This is a randomized, double-blind, placebo-controlled, ascending single-dose study evaluating AMG 333 in healthy subjects and subjects with migraines. The study will consist of 8 cohorts: 7 cohorts of healthy subjects and 1 cohort of subjects with migraines. For cohorts 1 to 7, 8 subjects each will be enrolled, and subjects will be randomized such that 6 subjects will receive AMG 333 and 2 subjects will receive placebo (3:1 ratio). In cohort 8, up to 24 subjects with migraines will be enrolled, depending on enrollment rate and emerging safety and tolerability data. These migraine subjects will be randomized to receive AMG 333 or placebo in a crossover fashion. Both healthy and migraine subjects will be monitored in house for 4 days then allowed to return home for the remainder of the 14 day observation period. Both healthy and migraine subjects will keep headache diaries.
