CGRP Antibodies Work Well for Japanese Migraine Patients, and Early Response Predicts Long-Term Success | Research

The takeaway

In 68 Japanese migraine patients who had failed oral preventives, CGRP-targeted antibodies cut monthly migraine days nearly in half and an early positive response strongly predicted continued success.

13.4 → 7.4 monthly migraine days
After 3 doses of CGRP antibody in Japanese patients who had failed oral preventives

What the researchers found

CGRP mAbs reduced monthly migraine days from 13.4 to 7.4 (p<0.0001) with a 50% response rate, and early response after 1-2 doses predicted sustained benefit at 3 doses (OR: 3.474, p=0.047).

Why it matters

Real-world data confirming CGRP antibody effectiveness in Japanese patients fills an important gap, since genetic and physiological differences can affect drug response across populations. The finding that early response predicts outcomes helps clinicians decide sooner whether to continue treatment.

The numbers in context

Three drugs evaluated: galcanezumab, fremanezumab, and erenumab at two Japanese headache centers.

How the study worked

Retrospective observational cohort study at two Japanese headache centers. 68 patients who failed ≥1 oral preventive received galcanezumab, fremanezumab, or erenumab. Primary endpoints: change in monthly migraine days and HIT-6 score after 3 dosing intervals.

Who was studied

Japanese migraine patients at two headache centers

What this study cannot tell us

Retrospective design with no control group. Relatively small sample (n=68). Single ethnicity (Japanese). Combined three different CGRP antibodies in one analysis. Short follow-up period (3 dosing intervals).

How to read the evidence

Moderate evidence from a real-world observational cohort. Consistent with RCT findings but limited by retrospective design and lack of control group.

When this study was published

Published in 2024. Adds Japanese real-world data to the growing global evidence base for CGRP antibodies.

The bigger picture

CGRP antibodies represent the first migraine-specific preventive therapy class. Confirming their effectiveness across diverse populations and in real-world settings (not just controlled trials) strengthens the evidence base. The early-response predictor finding has practical value for optimizing treatment decisions.

Questions still open

Are there differences in efficacy between galcanezumab, fremanezumab, and erenumab specifically in Japanese patients?
What predicts non-response to CGRP antibodies, and can these patients benefit from switching within the class?
How do long-term outcomes beyond 3 doses compare between early and late responders?

Common questions

What are CGRP antibodies and how do they prevent migraines?

CGRP (calcitonin gene-related peptide) is a molecule released during migraines that causes blood vessel dilation and pain signaling. CGRP antibodies (like galcanezumab and erenumab) block this molecule or its receptor, preventing the cascade that leads to migraine attacks.

How quickly can you tell if a CGRP antibody is working?

This study found that patients who responded well after just 1-2 doses were 3.5 times more likely to continue benefiting. So while full evaluation typically happens after 3 doses, early improvement is a strong positive sign.

Read the original research

Real-world experience with calcitonin gene-related peptide-targeted antibodies for migraine prevention: a retrospective observational cohort study at two Japanese headache centers.

BMC neurology, 24(1), 32

View on PubMed ↗Publisher’s paper ↗

Citation

Shibata, Mamoru; Fujita, Kazuki; Hoshino, Eri; Minami, Kazushi; Koizumi, Kenzo; Okada, Satoshi; Sakai, Fumihiko. (2024). Real-world experience with calcitonin gene-related peptide-targeted antibodies for migraine prevention: a retrospective observational cohort study at two Japanese headache centers.. BMC neurology, 24(1), 32. https://doi.org/10.1186/s12883-023-03521-y