This is a Phase 1 Study to Evaluate the Safety and tolerability of 3D-229 in health subjects

A Single-blind, Randomized, and Placebo-Controlled Phase 1 Study to Evaluate the Safety and tolerability of 3D-229 by Intravenous Single Dose Escalation(SAD) and Repeated Doses(RD) in Healthy Subjects. A SAD portion of the study consists of 2 sequential dose escalation cohorts, whereas RD portion of the study consists of a single cohort receiving 4 weekly doses of 3D229. In both SAD and RD study arms, subjects are randomized to receive either a study intervention (3D229) or matching placebo.

Inclusion Criteria:

1. Healthy subjects had no clinically significant condition or disease confirmed by medical history, medical assessment, physical examination, clinical laboratory tests, and 12-lead electrocardiogram (ECG) at screening and on the day prior to the first study drug administration;
2. Male or female, aged 18-55 years at the time of signing the informed consent form;
3. Body mass index (BMI) between 18 and 30 kg/m 2 (Containing 18 and 30 kg/m 2 ) within range;
4. Negative urine drug screen/alcohol breath test at screening and 1 day prior to first study drug administration;
5. Has not used tobacco products (including nicotine patches/gum) within 3 months prior to screening and agrees to avoid such products throughout the study;
6. Complete abstinence for at least 14 days prior to the first dose of study drug and Take effective contraceptive measures within 3 months after the last dose(including Complete abstinence、 barrier contraception and completed sterilization operation), no fertility, sperm donation, egg donation program
7. If the subject is female, the serum pregnancy test at screening and urine pregnancy test on the day before first dose should be negative;
8. Ability to fully read, understand and sign the informed consent form;
9. Ability to communicate adequately with the investigator and to comply with the requirements of the entire study.

Exclusion Criteria:

1. Blood pressure ≥ 140/90 mmHg or pulse > 100 beats/min at rest at screening;
2. QT interval corrected for heart rate using Fridericia ' s formula (QTcF) > 430 msec (males) and > 450 msec (females) at screening;
3. Pregnant or lactating women;
4. Males with partners in pregnancy;
5. Concurrently enrolled in another clinical trial, or received any study drug within 3 months prior to the first dose (or 5 drug half-lives, whichever is longer);
6. Subject has a history of drug or alcohol abuse or dependence within the past 1 year;
7. Use of any prescription or over-the-counter medications, including analgesics, hormonal contraceptives (oral contraceptives or implanted contraceptives), natural food supplements, or dietary/herbal supplements (including vitamins), 14 days or 5 drug half-lives, whichever is longer;
8. Donation of more than 200 mL of blood within 56 days prior to the first dose, or planned to donate blood during the study until 1 month after completion of the study;
9. Hepatitis B virus (HBV) surface antigen, hepatitis C virus antibody (HCV), or human immunodeficiency virus (HIV) test results are currently or ever positive;
10. Prior or current condition that, in the opinion of the investigator, may affect the conduct of the study or observations (to be confirmed by medical history);
11. History or current patient ' s clinically significant disease,Including but not limited to: active tuberculosis, asthma, angioedema, bronchospasm, ulcerative disease, gastrointestinal hemorrhage, coagulation disorder, hypertension, edema, heart failure, hypokalemia, hyperkalemia, cardiovascular disease, hypersensitivity to any biological agent, and significant impact on immune responseSevere skin diseases or other conditions of the force;