Harness Therapeutics nominates Huntington’s Disease drug and establishes clinical advisory board

Harness Therapeutics, a biotechnology company unlocking previously undruggable targets to transform the treatment of neurodegenerative diseases, today announces the nomination of HRN001 as its lead drug candidate for Huntington's disease and the formation of a clinical advisory board to support the programme's advancement towards clinical evaluation.

Huntington’s disease (HD) is a devastating, inherited neurodegenerative disorder that leads to progressive cognitive, psychiatric and motor decline, with death often occurring within 15 years of symptom onset. Despite significant advances in understanding HD disease biology, there are currently no approved disease-modifying treatments available.

HD is caused by the expansion of CAG repeats in the huntingtin (HTT) gene. Ongoing somatic expansion of these repeats is now recognised as a key driver of disease onset and progression. FAN1 nuclease has emerged as one of the most compelling targets to suppress somatic expansion, demonstrating the strongest genetic association to disease onset in genome-wide association studies.

Our first-in-class candidate HRN001 is a potent and specific antisense oligonucleotide targeting FAN1, designed to drive controlled upregulation of this key DNA repair nuclease. It leverages Harness' proprietary MISBA® (microRNA site blocking ASO) platform, which enables precise upregulation of target protein levels without risk of over-expression.

HRN001 has demonstrated robust upregulation of FAN1 and slowing of somatic expansion in models of HD, as well as favourable PK and tolerability characteristics. Preclinical development will continue throughout 2026 to support clinical entry in 2027. Harness is exploring the potential of the MISBA® platform in other triplet repeat disorders and across a broader pipeline of neurodegenerative disorders.

To support the progression of HRN001 towards the clinic, Harness has established a clinical advisory board (CAB) comprising leading experts in the HD field, including:

• Dr. Irina Antonijevic (Chair) – Chief Medical Officer, Trace Neuroscience
• Dr. Anne Rosser – Professor of Clinical Neuroscience, Cardiff University
• Dr. Jeffrey Long – Professor of Psychiatry and Biostatistics, University of Iowa Health Care
• Dr. Ralf Reilmann – Founding Director and Chief Executive Officer, George-Huntington-Institute
• Dr. Roger Barker – Professor of Clinical Neuroscience, University of Cambridge
• Dr. Sarah Tabrizi – Professor of Clinical Neurology, University College London
• Dr. William Gray – Professor of Functional Neurosurgery, Cardiff University

The CAB will provide strategic guidance on clinical development, trial design, and translational strategy as the programme advances towards the clinic.

Dr Andy Billinton, Chief Scientific Officer of Harness Therapeutics, will present the company's work in HD at the upcoming annual CHDI Huntington’s Disease Therapeutics Conference in Palm Springs, California, 23rd-26th February, providing further insights into the scientific rationale and development progress for HRN001.

Dr Jan Thirkettle, CEO of Harness Therapeutics, commented:

The nomination of HRN001 represents a pivotal milestone for Harness and underscores our commitment to the Huntington’s disease community. By precisely upregulating FAN1, a target with compelling genetic validation in delaying disease onset, HRN001 represents a differentiated, first-in-class therapeutic approach for addressing somatic expansion, a fundamental driver of disease progression. The formation of a Clinical Advisory Board brings deep clinical and translational expertise to the programme. The CAB will work closely with Harness as we advance HRN001 towards the clinic and seek to deliver a truly disease-modifying therapy for patients and families living with Huntington’s disease.

Dr Irina Antonijevic, Chair of Harness Therapeutics’ Clinical Advisory Board, added:

FAN1 is one of the most compelling and consistently validated genetic modifiers of Huntington’s disease identified to date, with a clear mechanistic link to somatic expansion and disease progression. Harness' approach with HRN001 offers a novel and highly targeted way to therapeutically modulate this pathway. We look forward to advising the Company, as it advances HRN001 toward the clinic, translating this promising science into a clinical programme that could meaningfully alter the course of this devasting disease.