This Study Will Investigate the Efficacy and Safety of A4250 in Children With PFIC 1 or 2

Progressive Familial Intrahepatic Cholestasis 2

This Study Will Investigate the Efficacy and Safety of A4250 in Children With PFIC 1 or 2 NAtural Course and Prognosis of PFIC and Effect of Biliary Diversion An Extension Study of Maralixibat in Patients With Progressive Familial Intrahepatic Cholestasis (PFIC) A Study to Evaluate the Efficacy and Safety of Maralixibat in Subjects With Progressive Familial Intrahepatic Cholestasis (MARCH-PFIC)