This is a single-center, randomized, double-blind, placebo-controlled, dose-escalating study to evaluate the safety, tolerability, PK profile, and immunogenicity of multiple SC administraion of CM326 at different doses in healthy subjects.

40 healthy male subjects will be enrolled in the study. The drug will be administered by dose-escalating principle at 4 dose levels: 55 mg Q2W, 110 mg Q2W, 220 mg Q2W, 220 mg Q4W.

Inclusion Criteria:

• Male healthy volunteers, aged between 18 and 65 years of age inclusive, with a body mass index (BMI) within 18-26 kg/m2 (inclusive);
• Medical history, vital signs, physical examination, 12-lead Electrocardiogram, chest X-ray and abdominal color ultrasound are normal or abnormal with no clinical significance;
• All variables of clinical laboratory tests are normal or abnormal with no clinical significance;
• Subjects and partners agree to take effective contraception throughout the study (from screening to 3 months after the end of treatment);
• Capable of understanding the nature of the study and voluntarily signing the Informed Consent Form.

Exclusion Criteria:

• Known allergy to monoclonal antibody drugs or other related drugs, or allergy to excipients of CM326 injection;
• History of any clinically serious disease or history of circulatory, endocrine, neurological or hematological, immune, psychiatric, and metabolic diseases;
• History of asthma and allergic reactions;
• Use of any prescription drugs within 2 weeks prior to dosing, use of traditional Chinese medicine or over-the-counter drugs within 1 week prior to dosing;
• Received any marketed or investigational biologics within 5 half-lives (if known) or 12 weeks (whichever is longer) prior to dosing, or any investigational non-biologics within 5 half-lives (if known) or 4 weeks (whichever is longer) prior to dosing.