Phase 3
N=139
Long-Term Evaluation of BIIB067 (Tofersen)
ALS Caused by Superoxide Dismutase 1 (SOD1) Mutation
Bottom Line
View on ClinicalTrials.gov: NCT03070119 ↗Enrolled (actual)
139
Serious AEs
51.1%
Results posted
Aug 2025
Primary outcome: Primary: Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Treatment Emergent Serious AEs (TESAEs) — 31; 63; 43; 16 Participants
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 3
- Interventions
- Tofersen (Drug)
- Age
- Adult, Older Adult · 18+ yrs
- Sex
- All
- Sponsor
- Biogen
- Primary completion
- Aug 2024
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Treatment Emergent Serious AEs (TESAEs) |
31; 63; 43; 16; 33; 22 | — |
| SECONDARY Plasma Concentration of BIIB067 |
1.22; 2.05 | — |
| SECONDARY Concentration of BIIB067 in Cerebrospinal Fluid (CSF) |
19.35; 9.18 | — |
| SECONDARY 233AS101 and 233AS102 Integrated Summary of Efficacy (ISE): Total CSF Superoxide Dismutase 1 (SOD1) Protein Ratio to Baseline |
0.78; 0.67; 0.81; 0.74; 0.75; 0.79 | =0.3711 |
| SECONDARY 233AS101 and 233AS102 ISE: Neurofilament Light Chain (NfL) Plasma Concentration Ratio to Baseline |
0.62; 0.50; 0.41; 0.33; 0.36; 0.33 | =0.2306 |
| SECONDARY 233AS101 and 233AS102 ISE: Change From Baseline in Total Amyotropic Lateral Sclerosis Functional Rating Scale - Revised (ALSFRS-R) Score |
-9.5; -5.9; -13.1; -9.4; -13.5; -9.9 | =0.1054 |
| SECONDARY 233AS101 and 233AS102 ISE: Change From Baseline in Percent Predicted Slow Vital Capacity (SVC) |
-18.7; -10.6; -23.7; -14.4; -18.1; -13.8 | =0.0963 |
| SECONDARY 233AS101 and 233AS102 ISE: Change From Baseline in Handheld Dynamometry (HHD) Overall Megascore |
-0.41; -0.15; -0.56; -0.42; -0.43; -0.38 | =0.3207 |
| SECONDARY 233AS101 and 233AS102 ISE: Change From Baseline in Individual Muscle Strength Assessed by HHD |
-3.42; -0.51; 0.17; -4.16; -2.48; -4.12 | — |
| SECONDARY 233AS101 and 233AS102 ISE: Time to Death or Permanent Ventilation |
NA; NA | =0.4202 |
| SECONDARY 233AS101 and 233AS102 ISE: Time to Death |
NA; NA | =0.3108 |
Summary
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.
Eligibility Criteria
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
Data sourced from ClinicalTrials.gov (NCT03070119). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.