Long-Term Evaluation of BIIB067 (Tofersen)

August 12, 2025 updated by: Biogen

An Extension Study to Assess the Long-Term Safety, Tolerability, Pharmacokinetics, and Effect on Disease Progression of BIIB067 Administered to Previously Treated Adults With Amyotrophic Lateral Sclerosis Caused by Superoxide Dismutase 1 Mutation

The primary objective of the study is to evaluate the long-term safety and tolerability of BIIB067 (tofersen) in participants with amyotrophic lateral sclerosis (ALS) and confirmed superoxide dismutase 1 (SOD1) mutation. The secondary objectives are to evaluate the pharmacokinetic (PK), pharmacodynamic (PD), biomarker effects, and efficacy of BIIB067 administered to participants with ALS and a confirmed SOD1 mutation.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
139

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Belgium
      • Leuven, Belgium, 3000
        • Research Site
  • Canada
    • Alberta
      • Calgary, Alberta, Canada, T2N 4Z6
        • Research Site
      • Edmonton, Alberta, Canada, T6G 2B7
        • Research Site
    • Ontario
      • Toronto, Ontario, Canada, M4N 3M5
        • Research Site
    • Quebec
      • Montreal, Quebec, Canada, H3A2B4
        • Research Site
  • Denmark
      • Copenhagen, Denmark, 2400
        • Bispebjerg Hospital
  • France
    • Puy De Dome
      • Clermont-Ferrand, Puy De Dome, France, 63003
        • Research Site
  • Germany
    • Baden-Wurttemberg
      • Ulm, Baden-Wurttemberg, Germany, 89081
        • Research Site
  • Italy
      • Torino, Italy, 10126
        • Research Site
  • Japan
      • Bunkyō City, Japan
        • Research Site
      • Kagoshima, Japan
        • Research Site
      • Shinjuku-ku, Japan
        • Research Site
      • Suita-shi, Japan
        • Research Site
  • United Kingdom
    • South Yorkshire
      • Sheffield, South Yorkshire, United Kingdom, S102HQ
        • Research Site
  • United States
    • Arizona
      • Phoenix, Arizona, United States, 85013
        • Research Site
    • California
      • La Jolla, California, United States, 92093-0949
        • Research Site
      • San Francisco, California, United States, 94118
        • Research Site
    • Florida
      • Jacksonville, Florida, United States, 32224
        • Research Site
      • Miami, Florida, United States, 33136
        • Research Site
      • Orlando, Florida, United States, 32806
        • Research Site
    • Georgia
      • Atlanta, Georgia, United States, 30322
        • Research Site
    • Illinois
      • Chicago, Illinois, United States, 60611
        • Research Site
    • Maryland
      • Baltimore, Maryland, United States, 21287
        • Research Site
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Research Site
    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Research Site
    • Missouri
      • St Louis, Missouri, United States, 63110
        • Research Site
    • Nebraska
      • Lincoln, Nebraska, United States, 68510
        • Research Site
    • Ohio
      • Cleveland, Ohio, United States, 44106
        • Research Site
    • Oregon
      • Portland, Oregon, United States, 97213
        • Research Site
    • Tennessee
      • Knoxville, Tennessee, United States, 37920
        • Research Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  • Must have diagnosis of superoxide dismutase 1-amyotrophic lateral sclerosis (SOD1-ALS), and must have completed the End of Study Visit for either Parts A, B, or C of Study 233AS101 (NCT02623699) (i.e., were not withdrawn).
  • If taking riluzole, participant must be receiving a stable dose for ≥30 days prior to Day 1.
  • If taking edaravone, participant must have initiated edaravone ≥60 days (2 treatment cycles) prior to Day 1. Edaravone may not be administered on dosing days during this study.
  • Medically able to undergo the study procedures, and to adhere to the visit schedule at the time of study entry, as determined by the Investigator.
  • For female participants of childbearing potential must agree to practice effective contraception during the study and be willing and able to continue contraception for 5 months after their last dose of study treatment.
  • Participants from Study 233AS101 Parts A and B must have a washout ≥16 weeks between the last dose of study treatment received in Study 233AS101 and the first dose of BIIB067 received in the current Study 233AS102.

