A Study in Migraine Prevention

Inclusion Criteria:

- Are migraine patients with migraine onset before 50 years of age

- Present with diagnosis of at least 1 year with migraine attack defined by
International Headache Society (IHS) guidelines

- Have a frequency of 4 to 14 migraine attacks, with or without aura, per month (with no
more than 14 headache days per month, migraine or non-migraine) for at least the last
6 months

- Female patients of childbearing potential must test negative for pregnancy at the time
of enrollment and agree to use a reliable method of birth control during the study

Exclusion Criteria:

- Are currently enrolled in, or discontinued within the previous 6 months from a
migraine clinical trial involving an investigational drug or device or off-label use
of a drug or device

- Are currently enrolled in, or discontinued within the previous 30 days from screening
from a non-migraine clinical trial involving an investigational drug or device or
off-label use of a drug or device, or concurrently enrolled in any other type of
medical research judged not to be scientifically or medically compatible with this
study

- Have previously completed or withdrawn from this study or any other study
investigating LY2300559

- Have known allergies to LY2300559 or related compounds (such as montelukast)

- Are under treatment with medication or procedures for prevention of migraine, or are
taking any other medications that are excluded by the protocol

- Have a history of alcohol or drug abuse/dependence within the past 3 months of
screening or are currently using alcohol, drugs of abuse (including opioids,
barbiturates, and marijuana), or any prescribed or over-the-counter medication in a
manner that the investigator considers indicative of abuse/dependence

- Screen positive for drugs of abuse

- Patients with medication overuse headache as per IHS definition

- Have a body mass index (BMI) of less than 18.5 or greater than or equal to 35.0

- Have history or presence of cardiovascular, respiratory, hepatic, renal,
gastrointestinal, endocrine, hematological or neurological disorders capable of
significantly altering the absorption, metabolism, or elimination of drugs,
constituting a risk when taking the study medication or interfering with the
interpretation of the data

- Show evidence of serious active neuropsychiatric disease including, but not limited
to, bipolar disorder, schizophrenia, psychosis, cluster B personality disorders [for
example (eg), borderline personality disorder or narcissistic personality disorder],
obsessive-compulsive disorder, or other serious mood, anxiety, depression, or
substance/alcohol use disorders

- Have ever in his/her lifetime attempted suicide, have any recent suicidal ideation
within the last 3 months, or are at significant risk to commit suicide, as judged by
the investigator

- Show evidence or have history of neurological disease such as cerebral vascular
accident, pseudotumor cerebri, multiple sclerosis, transient ischemic attack, syncopal
episodes, encephalitis, or meningitis

- Have a history or seizures other than febrile

- Female patients who are pregnant or breast-feeding

- Females of childbearing potential who are not using a clinically acceptable method of
birth control (eg, oral contraceptives or abstinence)

- Are unwilling or unable to comply with the use of a data collection device to directly
record patient data

- Are otherwise unable to comply with the requirements of the study