For decades, the prophylactic options for migraine were limited, and a number of migraine sufferers either didn’t respond to or didn’t tolerate the available drugs.
In 2010, onabotulinumtoxin A (Botox®) injections were approved for the prevention of chronic migraine. But since then, in meta-analyses, Botox has had only a small to modest benefit over placebo.
The biggest advantage to Botox might simply be its acceptance by patients. In a recent open-label trial funded by Allergan and presented at the American Headache Society meeting, Botox was compared with topiramate, a first-line migraine prevention drug.
Of those patients completing the trial, 40% in the Botox arm achieved a 50% reduction in headache days compared with 12% in the topiramate arm. What’s striking is that more than 80% of the patients stopped topiramate because of intolerable side effects or lack of efficacy, compared with 18% of the Botox group. However you define “success” in migraine prevention, the patient must be able to tolerate the treatment.
The newest option for the prevention of chronic migraine is Aimovig™, the first monoclonal antibody. It’s a calcitonin gene–related peptide inhibitor that targets the inflammation that’s believed to cause migraine. We’re waiting to see whether Aimovig will be viewed as a second- or third-line preventive therapy. Will patients be required to fail not only traditional migraine drugs, but also Botox, before they can try it?
Aimovig has the advantage of being a monthly self-administered injection; however, it’s expected to be more costly. And, at this stage, long-term safety data are limited. But with three other drugs of this class in the pipeline, clinicians will need to become familiar with these drugs to guide their patients’ treatment.