NCT05686551 · Phase 2 · ACTIVE NOT RECRUITING
GENERATION HD2. A Study to Evaluate the Safety, Biomarkers, and Efficacy of Tominersen Compared With Placebo in Participants With Prodromal and Early Manifest Huntington's Disease
This trial is testing tominersen, a drug injected into the spinal fluid, against a placebo in people with prodromal or early Huntington's Disease. The goal is to see whether it is safe and whether it slows disease progression. This is a Phase 2 trial, meaning researchers are still gathering evidence on whether it works — it is not approved or proven.
Eligibility criteria
Inclusion Criteria: DB Period: * HD gene expansion mutation carrier status with a cytosine-adenine-guanine-age product (CAP) score of 400-500 inclusive * Either: * Prodromal HD (defined as Diagnostic Confidence Level (DCL) 2 to 3, Independence Scale (IS) ≥70, and TFC ≥8); Or * Early manifest HD (defined as DCL 4, IS ≥70, and TFC ≥8) * Total body weight > 40 kilograms (kg) and a body mass index (BMI) within the range of 18-32 kilograms per meter square (kg/m\^2) * Study companion OLE Period: * Participants must have completed the DB treatment period * Participants must remain in the DB Safety follow-up period until OLE period starts Exclusion Criteria: DB Period: * Current or previous use of an antisense oligonucleotide (ASO) (including small interfering ribonucleic acid [RNA]) or any HTT lowering therapy (including tominersen) * Anti-platelet or anticoagulant therapy within 14 days prior to screening or anticipated use during the study, including, but not limited to, aspirin (unless ≤ 81 milligrams per day [mg/day]), clopidogrel, dipyridamole, warfarin, dabigatran, rivaroxaban, apixaban, and heparin * History of gene therapy, cell transplantation, or brain surgery * Hydrocephalus * Pregnancy or breastfeeding, or intention of becoming pregnant during the study or within 5 months after the final dose of study drug * History of attempted suicide or suicidal ideation with plan (i.e., active suicidal ideation) that required hospital visit and/or change in level of care within 12 months prior to screening OLE Period: * Early discontinuation from the DB treatment and the safety follow-up (SFU) periods * Pregnant or breastfeeding, or with the intention of becoming pregnant during the study or within the timeframe in which contraception is required * Current or previous use of an ASO other than tominersen (including small interfering RNA) or any other HTT-lowering therapy * Hydrocephalus * Received any active investigational treatment other than tominersen during or since completion of the DB treatment period Key inclusions/exclusion criteria are listed here. Other protocol-defined I/E criteria may apply.
The sponsor's own eligibility wording, lightly reformatted. The study team makes the final eligibility decision — worth discussing with your doctor.
Eligibility criteria as of 2026-05-22