A Study With Eptinezumab in Children and Adolescents (6 to 17 Years) With Chronic or Episodic Migraine

Inclusion Criteria: \- The participant must have completed Week12 (completion) visit of either Study19356A (CM) or Study19357A (EM) immediately prior to enrolment into this OLE study. Exclusion Criteria: * The participant has an adverse event or other safety concerns that are deemed related to double-blind treatment received in the lead-in study and is considered a potential safety risk by the investigator. * During lead-in Study19356A or Study19357A: * participant experienced ananaphylactic reaction or another severe and/or serious hypersensitivity reaction to the investigational medicinal product (IMP) infusion, as assessed by the investigator * the participant had a serum alanine aminotransferase (ALT) or aspartate aminotransferase(AST) value \>5 times the upper limit of the reference range that was confirmed by testing \<2 weeks later. * the participant had a serum ALT or AST value \>3times the upper limit of the reference range and a serum total bilirubin value \>2times the upper limit of the reference range.