This study contains two parts. Part I of the study is a single-center, randomized, open-label, 2-arm, parallel-controlled phase Ia study to compare the PK characteristics, safety, tolerability, and immunogenicity of HLX15 and daratumumab infusion (DARZALEX®, CN-sourced) in healthy Chinese male subjects.~A total of 24 healthy Chinese male subjects will be enrolled in this part and randomized to the HLX15 group or the CN-sourced DARZALEX® group in a 1:1 ratio, with 12 subjects in each group. The subjects will receive a single dose (8 mg/kg) of HLX15 or CN-sourced DARZALEX® via intravenous infusion.~There is a safety run-in period in the early stage of the study to investigate the safety and tolerability of HLX15 in healthy Chinese male subjects. Another 3-6 subjects will be enrolled to receive the investigational product HLX15 and safety observation will be conducted for 1 week. The Safety Review Committee (SRC) will decide whether to adjust the subsequent study plan based on the safety and tolerability data after administration.~Part II of the study is a multicenter, randomized, double-blind, 3-arm, parallel-controlled phase Ib study to compare similarity of the PK characteristics, safety, tolerability, and immunogenicity of HLX15 and daratumumab infusion (DARZALEX®, US-sourced; DARZALEX®, CN-sourced) in healthy Chinese male subjects.A total of 204 healthy Chinese male subjects are planned to be enrolled in this part and randomly assigned in a 1:1:1 ratio to the HLX15 group, the US-sourced DARZALEX® group, or the CN-sourced DARZALEX® group, with 68 subjects in each group. The subjects will receive a single dose (8 mg/kg) of HLX15, US-sourced DARZALEX®, or CN-sourced DARZALEX® via intravenous infusion.This part may be adjusted according to the results of Part I, including sample size and sampling time points
Phase I Study to Compare the Pharmacokinetic Characteristics, Safety, Tolerability, and Immunogenicity (Randomized, Double-blind, Parallel Controlled) of HLX15 with Daratumumab Injection in Healthy Chinese Male Subjects