CGRP Drug for Chronic Migraine: Very Promising Study Results
Amgen’s CGRP drug provided significant relief to participants with chronic migraine, according to new study results presented at an international conference in mid-September. The drug, called erenumab, was tested at two doses, 70 mg and 140 mg. “Both doses of erenumab were associated with significant improvements in health-related quality of life, headache impact, disability, and level of pain interference, compared to placebo,” according to Amgen’s press release announcing the study’s results.
Here’s a brief summary of the study’s details and it’s findings.
In the 12-week study, 667 participants were given monthly injections of either the drug, called erenumab, or a placebo. The breakdown was:
- 191 participants received 70 mg erenumab
- 190 participants received 140 mg erenumab
- 286 were injected with the placebo
All participants had chronic migraine. At the start of the study, they had an average of 18 migraine days per month and 21.1 headache days each month. The following outcomes were assessed during the last four weeks of the study.
- Reduction in migraine days per month: Those who were given erenumab (at either dose) had an average of 6.6 fewer migraine days a month.
- 50% or greater reduction in the number of migraine days per month: 40% of participants who received the drug at 70 mg and 41% who got 140 mg had their number of headache days decreased by at least half.
- Reduction in use of acute migraine drugs (abortives): Participants who received 70 mg of erenumab took abortives on 3.5 fewer days; those who received 140 mg reduced their medication use by 4.1 days.
- Reduction in headache hours: Participants who received 70 mg of erenumab had 64.8 fewer headache hours in the month; those who received 140 mg of erenumab had 74.5 fewer headache hours.
No adverse effect was reported in more than 5% of the participants. Those reported were:
- Injection site pain: 3.7% in participants who received the active drug at either dose; 1.1% placebo
- Upper respiratory tract infection: 2.6% at 70 mg; 3.7% at 140 mg; 1.4% placebo
- Nausea: 2.1% 70 mg; 3.2% 140 mg; 2.5% placebo
This yet is another promising report on the CGRP drugs that are in development for migraine prevention. All studies so far have found a notable reduction in migraine frequency and improvement in health-related quality of life for a significant portion of participants. Minimal side effects have been reported thus far. This was a Phase 2 study. Phase 3 studies, which are underway now, will include more participants and give us more information on side effects.
(Amgen has also issued a press release about the first CGRP drug Phase 3 results I’ve seen. Participants in the study had between four and 14 migraine days a month. Those given erenumab had an average of 2.9 fewer migraine days per month. With such a wide range in migraine frequency, it’s hard to tell how impressive that number is. But even for someone with 14 migraine days a month, the average would mean about 20% fewer migraine days.)