Fremanezumab (Ajovy) is the second CGRP monoclonal antibody to become after the introduction of erenumab (Aimovig) and it has some differentiating features. I injected myself with Aimovig twice and was able to drink more wine with relative impunity. The relief from my migraines was not complete, but very significant. However, I did experience constipation, which was quite unpleasant. Constipation is the only side effect of Aimovig reported with any frequency besides injection site reactions (an allergic rash can also occur). As one gets older (and I am 62), constipation becomes more prevalent. Although I could manage the constipation, it took an effort and I did not continue with Aimovig. My migraines are not at all disabling and I just cut back on wine. Besides wine, sleep deprivation and certain foods trigger my migraines, but they are easily managed with sumatriptan tablets or when I want fast onset of action, with sumatriptan injections.
After a couple of months, I decided to try Ajovy and took a shot on November 6. It worked at least as well as Aimovig and did not cause constipation. The effect lasted exactly a month and then migraines returned, so I took a second shot on December 13. Both Ajovy injections started to work within a day, although in some of my patients it takes a week.
I continue to prescribe Aimovig as well as Ajovy and sometimes, the third drug in this family, galcanezumab (Emgality). If someone is prone to constipation, my first choice is definitely Ajovy. Another small difference is the mode of delivery. You can give yourself a shot of Aimovig (and Emgality) with a push of a button, while Ajovy comes in a pre-filled syringe. Some patients find autoinjectors painful and opt for the prefilled syringe of Ajovy . Others, do not want to see the needle and prefer Aimovig’s pen-like device. One additional advantage of Ajovy is that it can be given every 3 months, although it requires 3 shots each time. Some of our patients who do not like giving themselves any kind of an injection opt for coming for a visit every 3 months and having our doctors or nurse practitioners administer Ajovy.
We have treated hundreds of patients with Aimovig and Ajovy and a few dozen with Emgality. Some who did not respond to Aimovig (we usually give two sets of monthly injections before giving up), responded well to Ajovy. This is probably due to the fact that they have a slightly different mechanism of action. Both are monoclonal antibodies that block the effect of CGRP, a neurotransmitter which is released during a migraine attack, but Aimovig blocks the CGRP receptor, while Ajovy (and Emgality) block the CGRP molecule. This difference may also explain why Aimovig constipates and the other two drugs do not.
About one fifth of patients have a dramatic relief from these medications, while about 50% have a 50% drop in the number of headaches. Some patients in the latter group may require continued treatment with Botox or oral medications, but together these treatments also result in a marked reduction in migraine-related disability. We also continue to prescribe abortive drugs such as sumatriptan (Imitrex) to all patients because even in complete responders an occasional migraine can still occur.
