Study to Evaluate the QTC Interval in Healthy Volunteers Dosed With Dexpramipexole (QTC = Electrocardiogram (ECG) Interval Measured From the Onset of the QRS Complex to the End of the T Wave Corrected for Heart Rate)

A Single-Center, Randomized, Blinded, Placebo- and Active-Controlled Crossover Study to Evaluate the Effect of Dexpramipexole (BIIB050) on the QTc Interval in Healthy Volunteers

To evaluate whether dexpramipexole prolongs the QTc interval when orally administered to healthy volunteers.

This is a Phase I, single-center, blinded (with respect to dexpramipexole administration), randomized, placebo- and active-controlled, 4-period crossover study in approximately 68 healthy volunteers. This thorough QT/QTc study will be conducted to formally evaluate the effect of dexpramipexole on QT prolongation.

Inclusion Criteria:

• Aged 18 to 60 years old inclusive on Day 1.
• Subjects who, in the opinion of the Investigator, are healthy as determined by pre study medical history, physical examination, and 12 lead ECG.
• Male subjects and female subjects of childbearing potential must practice effective contraception (per protocol specifications).
• Normal systemic blood pressure defined as a systolic blood pressure of 90 to 140 mmHg and a diastolic blood pressure of 50 to 90 mmHg.

Exclusion Criteria:

• History of cardiovascular disease (e.g., hypertension, arrhythmia, heart failure, Long QT Syndrome, or other conditions/diseases causing prolongation of the QT/QTc interval), in the opinion of the Investigator.
• A prolongation of QT/QTc interval (e.g., repeated demonstration of a QT/QTc interval >450 ms before study treatment administration.
• Clinically important abnormalities in resting ECG that may interfere with the interpretation of QTc interval changes at screening, check-in, or pre-dose on Day -1 of the first treatment period.
• Other medically significant illness.
• Clinically significant abnormal laboratory values.
• Pregnant women or women breastfeeding.