Key Exclusion Criteria:

  • History of allergies to a broad range of anesthetics.
  • Presence of risk for increased or uncontrolled bleeding and/or risk of bleeding that is not managed optimally and could place a participant at an increased risk for bleeding during or after a Lumbar Puncture (LP) procedure. These risks could include, but are not limited to, anatomical factors at or near the LP site (e.g., vascular abnormalities, neoplasms, or other abnormalities) and underlying disorders of the coagulation cascade, platelet function, or platelet count (e.g., hemophilia, Von Willebrand's disease, liver disease).
  • Presence of an implanted shunt for the drainage of CSF or an implanted central nervous system (CNS) catheter.
  • Prior or current treatment with small interfering ribonucleic acid (RNA), stem cell therapy, or gene therapy.
  • Treatment with another investigational drug, biological agent (excluding BIIB067), or device within 1 month or 5 half-lives of study agent, whichever is longer.
  • Current or anticipated need, in the opinion of the Investigator, of a diaphragm pacing system (DPS) during the study period.
  • Current or recent (within 1 month) use, or anticipated need, in the opinion of the Investigator, of copper (II) (diacetyl-bis(N4-methylthiosemicarbazone)) or pyrimethamine.
  • Female participants who are pregnant or currently breastfeeding.
  • Current enrollment in any other interventional study.

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: BIIB067
Participants who have completed Parts A, B, or C of study 233AS101 will be placed in this arm.
Drug: Tofersen
Participants will receive a loading dose regimen followed by maintenance dosing.
Other Names:
  • BIIB067
  • QALSODY

