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

Multicenter, Safety and Efficacy, Open-Label Extension Study of ACTIMMUNE® (Interferon γ-1b) in Children and Young Adults With Friedreich's Ataxia

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02593773
Acronym
STEADFAST
Enrollment
86
Registered
2015-11-02
Start date
2015-12-25
Completion date
2017-03-21
Last updated
2024-12-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Friedreich's Ataxia

Keywords

Interferon gamma

Brief summary

The purpose of this phase 3 multi-center, open-label extension study is to evaluate the long-term safety of ACTIMMUNE® (interferon-γ 1b) in participants with Friedreich's Ataxia.

Detailed description

Participants who complete 26 weeks of blinded treatment in HZNP-ACT-301 (NCT02415127), will be eligible to enter this 6-month study. All participants will receive ACTIMMUNE® 3 times a week (TIW) for 26 weeks. In order to maintain the study blind in HZNP-ACT-301 (NCT02415127), all participants in this open-label extension study will undergo ACTIMMUNE® titration, regardless if they received ACTIMMUNE® or placebo in HZNP-ACT-301 (NCT02415127). The Week 26 Visit from HZNP-ACT-301 (NCT02415127) will serve as the Baseline Visit (Day 1) for this study. During the treatment period, additional clinic visits are scheduled at Weeks 4, 13, and 26; in between clinic visits, participants (and/or caregivers) will be monitored via emails/phone calls on a weekly basis until participants reach their maximum tolerated dose, and on a monthly basis thereafter. Study with completed results acquired from Horizon in 2024.

Interventions

The study drug dose is planned to be escalated on a weekly basis over the first 4 weeks of treatment (from 10 µg/m² to 25, 50, and 100 µg/m²). The dose may be reduced, interrupted, or held based on tolerability. By Week 13, all participants are to be on a stable tolerated dose of study drug in order to continue study participation; the dose may not be further increased after Week 13, however, it may be reduced on a case-by-case basis to manage drug-related adverse events (AEs).

Sponsors

Friedreich's Ataxia Research Alliance
CollaboratorOTHER
Amgen
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
10 Years to 26 Years
Healthy volunteers
No

Inclusion criteria

* Written informed consent and child assent, if applicable. * Completed 26 weeks of blinded treatment in Study HZNP-ACT-301 (NCT02415127). * 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 urine pregnancy test result at Baseline/Day 1 (Week 26 of Study HZNP-ACT-301 \[NCT02415127\]), 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

* Subjects will be ineligible if, in the opinion of the Investigator, they are unlikely to comply with the study protocol or have a concomitant disease or condition that could interfere with the conduct of the study or potentially put the subject at unacceptable risk. NOTE: Additional inclusion/

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants With Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEsBaseline/Day 1 (Week 26 of Study HZNP-ACT-301 [NCT02415127]) through Week 28 (follow-up safety visit)An adverse event (AE) is any untoward medical occurrence, whether or not the event is considered related to the investigational product. A TEAE is any adverse change from the subject's baseline condition, including any laboratory test value abnormality judged as clinically significant by the investigator, that occurs on or after the date of the first dose of study drug administered at home and throughout the duration of the clinical study, whether the adverse event is considered related to the treatment or not. An SAE is an AE that results in death, is life-threatening, results in persistent or significant disability or incapacity, inpatient hospitalization or prolongation of an existing hospitalization, is a congenital anomaly or birth defect, or other medically important event.
Number of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsBaseline/Day 1 (Week 26 of Study HZNP-ACT-301 [NCT02415127]), Week 4, Week 13, Week 26, and Week 28 (follow-up safety visit)NAb testing only for those participants with a positive ADA test. Baseline is defined as the last non-missing measurement/assessment on the date of Week 26 Visit from study HZNP-ACT-301 (NCT02415127). If this measurement was missing or otherwise unavailable, it was the last non-missing measurement/assessment on or prior to first dose in this study. If the participant discontinued the study, then premature withdrawal assessments were mapped to the nearest scheduled visit based on schedule of the assessment and the study day. If the mapped visit was already available then the visit was mapped to the next schedule visit. Last on study assessment is the last non-missing post-baseline assessment for each participant.
Change From Baseline to Week 26 in the Friedreich's Ataxia Rating Scale (FARS)-mNeuro ScoreFrom Baseline to Week 26 for all participants and from Baseline of HZNP-ACT-301 (NCT02415127)to Week 26 of HZNP-ACT-302 (52-week treatment duration) for participants receiving active treatment in both studies.The FARS assessment includes neurological signs that specifically reflect neural substrates affected in FA. Based on a neurological examination, bulbar, upper limb, lower limb, peripheral nerve, and upright stability/gait functions were assessed. The FARS-mNeuro score excludes the peripheral nervous system subscale score and the facial and tongue atrophy and fasciculations from the bulbar subscale score. Scores range from 0 (normal) to 93 (most impairment). A negative change from baseline is an improvement.

