Efficacy and Safety of Erenumab in Pediatric Subjects With Chronic Migraine

Inclusion Criteria:

• Children (6 to less than 12 years of age) or adolescent (12 to less than 18 years ofage) at the time of signing, if developmentally appropriate, the formal assent toparticipate to the study.

• Participant's parent or legal representative has provided written informed consentbefore initiation of any study-specific activities/procedures.

• History of migraine (with or without aura) for ≥ 12 months before screeningaccording to the IHS Classification ICHD-3 (Headache Classification Committee of theInternational Headache Society, 2013) ICHD-3 specifications for pediatric migraine (participants aged less than 18 years), should be considered for the diagnosis ofmigraine.

• History of ≥ 15 headache days per month of which ≥ 8 headache days were assessed bythe participant as migraine days per month in each of the 3 months prior toscreening.

• Migraine frequency: greater than or equal to 8 migraine days based on the eDiarydata during the last 28 days of the baseline phase if more than 28 days in duration.

• Headache frequency of greater than or equal to 15 headache days based on the eDiarydata during the last 28 days of the baseline phase if more than 28 days in duration.

• Demonstrated at least 80% compliance with the eDiary based on the last 28 days ofthe baseline period, if more than 28 days in duration (eg, completing eDiary itemsfor at least 23 out of the last 28 days of the baseline phase).

Key Exclusion Criteria:

• History of cluster headache or hemiplegic migraine headache.

• Chronic migraine with continuous pain, in which the participant does not have anypain free periods (of any duration) during the 1 month prior to screening.

• No therapeutic response with greater than 3 medication categories for prophylactictreatment of migraine after an adequate therapeutic trial. No therapeutic responseis defined as no reduction in headache frequency, duration, or severity afteradministration of the medication for at least 6 weeks at the generally-acceptedtherapeutic dose(s) based on the investigator's assessment.

• History of suicidal behavior or the participant is at risk of self-harm or harm toothers.

• History of major psychiatric disorder. Participants with anxiety disorder and/ormild major depressive disorder (Patient Health Questionnaire Modified forAdolescents [PHQ-A] score 9 for adolescents or based on medical judgement of theinvestigator for children) are permitted in the study if they are considered by theinvestigator to be stable and are taking no more than 1 medication for eachdisorder. Participants must have been on a stable dose within the 3 months beforethe start of the baseline phase.