Lasmiditan Compared to Placebo in the Acute Treatment of Migraine:

Participants will be asked to treat a migraine attack with study drug on an outpatient basis. Participants will be provided with a dosing card containing a dose for initial treatment and a second dose to be used for rescue or recurrence of migraine. Each participant's study participation will consist of a screening visit (Visit 1) with a telephone contact within 7 days to confirm eligibility, a Treatment Period of up to 8 weeks, and an End-of-Study (EoS) visit (Visit 2) within one week (7 days) of treating a single migraine attack. The total time on study is approximately 11 weeks.

Inclusion criteria

• Able and willing to give written informed consent.
• Participants with migraine with or without aura fulfilling the International Headache Society (IHS) diagnostic criteria 1.1 and 1.2.1 (International Headache Classification (ICHD) 2004).
• History of disabling migraine for at least 1 year.
• MIDAS score ≥11.
• Migraine onset before the age of 50 years.
• History of 3 - 8 migraine attacks per month (< 15 headache days per month).
• Male or female, aged 18 years or above.
• Females of child-bearing potential must be using or willing to use a highly effective form of contraception (e.g. combined oral contraceptive, intrauterine device (IUD), abstinence or vasectomized partner).
• Able and willing to complete an electronic diary.

Exclusion criteria

• Pregnant or breast-feeding women.
• Women of child-bearing potential not using or not willing to use highly effective contraception.
• Known coronary artery disease, clinically significant arrhythmia or uncontrolled hypertension.
• History or evidence of hemorrhagic stroke, epilepsy or any other condition placing the participant at increased risk of seizures.
• History of recurrent dizziness and/or vertigo including benign paroxysmal positional vertigo (BPPV), Meniere's disease, vestibular migraine, and other vestibular disorders.
• History of diabetes mellitus with complications (diabetic retinopathy, nephropathy or neuropathy).
• History within the previous three years or current evidence of abuse of any drug, prescription or illicit, or alcohol.
• History of orthostatic hypotension with syncope.
• Significant renal or hepatic impairment.
• Participant is at imminent risk of suicide (positive response to question 4 or 5 on the C-SSRS) or had a suicide attempt within six months prior to the screening visit.
• Known Hepatitis B or C or HIV infection.
• History, within past 12 months, of chronic migraine or other forms of primary or secondary chronic headache disorder (e.g. hemicranias continua, medication overuse headache) where headache frequency is greater than 15 headache days per month.
• Use of more than 3 doses per month of either opiates or barbiturates.
• Initiation of or a change in concomitant medication to reduce the frequency of migraine episodes within three (3) months prior to Screening/Visit 1.