Amgen 's Aimovig (erenumab) was recently approved by the FDA for the prevention of migraine; it is expected to launch in the US this week, securing the first-to-market position within a new class of drugs for migraine, the calcitonin gene-related peptide (CGRP) receptor antagonists. Although Teva, Eli Lilly, and Alder are following hot on the heels of Amgen with their respective anti-CGRPs, Amgen is expected to maintain its dominance in the preventative migraine space.