A Study to Assess the Bioequivalence of Efgartigimod PH20 SC Between Autoinjector and Prefilled Syringe in Healthy Adult Participants

The aim of this study is to compare the amount of efgartigimod in the blood over time after it is injected via Prefilled syringe (PFS) and Autoinjector (AI). The study will comprise 2 study periods of 3 weeks each. Each participant receives both efgartigimod PH20 SC AI and PFS treatments, in a different order. Participants will be in the study for up to approximately 9 weeks.

Inclusion Criteria: * Is at least the local legal age of consent and aged 18 to 55 years, inclusive, when signing the ICF. * Has a body weight between 50 and 100 kg and a BMI between 18 and 30 kg/m2, inclusive. Exclusion Criteria: * Has any current or past clinically meaningful medical or psychiatric condition that, in the investigator's opinion, would confound the study results or put the participant at undue risk. * Has received any medications, including nonprescription and prescription medications, within 2 weeks before the first IMP administration, except for hormonal contraceptives and hormone replacement therapy in female participants. The occasional use of acetaminophen or ibuprofen is allowed. * Previously participated in an efgartigimod clinical study and received at least 1 dose of IMP.