RecruitingPhase 2Drug trialA Study of Pegcetacoplan in Pediatric Patients With Paroxysmal Nocturnal Hemoglobinuria (PNH)The purpose of this study is to evaluate the safety, effectiveness, and biological activity (how the investigational medication is processed by the body) of pegcetacoplan in 12-17 year-olds (adolescents) who have paroxysmal nocturnal hemoglobinuria (PNH).