A Study of Subcutaneous Gefurulimab Using Prefilled Syringe Versus Autoinjector in Healthy Adult Participants

This study checks how **gefurulimab**, a type of medicine, works and how safe it is when given through a prefilled syringe or an autoinjector. **Pharmacokinetics (PK)** is the study of how a drug moves through the body, and **pharmacodynamics (PD)** is how a drug affects the body. The study lasts up to 162 days, starting with a screening period of up to 70 days, followed by an evaluation period of 92 days. Participants will receive one dose of 600 mg gefurulimab and stay in a clinic for a few days, with follow-up visits. Only healthy adults aged 18-65 with certain weight and health conditions can join. It’s important participants are vaccinated against some infections and follow specific guidelines, like using contraceptives. The study excludes those with certain medical histories or infections. Participants should be aware of the time commitment and the need for multiple clinic visits.

• Total study duration is up to 162 days.
• Participants will be closely monitored with multiple clinic visits.
• Only healthy adults within the specified weight range may join.