Secondary

MeasureTime frameDescription
Change From Baseline to Week 26 in Activities of Daily Living (ADL) ScoreFrom Baseline to Week 26 for all participants and from Baseline of HZNP-ACT-301 (NCT02415127)to Week 26 of HZNP-ACT-302 (52-week treatment duration) for participants receiving active treatment in both studies.Participants and/or their caregivers rated 9 areas of daily living skills (speech, swallowing, cutting food and handling utensils, dressing, personal hygiene, falling, walking, quality of sitting position, and bladder function) on a 5-point scale (0=normal, 4=greatest loss of function) with allowable increments of 0.5 if the participant or caregiver strongly felt that a task falls between 2 scores. ADL scores can range from 0 (normal) to 36 (greatest loss of function). A negative change from baseline indicates improvement.
Change From Baseline to Week 26 in Total Friedreich Ataxia Rating Scale Score (FARStot)From Baseline to Week 26 for all participants and from Baseline of HZNP-ACT-301 (NCT02415127)to Week 26 of HZNP-ACT-302 (52-week treatment duration) for participants receiving active treatment in both studies.The FARS assessment includes neurological signs that specifically reflect neural substrates affected in FA. Based on a neurological examination, bulbar, upper limb, lower limb, peripheral nerve, and upright stability/gait functions are assessed. FARStot scores range from 0 (normal) to 125 (most impairment). A negative change from baseline indicates improvement.
Change From Baseline at Week 26 in Timed 25-Foot Walk (T25FW)From Baseline to Week 26 for all participants and from Baseline of HZNP-ACT-301 (NCT02415127)to Week 26 of HZNP-ACT-302 (52-week treatment duration) for participants receiving active treatment in both studies.The T25FW is a quantitative measure of lower extremity function. Participants are directed to 1 end of a clearly marked 25-foot course and instructed to walk 25 feet as quickly as possible, but safely. The task is immediately administered again by having the participant walk back the same distance, and the score for the test is the average of the 2 walks (after reciprocal transformation). Participants may use assistive devices when performing this task, with the same assistive device used at each assessment. A negative change from Baseline indicates improvement.
Number of FARS-mNeuro Responders and Non-Responders at Week 26Week 26A participant was considered a responder if they had an improvement (decrease) of at least 3 points from Baseline at Week 26 for the FARS-mNeuro score. The FARS assessment includes neurological signs that specifically reflect neural substrates affected in FA. Based on a neurological examination, bulbar, upper limb, lower limb, peripheral nerve, and upright stability/gait functions were assessed. The FARS-mNeuro score excludes the peripheral nervous system subscale score and the facial and tongue atrophy and fasciculations from the bulbar subscale score. Scores range from 0 (normal) to 93 (most impairment).

Countries

United States

Participant flow

Participants by arm

ArmCount
Interferon γ-1b
SC ACTIMMUNE® TIW for a total of 26 weeks. The study drug dose was escalated on a weekly basis over the first 4 weeks of treatment (from 10 μg/m² to 25, 50, and 100 μg/m²), based on tolerability, with all participants on a stable tolerated dose by Week 13. Dose may have been reduced, interrupted, or held based on tolerability thereafter.
86
Total86

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyDeath1
Overall StudyStudy Terminated by Sponsor31
Overall StudyVoluntary Withdrawal3

