Preventive Therapies for Chronic Migraine

To the Editor: In the November 30 issue, two groups of researchers report the results of phase 3 clinical trials of drugs for the prevention of migraine. Silberstein et al. 1 describe the efficacy of fremanezumab, a monoclonal antibody targeting calcitonin gene–related peptide (CGRP), and Goadsby et al. 2 describe the efficacy of the anti-CGRP receptor erenumab. With respect to the effects of these two drugs, we note that CGRP is a potent endogenous vasodilator. Our group has been investigating the role of CGRP in vascular tone in experimental models. CGRP seems to play a larger role in altering vascular tone in . . .