This study will assess the effect of cimetidine on the pharmacokinetics (PK) of dexpramipexole in healthy volunteer and evaluate the safety and tolerability of dexpramipexole when given with or without cimetidine. Additionally, this study will explore the influence of genetic variation on the PK of dexpramipexole when given with or without cimetidine.

This is a single-center, open-label, randomized, two-period, crossover study in approximately 14 healthy subjects. The goals of this study are as follows:

To assess the effect of cimetidine on the pharmacokinetics (PK) of dexpramipexole in healthy volunteers.

To evaluate the safety and tolerability of dexpramipexole when given with or without cimetidine.

To explore the influence of genetic variation on the PK of dexpramipexole when given with or without cimetidine.

Inclusion Criteria:

• Subjects who, in the opinion of the Investigator, are healthy as determined by medical history, physical examination, and 12 lead ECG
• Adult males/females aged 18 to 55 years inclusive
• Male and female subjects of childbearing potential must practice effective contraception during the study and up to 90 days after their last dose.

Exclusion Criteria:

• History of malignant disease, including solid tumors and hematologic malignancies.
• History of clinically significant endocrine, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, psychiatric, and renal, or other major diseases, as determined by the Investigator.
• Treatment with prescription medication and/or over-the-counter products and herbal-containing and/or alternative health preparations and procedures.
• Surgery within 90 days prior to check-in.