Inclusion Criteria:
1. Participants \[c1.1\]must be informed of the study before it begins, fully understand the study content, procedures, and potential adverse reactions, and voluntarily sign the written ICF;
2. Healthy male participants aged 18 to 55 years;
3. Body weight between 55.0 and 85.0 kg, and body mass index between 19.0 and 26.0 kg/m²;
4. Physical examination, vital signs, 12-lead electrocardiogram, laboratory tests, and other examination results are normal, or abnormal but without clinical significance;
5. Participants and their partners agree to use effective and reliable contraceptive methods from signing the ICF until 3 months after dosing;
6. Participants are able to communicate well with the investigator, and to understand and comply with the requirements of the study.
Exclusion Criteria:
1. History of chronic diseases or severe diseases involving the circulatory system, blood or hematopoietic system, respiratory system, endocrine system, urinary system, digestive system, immune system, psychiatric or nervous system, reproductive system, etc.;
2. Presence or suspicion of any active viral, bacterial, fungal, or parasitic infection within 14 days before dosing;
3. Participants who have undergone major surgery within 3 months before screening, or who plan to undergo major surgery during the study period;
4. History of allergies to drugs, food, etc., or Participants who may be allergic to the study drug or its components in the Investigator's judgment;
5. Positive result for any of the following: hepatitis B surface antigen, hepatitis C antibody, Treponema pallidum antibody, human immunodeficiency virus antigen/antibody;
6. History of drug abuse, or use of illicit drugs within 3 months before screening, or habitual use of any psychotropic drugs (including herbal medicines), or a positive urine drug screen;
7. Blood loss or blood donation of more than 200 mL within 3 months before screening;
8. Intolerance to subcutaneous injection, or presence of abdominal scars that affect subcutaneous administration, and any skin abnormalities and/or tattoos that may affect the safety assessment of the injection site;
9. Use of any prescription drugs, over-the-counter drugs, herbal medicines or vitamin and dietary supplements within 14 days or 5 half-lives (whichever is longer) before dosing;
10. Use of any marketed or investigational biological products within 6 months or 5 half-lives (whichever is longer) before dosing;
11. Participants who have previously used CM326 or drugs targeting TSLP;
12. Vaccination within 4 weeks before screening, or plan to receive such vaccines during the study;
13. Participation in any clinical trial within 3 months before screening;
14. Average daily smoking of more than 5 cigarettes within 3 months before screening, or unwilling to avoid using any tobacco products during the study;
15. Regular alcohol consumption within 3 months before screening, defined as weekly alcohol consumption exceeding 14 units (1 unit = 360 mL of 5% alcohol beer or 45 mL of 40% alcohol spirits or 150 mL of 12% alcohol wine), or inability to stop alcohol intake during the study, or a positive blood alcohol test;
16. Regular consumption of excessive amounts of tea, coffee, and/or caffeinated beverages within 3 months before screening;
17. Participants who have special dietary requirements and are unable to comply with the standardized diet;
18. History of needle phobia or hemophobia, or d difficulty with venipuncture or unable to tolerate venous puncture;
19. Participants who, in the Investigator's judgment, may be unable to complete the study for other reasons or are considered unsuitable for enrollment.
