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 anassistive 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 pregnantduring the study, or within 30 days after the last dose of study drug. Femalesubjects of child-bearing potential must have a negative serum pregnancy test resultat Screening, a negative urine pregnancy test result at Baseline, and agree to use areliable method of contraception throughout the study and for 30 days after the lastdose of study drug.

Exclusion Criteria:

• Any unstable illness that in the investigator's opinion precludes participation inthe 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 theinvestigator based on electrocardiogram [ECG] and echocardiogram results atScreening). Specifically, an ejection fraction of <40% or a prolonged QT interval (>50% of cycle duration) will result in exclusion. If the investigator notes anyother clinically significant abnormalities on the ECG or echocardiogram, the subjectmay 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 <50mL/min) or hepatic disease (aspartate aminotransferase [AST] or alanineaminotransferase [ALT] >2x the upper limit of normal) as evidenced by laboratoryresults at Screening.

• Clinically significant abnormal white blood cell count, hemoglobin, or plateletcount as evidenced by laboratory test results at Screening.