A TEAE is defined as the reported AEs that first occurred or worsened during the post-baseline phase compared with the baseline phase. An SAE is any adverse event from this study that results in 1 of the following: Death, initial or prolonged inpatient hospitalization, a life-threatening experience (that is, immediate risk of dying), persistent or significant disability/incapacity, congenital anomaly/birth defect, Important medical events that may not be immediately life-threatening or result in death or hospitalization but may jeopardize the subject or may require intervention to prevent 1 of the other outcomes listed in the definition above. A summary of serious and other non-serious adverse events regardless of causality is located in the reported adverse events module.

C-SSRS is a scale capturing occurrence, severity, and frequency of suicide-related thoughts and behaviours, and has a binary response (yes/no). * Suicidal Ideation: a "yes" answer to any one of 5 suicidal ideation questions: Wish to be Dead, Non-specific Active Suicidal Thoughts, Active Suicidal Ideation with Any Methods (Not Plan) without Intent to Act, Active Suicidal Ideation with Some Intent to Act, without Specific Plan, Active Suicidal Ideation with Specific Plan and Intent. * Suicidal Behaviour: a "yes" answer to any of 5 suicidal behaviour questions: Preparatory Acts or Behaviour, Aborted Attempt, Interrupted Attempt, Actual Attempt (non-fatal), Completed Suicide.

Number of cluster headache attacks was recorded daily by study participants in their ePRO Diary. Overall mean change from baseline is derived from the average of weeks 1 to 3 from mixed model repeated measures (MMRM) analysis. Least Square (LS) means were calculated using MMRM model with treatment, sex, pooled investigative site, week, baseline, and treatment by week as fixed effects.