This clinical trial is the first-in-human study of Kylo-0603. The purpose of this randomized, double-blind, placebo-controlled phase 1 study is to assess the safety, tolerability, pharmacokinetics, pharmacodynamics and effect of food of Kylo-0603 in healthy Chinese adult subjects.

The study consists of three parts: single ascending doses (Part 1), food effect (Part 2) and multiple ascending doses (Part 3).

Inclusion Criteria:

• Men and women aged 18 to 55 years old, inclusive;
• Body mass index (BMI) between 19 kg/m2 and 30 kg/m2, inclusive；
• Having no clinically significant disorder, condition or disease at screening and before first dosing;
• Female subjects must not be able to get pregnant and male subjects must agree to adhere to contraception restrictions;
• Willing to comply with protocol required visits and assessments, and provide written informed consent.

Exclusion Criteria:

• History of cardiovascular, respiratory, digestive, liver, urinary, hematological, endocrine, metabolic, immune, cutaneous, or psychoneurotic diseases；
• History of evidence of malignant tumor or Gilbert syndrome;
• Positive screen of Hepatitis B surface antigen, hepatitis C virus, human immunodeficiency virus or syphilis infection;
• History of tuberculosis infection;
• History of alcohol abuse within 12 months before dosing;
• History of drug abuse within 3 months before screening;
• History of blood donations or blood loss of 400 ml and more within 3 months before dosing;
• Pregnant or breast-feeding women;
• Other exclusion criteria applied per protocol.