A Phase 2 Study to Evaluate the Efficacy and Safety of Erenumab (AMG 334) in Migraine Prevention

The study is composed of an initial screening phase (up to 3 weeks), a 4-week baseline phase,
a 12-week double-blind treatment phase, an open-label treatment phase for up to 256 weeks,
and an 8-week safety follow-up (12 weeks after the last dose of investigational product).
After implementation of Protocol Amendment 3, participants will increase open-label erenumab
to 140 mg monthly and will have a 12-week safety follow-up (16 weeks after the last dose of
investigational product).

This study is currently ongoing, with 225 participants continuing in the open-label extension
phase. An analysis of the double-blind phase of the study was performed with a data cutoff
date of 25 September 2014.

Inclusion Criteria:

- History of migraine for more than12 months prior to screening

- Migraine frequency: ≥ 4 and ≤ 14 migraine days per month in each of the 3 months prior
to screening and during baseline phase

- Headache frequency: < 15 headache days per month (with > 50% of the headache days
being migraine days) in each of the 3 months prior to screening and during baseline
phase

- Demonstrated at least 80% compliance with the eDiary during baseline phase

Exclusion Criteria:

- Older than 50 years of age at migraine onset

- History of cluster headache or basilar or hemiplegic migraine headache

- Unable to differentiate migraine from other headaches

- No therapeutic response with > 2 of the following eight medication categories for
prophylactic treatment of migraine after an adequate therapeutic trial. Medication
categories are:

- Category 1: Divalproex sodium, sodium valproate

- Category 2: Topiramate

- Category 3: Beta blockers (for example: atenolol, bisoprolol, metoprolol,
nadolol, nebivolol, pindolol, propranolol, timolol)

- Category 4: Tricyclic antidepressants (for example: amitriptyline, nortriptyline,
protriptyline)

- Category 5: Venlafaxine, desvenlafaxine, duloxetine, milnacipran

- Category 6: Flunarizine, verapamil

- Category 7: Lisinopril, candesartan

- Category 8: Butterbur, feverfew, magnesium (≥ 600 mg/day), riboflavin (≥ 100
mg/day)

- Overuse of acute migraine medications in any month during the 3 months prior to
screening or during screening