Consistent efficacy and safety of erenumab over time in patients with episodic migraine who completed a 5-year, open-label extension study
Messoud Ashina1, Peter Goadsby2, Uwe Reuter3, Stephen Silberstein4, David Dodick5, Feng Zhang6, Fei Xue6, Sunfa Cheng6, Denise Chou6, Gabriel Paiva da Silva Lima6
1Dept. of Neurology, 2University of California, Los Angeles, 3Dept Neurology, Charité Universitätsmedizin Berlin, 4Jefferson Headache Center, 5Mayo Clinic Arizona, 6Amgen Inc.
Objective:

Evaluate long-term efficacy and safety of erenumab in patients with episodic migraine who completed a 5-year open-label treatment phase (OLTP; NCT01952574).

Background:

Erenumab demonstrated significant reduction in migraine frequency in short-term studies; however, long-term data are not available.

Design/Methods:
Following a 12-week placebo-controlled, double-blind treatment period (DBTP), 383 patients continued in the OLTP, receiving erenumab 70mg every 4 weeks, and increasing to 140mg after a protocol amendment (after ~2 years in OLTP). A separate protocol amendment was implemented to resume efficacy data collection in years 4–5. 215 patients completed the 5-year OLTP; 137 had efficacy data at week 268 (end of 5-year OLTP) and were included in this analysis.
Results:

Mean (SD) change in monthly migraine days (MMD) from DBTP baseline of 8.5(2.5) days was –4.8(3.9) at week 64 (mean of last 4 weeks of 1-year OLTP; N=129), and –5.3(3.9) at week 268 (mean of last 4 weeks of 5-year OLTP). The percentage of patients achieving MMD response at week 64/268 was 62%/69% for achievement of ≥50% reduction; 41%/48% for ≥75% reduction; and 26%/36% for 100% reduction. Among acute migraine-specific medication (AMSM) users at baseline (6.1[2.7] treatment days/month), mean(SD) change in AMSM days was –3.2(3.5) at week 64 and –4.4(3.3) at week 268. Clinically meaningful improvements were observed in HIT-6TM: 68%/72% of patients achieved ≥5-point reduction from baseline at weeks 64/268. Exposure-adjusted patient incidence of AEs and serious AEs during OLTP were 92.3 and 2.6 per 100 subject-years, respectively; this was lower than that observed for placebo during DBTP. One fatality (“death unattended”) occurred during safety follow-up period when no erenumab was administered and was considered unrelated to study drug by the investigator.

Conclusions:
Patients receiving erenumab through 5 years of treatment demonstrated consistent and sustained response. Safety was comparable to that observed in the full population during the randomized phase of the trial.