Anti-CGRP Monoclonal Antibodies: the Next Era of Migraine Prevention?

Migraine is a very disabling disorder with severe impact on patients' lives and substantive costs to society in terms of healthcare costs and lost productivity. Prevention is a key component of migraine therapy, and while numerous preventive options exist, each is burdened by either troublesome side effects or insufficient efficacy. All migraine preventives currently in clinical use were licensed for other purposes and, by chance, have efficacy against migraine. As our understanding of migraine has evolved, calcitonin gene-related peptide (CGRP) has moved to the forefront as a neuropeptide central to migraine pathophysiology. Six small molecule CGRP receptor antagonists were shown to be effective for acute treatment of migraine; two were stopped for hepatotoxicity or one for formulation concern issues and one is now in phase III. Monoclonal antibodies against CGRP or the CGRP receptor have a longer duration of action and have been investigated for migraine prevention. Four are in development and three have completed phase II and one phase III trials; every reported study has been positive. Furthermore, no safety issues have arisen to date, including hepatic or cardiovascular effects, and initial tolerability appears to be excellent. Monoclonal antibodies antagonizing the CGRP pathway represent a novel approach to prevention: a mechanism-specific migraine-targeted therapy. While we must await the results of all the phase III trials, cautious excitement seems warranted as we enter a new era of better tolerated, well-understood, bespoke migraine treatment for this common and disabling neurological disorder.