Biomarker and Genetic Predictors of Erenumab Treatment ResponseINTERROGATE

• Subject has provided informed consent prior to initiation of any study-specific activities/procedures • Age greater than or equal to 18 years upon entry into screening • History of migraine (with or without aura) for greater than or equal to 12 months before screening according to the International Headache Society (IHS) Classification ICHD-3 (Headache Classification Committee of the International Headache Society, 2018) based on medical records and/or patient self report • Greater than or equal to 4 headache days that meet criteria as migraine days per month on average across the 3 months before screening After baseline period • Must have demonstrated greater than or equal to 75% compliance in eDiary usage during baseline period

Subjects are excluded from the study if any of the following criteria apply: Disease Related • Greater than 50 years of age at migraine onset • History of cluster headache or hemiplegic migraine headache • Inability to differentiate between migraine from other headaches. Other Medical Conditions • The subject is at risk of self-harm or harm to others as evidenced by past suicidal behaviour • History or evidence of any other clinically significant disorder, condition or disease (with the exception of those outlined above) that, in the opinion of the investigator or Amgen physician, if consulted, would pose a risk to subject safety or interfere with the study evaluation, procedures or completion. Prior/Concomitant Therapy • Previously received erenumab (Aimovig®) • Received an anti-CGRP monoclonal antibody within 3 months prior to the start of the baseline period • Initiation, discontinuation, or change of dosing of migraine prophylactic medications within 2 months prior to the start of the baseline period, during the baseline period or planned during the study. Prior/Concurrent Clinical Study Experience • Currently receiving treatment in another investigational device or drug study, or less than 30 days or 5 half-lives since ending treatment on another investigational device or drug study (ies). Other investigational procedures while participating in this study are excluded. Other Exclusions • Female subjects of childbearing potential with a positive pregnancy test assessed at screening or day 1 by a urine pregnancy test • Female subject is pregnant or breastfeeding or planning to become pregnant or breastfeed during treatment and for an additional 16 weeks after the last dose of investigational product • Female subjects of childbearing potential unwilling to use 1 acceptable method of effective contraception during treatment and for an additional 16 weeks after the last dose of investigational product • Evidence of current pregnancy or breastfeeding per subject self-report or medical records • Subject has known sensitivity to any of the products or components to be administered during dosing • Subject likely to not be available to complete all protocol-required study visits or procedures, and/or to comply with all required study procedures (e.g, Clinical Outcome Assessments) to the best of the subject and investigator’s knowledge