['episodic cluster headache']
['galcanezumab', 'placebo']

        Inclusion Criteria:

          -  Have a diagnosis of cluster headache as defined by International Headache Society
             (IHS) International Classification of Headache Disorders (ICHD)-3 beta guidelines with
             a history of episodic cluster headache with at least two cluster periods lasting from
             7 days to 1 year (when untreated) and separated by pain-free remission periods of >=1
             month.

          -  Participants are able to distinguish cluster headache attacks from other headaches.

        Exclusion Criteria:

          -  Current enrollment in or discontinuation within the last 30 days from, a clinical
             trial involving any investigational drug or device.

          -  Current use or any prior exposure to any calcitonin-gene-related peptide (CGRP)
             antibody, any antibody to the CGRP receptor, or antibody to nerve growth factor (NGF).

          -  Are taking indomethacin and/or are suspected of having another distinct trigeminal
             autonomic cephalalgia.

          -  A history of migraine variants that could implicate or could be confused with
             ischemia.

          -  Known hypersensitivity to multiple drugs, monoclonal antibodies or other therapeutic
             proteins.

          -  A history or presence of other medical illness that indicates a medical problem that
             would preclude study participation.

          -  Evidence of significant active or unstable psychiatric disease, in the opinion of the
             investigator.

          -  Women who are pregnant or nursing.
      