Randomised, controlled trial of erenumab for the prevention of episodic migraine in patients from Asia, the Middle East, and Latin America: The EMPOwER study

Abstract

Objective: EMPOwER, a double-blind, randomised, phase 3 study, evaluated the efficacy and safety of erenumab in adults with episodic migraine from Asia, the Middle East, and Latin America.

Methods: Randomised patients (N = 900) received monthly subcutaneous injections of placebo, erenumab 70 mg, or 140 mg (3:3:2) for 3 months. Primary endpoint was change from baseline in monthly migraine days at Month 3. Other endpoints included achievement of ≥50%, ≥75%, and 100% reduction in monthly migraine days, change in monthly acute migraine-specific medication treatment days, patient-reported outcomes, and safety assessment.

Results: At baseline, mean (standard deviation) age was 37.5 (9.9) years, 81.9% were women, and monthly migraine days was 8.2 (2.8). At Month 3, change from baseline in monthly migraine days (primary endpoint) was -3.1, -4.2, and -4.8 days for placebo, erenumab 70 mg, and erenumab 140 mg, respectively, with a statistically significant difference for erenumab versus placebo (P = 0.002 [70 mg], P < 0.001 [140 mg]). Both erenumab doses were also significantly superior to placebo on all secondary endpoints, including the proportion of patients achieving ≥50% reduction from baseline in monthly migraine days, change from baseline in monthly acute migraine-specific medication treatment days and change from baseline in the Headache Impact Test-6™ scores. The safety profile of erenumab was comparable with placebo; no new safety signals were observed.

Conclusions: This study of erenumab in patients with episodic migraine from Asia, the Middle East, and Latin America met all primary and secondary endpoints. A consistent numerical benefit was observed with erenumab 140 mg versus erenumab 70 mg across all efficacy endpoints. These findings extend evidence of erenumab's efficacy and safety to patients under-represented in previous trials.ClinicalTrials.gov identifier: NCT03333109.

Keywords: Asia; Latin America; calcitonin gene-related peptide; episodic migraine; erenumab; randomised controlled trial.

Figure 1.

Study design. n, patients who entered the safety follow-up phase; N, number of patients randomised; QM, every 4 weeks; SC, subcutaneous.

Figure 2.

Trial profile (randomised analysis set). A patient is defined as completer for the DBTP, if completed all DBTP visits and performed End of Trial assessment. A patient is defined as DBTP discontinuer if patient status is not ticked as “Completed” for study disposition page during DBTP or if he missed any DBTP visit. A patient is defined as completer for the study if patient status is ticked as “Completed” for the study disposition page (if completed the safety follow-up visit at week 24). Patients who entered the safety follow-up period are those who completed the End of Trial visit and did not discontinue study at that visit. Five patients discontinued from DBTP and still entered safety follow-up. Six randomised patients did not take study medication and not formally entered into DBTP. DBTP, double-blind treatment phase.

Figure 3.

Change from baseline in monthly migraine days by treatment and visit (modified intention-to-treat analysis set). Error bars represent the standard error. Intention-to-treat analysis set included all patients who were randomised in the study. P < 0.05 was considered as statistically significant. CI, confidence interval; MMD, monthly migraine days; PL, placebo; TD, treatment difference.

Figure 4.

Proportion of patients with: (a) ≥50% reduction from baseline in monthly migraine days, (b) ≥75% reduction from baseline in monthly migraine days, and (c) 100% reduction from baseline in monthly migraine days (modified intention-to-treat analysis set). Statistical analysis utilises a Cochran-Mantel-Haenszel test adjusting for stratification factor after missing data are imputed as non-response. Intention-to-treat analysis set included all patients who were randomised in the study. P<0.05 was considered as statistically significant. CI, confidence interval; MMD, monthly migraine days; N, the number of patients who responded; OR, odds ratio; PL, placebo.