A Study to Evaluate the Efficacy and Safety of Eptinezumab for the Prevention of Migraine in Participants That Are Not Helped by Previous Preventive Treatments

Inclusion Criteria:

• The participant has a diagnosis of migraine, with a history of chronic or episodicmigraines of at least 12 months prior to the Screening Visit
• The participant has a migraine onset of ≤50 years of age.
• The participant has ≥4 migraine days per month for each month within the past 3 monthsprior to the Screening Visit.
• The participant has demonstrated compliance with the Headache eDiary by entry of datafor at least 24 of the 28 days following the Screening Visit.
• The participant fulfils the following criteria for chronic migraine (CM) or episodicmigraine (EM) in prospectively collected information in the eDiary during thescreening period:
• For participants with CM: Migraine occurring on ≥8 days and headache occurring on >14days
• For participants with EM: Migraine occurring on ≥4 days and headache occurring on ≤14days
• The participant has documented evidence of treatment failure (must be supported bymedical record or by physician's confirmation specific to each treatment) in the past 10 years of 2-4 different migraine preventive medications.
• The participant has a history of either previous or active use of triptans formigraine.

Exclusion Criteria:

• The participant has experienced failure on a previous treatment targeting thecalcitonin gene-related peptide (CGRP) pathway.
• The participant has a treatment failure on valproate/divalproex or botulinum toxin A/Band the treatment is not the latest preventive medication prior to study inclusion.The medication is regarded as the latest if the medication start date is after thestart date of the other preventive medications and the medication stop date is afterthe stop date of the other preventive medications.
• The participant has confounding and clinically significant pain syndromes, (forexample, fibromyalgia, chronic low back pain, complex regional pain syndrome).
• The participant has a diagnosis of acute or active temporomandibular disorder.
• The participant has a history or diagnosis of chronic tension-type headache, hypnicheadache, cluster headache, hemicrania continua, new daily persistent headache, orunusual migraine subtypes such as hemiplegic migraine (sporadic and familial),ophthalmoplegic migraine, and migraine with neurological accompaniments that are nottypical of migraine aura (diplopia, altered consciousness, or long duration).
• The participant has a psychiatric condition that is uncontrolled and/or untreated fora minimum of 6 months prior to the Screening Visit. Participants with a lifetimehistory of psychosis and/or mania in the last 5 years prior to the Screening Visit areexcluded.
• The participant has a history of clinically significant cardiovascular disease orvascular ischaemia or thromboembolic events (for example, cerebrovascular accident,deep vein thrombosis, or pulmonary embolism). Other in- and exclusion criteria may apply