INTRODUCTION: Erenumab, a first-in-class monoclonal antibody targeting the 
calcitonin gene-related peptide pathway, was approved by the US Food and Drug 
Administration in 2018 for the prevention of migraine in adults. There is 
limited data available on its impact in real-world settings. The study aim was 
to characterize the real-world treatment profiles, clinical outcomes, and 
healthcare resource utilization of patients prescribed erenumab from select 
major US headache centers.
METHODS: A retrospective chart review of patients with migraine treated with 
erenumab for at least 3 months across five major headache centers was conducted. 
Data was collected from patient charts between April 2019 and April 2020 and 
included patient and clinical characteristics, migraine medication use, and 
outpatient visits. The date of the first prescription fill of erenumab was 
defined as the index date. The baseline period comprised the 3 months prior to 
the index date and the study period comprised the at least 3 months on erenumab 
treatment.
RESULTS: Data from a total of 1034 patients with chronic migraine with a mean of 
9.3 months of erenumab treatment were analyzed. Patients were on average 
48 years old, 86% were female, and 79% were white. Patients had a mean of 5 
preventive treatment failures prior to erenumab initiation. Patients used a mean 
of 2 preventive treatments (excluding erenumab) and 2 acute treatments during 
baseline and study periods. Among patients with effectiveness data, 45% of 
patients had improvement in physician-reported migraine severity and 35% 
experienced at least 50% reduction in mean headache/migraine days per month. The 
average number of monthly outpatient visits was 0.43 and 0.30 before and after 
erenumab initiation, respectively.
CONCLUSION: In this predominantly refractory chronic migraine population treated 
in select headache centers, patients had fewer headache/migraine days per month 
and outpatient visits after initiating erenumab. However, patients largely 
continued to be managed via a polypharmacy approach after erenumab initiation.