A Study to Learn More About the Effects and Long-Term Safety of BIIB141 (Omaveloxolone) in Participants With Friedreich's Ataxia Aged 2 to 15 Years Old

DRUG

Omaveloxolone

Administered as specified in the treatment arm.

DRUG

Placebo

Administered as specified in the treatment arm.

Part 1: Change From Baseline in Upright Stability Score (USS) Subscale E of Modified Friedreich's Ataxia Rating Scale (mFARS) at Week 52

Time frame: Baseline, Week 52

The mFARS is a validated and sensitive rating scale that was developed to quantitatively assess the severity of the neurologic features of FA in adults and adolescents. Scores on the mFARS range from 0 to 93, with lower scores indicating better neurological function. The subscales of the mFARS assessment and maximum score for each subscale are: bulbar function (Subscale A; 2 assessments of speech and cough; maximum score = 5), upper limb coordination (Subscale B; 5 assessments of coordination of movement and function in arms and hands with each limb scored individually; maximum score = 36), lower limb coordination (Subscale C; 2 assessments of coordination of movement and function of lower limbs with each limb scored individually; maximum score = 16), and upright stability (USS, Subscale E; 9 assessments of sitting posture, stance, tandem walk, and gait assessments; maximum score = 36).

Part 2A: Change From Baseline in USS Subscale E of mFARS at Week 52

Time frame: Baseline (Week 52 of Part 1), Week 52

The mFARS is a validated and sensitive rating scale that was developed to quantitatively assess the severity of the neurologic features of FA in adults and adolescents. Scores on the mFARS range from 0 to 93, with lower scores indicating better neurological function. The subscales of the mFARS assessment and maximum score for each subscale are: bulbar function (Subscale A; 2 assessments of speech and cough; maximum score = 5), upper limb coordination (Subscale B; 5 assessments of coordination of movement and function in arms and hands with each limb scored individually; maximum score = 36), lower limb coordination (Subscale C; 2 assessments of coordination of movement and function of lower limbs with each limb scored individually; maximum score = 16), and upright stability (USS, Subscale E; 9 assessments of sitting posture, stance, tandem walk, and gait assessments; maximum score = 36).

Part 2B: Number of Participants With Treatment-Emergent Adverse Event (TEAE) and Treatment-Emergent Serious Adverse Event (TESAE)

Time frame: From the first dose of the study drug in Part 2B up to the end of follow-up period in Part 2B (up to Week 104)

Part 2B: Number of Participants With Change From Baseline in Cardiac Function Assessed by Echocardiogram (ECHO) at Weeks 52 and Week 104

Time frame: Baseline (Week 52 of Part 1), Weeks 52 and 104

Part 2B: Change From Baseline in Height at Weeks 52 and Week 104

Time frame: Baseline (Week 52 of Part 1), Weeks 52 and 104

Part 2B: Change From Baseline in Weight at Weeks 52 and Week 104

Time frame: Baseline (Week 52 of Part 1), Weeks 52 and 104

Part 2B: Change From Baseline in Body Mass Index (BMI) at Weeks 52 and Week 104

Time frame: Baseline (Week 52 of Part 1), Weeks 52 and 104

Part 2B: Change From Baseline in Columbia Suicide Severity Rating Scale (C-SSRS) at Weeks 52 and Week 104

Time frame: Baseline (Week 52 of Part 1), Weeks 52 and 104

The C-SSRS is a low-burden measure of the spectrum of suicidal ideation and behavior that was developed to assess severity and track suicidal events through any treatment of individuals ≥ 6 years of age. The C-SSRS is a clinical interview providing a summary of both ideation and behavior that can be administered by the clinician during any evaluation or risk assessment to identify the level and type of suicidality present. The assessment includes "yes" or "no" responses for 5 questions each, related to suicidal ideation (wish to be dead, non-specific active suicidal thoughts, active suicidal ideation with any methods, active suicidal ideation with some intent, active suicidal ideation with specific plan) and suicidal behavior (preparatory acts or behavior, aborted attempt, interrupted attempt, actual attempt, suicide). Numeric ratings are provided for severity of ideation, from 1 to 5, with 5 being the most severe.

Part 2B: Percentage of Participants at Each Tanner Stage at Weeks 52 and Week 104

Time frame: Baseline (Week 52 of Part 1), Weeks 52 and 104

Assessment of Tanner stages (a scale of physical development) will be performed by a medical doctor experienced with this assessment. Tanner score ranges from Stage 1 (childhood) to Stage 5 (full physical maturity). Information regarding Tanner staging will be collected at baseline for all participants and will be stopped once the participant reaches Tanner Stage 5 in all gender-appropriate scales.

Part 2B: Number of Participants at Each Tanner Stage at Weeks 52 and Week 104

Time frame: Baseline (Week 52 of Part 1), Weeks 52 and 104

Assessment of Tanner stages (a scale of physical development) will be performed by a medical doctor experienced with this assessment. Tanner score ranges from Stage 1 (childhood) to Stage 5 (full physical maturity). Information regarding Tanner staging will be collected at baseline for all participants and will be stopped once the participant reaches Tanner Stage 5 in all gender-appropriate scales.

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.