Efficacy and Safety of Erenumab in Pediatric Subjects With Chronic Migraine

This study is a Phase 3, randomized, double-blind, placebo-controlled, parallel-group study
to evaluate the efficacy and safety of Erenumab in migraine prevention in children (6 to <12
years) and adolescents (12 to <18 years) with chronic migraine.

The trial consists of four phases: screening (up to 3 weeks of initial screening and a 4-week
prospective baseline phase); the double-blind treatment phase (24 weeks) in which
participants receive placebo or Erenumab dose 1, dose 2 or dose 3 (based on participant's
body weight) via subcutaneous injection once a month; the optional dose level blinded
extension phase (40 weeks), in which all participants are assigned to receive dose 1, dose 2
or dose 3 of Erenumab; and a 12 weeks safety follow-up phase (16 weeks after the last dose of
investigational drug).

The study intends to enroll 286 participants (256 adolescents and 30 children).

Inclusion Criteria:

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

- Subject's parent or legal representative has provided written informed consent before
initiation of any study-specific activities/procedures.

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

- History of ≥ 15 headache days per month of which ≥ 8 headache days were assessed by
the subject as migraine days per month in each of the 3 months prior to screening.

- Migraine frequency: greater than or equal to 8 migraine days during the baseline phase
based on the electronic diary (eDiary) calculations.

Key Exclusion Criteria:

- History of cluster headache or hemiplegic migraine headache.

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

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

- History of suicidal behavior or the subject is at risk of self-harm or harm to others.

- History of major psychiatric disorder. Subjects with anxiety disorder and/or mild
major depressive disorder (Patient Health Questionnaire Modified for Adolescents
[PHQ-A] score 9) are permitted in the study if they are considered by the investigator
to be stable and are taking no more than 1 medication for each disorder. Subjects must
have been on a stable dose within the 3 months before the start of the baseline phase.