Huntington's DiseasePhase 1NCT06585449
A Study to Evaluate ALN-HTT02 in Adult Patients With Huntington's Disease
A Phase 1 study testing ALN-HTT02 in people with Huntington's Disease, run by Alnylam Pharmaceuticals at 19 sites in 3 countries.
Trial summary
The purpose of this study is to evaluate the safety, tolerability, pharmacodynamics (PD) and pharmacokinetics (PK) of single or repeat doses of ALN-HTT02. Read more about this study
- Who is it for?
- Ages 25 to 70 years
- Conditions the study is for
- Huntington's Disease
- What is being tested?
- ALN-HTT02
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 66 participants
- Where
- 19 sitesin 3 countries
- Study dates
- 14 Oct 2024to 5 Jul 2028
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 25 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Has stage 2 or early Stage 3 Huntington's disease (HD), per the Huntington's Disease Integrated Staging System (HD-ISS)
Who cannot join
- Has significant structural or degenerative neurologic disease other than Huntington's Disease (HD) at screening
- Has primary or secondary immune compromise at screening due to infections, medical conditions, or chronic therapies
- Has alanine aminotransferase or aspartate aminotransferase >2× upper limit of normal (ULN)
- Has an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73m^2 at screening
- Has received an investigational agent within the last 1 year or 5 half-lives (if known)
- Note: other protocol defined inclusion / exclusion criteria apply
Trial locations and contacts
19 sites in 3 countries. Contact the study team or a site near you to ask about taking part.
19 sites in 3 countries
United Kingdom8 sites, 8 recruiting
- Recruiting
Clinical Trial Site
Birmingham, B15 2TT
- Recruiting
Clinical Trial Site
Cambridge, CB2 0PY
- Recruiting
Clinical Trial Site
Cardiff, CF103AX
- Recruiting
Clinical Trial Site
Glasgow, G51 4TF
- Recruiting
Clinical Trial Site
Greater Manchester, M13 9WL
- Recruiting
Clinical Trial Site
London, WC1N 3BG
- Recruiting
Clinical Trial Site
Oxford, OX3 9DU
- Recruiting
Clinical Trial Site
Plymouth, PL6 8DH
Germany7 sites, 7 recruiting
- Recruiting
Clinical Trial Site
Berlin, 10117
- Recruiting
Clinical Trial Site
Bochum, 44791
- Recruiting
Clinical Trial Site
Bonn, 53127
- Recruiting
Clinical Trial Site
Dresden, 01307
- Recruiting
Clinical Trial Site
Münster, 48149
- Recruiting
Clinical Trial Site
Taufkirchen, 84416
- Recruiting
Clinical Trial Site
Ulm, 89081
Canada4 sites, 4 recruiting
- Recruiting
Clinical Trial Site
Edmonton, T6G 2B7
- Recruiting
Clinical Trial Site
Montreal, H2W 1T8
- Recruiting
Clinical Trial Site
Ottawa, K1Y4E9
- Recruiting
Clinical Trial Site
Vancouver, V6T 2B5
About this study
Official title: A Randomized, Double-blind, Placebo-controlled Study, to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Intrathecally Administered Single Ascending Doses of ALN-HTT02 in Adult Patients With Huntington's Disease
The purpose of this study is to evaluate the safety, tolerability, pharmacodynamics (PD) and pharmacokinetics (PK) of single or repeat doses of ALN-HTT02.
- Conditions
- Huntington's Disease
- Being tested
- ALN-HTT02, Placebo
- Keywords
- siRNA, ALN-HTT02, Intrathecal, HD-ISS Stage 2, HD-ISS early Stage 3, Neurodegenerative disorder
- Medical subject headings
- Huntington Disease, Neurodegenerative Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ALN-HTT02Drug
ALN-HTT02 will be administered intrathecally
PlaceboDrug
Placebo will be administered intrathecally
| Study group | Role | What they receive |
|---|---|---|
| ALN-HTT02 | Experimental | Participants will be administered a single dose of ALN-HTT02 during the Double-blind Part of the study. Participants who received ALN-HTT02 in the Double-blind part of the study will not receive an additional dose during the Open-label Part of the study. Participants have the option to receive repeat doses of ALN-HTT02 in the Open-label Extension (OLE) Part of the study. Receives: Drug: ALN-HTT02 |
| Placebo + ALN-HTT02 | Placebo comparator | Participants will be administered a single dose of placebo during the Double-blind Part of the study. Participants will have the option to receive a single dose of ALN-HTT02 during the Open-label Part of the study. Participants have the option to receive repeat doses of ALN-HTT02 in the OLE Part of the study. Receives: Drug: ALN-HTT02; Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Frequency of Adverse Events (AEs) in the Double-blind Part of the Study
Measured: Up to 12 months
Frequency of AEs in the Open-label Part of the Study
Measured: Up to 12 months
Frequency of AEs in the OLE Part of the Study
Measured: Up to 36 months
Secondary outcomes (4)
Change from Baseline in Levels of Mutant Huntingtin (mHTT) in Cerebrospinal Fluid (CSF)
Measured: Baseline up to Month 12 in the Double-blind Part of the study; Baseline up to Month 12 in the Open-label Part of the study ; Baseline up to Month 36 in the OLE Part of the study
Concentrations of ALN-HTT02 in Plasma
Area Under the Plasma Concentration-time Curve (AUC) Maximum Observed Plasma Concentration (Cmax) Time to Maximum Plasma Concentration (Tmax)
Measured: Up to Month 12 in the Double-blind Part of the study; Up to Month 12 in the Open-label Part of the study; Up to Month 36 in the OLE Part of the study
Concentrations of ALN-HTT02 in Cerebrospinal Fluid (CSF)
Measured: Up to Month 12 in the Double-blind Part of the study; Up to Month 12 in the Open-label Part of the study ; Up to Month 36 in the OLE Part of the study
Concentrations of ALN-HTT02 in Urine
Fractional Excretion of ALN-HTT02
Measured: Up to Month 12 in the Double-blind Part of the study; Up to Month 12 in the Open-label Part of the study; Up to Month 36 in the OLE Part of the study
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Sep 2024
- Study start14 Oct 2024
- Primary completion5 Jul 2028 (estimated)
- Study completion5 Jul 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Huntington's DiseaseStudies of the same condition, open and under way.