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Treatment Emergent Serious AEs (TESAEs)
Time Frame: From first dose of the study drug in the current study up to end of follow-up period (up to Week 364)
An AE is any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product. An SAE is any untoward medical occurrence that at any dose results in death, life-threatening event, requires inpatient hospitalization, significant disability/incapacity or congenital anomaly. TEAEs were defined as any AEs or SAE with an onset date and time that was on or after the first dose of study drug, or any pre-existing condition that worsened in severity after the first dose of study drug.
From first dose of the study drug in the current study up to end of follow-up period (up to Week 364)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Plasma Concentration of BIIB067
Time Frame: Week 4
Week 4
Concentration of BIIB067 in Cerebrospinal Fluid (CSF)
Time Frame: Week 4
Week 4
233AS101 and 233AS102 Integrated Summary of Efficacy (ISE): Total CSF Superoxide Dismutase 1 (SOD1) Protein Ratio to Baseline
Time Frame: Baseline, Weeks 52, 104 and 148
This outcome measure was not a standalone analysis for 233AS102. Analysis was performed on the data collected from both 233AS101 and 233AS102 studies. This is reported as a part of the final integrated analyses. Baseline is defined as the Day 1 of 233AS101 Part C. Data has been reported for Weeks 52, 104 and 148 from the 233AS101 Part C baseline.
Baseline, Weeks 52, 104 and 148
233AS101 and 233AS102 ISE: Neurofilament Light Chain (NfL) Plasma Concentration Ratio to Baseline
Time Frame: Baseline, Weeks 52, 104 and 148
This outcome measure was not a standalone analysis for 233AS102. Analysis was performed on the data collected from both 233AS101 and 233AS102 studies. This is reported as a part of the final integrated analyses. Baseline is defined as the Day 1 of 233AS101 Part C. Data has been reported for Weeks 52, 104 and 148 from the 233AS101 Part C baseline.
Baseline, Weeks 52, 104 and 148
233AS101 and 233AS102 ISE: Change From Baseline in Total Amyotropic Lateral Sclerosis Functional Rating Scale - Revised (ALSFRS-R) Score
Time Frame: Baseline, Weeks 52, 104 and 148
The ALSFRS-R measures 4 functional domains, including respiratory, bulbar function, gross motor skills, and fine motor skills. There are 12 questions, each scored from 0 (no function) to 4 (full function). The ALSFRS-R total score was calculated as the sum of the 4 functional domain scores, ranging from 0 to 48, where higher scores representing better function. Negative change from baseline indicates disease progression. This outcome measure was not a standalone analysis for 233AS102. Analysis was performed on the data collected from both 233AS101 and 233AS102 studies. This is reported as a part of the final integrated analyses. Baseline is defined as the Day 1 of 233AS101 Part C. Data has been reported for Weeks 52, 104 and 148 from the 233AS101 Part C baseline.
Baseline, Weeks 52, 104 and 148
233AS101 and 233AS102 ISE: Change From Baseline in Percent Predicted Slow Vital Capacity (SVC)
Time Frame: Baseline, Weeks 52, 104 and 148
Vital capacity was measured by means of an SVC test, administered in the upright position. Upright SVC was determined by performing 3 to 5 measures, in accordance with criteria established by the American Thoracic Society and the European Respiratory Society. The percent predicted SVC was calculated as [observed SVC divided by predicted SVC]*100%. The predicted SVC was adjusted by sex, age, height, which was programmed into and performed by the equipment used. Negative change from baseline indicated worsening of respiratory capacity. This outcome measure was not a standalone analysis for 233AS102. Analysis was performed on the data collected from both 233AS101 and 233AS102 studies. This is reported as a part of the final integrated analyses. Baseline is defined as the Day 1 of 233AS101 Part C. Data has been reported for Weeks 52, 104 and 148 from the 233AS101 Part C baseline.
Baseline, Weeks 52, 104 and 148
233AS101 and 233AS102 ISE: Change From Baseline in Handheld Dynamometry (HHD) Overall Megascore
Time Frame: Baseline, Weeks 52, 104 and 148
Quantitative muscle strength was evaluated using the HHD Megascore, which tests isometric strength of multiple muscles using standard participant positioning. Approximately 8 muscle groups were examined (per each side) in both upper and lower extremities. The muscle strength values were normalized to Z scores as (post-baseline measurements - mean)/SD and averaged to provide HHD overall megascore. The overall megascore was created by averaging all eight bilateral measurement Z scores, if no more than 10 (≤ 10) measures are missing. A negative change from baseline indicated decreased muscle strength. This outcome measure was not a standalone analysis for 233AS102. Analysis was performed on the data collected from both 233AS101 and 233AS102 studies. This is reported as a part of the final integrated analyses. Baseline is defined as the Day 1 of 233AS101 Part C. Data has been reported for Weeks 52, 104 and 148 from the 233AS101 Part C baseline.
Baseline, Weeks 52, 104 and 148
233AS101 and 233AS102 ISE: Change From Baseline in Individual Muscle Strength Assessed by HHD
Time Frame: Baseline, Weeks 52, 104 and 148
Individual muscle strength was evaluated using handheld dynamometer which tests the isometric strength of multiple muscles using standard participant positioning. Eight muscle groups were examined (per each side) in both upper and lower extremities. Negative change from baseline=decreased muscle strength. The analyses was based on observed data. This outcome measure was not a standalone analysis for 233AS102. Analysis was performed on data collected from both 233AS101 & 233AS102 studies. This is reported as a part of final integrated analyses.
Baseline, Weeks 52, 104 and 148
233AS101 and 233AS102 ISE: Time to Death or Permanent Ventilation
Time Frame: From the baseline of the study 233AS101 up to the end of the follow-up period of the current study (up to Week 364)
Permanent ventilation was defined as ≥ 22 hours of mechanical ventilation [invasive or noninvasive] per day for ≥ 21 consecutive days. An event of permanent ventilation was based on an adjudicated event (i.e., adjudicated by the Endpoint Adjudication Committee (EAC) as having met the permanent ventilation criteria defined in the protocol). Time to death or permanent ventilation was defined as the time to the earliest occurrence of death or permanent ventilation. The start date for calculating time to death or permanent ventilation in days was date of first dose. Participants without an event were censored at the last known alive dates. This outcome measure was not a standalone analysis for 233AS102. Analysis was performed on data collected from both 233AS101 & 233AS102 studies. This is reported as a part of final integrated analyses. Time to permanent ventilation or death was summarized using the Kaplan-Meier product limit method.
From the baseline of the study 233AS101 up to the end of the follow-up period of the current study (up to Week 364)
233AS101 and 233AS102 ISE: Time to Death
Time Frame: From the baseline of the study 233AS101 up to the end of the follow-up period of the current study (up to Week 364)
Time to death was defined as the time from first dose received in 233AS101 to death. Participants who do not meet the endpoint definition were censored at the participant's last known alive date. Only events that were adjudicated by the EAC are included. This outcome measure was not a standalone analysis for 233AS102. Analysis was performed on data collected from both 233AS101 & 233AS102 studies. This is reported as a part of final integrated analyses. Time to death was summarized using the Kaplan-Meier product limit method.
From the baseline of the study 233AS101 up to the end of the follow-up period of the current study (up to Week 364)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Biogen

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Ionis Pharmaceuticals, Inc.

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Medical Director, Biogen

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 8, 2017

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 12, 2024

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 12, 2024

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 28, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 28, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 3, 2017

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 29, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 12, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 233AS102
  • 2016-003225-41 (EudraCT Number)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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