Anti-CGRP Antibodies Outperform Botox for Chronic Migraine in Real-World Taiwan Study | Research

The takeaway

In 649 chronic migraine patients, CGRP monoclonal antibodies reduced monthly migraine days by 13.0 vs. 8.7 for onabotulinumtoxinA, with a 74.7% vs. 50.7% responder rate and fewer adverse events — advantages that held even in difficult-to-treat patients.

74.7% vs. 50.7% responder rate
CGRP mAbs vs. onabotulinumtoxinA at 6 months in chronic migraine — with CGRP mAbs also showing 3.5x fewer adverse events (6.0% vs. 21.0%)

What the researchers found

CGRP monoclonal antibodies achieved significantly greater migraine day reduction (-13.0 vs. -8.7 days), higher responder rates (74.7% vs. 50.7%), and fewer adverse events (6.0% vs. 21.0%) compared to onabotulinumtoxinA in chronic migraine patients, including difficult-to-treat cases.

Why it matters

Chronic migraine patients need the most effective treatment available, and many have failed multiple preventives. This large real-world comparison provides practical guidance that clinical trials haven't delivered — showing CGRP mAbs outperform the established standard (onabotulinumtoxinA) even in the hardest-to-treat patients, with better tolerability.

The numbers in context

The study included patients from multiple centers in Taiwan, with outcomes measured at 6 months. Both treatments significantly reduced monthly migraine days. Difficult-to-treat patients (3+ prior preventive failures) were analyzed separately.

How the study worked

Multicenter retrospective analysis of prospectively collected data from chronic migraine patients treated with CGRP mAbs (n=316) or onabotulinumtoxinA (n=333) in Taiwan. Outcomes at 6 months: monthly migraine days (prospective diaries), ≥50% responder rate, MIDAS disability scores, and adverse events. Subgroup analyses for difficult-to-treat and medication-overuse headache patients.

Who was studied

Chronic migraine patients in Taiwan, including difficult-to-treat subgroup

What this study cannot tell us

Retrospective analysis — not a randomized controlled trial. Treatment selection bias (patients may have received CGRP mAbs vs. Botox for different reasons). All data from Taiwan — results may not generalize to other populations. The specific CGRP mAbs used weren't differentiated (erenumab, galcanezumab, fremanezumab). Follow-up limited to 6 months.

How to read the evidence

Moderate — large multicenter real-world study with prospective data collection, but retrospective analysis and non-randomized design. The consistent superiority across subgroups strengthens the findings.

When this study was published

Published in 2024, providing timely real-world comparison data as anti-CGRP therapies become increasingly available globally.

The bigger picture

This study provides some of the strongest real-world evidence yet that anti-CGRP therapy represents a genuine advance over the previous standard of care (onabotulinumtoxinA) for chronic migraine. The superiority in difficult-to-treat patients is particularly significant, as these patients have the greatest unmet need. The dramatically lower adverse event rate also suggests better long-term treatment adherence potential.

Questions still open

Which specific CGRP mAb (erenumab, galcanezumab, fremanezumab) performs best against onabotulinumtoxinA?
Would switching from onabotulinumtoxinA to CGRP mAbs benefit current Botox non-responders?
Do these advantages persist beyond 6 months of treatment?

Common questions

Are anti-CGRP drugs better than Botox for chronic migraine?

This large real-world study found yes — CGRP antibodies reduced migraine days by about 50% more than Botox (13 vs. 8.7 fewer days), nearly 75% of patients responded well (vs. about 51% with Botox), and side effects were 3.5 times less frequent. These advantages held even in the hardest-to-treat patients. However, this wasn't a randomized trial, so some bias in patient selection is possible.

Should chronic migraine patients switch from Botox to a CGRP antibody?

If Botox isn't providing adequate relief, this data supports trying a CGRP antibody — especially since the study showed advantages even in patients who had failed 3+ previous preventives. However, some patients do well on Botox, and treatment decisions should be individualized with your neurologist. Both treatments are well tolerated with no patients discontinuing due to side effects.

Read the original research

Comparative effectiveness and tolerability of calcitonin gene-related peptide (CGRP) monoclonal antibodies and onabotulinumtoxinA in chronic migraine: A multicenter, real-world study in Taiwan.

European journal of neurology, 31(9), e16372

View on PubMed ↗Publisher’s paper ↗

Citation

Wang, Yen-Feng; Yang, Fu-Chi; Chen, Lu-An; Chang, Ting-Yu; Su, Hui-Chen; Yang, Chun-Pai; Tu, Yi-Hsien; Tzeng, Yi-Shiang; Chen, Shih-Pin; Fuh, Jong-Ling; Lai, Kuan-Lin; Ling, Yu-Hsiang; Chen, Wei-Ta; Wang, Shuu-Jiun. (2024). Comparative effectiveness and tolerability of calcitonin gene-related peptide (CGRP) monoclonal antibodies and onabotulinumtoxinA in chronic migraine: A multicenter, real-world study in Taiwan.. European journal of neurology, 31(9), e16372. https://doi.org/10.1111/ene.16372