AbstractPegcetacoplan is a complement component 3 inhibitor approved to treat adults with paroxysmal nocturnal hemoglobinuria, a rare disease characterized by life-threatening complement-mediated hemolysis (often leading to anemia) and thrombosis. Pegcetacoplan is self-administered as a subcutaneous (SC) injection with an at-home infusion pump. A newly approved, more convenient, wearable, single-use automatic injector was evaluated in a human factors study for the safe and effective SC delivery of pegcetacoplan in the abdominal area. Adult patients with anemia (representative of PNH) and caregivers (n=15 each) received formal injector use training (2-hour session followed by 1-hour decay) and reviewed the instructions for use (IFU), whereas health care providers (HCPs; n=15) only received the IFU. Participants completed a use test, knowledge-based assessment (KBA), and interviews. Forty-four of 45 participants (98%) passed the use test. Residual risks from observed errors (17 critical use and 6 KBA errors) were deemed acceptable. This study validated the injector for ease of use and safe and effective SC delivery of pegcetacoplan at home, which may potentially reduce treatment burden for patients with PNH.