Safety, Tolerability and Efficacy of ACTIMMUNE® Dose Escalation in Friedreich's Ataxia

Inclusion Criteria: * Written informed consent and child assent, if applicable. * FA confirmed by genetic testing with two expanded guanine-adenine-adenine (GAA) repeats. * FA functional stage of \>1 to \<5 and ability to walk 25 feet with or without an assistive device. * Male or female subject between the ages of 10 and 25 years, inclusive. * If female, the subject is not pregnant or lactating or intending to become pregnant during the study, or within 30 days after the last dose of study drug. Female subjects of child-bearing potential must have a negative serum pregnancy test result at Screening, a negative urine pregnancy test result at Baseline, and agree to use a reliable method of contraception throughout the study and for 30 days after the last dose of study drug. Exclusion Criteria: * Any unstable illness that in the investigator's opinion precludes participation in the study. * Use of any investigational product within 30 days prior to randomization. * A history of substance abuse. * Presence of clinically significant cardiac disease (as determined by the investigator based on electrocardiogram \[ECG\] and echocardiogram results at Screening). Specifically, an ejection fraction of \<40% or a prolonged QT interval (\>50% of cycle duration) will result in exclusion. If the investigator notes any other clinically significant abnormalities on the ECG or echocardiogram, the subject may be eligible if they are provided clearance from a cardiologist. * History of hypersensitivity to interferon (IFN)-ɣ or E. coli-derived products. * Presence of moderate or severe renal disease (estimated creatinine clearance \<50 mL/min) or hepatic disease (aspartate aminotransferase \[AST\] or alanine aminotransferase \[ALT\] \>2x the upper limit of normal) as evidenced by laboratory results at Screening. * Clinically significant abnormal white blood cell count, hemoglobin, or platelet count as evidenced by laboratory test results at Screening.