Background With several clinical trials in progress and more expected to launch in the next few years exploring novel therapeutic approaches for treating Huntington’s disease, biomarkers are needed to evaluate target engagement, efficacy and disease progression.

Cerebrospinal fluid (CSF) is ideal for assessing HD biomarkers, due to its proximity to the brain. There is currently no high-quality repository of CSF from well-characterised HD gene expansion carriers spanning the disease spectrum.

Aims Now underway, HDClarity is a multisite, multinational initiative that aims to establish the largest, highest-quality repository of CSF from well-characterised HD mutation carriers and matched controls, to expedite research into biomarkers and evaluate pathways to enable development of novel treatments for HD.

Methods/techniques CSF and blood samples will be collected at up to 30 sites using a standardised protocol. Careful collection of clinical and phenotypic data on each donor will enable us to appropriately select subsets of samples for each set of experimental assays. HDClarity uses a custom data capture system built upon the Enroll-HD Platform to identify participants and collect standardised data.

HDClarity will recruit up to 600 participants from six cohorts:

1. Healthy controls

2. Early Pre-manifest HD

3. Late Pre-manifest HD

4. Early Manifest HD

5. Moderate Manifest HD

6. Advanced Manifest HD

Participants attend two study visits: a Screening Visit and a Sampling Visit. Some participants are invited to return for an optional repeat sampling visit 4–8 weeks later.

Custom biosample kits are supplied by BioRep to supply all equipment for standardised CSF and plasma collection and processing. BioRep is also the sample biorepository.

In one usage, the sample collection will be assayed to determine whether the kynurenine pathway (KP) is dysregulated in HD. It will also enable the further development and validation of assays to measure huntingtin protein in CSF. The biorepository will enable the continued evaluation of potential novel biomarkers. A CSF Consortium will provide scientific oversight into the use of samples and data.

HDClarity is sponsored by University College London and coordinated by UCL Huntington’s disease Centre. It is funded and supported by CHDI Foundation, Inc.

For more information or to enquire about establishing an HDClarity clinical site, please email the Chief Investigator (e.wild{at}ucl.ac.uk)