Recruiting
Phase 1

ALN-SNCA

Sponsor:

Regeneron Pharmaceuticals

Code:

NCT07216066

Conditions

Parkinsons Disease

Eligibility Criteria

Sex: All

Age: 50 - 70+

Healthy Volunteers: Not accepted

Interventions

ALN-SNCA

Placebo

Study Details

Brief summary:

This study is researching an experimental drug called ALN-SNCA (called "study drug"). The study is focused on people with early Parkinson's disease, a disorder of the nervous system that affects movement. Parkinson's disease is caused by a gradual loss of nerve cells in the brain, especially those due to the harmful build-up of a protein called α-synuclein.

The aim of the study is to see if the study drug is safe and tolerated well enough to continue testing it in future studies and what side effects may happen from taking the study drug.

The study is looking at several other research questions, including:

  • Whether the study drug can lower the level of α-synuclein protein in the Cerebrospinal Fluid (also referred to as "CSF", the fluid that surrounds the brain and spinal cord)
  • How much study drug is in the blood, urine, and CSF at different times
  • Compatible research to better understand the study drug (ALN-SNCA) and Parkinson's disease, including (but not limited to), whether the study drug can slow down the progression of Parkinson's disease symptoms

Conditions

Parkinsons Disease

Study ID

NCT07216066

Start date

Dec 5, 2025

Status verified date

Apr, 2026

Completion date

Jun 7, 2029

Anticipated

Primary completion date

Jun 7, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 50 - 70+

Healthy Volunteers: Not accepted

Key Inclusion Criteria:

1. Diagnosis of Parkinson's disease according to the Movement Disorder Society (MDS) criteria, as assessed by the investigator, with bradykinesia plus at least one of the other cardinal signs of Parkinson's disease (resting tremor, rigidity), without any other known or suspected cause of Parkinsonism
2. A diagnosis of Parkinson's disease for 4 years or less at the screening visit
3. Participant must meet one of the following criteria:

1. Currently not receiving any standard-of-care (SoC) therapy for Parkinson's disease, has not been on oral dopaminergic therapy (ie, levodopa, dopamine agonists, or Monoamine Oxidase B \[MAO-B\] inhibitors) prior to dosing, and is not anticipated to require SoC therapy for Parkinson's disease within approximately 6 months following dosing, or
2. Has been on a stable regimen of oral dopaminergic therapy for at least 3 months prior to dosing and is not anticipated to require dose adjustments within approximately 6 months following dosing
4. BMI ≤35 kg/m\^2 at time of screening visit

Key Exclusion Criteria:

1. Medical history indicating a Parkinsonian syndrome other than Parkinson's disease, as defined in the protocol
2. Clinically significant cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, hematological, psychiatric or neurological disease (excluding Parkinson's disease) that, as assessed by the investigator, may confound the results of the study or pose an additional risk to the participant during study participation
3. Medical history of brain or spinal disease/injury that would interfere with the Lumbar Puncture (LP) procedure or CSF circulation, as defined in the protocol
4. Any contraindications to undergo a brain Magnetic Resonance Imaging (MRI)
5. An established allergy or intolerance to lidocaine anesthetic, as defined in the protocol
6. History of intolerance to Intrathecal (IT) injection(s)
7. Current history of bleeding diatheses that would increase risk of bleeding upon LP
8. Has undergone gene therapy, cell therapy or surgical treatment, including deep brain stimulation, for Parkinson's disease

NOTE: Other Protocol-defined Inclusion/Exclusion Criteria Apply

Study Design

Enrollment

46 participants

Anticipated

Allocation

Randomized

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: ALN-SNCA Dose Escalation

placebo comparator: Matching Placebo

Interventions

ALN-SNCA

Administered per the protocol

Placebo

Administered per the protocol

Primary outcome measure

  • Occurrence of Treatment-Emergent Adverse Events (TEAEs) [ Time Frame: Through Week 80 ]
  • Severity of TEAEs [ Time Frame: Through Week 80 ]

Central Contacts and Locations

Central contacts

Clinical Trials Administrator

844-734-6643clinicaltrials@regeneron.com

Locations

Montreal Neurological Institute and Hospital

Recruiting

Montreal, Quebec, Canada, H3A 2B4

More Information

Sponsor

Regeneron Pharmaceuticals

Last update posted

Apr 14, 2026

Last verified

Apr, 2026

Keywords

  • Early Parkinsons disease
  • Motor and non-motor brain systems
  • Bradykinesia plus
  • Resting tremor
  • Rigidity
  • Postural instability
  • Cognitive impairment
  • Mood disorders
  • Sleep disturbances
  • Autonomic dysfunction

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Regeneron Pharmaceuticals on 2026-04-14.