VIP and headache disorder: In a randomized, double-blind, parallel-group, single-dose, placebo-controlled study of Lu AG09222, healthy volunteers aged 18–45 years without history of headache disorders were randomly allocated to three treatment sequences (1:2:2) on two experimental infusion visits with 9 ± 3 days’ interval: placebo + saline + saline (n = 5), placebo + PACAP38 + VIP (n = 10), and Lu AG09222 + PACAP38 + VIP (n = 10).