Aimovig new CGRP migraine preventive
In May the FDA approved a novel medication, Aimovig (erenumab-aooe), codeveloped by Amgen and Novartis, for the prevention of migraines. It’s novel in the classic sense that its mechanism of action is different than other migraine medications. But perhaps more interestingly, it is the first drug recently developed specifically for migraine prevention. The only other one, Sansert, was used during the ’60s but is off the market. Prior to Aimovig, medications used for prevention were products originally developed for other medical conditions: Anticonvulsants such as topiramate, beta blockers and calcium-channel blockers for heart disease, antidepressants, and even the wrinkle treatment, Botox. They all have some efficacy, but none are stars.
Aimovig, a monthly injectable approved at 70-mg and 140-mg doses, targets a neuropeptide called calcitonin gene–related peptide (CGRP) that is believed to be involved in inflammatory processes that are at the heart of migraines. Medications that home in on CGRPs are a new class of medications. Three other companies have CGRP products in the queue for FDA approval or in phase 3 trials. Eli Lilly is developing galcanezumab, Teva has fremanezumab, and Alder, a biotech developer focused on neurological conditions, is working on eptinezumab.
The CGRPs finally move migraine medication away from combating cerebrovascular changes and vasodilation. An increasing number of studies show that vasodilation is not significant in migraines, and clinicians and some informed patients are excited that a new pathway is being pursued that will get at the excruciating pain migraines can cause.
Far fewer ‘migraine days’
Aimovig’s approval was based upon three clinical trials. In the largest, called STRIVE, 955 patients with an average of 8.3 migraines per month were randomized to Aimovig or placebo. At the end of six months, patients taking the 70-mg dose had 3.2 fewer “migraine days” per month compared with 1.8 fewer days for those assigned to the placebo group. The reduction with the 140-mg dose was 3.7 days per month.
Another way to tally the migraine results is by the number of people whose migraine days were cut in half. Among those who were assigned to the 70-mg dose, 43.3% had their migraine days cut by at least 50%, compared with 26.6% with placebo. Exactly half (50%) who took the 140-mg dose experienced a 50% reduction in monthly migraine days.
STRIVE also showed a reduction in the days that patients had to take a rescue medicine for an acute migraine and statistically significant improvements in the Migraine Physical Function Impact Diary (MPFID), which measures daily functioning.
The value of the CGRP class is its potential to significantly reduce migraines for a reasonable number of patients, points out Alan Rapoport, MD, of UCLA’s David Geffen Medical School.
From one perspective, Aimovig’s performance relative to a placebo treatment is not that great; it’s not even twice as effective as placebo in reducing the number of migraine days or in reaching a 50% reduction in monthly migraines.
But in the clinic, outside of the rarefied circles of clinical trials, clinicians are excited. “The most exciting thing about these drugs is not the FDA-required endpoints,” says Alan Rapoport, MD, a clinical professor of neurology at UCLA’s David Geffen Medical School who has been a leader in headache research and treatment. The value of the CGRP class is its potential to significantly reduce migraines for a reasonable number of patients. He says about 30% of patients may see 75% reduction, and between 15% and 20% may see a 100% reduction.
Nonresponse and side effects were common with prior medications, says Rapoport. A study funded by Amgen in the October 2017 journal Headache provides insight to the therapy challenges. The study tracked 107,122 patients who started migraine prevention between Jan. 1, 2008, and Dec. 31, 2011. The cohort included 52,275 patients (49%) on topiramate, 22,658 (21%) taking beta blockers, and 32,189 (30%) on tricyclic antidepressants. Persistence with a medication was low; 81% of patients had gaps of greater than 90 days during the 12-month period. Of those who discontinued, only 10% restarted prophylactic therapy during the year.
Go to the Aimovig web site for information:
Go to Aimovigaccesscard.com, then register, print discount card, take the card to the pharmacy with your prescription, it should be free or $5.00 copay.