NCT07743866

Brief Summary

The purpose of this research study is to identify the optimal biological dose for tTIS that targets DN in SCA3 while achieving the best possible balance between therapeutic efficacy and safety.

Trial Health

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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
24

participants targeted

Target at below P25 for not_applicable

Timeline
7mo left

Started Aug 2026

Shorter than P25 for not_applicable

Geographic Reach
1 country

1 active site

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

July 29, 2026

Completed
6 days until next milestone

First Posted

Study publicly available on registry

August 4, 2026

Completed
3 days until next milestone

Study Start

First participant enrolled

August 7, 2026

Expected
4 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

November 30, 2026

3 months until next milestone

Study Completion

Last participant's last visit for all outcomes

February 28, 2027

Last Updated

August 4, 2026

Status Verified

July 1, 2026

Enrollment Period

4 months

First QC Date

July 29, 2026

Last Update Submit

July 31, 2026

Conditions

Spinocerebellar Ataxia Type 3

Keywords

Transcranial Temporal Interference stimulationSpinocerebellar ataxia type 3Cerebellar dentate nucleusStimulation difference frequencyIndividualized head modeling

Outcome Measures

Primary Outcomes (3)

  • Safety: Incidence of Dose-Limiting Toxicity (DLT)

    DLT event is defined as any one of the following 5 categories: 1. Grade Ⅱ (moderate) or higher adverse events per the NCI-CTCAE grading criteria\[1\] that require topical or non-invasive intervention, such as skin burns (skin breakdown, blister formation); 2. Clinically observable seizures during stimulation; 3. Severe headache with vomiting, confusion, or severe dizziness leading to syncope; 4. Severe sleep disturbance with psychiatric abnormalities (anxiety, depression, hallucinations, etc.); 5. New brain lesions on imaging, or decreased apparent diffusion coefficient (ADC) values in the subcortex beneath the stimulation site. References \[1\] Antal A, et al. Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines (2017-2025: An update) - endorsed by the European Society for Brain Stimulation (ESBS) and by the International Federation for Clinical Neurophysiology (IFCN). Clin Neurophysiol. 2026. 184: 2111436

    At any point during or immediately following intervention on day of tTIS application

  • Efficacy: To assess the proportion of patients with SARA improvement (decrease) of at least 1.5 from baseline after 5 days

    The Scale for the Assessment and Rating of Ataxia (SARA) evaluates the severity of ataxia symptoms, including gait, posture, speech, and limb kinetic functions. Score range: 0-40 Higher scores indicate more severe ataxia. Response is defined as a reduction of ≥1.5 points from baseline.

    Baseline and within 24 hours after completing the 5-day tTIS treatment

  • Comprehensive Benefit-Risk: Utility

    Utility is a composite measure integrating dose-limiting toxicity (DLT) and efficacy response to quantify the overall benefit-risk balance for each dose group. During the trial, the Utility value for each dose group is dynamically calculated using the U-BOIN design platform. In Stage II, the Utility value determines dose allocation for subsequent cohorts. At study completion, the dose group with the highest Utility value is identified as the optimal biological dose.

    Within 24 hours after completing the 5-day tTIS treatment

Other Outcomes (6)

  • The International Cooperative Ataxia Rating Scale (ICARS)

    Baseline and within 24 hours after completing the 5-day tTIS treatment

  • The European Quality of Life 5-Dimension (EQ-5D)

    Baseline and within 24 hours after completing the 5-day tTIS treatment

  • Patient Global Impression of Change (PGI-C)

    Within 24 hours after completing the 5-day tTIS treatment

  • +3 more other outcomes

Study Arms (3)

30 Hz Difference Frequency tTIS

EXPERIMENTAL

Transcranial Temporal Interference Stimulation (tTIS) uses a difference frequency (Δf) of 30 Hz.

Device: Transcranial Temporal Interference Stimulation (tTIS)

40 Hz Difference Frequency tTIS

EXPERIMENTAL

Transcranial Temporal Interference Stimulation (tTIS) uses a difference frequency (Δf) of 40 Hz.

