This is a the first in human study to evaluate the safety, tolerability, PK and PD of single subcutaneous or intravenous dose of IBI112 in healthy subjects

In this first in human, phase 1, randomized, double-blind, placebo-controlled study, a single subcutaneous or intravenous dose of IBI112 will be administered to 46 healthy subjects.

Inclusion Criteria:

1. Healthy male or female 18 to 45 years of age at the time of consent
2. BMI of 19-26Kg/m2 and weight of 50-100kg
3. Must provide written informed consent, and in the investigator's opinion, subject is able to understand the nature of the study and any risks involved in participation, and willing to cooperate and comply with the protocol restrictions and requirements

Exclusion Criteria:

1. Subjects who have a medical history of liver, kidney, cardiovascular, nervous / mental, gastrointestinal, respiratory, urinary, endocrine
2. Subjects who have a history of relapse or chronic infection, or a history of acute infection within 2 weeks;
3. Subjects who have previously used anti-IL-12 / 23 or anti-il-23 drugs;
4. Subjects who have clinically significant abnormalities determined by vital signs, physical examination, and laboratory measurements;
5. Subjects who are not suitable for this trial due to other reasons In the investigator' opinion