The NAD-HD Study: A Study to Investigate Efficacy and Safety of Nicotinamide Riboside Compared With Placebo in Huntington's Disease

What Was Tested

The trial (phase 2) is built around NAD+.

The goal of this clinical trial is to learn if oral supplement of nicotinamide riboside (NR), a form of vitamin B3, slows disease progression in adults with Huntington's disease.

It will also learn about the safety of nicotinamide riboside.

The main questions it aims to answer are: * Does NR slow progression of overall symptom burden in Huntington's disease? * Does NR have an effect on any specific symptom domain in Huntington's disease? * Does supplementation with NR cause side-effects or safety issues when used for 2 years in Huntington's disease? * Does NR have an effect on selected blood, imaging, and oculomotor biomarkers in Huntington's disease?

It had two arms (groups): Nicotinamide riboside (experimental) and Placebo (placebo comparator).

The registry classes the interventions as dietary supplement.

Who Took Part

120 planned participants were the target.

It was open to people of any sex aged from 18 years up to 80 years.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: Confirmed HD gene expansion carrier status with a diagnostic genetic test confirming ≥36 CAG-repeats in HTT. Clinically manifest HD with objective neurological signs corresponding to Diagnostic Confidence Level 4 based on the Total Motor Score of the UHDRS. Early or mid-stage disease corresponding to Shoulson-Fahn stage 1-340 and Total Functional Capacity (TFC) \> 2. Ability to walk indoors unassisted or by the help of walking aids only as determined at screening and baseline visits. Ability to write and perform pen-and-paper tests (SDMT, SWRT, MoCA) and complete questionnaires (HADS-SIS, SF-12) included in the study protocol.

The full record lists 9 inclusion and 12 exclusion criteria; among the exclusions: attempted suicide or active suicidal ideation within 12 months prior to screening; electroconvulsive therapy; any history of gene therapy exposure for the treatment of hd.

How the Study Was Run

It was run as a randomized, parallel-group and quadruple-blind study.

Because people in this NAD+ study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

The NAD+ group and the comparison group ran side by side rather than switching.

As a double-blind NAD+ study, the assignments were hidden from both participants and investigators until the end.

Those kept unaware of assignments: participant, care provider, investigator and outcomes assessor.

It started in 2025-03-18 with completion listed for 2029-03.

It ran at 1 site in Norway.

Its stated primary purpose is treatment.

What Was Measured

Researchers chose this as the main measure: Change from Baseline in the composite Unified Huntington's Disease Rating Scale at 730 days (time frame: From baseline to the end of treatment at 730 days (2 years)).

It also tracked 4 secondary outcomes, for example Number of Participants with Adverse Events, Change from Baseline in the Unified Huntington's Disease Total Motor Score at 730 days and Change from Baseline in the Montreal Cognitive Assessment at 730 days.

What This Means in Plain Language

Put simply, this is a phase 2, randomized trial of NAD+ in 120 people.

It is still recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the NAD+ compound page, all human trials.