Baseline characteristics

CharacteristicInterferon γ-1b
Age, Continuous16.8 years
STANDARD_DEVIATION 4.05
Ethnicity (NIH/OMB)
Hispanic or Latino
4 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
82 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Race (NIH/OMB)
American Indian or Alaska Native
1 Participants
Race (NIH/OMB)
Asian
0 Participants
Race (NIH/OMB)
Black or African American
0 Participants
Race (NIH/OMB)
More than one race
2 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
2 Participants
Race (NIH/OMB)
White
81 Participants
Sex: Female, Male
Female
49 Participants
Sex: Female, Male
Male
37 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
1 / 86
other
Total, other adverse events
66 / 86
serious
Total, serious adverse events
4 / 86

Outcome results

Primary

Change From Baseline to Week 26 in the Friedreich's Ataxia Rating Scale (FARS)-mNeuro Score

The FARS assessment includes neurological signs that specifically reflect neural substrates affected in FA. Based on a neurological examination, bulbar, upper limb, lower limb, peripheral nerve, and upright stability/gait functions were assessed. The FARS-mNeuro score excludes the peripheral nervous system subscale score and the facial and tongue atrophy and fasciculations from the bulbar subscale score. Scores range from 0 (normal) to 93 (most impairment). A negative change from baseline is an improvement.

Time frame: From Baseline to Week 26 for all participants and from Baseline of HZNP-ACT-301 (NCT02415127)to Week 26 of HZNP-ACT-302 (52-week treatment duration) for participants receiving active treatment in both studies.

Population: Because the Sponsor discontinued the development of ACTIMMUNE® for the treatment of Friedreich's Ataxia, the planned analyses of the efficacy endpoints were not conducted. Any raw data collected for this endpoint exist as by-subject listings only, and are unanalyzed per protocol.

Primary

Number of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) Tests

NAb testing only for those participants with a positive ADA test. Baseline is defined as the last non-missing measurement/assessment on the date of Week 26 Visit from study HZNP-ACT-301 (NCT02415127). If this measurement was missing or otherwise unavailable, it was the last non-missing measurement/assessment on or prior to first dose in this study. If the participant discontinued the study, then premature withdrawal assessments were mapped to the nearest scheduled visit based on schedule of the assessment and the study day. If the mapped visit was already available then the visit was mapped to the next schedule visit. Last on study assessment is the last non-missing post-baseline assessment for each participant.

Time frame: Baseline/Day 1 (Week 26 of Study HZNP-ACT-301 [NCT02415127]), Week 4, Week 13, Week 26, and Week 28 (follow-up safety visit)

Population: Safety Population, defined as all participants who received at least 1 dose of open-label study drug after the Baseline Visit. Participants with an assessment at each time point are presented.

ArmMeasureGroupValue (NUMBER)
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsBaseline NAb = negative1 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsWeek 28 (Follow-up) ADA = positive0 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsBaseline ADA = negative85 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsBaseline ADA = positive1 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsBaseline NAb = positive0 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsWeek 4 ADA = negative84 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsWeek 4 ADA = positive0 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsWeek 13 ADA = negative79 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsWeek 13 ADA = positive0 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsWeek 26 ADA = negative64 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsWeek 26 ADA = positive0 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsWeek 28 (Follow-up) ADA = negative56 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsLast On Study Assessment ADA = negative85 participants
Interferon γ-1bNumber of Participants With Positive/Negative Neutralizing Antibody (NAb) and Anti-Drug Antibody (ADA) TestsLast On Study Assessment ADA = positive0 participants
Primary

Number of Participants With Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs

An adverse event (AE) is any untoward medical occurrence, whether or not the event is considered related to the investigational product. A TEAE is any adverse change from the subject's baseline condition, including any laboratory test value abnormality judged as clinically significant by the investigator, that occurs on or after the date of the first dose of study drug administered at home and throughout the duration of the clinical study, whether the adverse event is considered related to the treatment or not. An SAE is an AE that results in death, is life-threatening, results in persistent or significant disability or incapacity, inpatient hospitalization or prolongation of an existing hospitalization, is a congenital anomaly or birth defect, or other medically important event.

Time frame: Baseline/Day 1 (Week 26 of Study HZNP-ACT-301 [NCT02415127]) through Week 28 (follow-up safety visit)

Population: Safety Population, defined as all participants who received at least 1 dose of open-label study drug after the Baseline Visit.

