A 1-year Trial to Inform About Long-term Exposure to Eptinezumab in Participants With Chronic Cluster Headache (cCH)

Inclusion Criteria: * The participant has a diagnosis of cCH as defined by International Headache Society (IHS) International Classification of Headache Disorders third edition (ICHD-3) classification with a history of cCH of at least 12 months prior to the Screening Visit. * The participant has a medical history of onset of cluster headache at ≤50 years of age. * The participant has an adequately documented record of previous abortive, transitional and preventive medication use for cCH, for at least 12 months prior to the Screening Visit. * The participant is able to distinguish cluster headache attacks from other headaches (such as tension-type headaches, migraine). Exclusion Criteria: * The participant has experienced failure on a previous treatment targeting the calcitonin gene-related peptide (CGRP) pathway (anti-CGRP monoclonal antibodies \[mAbs\] and gepants). * The participant has confounding and clinically significant pain syndromes (for example, fibromyalgia, complex regional pain syndrome). * The participant has a history or diagnosis of chronic tension-type headache, hypnic headache, hemicrania continua, new daily persistent headache, chronic migraine or unusual migraine subtypes such as hemiplegic migraine (sporadic and familial), recurrent painful ophthalmoplegic neuropathy, migraine with neurological accompaniments that are not typical of migraine aura (diplopia, altered consciousness, or longer than 1 hour). * Participants with a lifetime history of psychos…