This is a randomised, double-blind, intravenous single-dose, four-arm parallel study designed to compare the PK of HLX11 and US, EU, and CN-sourced Perjeta® in healthy Chinese adult male subjects, and to assess the safety, tolerability, and immunogenicity of these 4 drugs.

Inclusion Criteria:

• Healthy Chinese males
• aged ≥ 18 and ≤ 45
• body mass index (BMI) ≥ 19 and ≤ 26 kg/m2
• LVEF≥ 55%

Exclusion Criteria:

• A history of any serious clinical disease such as haematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, mental, neurological diseases, and tumour, or allergic diseases
• Use of a monoclonal antibody or any biological product within 6 months before study drug administration
• A history of allergic reactions or anaphylaxis, including such reactions to any drug or excipient in the clinical study
• Use of prescription drugs, over-the-counter drugs (OTC), or traditional Chinese medicine (TCM) (excluding vitamins, mineral supplements, and dietary supplements) within 28 days before study drug administration
• A history of blood donation within 3 months before study drug administration
• Participation in other clinical study and use of the investigational product/comparator within 3 months before study drug administration
• Positive for hepatitis B surface antigen (HbsAg), hepatitis C virus (HCV) antibody, human immunodeficiency virus (HIV) antibody, or treponema pallidum antibody
• A history of drug abuse
• Failure to comply with protocol requirements, instructions, and study limitations, such as uncooperative attitude, failure to return to the study site for follow-up visits, or failure to complete the entire clinical study, as judged by investigators