Erenumab

To evaluate the effect of erenumab compared with placebo on the change in MMDs from baseline to week 9 through week 12 (month 3) of DBTP.

A migraine day was any calendar day in which the participant experienced a qualified migraine headache (onset, continuation, or recurrence of the migraine headache). A qualified migraine headache was defined either as a migraine with or without aura, lasting for ≥ 4 hours, and meeting at least 1 of the following criteria: 1. ≥ 2 of the following pain features: * unilateral * throbbing * moderate to severe * exacerbated with exercise/physical activity 2. ≥ 1 of the following associated symptoms: * nausea * vomiting * photophobia and phonophobia The change from baseline in monthly migraine days was calculated as the average number of migraine days per month during the last 3 months (months 4, 5, and 6) of the 24-week double-blind treatment period minus the number of migraine days during the 4-week baseline period.

A migraine day was any calendar day in which the participant experienced a qualified migraine headache (onset, continuation, or recurrence of the migraine headache). A qualified migraine headache was defined either as a migraine with or without aura. The change from baseline in monthly migraine days was calculated as the number of migraine days during the last 4 weeks of the 12-week double-blind treatment phase - the number of migraine days during the 4-week baseline phase.

A migraine day was any calendar day in which the participant experienced a qualified migraine headache (onset, continuation, or recurrence of the migraine headache). A qualified migraine headache was defined either as a migraine with or without aura. The change from baseline in monthly migraine days was calculated as the average number of migraine days per month during the last 3 months (months 4, 5, and 6) of the 24-week double-blind treatment phase - the number of migraine days during the 4-week baseline phase.

A migraine day was defined as any calendar day in which the participant experienced a qualified migraine headache (onset, continuation or recurrence of the migraine headache). A qualified migraine headache was a migraine with or without aura, lasting for ≥ 30 minutes, and meeting at least one of the following criteria: a) ≥ 2 of the following pain features: unilateral, throbbing, moderate to severe, exacerbated with exercise/physical activity; b) ≥ 1 of the following associated symptoms: nausea and/or vomiting, photophobia and phonophobia. Change from baseline was calculated using the mean monthly migraine days from months 4, 5 and 6 of the DBTP minus the number of migraine days during the 4-week baseline phase. Least squares (LS) mean was estimated using a generalized linear mixed model which included treatment, visit, treatment by visit interaction, stratification factor (current, prior only, or no prior/current treatment), and baseline value as covariates.

On CHU day 29 and day 57, site staff interviewed sub-study participants and asked if they administered a full, partial, or no dose of erenumab (after explaining that a full dose means that the entire volume of the AI/pen was injected) and documented the participant's response in the electronic case report form. Data presented are the percentage of participants who reported "full administration," "not full administration," or "discontinued investigational product (ie, no dose)." (Day 1 of the CHU substudy occurred at any OLTP study visit \[up to week 88\] as long as the participant had previously received at least 1 OL dose of erenumab 140 mg.)

Total exercise time was assessed using an exercise treadmill test according to the standard Bruce protocol. The Bruce protocol is a standardized multistage treadmill test for assessing cardiovascular health, where the participant walks on an uphill treadmill in a graded exercise test with electrodes on the chest to monitor cardiac function. Every 3 minutes, the speed and incline of the treadmill are increased. There are 7 such stages for a total possible exercise time of 21 minutes.

Adverse events (AEs) were graded for severity using the Common Terminology Criteria for Adverse Events (CTCAE) version 4.03, where Grade 1 = mild AE, asymptomatic or mild symptoms; Grade 2 = Moderate AE; Grade 3 = Severe or medically significant but not immediately life-threatening; Grade 4 = Life-threatening consequences; urgent intervention indicated; Grade 5 = Death related to AE.

At the CHU substudy day 28 and day 56 visits, the site provided erenumab 140 mg to participants to self-administer at home on the following day. Study site staff then called the participants and asked if they administered a full, partial, or no dose of erenumab. A full dose was defined when the entire volume of both prefilled syringes or autoinjector/pens were injected.

A migraine day was any calendar day in which the participant experienced a qualified migraine headache (onset, continuation, or recurrence of the migraine headache). A qualified migraine headache was defined either as a migraine with or without aura. The change from baseline in monthly migraine days was calculated as the number of migraine days during the last 4 weeks of the 12-week treatment phase - the number of migraine days during the 4-week baseline phase.

