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.

Key Inclusion Criteria

-Huntington's disease (HD) gene expansion mutation carrier status with a CAP score of 400-500 inclusive

Either:

1. Prodromal HD (defined as DCL 2 to 3, Independence Scale (IS) ⩾70, and ⩾TFC8); or
2. Early manifest HD (defined as DCL 4, Independence Scale (IS) ⩾70, and ⩾TFC8);
3. Total body weight > 40 kg and a body mass index within the range of 18-32 kg/m2
4. Study Companion

Key Exclusion Criteria

1. Current or previous use of an ASO (including small interfering RNA) or any HTT lowering therapy (including tominersen)
2. Anti-platelet or anticoagulant therapy within 14 days prior to screening or anticipated use during the study, including, but not limited to, aspirin (unless
3. History of gene therapy, cell transplantation, or brain surgery
4. Hydrocephalus
5. Pregnancy or breastfeeding, or intention of becoming pregnant during the study or within 5 months after the final dose of study drug
6. 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