A Study to Learn More About the Long-Term Safety of Tofersen (Qalsody) in Chinese Participants With SOD-1 Amyotrophic Lateral Sclerosis (ALS)

NCT07223723 | Recruiting Phase 4

• 1 other identifier: 233AS402
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

In this study, researchers will learn more about the safety of tofersen, also known as Qalsody®. This is a drug available for doctors to prescribe for people with a certain type of amyotrophic lateral sclerosis, also known as ALS. This type is in people who have a mutation in the superoxide dismutase 1 gene, also known as SOD-1. This is known as a "postmarketing" study. In this kind of the study, the goal is to learn more about how a drug works after it has been approved for use in the general public. Tofersen was approved in China in September 2024. The main goal of this study is to collect long-term safety information in Chinese participants with SOD-1 ALS. The main question researchers want to answer in this study is:

• How many participants have adverse events (AEs) and serious adverse events (SAEs)? An AE is a health problem that may or may not be caused by a drug during the study. An AE is considered serious when it results in death, is life-threatening, causes lasting problems, or requires hospital care. Researchers will also learn more about :
• How the body processes tofersen.
• How much tofersen is found in the cerebrospinal fluid (CSF), or the fluid that surrounds the brain and the spinal cord. This study will be done as follows:
• Participants will be screened to check if they can join the study. The screening period will be up to 4 weeks.
• After joining the study, participants will receive the first 3 doses of 100 milligrams (mg) of tofersen about 14 days apart. This will be given through an intrathecal (IT) injection. This means it will be given into the fluid surrounding the spine.
• After that, participants will receive 10 more doses every 28 days through IT injections. Participants will have up to 13 total doses of tofersen in this study.
• Participants will have up to 15 visits to their study research center. Each participant will be in the study for up to 52 weeks (1 year).

Conditions

Amyotrophic Lateral Sclerosis

Outcome Measures

Primary Outcomes (1)

• Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)

  From Screening up to end of study follow-up (up to 52 weeks)

Secondary Outcomes (4)

• Maximum Observed Plasma Concentration (Cmax) of Tofersen

  Predose and at multiple timepoints postdose on Day 1

• Time to Reach Maximum Plasma Concentration (Tmax) of Tofersen

  Predose and at multiple timepoints postdose on Day 1

• Area Under the Concentration-Time Curve (AUC) of Tofersen in Plasma

  Predose and at multiple timepoints postdose on Day 1

• Tofersen Cerebrospinal Fluid (CSF) Concentration

  Up to 44 weeks

Study Arms (1)

Tofersen 100 milligrams (mg)

EXPERIMENTAL

Participants will receive tofersen 100 mg by intrathecal (IT) injection as 3 loading doses once every 2 weeks (Days 1, 15, and 29), followed by 10 maintenance doses once every 4 weeks (approximately every 28 days), for a maximum total of 13 doses per participant over a 44- week treatment period.

Drug: Tofersen

Interventions

Tofersen DRUG

Administered by IT injection.

Also known as: BIIB067, QALSODY

Tofersen 100 milligrams (mg)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥ 18 years at the time of informed consent.
• Must have diagnosis of SOD1-ALS.
• If taking riluzole, participant must be on a stable dose for ≥ 30 days prior to Day 1 and expected to remain at that dose until the final study visit.
• If taking edaravone, participant must have initiated edaravone ≥ 60 days (2 treatment cycles) prior to Day 1 and expected to remain at that dose until the final study visit, unless the Investigator determines that edaravone should be discontinued for medical reasons, in which case it may not be restarted during the study.
• All women of childbearing potential must practice effective contraception during the study.

You may not qualify if:

• Hypersensitivity to the active substance or any of the excipients of tofersen injection.
• Current or past administration of tofersen injection, in either a commercial or a clinical study setting.
• Prior or current treatment with small interfering ribonucleic acid (RNA), stem cell therapy, or gene therapy.
• Treatment with another investigational drug, biological agent, or device within 1 month or 5 half-lives of study agent, whichever is longer, prior the Baseline Visit.
• Participants who are pregnant or currently breastfeeding, and those intending to become pregnant during the study.

Sponsors & Collaborators

• Biogen: lead

Study Sites (1)

Peking University Third Hospital

Beijing, Beijing Municipality, 100083, China

RECRUITING

MeSH Terms

Conditions

Amyotrophic Lateral Sclerosis

Interventions

tofersen

Condition Hierarchy (Ancestors)

Spinal Cord Diseases; Central Nervous System Diseases; Nervous System Diseases; Motor Neuron Disease; Neurodegenerative Diseases; TDP-43 Proteinopathies; Neuromuscular Diseases; Proteostasis Deficiencies; Metabolic Diseases; Nutritional and Metabolic Diseases

Study Officials

• Medical Director

  Biogen

  STUDY CHAIR

Central Study Contacts

US Biogen Clinical Trial Center

CONTACT

866-633-4636; clinicaltrials@biogen.com

Global Biogen Clinical Trial Center

CONTACT

clinicaltrials@biogen.com

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 31, 2025
• First Posted: November 3, 2025
• Study Start: December 11, 2025
• Primary Completion (Estimated): December 16, 2027
• Study Completion (Estimated): December 16, 2027
• Last Updated: January 20, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share

Locations

CN (1)