Millions of Americans suffer debilitating migraines, affecting their performance at work or school and contributing to anxiety and other mental-health issues. But few treatment options exist. Pharmaceutical firms Amgen and Novartis are seeking to change that with Aimovig, which in May became the first Food and Drug Administration–approved drug designed to prevent migraines. Administered by monthly injection, the drug works by blocking a protein receptor in the brain, preventing a peptide that may trigger migraines from attaching to its target. During trials, it halved the number of recipients’ migraine days. Cen Xu, Amgen’s scientific director for neuroscience, says she has been overwhelmed by positive feedback from the more than 52,000 people using Aimovig so far. “Seeing the handwritten letters, I get very emotional,” she says. Aimovig costs $575 per dose before insurance, but Amgen helps some patients, whose private health plans don’t cover the drug, get it at no cost for up to a year. —Jamie Ducharme