Device: Transcranial Temporal Interference Stimulation (tTIS)

70 Hz Difference Frequency tTIS

EXPERIMENTAL

Transcranial Temporal Interference Stimulation (tTIS) uses a difference frequency (Δf) of 70 Hz.

Device: Transcranial Temporal Interference Stimulation (tTIS)

Interventions

Transcranial Temporal Interference Stimulation (tTIS)DEVICE

Participants assigned to this intervention arm receive transcranial temporal interference stimulation (tTIS) with a difference frequency (Δf) of 30Hz/40Hz/70 Hz. Before treatment, individualized electric field modeling is performed based on each participant's 3D-T1 MRI data to optimize electrode placement and stimulation parameters. The stimulation target is the bilateral cerebellar dentate nuclei. A personalized finite element head model is generated, and electrode positions are determined through simulation-based optimization to achieve focused interference electric fields at the target region. During each treatment session, tTIS is delivered using two carrier frequencies of 2000 Hz and 2030Hz/2040Hz/2070 Hz, with a current intensity of 2.0 mA (zero-to-peak). Each session lasts 20 minutes. Treatment is administered twice daily, 5 days per week, for a total of 10 sessions.

30 Hz Difference Frequency tTIS40 Hz Difference Frequency tTIS70 Hz Difference Frequency tTIS

Eligibility Criteria

Age18 Years - 75 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • A physician-diagnosed SCA3 according to diagnostic criteria, with definite clinical symptoms and confirmed genetic testing;
  • Age 18-75 years;
  • Baseline total score of SARA: 8-30 points (inclusive); SARA gait function subscore: 2-6 points (inclusive);
  • Willing to participate and provide informed consent;
  • Have a reliable caregiver available;
  • No severe cognitive impairment that would preclude reliable reporting of adverse events or efficacy during treatment.

You may not qualify if:

  • History of seizures or convulsions, or a seizure within 6 months prior to enrolment;
  • History of severe traumatic brain injury or intracranial neurosurgery;
  • Presence of cardiac pacemakers, cochlear implants, intracranial implanted electronic devices, or other MRI-contraindicated ferromagnetic implants;
  • Severe cognitive impairment (Mini-Mental State Examination \[MMSE\] score ≤ 9) or severe visual, auditory, or speech dysfunction preventing cooperation with scale assessments and study procedures;
  • Pregnant or lactating women, or women of childbearing age not using reliable contraception;
  • Previous neuromodulation treatment (e.g., rTMS or tDCS) within the past year;
  • Skin breakdown or inflammation at the electrode placement site, or known allergy to conductive gel or electrode patch adhesives;
  • Currently participating in other interventional clinical trials, or planning to participate in other trials that might affect the outcome assessment of this study during the study period.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Department of Rehabilitation Medicine, The First Affiliated Hospital of Fujian Medical University

Fuzhou, Fujian, China

Location

MeSH Terms

Conditions

Machado-Joseph Disease

Condition Hierarchy (Ancestors)

Spinocerebellar AtaxiasCerebellar AtaxiaCerebellar DiseasesBrain DiseasesCentral Nervous System DiseasesNervous System DiseasesSpinocerebellar DegenerationsSpinal Cord DiseasesHeredodegenerative Disorders, Nervous SystemNeurodegenerative DiseasesAtaxiaDyskinesiasNeurologic ManifestationsGenetic Diseases, InbornCongenital, Hereditary, and Neonatal Diseases and Abnormalities

Central Study Contacts

Xin-Yuan Chen

CONTACT

+86 15005065282fychenxinyuan@fjmu.edu.cn

Kai-Xiong Chen

CONTACT

+86 152800968861002297884@qq.com

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NON RANDOMIZED
Masking
SINGLE
Who Masked
OUTCOMES ASSESSOR
Purpose
TREATMENT
Intervention Model
SEQUENTIAL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Attending Physician

Study Record Dates

First Submitted

July 29, 2026

First Posted

August 4, 2026

Study Start (Estimated)

August 7, 2026

Primary Completion (Estimated)

November 30, 2026

Study Completion (Estimated)

February 28, 2027

Last Updated

August 4, 2026

Record last verified: 2026-07

Data Sharing

IPD Sharing
Will not share

Locations

CN(1)