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Completed

NCT Number: NCT04514367

An Open Label Study of ANX005 in Participants With, or at Risk for, Manifest Huntington's Disease

This study is a multi-center, open-label study of intravenous (IV) ANX005 in participants with, or at risk for, manifest Huntington's Disease (HD).

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Key information

Conditions

Huntington Disease Basal Ganglia Diseases Brain Diseases Central Nervous System Diseases Chorea Cognition Disorders Congenital, Hereditary, and Neonatal Diseases and Abnormalities Dementia Dyskinesias Genetic Diseases, Inborn Heredodegenerative Disorders, Nervous System Mental Disorders Movement Disorders Nervous System Diseases Neurocognitive Disorders Neurodegenerative Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Annexon Investigational Site 02, Birmingham, Alabama, United States

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About this study

The objective of this study is to evaluate the effects of IV ANX005 administered for up to 22 weeks in participants with, or at risk for, manifest HD.

Participants will receive induction dosing of ANX005 administered by IV infusion on Days 1 and 5 or 6, followed by maintenance dosing every 2 weeks through Week 22, with follow up visits on Weeks 24, 28, and 36.

All participants will be contacted (in clinic visit or phone call) 6 months after study completion.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Diagnosis of or at risk for HD: Genetically confirmed disease by direct deoxyribonucleic acid (DNA) testing, total cytosine-adenine-guanine (CAG)-Age Product (CAP) score > 400 and UHDRS independence score ≥ 80.
  • Able to walk independently and self-sufficient in basic activities of daily living (for example, eating, dressing, bathing).
  • All HD concomitant medications stable.
  • If female, must be postmenopausal (no menses for at least 2 years without an alternative medical cause), surgically sterilized (bilateral tubal ligation, bilateral oophorectomy, or hysterectomy), or agree to use highly effective methods of contraception.
  • Males with a woman of childbearing potential partner must agree to use highly effective methods of contraception.
  • Previously vaccinated against encapsulated bacterial pathogens (Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae) or willing to undergo vaccination.
  • Able to tolerate electroencephalogram (EEG) and lumbar puncture (LP) procedures.

Exclusion criteria

  • Be at risk of suicide or self-harm within the preceding 12 months.
  • Chorea and/or cognitive deficits severe enough to interfere with study assessments.
  • Participants with body weight > 150 kilograms (kg).
  • Clinically significant findings on the screening laboratory testing or physical examination that are not specific to HD and may interfere with the conduct of the study or the interpretation of the data or increase participant risk.
  • Signs and symptoms of, or a diagnosis consistent with a chronic autoimmune disorder and/or an antinuclear antibody (ANA) titer ≥ 1:160.
  • History of previous infusion reactions, sensitivities, allergic, or anaphylactic reactions to previous medications, environmental stimuli or other substances.
  • Use of an experimental agent within 60 days or five half-lives prior to Screening or anytime over the duration of this study.
  • Prior treatment with any monoclonal antibody.
  • Presence of an implanted deep brain stimulation device.
  • Any history of gene therapy, ribonucleic acid (RNA) or DNA targeted HD specific investigational agents such as antisense oligonucleotides, cell transplantation or any experimental brain surgery.
  • Brain and spinal pathology that may interfere with cerebrospinal fluid homeostasis and circulation, increases intracranial pressure (implanted shunt or catheter), malformations or tumor.
  • Contraindication to undergoing an LP.
  • Hypersensitivity to any of the excipients in the ANX005 drug product.
  • Clinically significant intercurrent illness, medical condition, or medical history (including neurological or mental illness, human immunodeficiency virus [HIV], any active infection, including Hepatitis B or C) that would jeopardize the safety of the participant, limit participation, or compromise the interpretation of the data derived from the participant.
  • Any known genetic deficiencies of the complement-cascade system.
  • History of chronic oral or intravenous steroid use or immunosuppressant medication use.
  • Hemoglobin, bilirubin, or lactate dehydrogenase (LDH) values that are outside normal limits and clinically significant or suggestive of hemolytic anemia.

Treatment and study plan

ANX005

Drug

Intravenous Infusion

Primary outcomes

  1. Number of Participants With Treatment-Emergent Adverse Events (TEAEs)

    Time frame: From first dose of study drug up to end of study (Week 36)

    An adverse event (AE) was defined as any untoward medical occurrence that developed or worsened in severity during the conduct of a clinical study and does not necessarily have a causal relationship to study drug. Serious AEs (SAEs) included death, a life-threatening AE, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability or, a congenital anomaly or birth defect, or an important medical event that jeopardized the participant and required medical intervention to prevent 1 of the outcomes listed in this definition. A TEAE was any AE with an onset on or after the day of infusion through Week 36 (end of study). AEs were graded per National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE): Grade: 1=Mild, 2=Moderate, 3=Severe or medically significant but not immediately life-threatening. A summary of serious and non-serious AEs regardless of causality is located in 'Reported Adverse Events module'.

  2. Actual Dose of ANX005 Administered on Day 1

    Time frame: Day 1

  3. Actual Dose of ANX005 Administered on Week 22

    Time frame: Week 22

  4. Area Under the Concentration Versus Time Curve From Time 0 to t (AUC0-t) of ANX005 at Day 1

    Time frame: Pre-dose up to 4 hours post-dose on Day 1

  5. CSF Free Complement Component 1q (C1q) at Day 1

    Time frame: Predose at Baseline (Day 1)

  6. Blood Free C1q at Day 1

    Time frame: Predose at Baseline (Day 1)

  7. Change From Baseline in Complement C4a in CSF at Week 24

    Time frame: Baseline, Week 24

  8. Change From Baseline in Complement C4a in CSF at Week 36

    Time frame: Baseline, Week 36

  9. Change From Baseline in CSF NfL Level at Week 24

    Time frame: Baseline, Week 24

  10. Change From Baseline in CSF NfL Level at Week 36

    Time frame: Baseline, Week 36

  11. Change From Baseline in Blood NfL Level at Week 24

    Time frame: Baseline, Week 24

  12. Change From Baseline in Blood NfL Level at Week 36

    Time frame: Baseline, Week 36

Sponsors and collaborators

Lead sponsor

Annexon, Inc.

Industry

Registry information

Official study title

A Phase 2a Open Label Study to Assess the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of Intravenous ANX005 in Subjects With, or at Risk for, Manifest Huntington's Disease

Important dates

Study start
2020
Primary completion
2022
Study completion
2022
First posted
Aug 14, 2020
Registry last updated
Aug 25, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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