A Study to Compare the PK , Safety, Tolerability, and Immunogenicity of HLX15 With Daratumumab in Male Subjects

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 randomizedto the HLX15 group or the CN‐sourced DARZALEX┬« group in a 1:1 ratio, with 12 subjects ineach group. The subjects will receive a single dose (8 mg/kg) of HLX15 or CN‐sourcedDARZALEX┬« via intravenous infusion.There is a safety run‐in period in the early stage of the study to investigate the safetyand tolerability of HLX15 in healthy Chinese male subjects. Another 3‐6 subjects will beenrolled to receive the investigational product HLX15 and safety observation will beconducted for 1 week. The Safety Review Committee (SRC) will decide whether to adjust thesubsequent 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 204healthy Chinese male subjects are planned to be enrolled in this part and randomlyassigned in a 1:1:1 ratio to the HLX15 group, the US‐sourced DARZALEX┬« group, or theCN‐sourced DARZALEX┬« group, with 68 subjects in each group. The subjects will receive asingle dose (8 mg/kg) of HLX15, US‐sourced DARZALEX┬«, or CN‐sourced DARZALEX┬« viaintravenous infusion.This part may be adjusted according to the results of Part I,including sample size and sampling time points