ArmMeasureGroupValue (NUMBER)
Interferon γ-1bNumber of Participants With Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs≥ 1 TEAE Leading to Death1 participants
Interferon γ-1bNumber of Participants With Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs≥ 1 TEAE78 participants
Interferon γ-1bNumber of Participants With Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs≥ 1 Related TEAE61 participants
Interferon γ-1bNumber of Participants With Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs≥ 1 SAE4 participants
Interferon γ-1bNumber of Participants With Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs≥ 1 Related SAE0 participants
Interferon γ-1bNumber of Participants With Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs≥ 1 TEAE Leading to Discontinuation1 participants
Secondary

Change From Baseline at Week 26 in Timed 25-Foot Walk (T25FW)

The T25FW is a quantitative measure of lower extremity function. Participants are directed to 1 end of a clearly marked 25-foot course and instructed to walk 25 feet as quickly as possible, but safely. The task is immediately administered again by having the participant walk back the same distance, and the score for the test is the average of the 2 walks (after reciprocal transformation). Participants may use assistive devices when performing this task, with the same assistive device used at each assessment. A negative change from Baseline indicates improvement.

Time frame: From Baseline to Week 26 for all participants and from Baseline of HZNP-ACT-301 (NCT02415127)to Week 26 of HZNP-ACT-302 (52-week treatment duration) for participants receiving active treatment in both studies.

Population: Because the Sponsor discontinued the development of ACTIMMUNE® for the treatment of Friedreich's Ataxia, the planned analyses of the efficacy endpoints were not conducted. Any raw data collected for this endpoint exist as by-subject listings only, and are unanalyzed per protocol.

Secondary

Change From Baseline to Week 26 in Activities of Daily Living (ADL) Score

Participants and/or their caregivers rated 9 areas of daily living skills (speech, swallowing, cutting food and handling utensils, dressing, personal hygiene, falling, walking, quality of sitting position, and bladder function) on a 5-point scale (0=normal, 4=greatest loss of function) with allowable increments of 0.5 if the participant or caregiver strongly felt that a task falls between 2 scores. ADL scores can range from 0 (normal) to 36 (greatest loss of function). A negative change from baseline indicates improvement.

Time frame: From Baseline to Week 26 for all participants and from Baseline of HZNP-ACT-301 (NCT02415127)to Week 26 of HZNP-ACT-302 (52-week treatment duration) for participants receiving active treatment in both studies.

Population: Because the Sponsor discontinued the development of ACTIMMUNE® for the treatment of Friedreich's Ataxia, the planned analyses of the efficacy endpoints were not conducted. Any raw data collected for this endpoint exist as by-subject listings only, and are unanalyzed per protocol.

Secondary

Change From Baseline to Week 26 in Total Friedreich Ataxia Rating Scale Score (FARStot)

The FARS assessment includes neurological signs that specifically reflect neural substrates affected in FA. Based on a neurological examination, bulbar, upper limb, lower limb, peripheral nerve, and upright stability/gait functions are assessed. FARStot scores range from 0 (normal) to 125 (most impairment). A negative change from baseline indicates improvement.

Time frame: From Baseline to Week 26 for all participants and from Baseline of HZNP-ACT-301 (NCT02415127)to Week 26 of HZNP-ACT-302 (52-week treatment duration) for participants receiving active treatment in both studies.

Population: Because the Sponsor discontinued the development of ACTIMMUNE® for the treatment of Friedreich's Ataxia, the planned analyses of the efficacy endpoints were not conducted. Any raw data collected for this endpoint exist as by-subject listings only, and are unanalyzed per protocol.

Secondary

Number of FARS-mNeuro Responders and Non-Responders at Week 26

A participant was considered a responder if they had an improvement (decrease) of at least 3 points from Baseline at Week 26 for the FARS-mNeuro score. The FARS assessment includes neurological signs that specifically reflect neural substrates affected in FA. Based on a neurological examination, bulbar, upper limb, lower limb, peripheral nerve, and upright stability/gait functions were assessed. The FARS-mNeuro score excludes the peripheral nervous system subscale score and the facial and tongue atrophy and fasciculations from the bulbar subscale score. Scores range from 0 (normal) to 93 (most impairment).

Time frame: Week 26

Population: Because the Sponsor discontinued the development of ACTIMMUNE® for the treatment of Friedreich's Ataxia, the planned analyses of the efficacy endpoints were not conducted. Any raw data collected for this endpoint exist as by-subject listings only, and are unanalyzed per protocol.

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026