A Phase 1 interventional study of ALN-HTT02 and Placebo in Huntington's Disease, sponsored by Alnylam Pharmaceuticals. Recruiting at 19 sites in 3 countries. Open to participants aged 25 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-10-15.
Sponsored by Alnylam Pharmaceuticals · Phase 1, Interventional, and Treatment
The purpose of this study is to evaluate the safety, tolerability, pharmacodynamics (PD) and pharmacokinetics (PK) of single or repeat doses of ALN-HTT02.
293 studies on the registry are indexed under Huntington Disease; 54 are open to participants now.
This study's planned enrollment of 66 is above the median of 40 across 207 interventional studies indexed under Huntington Disease.
Browse Huntington Disease studies →Alnylam Pharmaceuticals is the lead sponsor of 84 studies on the registry; 19 are open to participants now.
Of its 18 completed or terminated interventional studies of FDA-regulated products, 15 (83%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria
Note: other protocol defined inclusion / exclusion criteria apply
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Drug: ALN-HTT02
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.
Drug: ALN-HTT02 · Drug: Placebo
ALN-HTT02 will be administered intrathecally
Placebo will be administered intrathecally
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
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
Area Under the Plasma Concentration-time Curve (AUC) Maximum Observed Plasma Concentration (Cmax) Time to Maximum Plasma Concentration (Tmax)
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
Fractional Excretion of ALN-HTT02
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
Plan to share: No
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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