Galcanezumab (Emgality) was the third drug in the family of CGRP monoclonal antibodies (mAbs) to become approved by the FDA for the prevention of migraines. It is more similar to fremanezumab (Ajovy) in its mechanism of action than to erenumab (Aimovig). Erenumab is an antibody that blocks the CGRP receptor, while galcanezumab and fremanezumab are antibodies that block the CGRP molecule. This may explain the fact that some patients who do not respond to one of these drugs may respond to another. Actually, even patients who do not respond or respond only partially to fremanezumab may respond to galcanezumab and the other way around. This should not be surprising since many drugs with the same mechanism of action may have different efficacy and side effects in different patients. In migraine treatment this applies to triptans, such as sumatriptan (Imitrex), rizatriptan (Maxalt), eletriptan (Relpax), and other, as well as beta blockers, such as propranolol (Inderal), atenolol (Tenormin), nebivolol (Bystolic).
Just like the other two CGRP mAbs, galcanezumab is injected monthly (although fremanezumab can be also given at a triple dose every three months). The initial dose is 240 mg, or two auto-injector pens, followed by a monthly dose of 120 mg. The main side effects are similar to the other two drugs, namely injection site reactions such as swelling, redness, and an allergic rash. Erenumab can be constipating, while the other two drugs are much less so.
The cost of all 3 drugs is the same – between $550 and $600 per monthly injection, but most insurers will pay for them if certain conditions are met. The main condition is that the patient first try and fail two oral preventive medications such as beta blockers listed above, an antidepressant such as amitriptyline (Elavil), nortriptyline (Pamelor), or duloxetine (Cymbalta), or an epilepsy drug such as topiramate (Topamax) or divalproex sodium (Depakote).
Another, more recent requirement from many insurers, is that the patient not be receiving Botox. This prohibition is very upsetting because it is not based on any science and because many patients find that together these treatments (Botox and a CGRP mAb) provide almost complete relief of their migraine attacks. Both Botox and CGRP mAbs can be life-changing on their own with dramatic relief in about 20% of patients, while another 50% of patients obtain only partial relief. This is a very rational combination because these treatments work in a totally different way and both are extremely safe with no drug interactions. The insurers justify their refusal by the fact that there are no published studies showing the safety of this combination, which is ludicrous. Some insurers, such as Cigna, go a step further in their obnoxiousness – even if a patient gets free mAb from the manufacturer or pays out of pocket, they refuse to pay for Botox. How do they know if the patient is getting a mAb? – to get prior approval for Botox we have to submit our medical notes.
All three manufacturers of mAbs, Amgen, Teva, and Eli Lilly provide up to one year of free medicine if your commercial insurance refuses to pay for it. Check each manufacturer’s website – Aimovig.com, Ajovy.com, and Emgality.com. Allergan, Botox manufacturer offers up to $700 off each quarterly treatment, so if you are paying out-of-pocket or have a high copay or deductible, check BotoxSavingsProgram.com
