Inclusion Criteria:  The patient has a diagnosis of CM as defined by IHS ICHD-3 guidelines confirmed at screening visit with a history of migraine onset at least 12 months prior to the Screening Visit. The patient has a migraine onset at ≤50 years of age. The patient has ≥8 migraine days per month for each month within the past 3 months prior to the Screening Visit. The patient fulfils the following criteria for migraine in prospectively collected information in the eDiary during the screening period: Migraine occurring on ≥8 days and headache occurring on ≥15 to ≤26 days. The patient has demonstrated compliance with the Headache eDiary by entry of data for at least 24 of the 28 days following the Screening Visit. The patient is aged ≥18 (≥20 for Taiwan) and ≤75 years at the Screening Visit.  Exclusion Criteria:  The patient has received any medication targeting the calcitonin gene-related peptide (CGRP) pathway as preventive treatment of migraine. The patient has confounding and clinically significant pain syndromes, (for example, fibromyalgia, chronic low back pain, complex regional pain syndrome). The patient has a diagnosis of acute or active temporomandibular disorder. The patient has a history or diagnosis of chronic tension-type headache, hypnic headache, cluster headache, hemicrania continua, new daily persistent headache, or unusual migraine subtypes such as hemiplegic migraine (sporadic and familial), ophthalmoplegic migraine, migraine with brainstem aura and migraine with neurological accompaniments that are not typical of migraine aura (diplopia, altered consciousness, or long duration). The patient has a lifetime history of psychosis, bipolar mania, or dementia. Patients with other psychiatric conditions whose symptoms are not controlled or who have not been adequately treated for a minimum of 6 months prior to screening are also excluded. The patient has a history of clinically significant cardiovascular disease, including uncontrolled hypertension, vascular ischaemia or thromboembolic events (for example, cerebrovascular accident, deep vein thrombosis, or pulmonary embolism).  Other inclusion and exclusion criteria may apply