Objectives To evaluate the efficacy and safety/tolerability of erenumab (AMG 334) in a phase 3 trial of subjects with episodic migraine (EM) (NCT02456740).

Methods In this multinational, double-blind, placebo-controlled trial, adults with EM (n=955) were randomised 1:1:1 to subcutaneous monthly placebo or erenumab 70 mg or 140 mg for 24 weeks. The primary endpoint was change from baseline in mean monthly migraine days (MMDs) over weeks 13-24. Secondary endpoints were ≥50% reduction in MMDs; change in mean acute migraine-specific medication days; change in mean Physical Impairment (PI) and Impact on Everyday Activities (EA) scores (as measured by the Migraine Physical Function Impact Diary (MPFID)). P-values for pairwise comparisons of each erenumab dose with placebo are presented. Statistical significance was determined after adjustment for multiple comparisons.

Results Subjects reported 8.3 MMDs at baseline and experienced −3.2, −3.7, and −1.8 day reductions in the 70 mg, 140 mg and placebo groups, respectively (p<0.001 for both). A≥50% reduction in MMDs was achieved by 43%, 50% and 27% in the 70 mg, 140 mg and placebo groups (p<0.001 for both), and monthly acute migraine-specific medication days were reduced by −1.1, −1.6 and −0.2 days (p<0.001 for both). Subjects had improved PI scores (−4.2, −4.8, −2.4 points in the 70 mg, 140 mg and placebo groups; p<0.001) and EA scores (−5.5, −5.9 and −3.3 points; p<0.001). The safety/tolerability profile of erenumab was similar to placebo; subjects most frequently reported nasopharyngitis, upper-respiratory-tract infection, and sinusitis.

Conclusions Erenumab 70 mg and 140 mg significantly reduced migraine frequency and use of migraine-specific medications, reducing migraine’s impact on physical impairment and EA compared with placebo in this EM trial. Numerically greater efficacy was observed for the 140 mg dose consistently across all endpoints.