A Clinical Trial to Evaluate Efficacy and Safety of Xeomin® Injections for Preventing Chronic Migraine

Inclusion Criteria: * Participant has a diagnosis of CM with or without aura according to the International Classification of Headache Disorders Edition 3 criteria for ≥ 12 months and is able to distinguish migraine headaches from all other types of headaches; * Participant age \< 50 years at the time of migraine onset; * Participant meeting the following headache and migraine day criteria in each of the 3 months prior to screening: history of ≥ 15 headache days per month and history of ≥ 8 migraine days per month; and * During the last 28 days of the screening period, participant experiencing: ≥ 15 headache days and ≥ 8 migraine days that qualify as such per the headache diary. Exclusion Criteria: * Diagnosis of other primary headache types, except tension-type headache, which is permitted; * Diagnosis of aura without headache, migraine with brainstem aura, hemicrania continua, hypnic headache, hemiplegic migraine, retinal migraine, persistent aura without infarction, migraine aura-triggered seizure, or previous migrainous infarction; * Diagnosis of secondary headache types, except medication overuse headache, which is permitted; * Currently taking \> 1 prescribed drug for the preventive treatment of migraine; * Discontinuation of anti-calcitonin gene-related peptide (CGRP) / anti-CGRP receptor monoclonal antibody treatment less than 5 months prior to screening.