- More trials run by Alnylam PharmaceuticalsThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 66 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Alnylam Pharmaceuticals
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Alnylam Pharmaceuticals
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06585449
- Sponsor's protocol ID
- ALN-HTT02-001
- Status last verified
- Oct 2026
- First submitted
- 3 Sep 2024
- Last updated
- 15 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized, Double-blind, Placebo-controlled Study, to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Intrathecally Administered Single Ascending Doses of ALN-HTT02 in Adult Patients With Huntington's Disease
- ClinicalTrials.gov ID
- NCT06585449
- Acronym / sponsor ID
- ALN-HTT02-001
- Conditions
- Huntington's Disease
- Keywords
- siRNA, ALN-HTT02, Intrathecal, HD-ISS Stage 2, HD-ISS early Stage 3, Neurodegenerative disorder
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 66 participants (estimated)
- Lead sponsor
- Alnylam PharmaceuticalsIndustry (pharma, biotech, devices)
- Study start
- 14 Oct 2024 (actual)
- Primary completion
- 5 Jul 2028 (estimated)
- Study completion
- 5 Jul 2028 (estimated)
- First posted
- 5 Sep 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to evaluate the safety, tolerability, pharmacodynamics (PD) and pharmacokinetics (PK) of single or repeat doses of ALN-HTT02.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| ALN-HTT02 | Experimental | Drug: ALN-HTT02Participants will be administered a single dose of ALN-HTT02 during the Double-blind Part of the study. Participants who received ALN-HTT02 in the Double-blind part of the study will not receive an additional dose during the Open-label Part of the study. Participants have the option to receive repeat doses of ALN-HTT02 in the Open-label Extension (OLE) Part of the study. |
| Placebo + ALN-HTT02 | Placebo comparator | Drug: ALN-HTT02, Drug: PlaceboParticipants will be administered a single dose of placebo during the Double-blind Part of the study. Participants will have the option to receive a single dose of ALN-HTT02 during the Open-label Part of the study. Participants have the option to receive repeat doses of ALN-HTT02 in the OLE Part of the study. |
Who may qualify
- Ages
- 25 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Has stage 2 or early Stage 3 Huntington's disease (HD), per the Huntington's Disease Integrated Staging System (HD-ISS)
Key exclusion criteria (6 listed)
- Has significant structural or degenerative neurologic disease other than Huntington's Disease (HD) at screening
- Has primary or secondary immune compromise at screening due to infections, medical conditions, or chronic therapies
- Has alanine aminotransferase or aspartate aminotransferase >2× upper limit of normal (ULN)
- Has an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73m^2 at screening
- Has received an investigational agent within the last 1 year or 5 half-lives (if known)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ALN-HTT02ALN-HTT02 will be administered intrathecally | Drug | ALN-HTT02, Placebo + ALN-HTT02 |
| PlaceboPlacebo will be administered intrathecally | Drug | Placebo + ALN-HTT02 |
Primary outcome
Frequency of Adverse Events (AEs) in the Double-blind Part of the Study
Time frame: Up to 12 months
Frequency of AEs in the Open-label Part of the Study
Time frame: Up to 12 months
Frequency of AEs in the OLE Part of the Study
Time frame: Up to 36 months
4 secondary outcomes
Change from Baseline in Levels of Mutant Huntingtin (mHTT) in Cerebrospinal Fluid (CSF)
Time frame: Baseline up to Month 12 in the Double-blind Part of the study; Baseline up to Month 12 in the Open-label Part of the study ; Baseline up to Month 36 in the OLE Part of the study
Concentrations of ALN-HTT02 in Plasma
Time frame: Up to Month 12 in the Double-blind Part of the study; Up to Month 12 in the Open-label Part of the study; Up to Month 36 in the OLE Part of the study
Concentrations of ALN-HTT02 in Cerebrospinal Fluid (CSF)
Time frame: Up to Month 12 in the Double-blind Part of the study; Up to Month 12 in the Open-label Part of the study ; Up to Month 36 in the OLE Part of the study
Concentrations of ALN-HTT02 in Urine
Time frame: Up to Month 12 in the Double-blind Part of the study; Up to Month 12 in the Open-label Part of the study; Up to Month 36 in the OLE Part of the study
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Medical Director study director
Alnylam Pharmaceuticals
19 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing ALN-HTT02 in people with Huntington's Disease, run by Alnylam Pharmaceuticals at 19 sites in 3 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 15 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 19 sites in United Kingdom, Germany, Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Alnylam Clinical Trial Information Line (1-877-ALNYLAM, clinicaltrials@alnylam.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Frequency of Adverse Events (AEs) in the Double-blind Part of the Study (time frame: Up to 12 months). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Oct 2026.