Summary of the results from published randomized controlled trials
See below the table for comments and how to read it.
| 50% RR | 75% RR | |
| Episodic migraine [1]
STRIVE (70, 140 mg) |
5/10 | 2/10 |
| Episodic migraine
ARISE (70 mg) |
4/10 | NA |
| Refractory EPISODIC
(fail 2-4 preventive) LIBERTY (140 mg) |
3/10 | 1/10 |
| Chronic migraine [2]
(70, 140 mg) |
4/10 | 2/10 |
| With medication overuse | 3.5/10 | NA |
| Refractory CHRONIC
Subanalysis Phase 2 (2+ failure) |
4/10 | 1/10 (70 mg)
2/10 (140 mg) |
NA = not available
Each X/10 number is an approximation (+/- 1-2%) coming from the published results of the studies on erenumab (Aimovig). The references for the studies can be found at the bottom of this page. Abstracts can be found for free on Pubmed.
A 3/10 number means that if a physician prescribes Aimovig to a patient similar to the ones in these studies, this person has 3 chances over 10 (roughly) to achieve a 50% or 75% response.
The results were not very different between the 70 mg and the 140 mg dose, except in patients with previous preventive medication failures.
What is the 50% Response Rate?
This is a common parameter used in migraine research. A 50% response is a decrease in the migraine days of 50%. For someone with chronic migraine at 22 days per month, this would be equivalent to going down to 11 days per month. For someone with episodic migraine at 10 days per month, then the 50% RR would be a frequency of 5 days per month.
The 75%RR follows then same concept.
Episodic Migraine: migraine with or without aura [3] 14 days per month or less.
Chronic Migraine: a history of migraine with or without aura, 15 days of headache per month, 8 days have to be migraines and not only headaches.
Refractory chronic migraine: when the chronic migraine has not been improved by two migraine preventives. Please remember than in the studies, patients having failed 3 or more were excluded. Patients in the LIBERTY study had failed 2 to 4 preventives.
Medication overuse is the frequent intake of acute medications to treat migraine attacks. The term overuse stems from the fact that frequent use may lead to the deterioration of migraine, therefore using frequently is probably «too much». The usual numbers to talk about overuse are 15 days per months (for acetaminophen or NSAIDs only) and 10 days (for triptans [4], opioids or any combinations).
References:
STRIVE (episodic migraine) : Goadsby, et al. N Engl J Med. 2017;377:2123-2132.
ARISE (episodic migraine): Dodick et al Cephalalgia, 38(6), 1026–1037.
Chronic migraine study: Tepper, et al. Lancet Neurol. 2017;16:425-434.
LIBERTY (failure in episodic): Reuter, Lancet. 2018 Nov 24;392(10161):2280-2287
Previous failure CM subanalysis: Ashina, et al. Cephalalgia. 2018;38(10):1611-1621
Medication overuse subanalysis : Tepper, et al. Neurology. 2019 Apr 17 online