Trial of BIIB132 in Adults with Spinocerebellar Ataxia

  • Study Director: Cameron Dietiker
  • Sponsor: Biogen
  • Recruiting? Yes
  • Official Study Title: A Phase 1, Blinded, Randomized, Placebo-controlled Study to Investigate the Safety, Tolerability, and Pharmacokinetics of Multiple Ascending Doses of BIIB132 Administered Intrathecally to Adults with Spinocerebellar Ataxia 3
  • Identifier: NCT05160558
  • Conditions Studied: Spinocerebellar Ataxia (SCA)
  • Intervention: BIIB132 is an investigational anti-sense oligonucleotide developed to target ataxin-3 (ATXN3) pre-messenger ribonucleic acid (pre-mRNA).
  • Phase: Phase 1
  • Duration of Participation: Approximately 9 months 

Purpose of the Study

The primary objective of this study is to evaluate the safety and tolerability of multiple ascending doses of BIIB132 administered via intrathecal (IT) injection to participants with spinocerebellar ataxia type 3 (SCA3). The secondary objective of this study is to characterize the multiple-dose pharmacokinetics (PK) of BIIB132 administered via IT injection to participants with SCA3.

Study Details

Inclusion Criteria:

  • Diagnosis of SCA3 with CAG repeats ≥60 in ATXN3 gene.
  • Symptomatic ataxia with a screening Scale for Assessment and Rating of Ataxia (SARA) score 3 to 15 (still ambulatory) and a minimum SARA gait subscore of 1.
  • Able to ambulate 8 m independently without any assistive device.
  • Treatment naïve or on a stable dose of symptomatic therapy for a minimum of 4 weeks prior to screening.

Exclusion Criteria:

  • Unstable psychiatric illness or untreated major depression within 90 days before screening.
  • History or screening magnetic resonance imaging (MRI) results show evidence of structural abnormalities that could contribute to the participant's clinical state other than findings typical of SCA3 or any finding that might pose a risk to the participant.
  • MRI brain findings of prior cerebellar stroke or clinical stroke within 12 months before screening.
  • History of brain surgery regardless of purpose.
  • Any contraindications to undergoing brain MRI.
  • History of, or ongoing, malignant disease, (with the exception of basal cell carcinomas and squamous cell carcinomas that have been completely excised and considered cured at least 12 months prior to screening). Participants with cancers in remission for longer than 5 years may be included.
  • History of epilepsy or the occurrence of seizures within 3 years prior to screening.
  • Evidence of untreated/unstable thyroid disease.
  • Poorly controlled diabetes mellitus.
  • History of alcohol or substance abuse within the past year prior to screening.
  • Use of off-label drugs for ataxia within 4 weeks prior to screening.
  • Prior enrollment in any interventional clinical study in which an investigational treatment or approved therapy for investigational use is administered within 5 half-lives or 3 months, whichever is longer, prior to the screening visit.
  • Any antiplatelet [except for aspirin up to 100 milligrams per day (mg/day)] or anticoagulant medication that cannot be safely interrupted for a lumbar puncture (LP) procedure.
  • Any contraindications to LP procedures.
  • Participants who are pregnant or currently breastfeeding and those intending to become pregnant during the study.
  • Prior enrollment in any interventional clinical study in which an investigational treatment or approved therapy for investigational use is administered within 3 months prior to the screening visit.

What to Expect


  • A screening visit to confirm eligibility. Approved subjects will complete a baseline visit and then begin the investigational period.
  • Safety, tolerability and efficacy assessments will be performed at all visits.
  • Functional tests and questionnaires relating to symptoms will be performed at all visits.
  • Local and on-site blood draws.
  • Lumbar punctures will be performed at all dosing visits to administer the study medication.
  • One 28-hour inpatient study visit for the first dose.
  • 9-hour outpatient visits for each subsequent dose.
  • Telephone calls lasting approximately 30 minutes.
  • Subjects will be dosed with either drug or placebo for 12 weeks.
  • A follow-up visit 2 weeks after the last dose of medication. Subjects will come in for a visit to confirm safety and study termination status.

The Frequency of Visits

Every four weeks.

Materials Needed Before Evaluation

Medical history and confirmed genetic diagnosis, or suspected diagnosis based on family history


All study procedures will be billed to or reimbursed by the study.

Contact Information

If you are interested in participating in this trial or have any questions, please contact the study coordinator, Chelsea Chen, at 415.353.8231 or [email protected].

Additional information at UCSF Clinical Trials.