A Study to Evaluate the Safety, Tolerability and Pharmacokinetic Properties of 9MW3811 in Healthy Subjects

The single ascending dose study will comprise 4 dose cohorts of 8 healthy participants each. In each cohort, participants will be randomized to receive 9MW3811 or placebo by 6:2.

Inclusion criteria

• Male or female participants between 18 and 55 years of age, inclusive.
• Male body weight ≥50.0 kg, or female body weight ≥45.0 kg, and body mass index (BMI) between 18.0 and 30.0 kg/m2, inclusive.
• In good health determined by the investigator based on a medical evaluation, including a detailed medical and surgical history, as well as a complete physical examination including vital signs, 12-lead ECG, laboratory evaluations.

Exclusion criteria

• Clinically significant histories determined by the investigator of cardiovascular, hepatic, renal, gastrointestinal, neurological, respiratory, hematological, endocrinological, immunological, metabolic, and musculoskeletal abnormalities.
• Having any history of an allergy to biological agents or any components of study drug; those who have a history of allergies and judged by the investigator to be ineligible for enrolment.
• Use of any prescription medication 14 days prior to dosing or over-the-counter medication, vitamins, and/or herbal medicines 7 days prior to dosing (Excluding oral contraception, occasional paracetamol, ibuprofen and standard dose of multivitamins at the discretion of the PI or designee)
• Participants who have been vaccinated within 4 weeks prior to screening or who are scheduled to be vaccinated during the study
• Participants who received immunosuppressants except for previous use of inhaled or nasal corticosteroids 4 weeks earlier before administration or any oral corticosteroids 8 weeks earlier before administration, and who had received a single dose of monoclonal antibodies for any reason within 1 year prior to screening
• Participants with one or more clinically significant positive test results of hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibody or human immunodeficiency virus (HIV) antibody
• History of drug abuse including narcotic and psychiatric drugs within 6 months prior to screening or a positive drug abuse test result at baseline (Morphine, Methamphetamine, Tetrahydrocannabinol acid, Cocaine)
• Participants with a positive SARS-CoV-2 test prior to admission (polymerase chain reaction (PCR) and/or rapid antigen testing (RAT), per site policy and PI discretion)