A Study to Evaluate ALN-HTT02 in Adult Patients With Huntington's Disease

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.

Inclusion Criteria

• Has stage 2 or early Stage 3 Huntington's disease (HD), per the Huntington's Disease Integrated Staging System (HD-ISS)

Exclusion Criteria

• 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