The aim of this trial is to investigate the pharmacodynamic (PD), pharmacokinetic (PK), safety, tolerability, and immunogenicity of efgartigimod co-administered with rHuPH20, and to measure the time to inject the full dose of investigational medicinal product (IMP) of different dose levels of efgartigimod co-administered with a fixed concentration of rHuPH20 by the subcutaneous (SC) route of administration in healthy adult male subjects.

Inclusion Criteria:

1. Subject is male, between 18 to 70 years of age
2. Subject is healthy
3. Subject has a body mass index (BMI) between 18 kg/m2 to 30 kg/m2
4. Subject is willing and able to understand the purpose and risks of the trial and provide signed and dated informed consent,
5. Others as defined in the protocol

Exclusion Criteria:

1. Previous participation in clinical trials with efgartigimod and/or any products with rHuPH20.
2. Known hypersensitivity to IMP ingredients or history of a severe allergic or anaphylactic reaction to any drug as determined by the investigator.
3. Known seropositivity or positive test at screening for an active viral infection with Hepatitis B virus (HBV), Hepatitis C virus (HCV), Human immunodeficiency virus (HIV).
4. Known clinically relevant immunological disorders.
5. Known history or any symptom of clinically significant illness in the 6 months before IMP administration.
6. Others as defined in the protocol