A meta-analysis of nearly 7,000 patients found that monthly injections of anti-CGRP monoclonal antibodies significantly reduced migraine days within the first month, with effects lasting through 12 weeks and a safety profile comparable to placebo.
-2.07 monthly migraine daysReduction vs placebo at 4 weeks across erenumab, fremanezumab, and galcanezumab (p<0.001)
What the researchers found
All three CGRP monoclonal antibodies significantly reduced monthly migraine days compared to placebo at every time point measured: by 2.07 days at 4 weeks, 1.78 days at 8 weeks, and 1.80 days at 12 weeks (all p<0.001). These effects were consistent across erenumab 70 mg, fremanezumab 225 mg, and galcanezumab 120 mg individually.
Beyond migraine day reduction, patients on active treatment used fewer acute migraine medications and had significantly higher rates of achieving a 50% or greater reduction in migraine frequency. Treatment-related adverse events showed no significant difference between active treatment and placebo groups.
Why it matters
Before CGRP antibodies arrived, migraine prevention relied on medications originally designed for other conditions — blood pressure drugs, antidepressants, and anti-seizure medications — all with significant side effects. This meta-analysis confirmed that targeting the CGRP peptide pathway directly provides consistent migraine relief with a clean safety profile, validating an entirely new class of peptide-based preventive therapy.
How the study worked
This was a systematic review and meta-analysis of double-blind, placebo-controlled randomized clinical trials. Researchers searched for studies evaluating monthly subcutaneous injections of CGRP monoclonal antibodies in patients with chronic or episodic migraine. They analyzed 13 eligible RCTs encompassing 6,979 patients (about 85% female), comparing changes in monthly migraine days, acute medication use, 50% responder rates, and treatment-related adverse events.
What this study cannot tell us
The analysis only included trials using monthly subcutaneous dosing at specific doses, so results may not apply to other dosing regimens (e.g., quarterly eptinezumab infusions, which had no eligible studies). Most participants were female (~85%), reflecting migraine epidemiology but limiting generalizability to males. The longest follow-up was 12 weeks, so longer-term efficacy and safety are not captured. Publication bias and heterogeneity between trials are inherent limitations of any meta-analysis.
How to read the evidence
This is a meta-analysis of 13 double-blind, placebo-controlled randomized trials — one of the highest levels of clinical evidence. The large pooled sample size (6,979 patients) and consistent results across individual drugs strengthen confidence in the findings.
When this study was published
Published in 2020, this meta-analysis captured the initial wave of CGRP antibody trials. Since then, additional long-term data and real-world studies have been published, but the core findings remain well-supported.
The bigger picture
CGRP is one of the most successful examples of translating peptide biology into mainstream medicine. The discovery that CGRP drives migraine pathophysiology led to two distinct drug classes: small-molecule CGRP receptor antagonists (gepants) and the monoclonal antibodies analyzed here. This meta-analysis strengthens the evidence that blocking the CGRP pathway is both effective and well-tolerated, and it helped establish anti-CGRP antibodies as a first-line preventive option for many migraine patients.
Questions still open
- Do the benefits of CGRP antibodies persist beyond 12 weeks, and does efficacy change with long-term continuous use?
- How do CGRP monoclonal antibodies compare head-to-head with small-molecule CGRP antagonists (gepants) for prevention?
- Are there patient subgroups (by migraine type, frequency, or prior treatment failure) who benefit more or less from CGRP antibodies?
Common questions
How quickly do anti-CGRP antibodies start working for migraine prevention?
Are anti-CGRP antibodies safe compared to older migraine prevention drugs?
Read the original research
Monoclonal antibodies as a preventive therapy for migraine: A meta-analysis.
Clinical neurology and neurosurgery, 195, 105900
Citation
Alasad, Yousef Waleed; Asha, Mohammad Zaki. (2020). Monoclonal antibodies as a preventive therapy for migraine: A meta-analysis.. Clinical neurology and neurosurgery, 195, 105900. https://doi.org/10.1016/j.clineuro.2020.105900