A fremanezumab trial failed to show efficacy for post-traumatic headache, suggesting CGRP blocking alone may not work for this condition, while onabotulinumtoxin A's multi-pathway mechanism may make it more promising.
CGRP antibody trial failedFremanezumab, proven effective for migraine, did not demonstrate significant efficacy for post-traumatic headache in Phase 2 testing
What the researchers found
A Phase 2 trial of fremanezumab (anti-CGRP mAb) failed to demonstrate significant efficacy in post-traumatic headache, despite its proven effectiveness in migraine. Evidence for onabotulinumtoxin A in PTH is limited to one small trial with abobotulinumtoxin A in 40 subjects. The review concludes that CGRP inhibition alone may be insufficient for PTH due to the condition's complex, multi-pathway pathophysiology, while ONA's broader mechanism (affecting multiple pain pathways) may offer advantages. ONA also has potential cost-effectiveness and adherence benefits.
Why it matters
Post-traumatic headache affects up to 90% of TBI patients and can persist for years, yet has no approved treatments. The failure of CGRP-blocking drugs — which revolutionized migraine treatment — to work in PTH reveals that not all headaches are created equal. This has major implications for the millions of people with traumatic brain injuries (military personnel, athletes, accident victims) who need effective headache treatment.
How the study worked
Comprehensive literature review searching PubMed through September 2024 for studies on onabotulinumtoxin A and anti-CGRP mAbs in post-traumatic headache. Both clinical trials and observational studies were reviewed.
What this study cannot tell us
Very limited evidence base — only one small trial for botulinum toxin and one Phase 2 trial for anti-CGRP in PTH. Current treatment strategies are extrapolated from other headache disorders, not validated for PTH. The fremanezumab trial failure could reflect trial design issues rather than definitive proof that CGRP targeting doesn't work. The review is narrative, not systematic.
How to read the evidence
This is a narrative review summarizing very limited evidence — one failed Phase 2 trial for anti-CGRP and one small botulinum toxin trial (n=40). The evidence base is insufficient to draw firm conclusions about either treatment for PTH.
When this study was published
Published in 2024 with literature through September 2024, this review captures the current state of a field with very limited clinical trial data for PTH treatment.
The bigger picture
The failure of CGRP-blocking antibodies in PTH challenges the assumption that all migraine-like headaches share the same underlying biology. This has implications beyond PTH — it suggests that the CGRP pathway, while central to migraine, may not be the primary driver of all headache types. The finding reinforces the need for headache treatment to be tailored to the specific condition rather than applying a one-size-fits-all approach.
Questions still open
- Is CGRP truly not involved in post-traumatic headache, or was the fremanezumab trial design unable to detect a benefit?
- Would combining CGRP blocking with other approaches (like onabotulinumtoxin A) work better than either alone for PTH?
- What specific pain pathways beyond CGRP are driving post-traumatic headache?
Common questions
Why don't migraine drugs work for post-traumatic headache?
Why might Botox work better than CGRP drugs for post-traumatic headache?
Read the original research
Onabotulinumtoxin A for the Treatment of Post-Traumatic Headache: Is It Better than Anti-CGRP Antibodies?
Toxins, 16(10)
Citation
Pellesi, Lanfranco; Onan, Dilara; Martelletti, Paolo. (2024). Onabotulinumtoxin A for the Treatment of Post-Traumatic Headache: Is It Better than Anti-CGRP Antibodies?. Toxins, 16(10). https://doi.org/10.3390/toxins16100427