) [Pre-dose and Day 8 post-dose]: Number of participants who tested positive for neutralizing antibody after single dose administration.
• Cumulative Urinary Excretion Amount of Recombinant Anfibatide [Pre-dose through 48 hours post-dose]: Total amount of recombinant anfibatide recovered in urine over scheduled collection intervals.
• Cumulative Urinary Excretion Percentage of Recombinant Anfibatide [Pre-dose through 48 hours post-dose]: Percentage of the administered dose recovered in urine over scheduled collection intervals.

Sex: All, ages: 18 Years to 45 Years, accepts healthy volunteers

Inclusion Criteria:

* Healthy male or female participants aged 18-45 years;
* Body weight: body mass index = weight (kg)/height² (m²) within 19.0-26.0 (inclusive), and body weight ≥50 kg;
* Participants are in generally good health without a history of significant disease, with normal findings on physical examination, vital signs, 12-lead ECG, and laboratory tests. If abnormal, the clinical judgment that the findings are clinically insignificant permits participation in the clinical trial;
* Participants volunteer to participate and sign the informed consent form;
* Participants of childbearing potential have no plans for pregnancy, sperm donation, or egg donation from two weeks before screening of this study until 6 months after the end of the trial, and voluntarily take appropriate contraceptive measures.

Exclusion Criteria:

* Any clinically significant medical history or disease
* Conditions that may increase bleeding risk (e.g., bleeding disorders, recent surgery, abnormal coagulation parameters)
* History of hypertension, syncope, or convulsions
* HBV, HCV, HIV, or syphilis infection
* Drug or alcohol abuse
* Recent participation in another clinical trial or blood donation
* Pregnancy or breastfeeding
* Hypersensitivity to study drug components
* Use of any medications within 14 days prior to dosing