Evaluation of Safety and Efficacy of Gene Therapy Drug in the Treatment of Spinal Muscular Atrophy (SMA) Type 3 Patients

A Multi-center, Open Label, Single-arm, Dose Ascending Clinical Trial for Evaluation of Safety and Efficacy of Gene Therapy Drug GC101 in the Treatment of Spinal Muscular Atrophy (SMA) Type 3 Patients

Evaluation of Safety and Efficacy of Gene Therapy Drug in the Treatment of Spinal Muscular Atrophy (SMA) Type 3 Patients (NCT06421831) is a Phase 1 / Phase 2 interventional studying Spinal Muscular Atrophy Type 3, sponsored by GeneCradle Inc. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

The study will evaluate safety and efficacy of intrathecal delivery of GC101 gene therapy drug as a treatment of spinal muscular atrophy Type 3 (SMA 3) patients.

What Stage of Research Is This?

Phase 1 trials test a new treatment for the first time in humans, focusing on safety, dosing, and how the body processes the drug. For Spinal Muscular Atrophy Type 3, a Phase 1 study typically enrolls a small number of participants — often healthy volunteers or patients who have exhausted standard treatment options. Phase 1 results determine whether a treatment moves into larger Phase 2 efficacy studies.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

With a target enrollment of 21 participants, this is a small study — typical of early-phase research, rare-disease trials, or pilot studies designed to generate preliminary signal before a larger study is launched.

Who May Be Eligible (Plain English)

Who May Qualify: - ≥2 years of age on the day of signing the willing to sign a consent form form; - Genetic and clinical diagnosis of type 3 SMA with bi-allelic deletion of SMN1 of 5qSMA; - Hammersmith Functional Motor Scale - Expanded (HFMSE) score is between 10 and 54 at screening; - Female patients of childbearing age who are pregnant or lactating, as well as all enrolled patients （both male and female), should take effective contraceptive measures within 6 months after the treatment; - Patients or patient's legal guardian(s) must be able to understand the purpose and risks of the study and voluntarily provide signed and dated willing to sign a consent form prior to any study-related procedures being performed. Who Should NOT Join This Trial: - Patient who has participated in any previous gene therapy research trials; - Patient who has AAV9 neutralizing antibody titer ≥1:200; - Patient who has received Nusinersen within 120 days and Risdiplam within 15 days before treatment; - Patient who requires invasive or non-invasive ventilatory support averaging≥16 hours/day at screening; - SMN2 copy numbers \>4； - Patient who needs nasal or gastric tube feeding for eating; - Patient who is positive for human weakened immune system virus (HIV) antibody, hepatitis B surface antigen, hepatitis C antibody, or treponema pallidum antibody; - Known allergy or hypersensitivity to prednisolone or other glucocorticosteroids or their excipients - Severe contractures at screening that interfere with either the ability to attain/demonstrate functional measures or with the ability to receive intrathecal (IT) dosing; ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: * ≥2 years of age on the day of signing the informed consent form; * Genetic and clinical diagnosis of type 3 SMA with bi-allelic deletion of SMN1 of 5qSMA; * Hammersmith Functional Motor Scale - Expanded (HFMSE) score is between 10 and 54 at screening; * Female patients of childbearing age who are pregnant or lactating, as well as all enrolled patients （both male and female), should take effective contraceptive measures within 6 months after the treatment; * Patients or patient's legal guardian(s) must be able to understand the purpose and risks of the study and voluntarily provide signed and dated informed consent prior to any study-related procedures being performed. Exclusion Criteria: * Patient who has participated in any previous gene therapy research trials; * Patient who has AAV9 neutralizing antibody titer ≥1:200; * Patient who has received Nusinersen within 120 days and Risdiplam within 15 days before treatment; * Patient who requires invasive or non-invasive ventilatory support averaging≥16 hours/day at screening; * SMN2 copy numbers \>4； * Patient who needs nasal or gastric tube feeding for eating; * Patient who is positive for human immunodeficiency virus (HIV) antibody, hepatitis B surface antigen, hepatitis C antibody, or treponema pallidum antibody; * Known allergy or hypersensitivity to prednisolone or other glucocorticosteroids or their excipients * Severe contractures at screening that interfere with either the ability to attain/demonstrate functional measures or with the ability to receive intrathecal (IT) dosing; * Patient who has other serious diseases, such as severe cardiovascular and cerebrovascular diseases, digestive system diseases, urinary system diseases, endocrine system diseases, hematological diseases, immune system diseases, nervous system diseases (including but not limited to epilepsy, meningitis, history of convulsions or seizures, cerebrospinal fluid circulation disorders), and mental illnesses, etc.; * Patient with previous injuries (such as upper or lower limb fractures) or surgical operations that have not fully recovered or reached a stable state; * Vaccination no longer than 2 weeks before treatment; * Patient who has any other condition that, in the opinion of the investigator, makes the subject unsuitable for participation in the study.

Treatments Being Tested

GENETIC

GC101

Self-complementary AAV9 carrying a codon-optimized SMN coding sequence(coSMN1) driven by CMV enhancer and chicken β-actin promoter

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Beijing Tiantan Hospital, Capital Medical University

Beijing, Beijing Municipality, China

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT06421831), the sponsor (GeneCradle Inc), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT06421831 clinical trial studying?

The study will evaluate safety and efficacy of intrathecal delivery of GC101 gene therapy drug as a treatment of spinal muscular atrophy Type 3 (SMA 3) patients. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT06421831?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT06421831?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT06421831. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT06421831. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.