Across 20 randomized trials with 5,212 patients, the CGRP receptor antibody erenumab significantly reduced monthly migraine days, medication use, and headache impact, with only constipation as a notable side effect.
1.78 fewer migraine days per monthAcross 5,212 patients in 20 randomized trials, erenumab consistently reduced monthly migraine frequency with P < 0.00001
What the researchers found
At three months, erenumab produced statistically significant improvements across all outcomes: monthly migraine days reduced by 1.78 (95% CI: -2.37 to -1.20, P < 0.00001), monthly medication days reduced by 1.36 (95% CI: -1.92 to -0.81, P < 0.00001), HIT-6 headache impact score improved by 2.83 points (95% CI: -3.83 to -1.82, P < 0.00001), and 52% more patients achieved ≥50% reduction in migraine days (RR: 1.52, 95% CI: 1.31 to 1.76, P < 0.00001). Subgroup analysis showed greater efficacy in patients with prior treatment failures. No significant difference between 70 mg and 140 mg doses except for medication day reduction.
Why it matters
Migraine affects 14% of the global population, and many patients don't respond well to traditional preventives (beta-blockers, antidepressants, anticonvulsants). This meta-analysis provides the strongest pooled evidence to date that erenumab — which specifically targets the CGRP peptide pathway involved in migraine — offers consistent relief with minimal side effects. The finding that it works best for patients who've failed other treatments is especially important, as these are the patients with the most unmet need.
How the study worked
Systematic review and meta-analysis of 20 randomized controlled trials (n=5,212) identified from six electronic databases through July 2024. Analysis used Review Manager 5.4 with weighted mean difference for continuous outcomes and risk ratio for dichotomous outcomes. Subgroup analyses were performed by migraine type (episodic vs. chronic), dose (70 mg vs. 140 mg), and prior treatment failure status. Evidence quality was assessed using GRADE methodology. Registered on PROSPERO (CRD42024573300).
What this study cannot tell us
The 3-month follow-up may not capture long-term efficacy or safety. Individual trial populations and designs varied, which could introduce heterogeneity. The subgroup finding of greater benefit in treatment-failure patients could reflect regression to the mean or selection effects. Publication bias cannot be entirely excluded. The analysis doesn't compare erenumab head-to-head against other CGRP antibodies.
How to read the evidence
This is a GRADE-assessed systematic review and meta-analysis of 20 randomized controlled trials — among the highest levels of clinical evidence. The large pooled sample size, consistent effect sizes, and rigorous methodology provide strong confidence in the findings.
When this study was published
Published in 2025 with literature searched through July 2024, this represents a current and comprehensive assessment of erenumab's evidence base, including the most recent clinical trials.
The bigger picture
Erenumab was the first CGRP-pathway antibody approved for migraine prevention, and this comprehensive meta-analysis solidifies its position in the treatment landscape. The CGRP pathway has become the most important target in modern migraine therapy, with multiple drugs (erenumab, fremanezumab, galcanezumab, eptinezumab) now available. This analysis helps clinicians understand exactly how effective erenumab is and for whom it works best, supporting more informed treatment decisions in a class with several competing options.
Questions still open
- How does erenumab's efficacy compare directly to other CGRP-targeting antibodies in head-to-head trials?
- Does the benefit persist or increase beyond three months of treatment?
- What predicts which treatment-failure patients will respond best to erenumab?
Common questions
What is erenumab and how does it work?
Is erenumab better for people who haven't responded to other migraine medications?
Read the original research
Unveiling the efficacy and safety of Erenumab, a monoclonal antibody targeting calcitonin gene-related peptide (CGRP) receptor, in patients with chronic and episodic migraine: a GRADE-assessed systematic review and meta-analysis of randomized clinical trials with subgroup analysis.
Head & face medicine, 21(1), 19
Citation
Haseeb, Mohamed E; Mohammed, Hazem E; Yaser, Hatem; Hanen, George; Nasser, Mohamed; Yaser, Shehab; Bady, Zeyad. (2025). Unveiling the efficacy and safety of Erenumab, a monoclonal antibody targeting calcitonin gene-related peptide (CGRP) receptor, in patients with chronic and episodic migraine: a GRADE-assessed systematic review and meta-analysis of randomized clinical trials with subgroup analysis.. Head & face medicine, 21(1), 19. https://doi.org/10.1186/s13005-025-00494-w