
    futility analysis revealed that the primary endpoint is unlikely to be met. there were no
    safety concerns observed with fremanezumab treatment in the trial.
  
['chronic cluster headache']
['fremanezumab', 'placebo']

        Inclusion Criteria:

          -  The participant has a history of CCH according to the International Classification of
             Headache Disorders - 3 beta criteria (Headache Classification Committee of the
             International Headache Society [IHS] 2013) for greater than or equal to (≥)12 months
             prior to screening.

          -  The participant has a total body weight of ≥45 kilograms (kg) (99 pounds [lbs]).

          -  The participant is in good health in the opinion of the Investigator.

          -  Women of childbearing potential (WOCBP) whose male partners are potentially fertile
             (that is, no vasectomy) must use highly effective birth control methods for the
             duration of the study.

          -  Men must be sterile, or if they are potentially fertile/reproductively competent (not
             surgically [for example, vasectomy] or congenitally sterile) and their female partners
             are of childbearing potential, must agree to use, together with their female partners,
             acceptable birth control.

          -  If a participant is receiving Botox, it should be in a stable dose regimen, which is
             considered as having ≥2 cycles of Botox prior to screening. The participant should not
             receive Botox during the run-in period up to the evaluation period (12 weeks) where
             the primary endpoint is evaluated.

               -  Additional criteria apply, please contact the Investigator for more information.

        Exclusion Criteria:

          -  The participant has used systemic steroids for any medical reason (including treatment
             of the current cluster headache (CH) cycle within less than or equal to (≤)7 days
             prior to screening. The participant has used an intervention/device (for example,
             scheduled nerve blocks) for headache during the 4 weeks prior to screening.

          -  The participant has clinically significant hematological, renal, endocrine,
             immunologic, pulmonary, gastrointestinal, genitourinary, cardiovascular, neurologic,
             hepatic, or ocular disease at the discretion of the Investigator.

          -  The participant has evidence or medical history of clinically significant psychiatric
             issues determined at the discretion of the Investigator.

          -  The participant has a past or current history of cancer or malignant tumor in the past
             5 years, except for appropriately treated non-melanoma skin carcinoma.

          -  The participant is pregnant or lactating.

          -  The participant has a history of hypersensitivity reactions to injected proteins,
             including monoclonal antibodies.

          -  The participant has participated in a clinical study of a monoclonal antibody within 3
             months or 5 half-lives before administration of the first dose of the investigational
             medicinal product (IMP), whichever is longer, unless it is known that the participant
             received placebo during the study.

          -  The participant has a history of prior exposure to a monoclonal antibody targeting the
             calcitonin gene-related peptide (CGRP) pathway (AMG 334, ALD304, LY2951742, or
             fremanezumab). If participant has participated in a clinical study with any of these
             monoclonal antibodies, it has to be confirmed that the participant received placebo in
             order to be eligible for this study.

          -  The participant is an employee of the sponsor/participating study center who is
             directly involved in the study or is the relative of such an employee.

          -  The participant has an active implant for neurostimulation used in the treatment of
             CH.

          -  The participant is a member of a vulnerable population (for example, people kept in
             detention).

          -  The participant has a history of alcohol abuse prior to screening and/or drug abuse
             that in the Investigator's opinion could interfere with the study evaluations or the
             participant's safety.

               -  Additional criteria apply, please contact the Investigator for more information.
      