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Amyotrophic Lateral Sclerosis (ALS)Early Phase 1RAG-21-FUS-ALSNCT07080801

Study on the Safety and Efficacy of RAG-21 in the Treatment of Amyotrophic Lateral Sclerosis Patients With FUS Gene Mutations

A Early Phase 1 study testing RAG-21 in people with Amyotrophic Lateral Sclerosis (ALS), run by Beijing Tiantan Hospital.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

Amyotrophic lateral sclerosis (ALS) is a chronic progressive neurodegenerative disease that remains incurable, with limited existing therapies or drugs available. Familial ALS can be caused by mutations in various genes. In Asia, mutations in the FUS gene are relatively common among early-onset familial ALS patients. Read more about this study

Who is it for?
Ages 18 to 75 years
Conditions the study is for
Amyotrophic Lateral Sclerosis (ALS)
What is being tested?
RAG-21
Could I receive a placebo?
No, everyone receives an active treatment
How many people
6 participants
Where
No sites listed yet
Study dates
Aug 2025to Dec 2026
Phase
Early Phase 1
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 75 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age 18-75 years, gender unlimited.
  • Clearly identify amyotrophic lateral sclerosis (ALS) patients with FUS gene mutations (known FUS mutation sites and reported disease progression).
  • Forced vital capacity (FVC) during screening period ≥ 50% of expected lung capacity.
  • ALS patients diagnosed according to the Gold Coast criteria (2020) with limb-onset weakness.
  • The patient or their legal representative clearly understands and voluntarily participates in the study and signs an informed consent form.
  • The subjects (including male subjects) have no family planning throughout the entire study and within 3 months after, voluntarily take effective contraceptive measures and without any plans to donate sperm or ovum.

Who cannot join

  • FUS mutation sites located within nucleotides 928-970 (calculated from the translation of FUS protein).
  • Patients who have previously received or are currently receiving Ulefnersen treatment.
  • Human immunodeficiency virus (HIV) test positive or positive test history.
  • Patients with active hepatitis C or hepatitis B infection.
  • Other experimental drugs used within one month or within five drug half-lives.
  • Lumbar diseases and deformities.
Show all 15Show fewer
  • ALS with bulbar-onset symptoms, or suffering from other diseases known to be related to motor neuron dysfunction, which may confuse or blur the diagnosis of ALS.
  • Other psychiatric disorders diagnosed according to Diagnostic and Statistical Manual of Mental Disorders (DSM-V) diagnostic criteria, or obvious suicidal intentions.
  • Combined with severe liver dysfunction, renal dysfunction, or severe heart dysfunction (severe liver dysfunction refers to alanine aminotransferase (ALT) value ≥ 2.0 times the upper limit of normal value or aspartate aminotransferase (AST) value ≥ 2.0 times the upper limit of normal value; severe renal dysfunction refers to creatinine (CRE) ≥ 1.5 times the upper limit of normal value or estimated glomerular filtration rate (eGFR) < 40mL/min/1.73m^2; severe heart dysfunction refers to New York College of Cardiology (NYHA) 3-4 levels).
  • Permanent and sustained dependence on ventilator assisted ventilation.
  • History of combined alcohol and drug abuse.
  • Pregnant, lactating, or potentially pregnant patients, as well as those planning to conceive.
  • Patients participating in other clinical trials or applying other biologics, drugs, or devices under study.
  • Patients who have received any vaccination within 28 days.
  • Those who can't complete follow-up due to other reasons.

Trial locations and contacts

No sites are listed yet. Contact the study team or a site near you to ask about taking part.

About this study

Amyotrophic lateral sclerosis (ALS) is a chronic progressive neurodegenerative disease that remains incurable, with limited existing therapies or drugs available. Familial ALS can be caused by mutations in various genes. In Asia, mutations in the FUS gene are relatively common among early-onset familial ALS patients. Reducing the levels of toxic FUS protein may be an effective therapeutic approach for such ALS patients without causing side effects.

RAG-21 is a small interfering ribonucleic acid (siRNA) with a molecular weight of 20 kDa. Through the RNA interference mechanism, it targets the FUS gene, recognizes the corresponding mRNA, and mediates its degradation, thereby downregulating FUS gene expression and reducing toxic FUS protein levels. Accordingly, this project plans to conduct a single-center, dose-escalation clinical study aimed at evaluating the safety, tolerability, and pharmacokinetics of intrathecal bolus administration of RAG-21 in ALS patients carrying FUS gene mutations.

Being tested
RAG-21
Keywords
RAG-21, FUS gene mutations
Medical subject headings
Amyotrophic Lateral Sclerosis

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • RAG-21Drug

    Intrathecal bolus administration of RAG-21 will be initiated at a dose of 120 mg, prepared with a dedicated solvent into a 10 mL sterile aqueous solution. Dosing will occur every 2 weeks, with the dose escalating to 180 mg after 3 administrations. Subsequently, the dosing interval will be extended to every 4 weeks. The investigator will then select an optimal dose from the completed dose cohorts or continue dose escalation until the maximum tolerated dose (MTD) is reached, with a predefined maximum dose of 210 mg. For continued treatment, the investigator-determined optimal dose will be administered as a fixed dose every 4 weeks, with a total treatment duration of 6 months (8 administrations).

Study groups in NCT07080801
Study groupRoleWhat they receive
RAG-21ExperimentalNot described
Receives: Drug: RAG-21

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. AE&SAE

    Incidence of Adverse Events (AEs) and Serious Adverse Events (SAEs) after RAG-21 treatment.

    Measured: 15±1, 29±2, 57±3, 85±3, 113±3, 141±3, 169±3, 197±7days after treatment

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted23 Jul 2025
  2. Study startAug 2025 (estimated)
  3. Primary completionAug 2026 (estimated)
  4. Study completionDec 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Early Phase 1
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
6 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07080801
Sponsor's protocol ID
HX-A-2025021
Acronym
RAG-21-FUS-ALS
Status last verified
Jul 2025
First submitted
6 Jul 2025
Last updated
23 Jul 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Early Phase 1 study testing RAG-21 in people with Amyotrophic Lateral Sclerosis (ALS), run by Beijing Tiantan Hospital.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 23 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Xinru Liu (13521588395, liuxinru0826@163.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

AE&SAE (time frame: 15±1, 29±2, 57±3, 85±3, 113±3, 141±3, 169±3, 197±7days after treatment). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Jul 2025.

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