Randomization
Patients were randomly allocated via an interactive response technology system to one of the two treatment groups: eptinezumab 100 mg or placebo, in a 1:1 ratio. Additionally, all patients were to receive eptinezumab 100 mg in the open-label period. Thus, no patient was denied access to active treatment with eptinezumab. The term “treatment sequence” is used to denote the treatment groups arising by combining the treatment received in the placebo-controlled period and the eptinezumab 100 mg received in the open-label period. Therefore, in the open-label period, the two treatment sequence groups were: placebo–eptinezumab 100 mg and eptinezumab 100 mg–eptinezumab 100 mg. The interactive response technology allocated patients to a treatment group and assigned a randomization number that was used to identify the patient throughout the study. Study site and number of MHDs (< 20/ ≥ 20 MHDs at baseline) data collected during the screening period was used to stratify the randomization.