Four monoclonal antibodies targeting the CGRP peptide pathway showed modest but consistent efficacy for migraine prevention with notably better tolerability than existing oral treatments.
Side effects matched placeboAcross Phase 2 and Phase 3 trials, CGRP antibodies showed no significant difference in adverse events versus placebo — a dramatic improvement over oral migraine preventives.
What the researchers found
Phase 2 and Phase 3 trial data for all four CGRP pathway antibodies confirmed consistent efficacy for both episodic and chronic migraine prevention. The efficacy was described as modest over placebo and broadly comparable to available oral preventive treatments.
The key differentiator was tolerability: safety reviews found no significant difference in total adverse events between the antibodies and placebo injections, except possibly for dizziness. Common side effects (upper respiratory tract infection, nasopharyngitis, nausea, injection-site pain, back pain) occurred at similar rates in treatment and placebo groups. The mechanism of action appears to be primarily peripheral, though central nervous system contributions could not be ruled out.
Why it matters
Migraine affects roughly 1 billion people worldwide and is a leading cause of disability. Many patients stop taking oral preventive medications because of side effects like weight gain, fatigue, and cognitive issues. The CGRP antibodies represented a paradigm shift — the first migraine treatments designed based on understanding the underlying peptide biology, offering comparable effectiveness with dramatically better tolerability. This review captured the evidence at a pivotal moment just before these drugs reached the market.
How the study worked
This is a narrative review article summarizing published Phase 2 and Phase 3 clinical trial data for four CGRP pathway monoclonal antibodies: eptinezumab, fremanezumab, galcanezumab (which bind the CGRP ligand), and erenumab (which binds the CGRP receptor). The review covers efficacy data, safety and tolerability profiles, pharmacokinetics, and mechanism of action.
What this study cannot tell us
At the time of this review, only short-term safety data were available — long-term effects of blocking the CGRP pathway (which has roles in cardiovascular protection and wound healing) remained unknown. The review noted that the efficacy was modest over placebo, raising questions about cost-effectiveness. Phase 3 data were still emerging, and the authors noted many more publications were expected. Additionally, which patients would respond best to CGRP-targeting therapy was not yet well understood.
How to read the evidence
This is a narrative review of Phase 2 and Phase 3 randomized controlled trial data, which represents the highest quality of clinical evidence. However, at the time of publication, Phase 3 results were still emerging and long-term safety data were limited.
When this study was published
Published in 2018, this review captured the evidence at a pivotal moment — just before the first CGRP antibodies received FDA approval. The drugs have since been widely adopted, and extensive real-world and long-term safety data now exist beyond what was available at the time.
The bigger picture
The CGRP antibodies represent one of the greatest success stories in translational peptide science. Decades of basic research identifying CGRP's role in migraine led directly to these targeted therapies. Since this 2018 review, all four drugs have been approved and have transformed migraine care. The success has also spurred development of small-molecule CGRP antagonists (gepants) for both prevention and acute treatment, further validating CGRP as a therapeutic target.
Questions still open
- What are the long-term safety implications of chronically blocking the CGRP pathway, given CGRP's protective roles in cardiovascular and wound healing processes?
- Can biomarkers be identified to predict which migraine patients will respond best to CGRP antibody therapy?
- How do CGRP antibodies compare head-to-head with the newer small-molecule CGRP antagonists (gepants)?
Common questions
What is CGRP and why is it targeted for migraine treatment?
Are CGRP antibodies better than existing migraine prevention medications?
Read the original research
Calcitonin-gene-related peptide pathway mAbs and migraine prevention.
Current opinion in neurology, 31(3), 274-280
Citation
Paemeleire, Koen; MaassenVanDenBrink, Antoinette. (2018). Calcitonin-gene-related peptide pathway mAbs and migraine prevention.. Current opinion in neurology, 31(3), 274-280. https://doi.org/10.1097/WCO.0000000000000548