To assess participants ability to administer a full dose of erenumab in home-use at day 29 (week 4) and day 57 (week 8), site staff called participants and asked whether the participant administered a full, partial, or no dose of erenumab. A full dose means that the entire volume of both prefilled syringes or autoinjector/pens were injected. Discontinued prior to dosing day indicates participants who had discontinued the investigational product and did not attempt to self-administer on day 29 or 57.

The pharmacokinetics of ethinyl estradiol (EE) were characterized during cycle 2 following the last active dose of oral contraceptive in the cycle (cycle day 21) without erenumab, and during cycle 3 following the last active dose of oral contraceptive in the cycle (cycle day 21), 11 days after a single dose of erenumab.

The pharmacokinetics of ethinyl estradiol (EE) were characterized during cycle 2 following the last active dose of oral contraceptive in the cycle (cycle day 21) without erenumab, and during cycle 3 following the last active dose of oral contraceptive in the cycle (cycle day 21), 11 days after a single dose of erenumab.

The pharmacokinetics of norgestrel (NG), an active metabolite of norgestimate, were characterized during cycle 2 following the last active dose of oral contraceptive in the cycle (cycle day 21) without erenumab, and during cycle 3 following the last active dose of oral contraceptive in the cycle (cycle day 21), 11 days after a single dose of erenumab.

The pharmacokinetics of norgestrel (NG), an active metabolite of norgestimate, were characterized during cycle 2 following the last active dose of oral contraceptive in the cycle (cycle day 21) without erenumab, and during cycle 3 following the last active dose of oral contraceptive in the cycle (cycle day 21), 11 days after a single dose of erenumab.

The pharmacokinetics of norelgestromin (NGMN), an active metabolite of norgestimate, were characterized during cycle 2 following the last active dose of oral contraceptive in the cycle (cycle day 21) without erenumab, and during cycle 3 following the last active dose of oral contraceptive in the cycle (cycle day 21), 11 days after a single dose of erenumab.

The pharmacokinetics of norelgestromin (NGMN), an active metabolite of norgestimate, were characterized during cycle 2 following the last active dose of oral contraceptive in the cycle (cycle day 21) without erenumab, and during cycle 3 following the last active dose of oral contraceptive in the cycle (cycle day 21), 11 days after a single dose of erenumab.

On day 1 of the double-blind randomization phase participants received 140 mg intravenous erenumab over 30 minutes or matching placebo. On day 8, participants received 10 mol/kg/minute PACAP-38 over 10 minutes and were observed for 24 hours after PACAP-38 infusion. A MLA was defined as fulfilling 1 of the 2 criteria: 1. Headache with at least 2 of the following characteristics: unilateral location, pulsating quality, moderate or severe pain intensity, aggravated by/causing avoidance of routine physical activity. Additionally, during the headache at least 1 of the following: nausea and/or vomiting, photophobia or phonophobia. 2. Headache described as mimicking usual migraine attack treated with triptan.

The severity of hot flashes was assessed by participants based on the following categories: * Mild: sensation of heat without sweating, mild flushing; * Moderate: sensation of heat, face flushed, slightly clammy, some sweating, able to continue activity, may want to remove layers of clothing or covers at night; * Severe: sensation of heat with more severe sweating, have to stop current activity, may have to change clothing. Baseline (BL) number of hot flashes is the average number of moderate or severe hot flashes per 24 hours from day -7 to day 1 predose based on geometric mean, and the week 4 number of hot flashes is the average number of moderate or severe hot flashes per 24 hours from day 21 to day 27 based on geometric mean. The ratio of week 4 to BL was used to assess change from BL to week 4 via a log transformation (log\[week4/BL\] = log\[week4\] - log\[BL\]), which was estimated using a repeated measures analysis. The ratio was obtained via an exponential back-transformation.

The C-SSRS is a measure of suicidal ideation and behavior. Ideation includes a wish to be dead or nonspecific thoughts about wanting to end life. Suicidal behavior includes actual attempts, interrupted or aborted attempts, and any preparatory acts.

Participants who had a negative or no result at baseline and were antibody positive postbaseline. Blood samples were first tested for anti-erenumab binding antibodies, samples testing positive for binding antibodies were also tested for neutralizing antibodies.