A Study to Learn About the Effects and Safety of RTA 408 (Omaveloxolone) in People Aged 16 to 40 With Friedreich's Ataxia

Cycle ergometry using a recumbent stationary bicycle was used to conduct maximal exercise testing and workload was increased incrementally. Peak work is defined as the workload at which participants reach maximal volition (defined as an inability to continue to exercise due to exhaustion). A positive change from baseline suggests an improvement.

An adverse event (AE) was any unfavorable and unintended sign (including any clinically significant abnormal laboratory test result), symptom, or disease temporally associated with the use of the study drug whether or not it is considered to be study drug related. An SAE was any untoward medical occurrence that at any dose resulted in death, in the view of the Investigator, placed the participant at immediate risk of death, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, resulted in a birth defect. TEAEs were defined as any AEs, regardless of relationship to study drug, that had an onset or worsened in severity on or after the first dose of study drug.

The Friedreich Ataxia Rating Scale (FARS) is a neurological-exam-based rating scale with five sections: Bulbar (section A), Upper Limb Coordination (section B), Lower Limb Coordination (section C), Peripheral Nervous System (section D), and Upright Stability (section E). mFARS is the sum of sections A (score 0 to 11), B (score 0 to 36), C (score 0 to 16), and E (score 0 to 36). The minimum score is 0 and the maximum score is 99. A lower score indicates better neurological function.

An AE was any unfavorable and unintended sign (including any clinically significant abnormal laboratory test result), symptom, or disease temporally associated with the use of the study drug whether or not it is considered to be study drug related. An SAE was any untoward medical occurrence that at any dose resulted in death, in the view of the Investigator, placed the participant at immediate risk of death, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, resulted in a birth defect. TEAEs were defined as any AEs, regardless of relationship to study drug, that had an onset or worsened in severity on or after the first dose of study drug.

The FARS is a neurological-exam-based rating scale with five sections: Bulbar (section A), Upper Limb Coordination (section B), Lower Limb Coordination (section C), Peripheral Nervous System (section D), and Upright Stability (section E). mFARS is the sum of sections A (score 0 to 11), B (score 0 to 36), C (score 0 to 16), and E (score 0 to 36). The minimum score is 0 and the maximum score is 99. A lower score indicates better neurological function.

The PGI-C is a 7-point scale that requires participants to assess how much their illness has improved or worsened relative to their baseline state at the beginning of the trial. Participants self-rated their perceived change by completing the following statement: "Since I began trial treatment, my overall status is:" 1=Very much improved, 2=Much improved, 3=Minimally improved, 4=No change, 5=Minimally worse, 6=Much worse and 7=Very much worse. Lower score indicates better improvement. The categories with at least one participant having a PGI-C score are reported.

The CGIC scale is a 7 point scale that requires the clinician to assess how much the participant's illness has improved or worsened relative to a baseline state at the beginning of an intervention. The CGIC was assessed by completing the following statement "Compared to the participant's condition at the start of the trial, this participant's overall status is", where 1=very much improved, 2=much improved, 3=minimally improved, 4=no change, 5=minimally worse, 6=much worse, 7=very much worse. Lower score indicates better improvement. The categories with at least one participant having a CGIC score are reported.

The 9-HPT is a brief, standardized, quantitative test of upper extremity (arm and hand) function. Both the dominant and nondominant hands were tested twice (2 consecutive trials of the dominant hand, followed immediately by 2 consecutive trials of the nondominant hand). The participant picks up pegs 1 at a time (9 in total), using 1 hand only, and places them into holes on the board as quickly as possible, in any order until all holes are filled. Then, without pausing, the participant removes the pegs 1 at a time and returns them as quickly as possible. The times recorded for the two trials for each hand are averaged, and the reciprocal average value for each hand was used in analyses. Longer test times reflect more impairment on the participant's upper extremity function, thus a negative change from baseline suggests an improvement.

The T25-FWT is a quantitative mobility and leg function performance test based on time (in seconds) to complete a 25-foot walk. Participants were instructed to attempt two T25-FWT trials at each visit. Both walk times were averaged, and the reciprocal average value was used in analyses. Longer test times reflect more impairment on the participant's ability to walk, thus a negative change from baseline suggests an improvement.

A fall was defined as "the participant unintentionally coming to rest on the ground or at a lower level." The total number of falls before and after study drug administration has been reported.

Cycle ergometry using a recumbent stationary bicycle was used to conduct maximal exercise testing and workload was increased incrementally. Peak work is defined as the workload at which participants reach maximal volition (defined as an inability to continue to exercise due to exhaustion). A positive change from baseline suggests an improvement.

The ADL scale examines the ability of participants to complete everyday tasks (e.g., holding a fork, dressing). The ADL is a 9-question assessment, with the total score being the sum of 9 questions. The ADL survey assesses 9 concepts: (1) speech; (2) swallowing; (3) cutting food and handling utensils; (4) dressing; (5) personal hygiene; (6) falling; (7) walking; (8) quality of sitting position; and (9) bladder function. Each of these is rated on a 5-point scale where 0= normal and 4= severe disability/inability to carry out activity independently, for a total possible score of 0 to 36, with higher scores representing greater disability/dependency. A negative change from baseline indicates improvement.