Sustained Efficacy and Long-term Safety of Erenumab in Patients with Episodic Migraine: 4+ Year Results of a 5-year, Open-label Treatment Period
Messoud Ashina1, Peter Goadsby2, Uwe Reuter3, Stephen Silberstein4, David Dodick5, Fei Xue6, Feng Zhang6, Sunfa Cheng6, Daniel Mikol6
1Dept. of Neurology, 2UCSF, 3Charité – Universitätsmedizin Berlin, 4Jefferson Headache Center, 5Mayo Clinic Arizona, 6Amgen
Objective:

To evaluate long-term efficacy and safety of erenumab (erenumab-aooe in the US).

Background:

Efficacy (1 year) and safety (3 years) of erenumab results from a comprehensive clinical development program resulted in approval for migraine prevention in over 40 countries to date. Longer-term efficacy and safety data are important for patients and clinicians.

Design/Methods:

4+-year, interim analysis of a 5-year, open-label treatment period (OLTP) in patients with episodic migraine (EM) who initially received 70 mg erenumab monthly and later switched to 140 mg monthly (protocol amendment after ~2 years).

Results:

Of 250 patients who switched from 70 to 140 mg, 221 (88%) completed the OLTP or remained on 140 mg at 4+ years. Mean (SD) change in monthly migraine days (MMD) from baseline of 8.7 (2.7) to end of the 4+-year period was ‑5.8 (3.8); ≥50%/≥75%/100% response rates were 77%/56%/33%. Among patients using acute migraine-specific medication (AMSM) at baseline (6.1 [2.7] treatment days), mean (SD) change was –4.6 (3.3) days.

Median (Q1, Q2) exposure for patients receiving ≥1 dose of open-label erenumab (n=383) was 58.5 (17.0, 62.2) months. Exposure-adjusted AE and SAE incidence rates were 124.9/100-patient-years and 3.8/100-patient-years. Nasopharyngitis (10.9/100-patient-years), upper respiratory tract infection (6.8/100-patient-years), and influenza (4.7/100-patient-years) were the most frequent AEs. Constipation did not increase with long-term treatment; 1.3/100-patient-years (n/N:9/383) for 70 mg and 2.6/100-patient-years (n/N:15/250) for 140 mg during 4+ years and 4.3/100-patient-years (n/N: 11/1043) for placebo, 5.6/100-patient-years (n/N:12/893) for 70 mg, and 13.3/100-patient-years (n/N:16/507) for 140 mg from pooled results across four 12-week, placebo-controlled studies. 19 patients (5.0%) discontinued due to AEs. There were no new safety signals nor increases in AE or SAE incidence over 4+ years of exposure vs the double-blind treatment phase.

Conclusions:
In this interim analysis, long-term erenumab treatment (4+ years) demonstrated sustained reductions in migraine frequency and was well-tolerated and safe.