Gene therapy from UniQure slows progression of Huntington’s disease by 75% in clinical trial

Huntington's disease is a severe, progressive disorder with a genetic cause. In patients with Huntington's disease, a mutant version of the huntingtin protein begins to accumulate, resulting in a range of increasingly severe symptoms as the disease progresses over a period of years. These symptoms include involuntary movements, deteriorating balance and speech, and difficulty swallowing, as well as cognitive decline. If left untreated, patients will first become unable to work, and ultimately lose their mobility and ability to care for themselves. Huntington's disease is also characterised by an early age of onset, typically between the ages of 30 and 50. Current treatments only address some of the symptoms and are unable to treat the underlying cause of the disease. Previous attempts to alter the course of disease progression have largely been unsuccessful, leaving the 20,000 diagnosed patients without effective treatment options.

On 24 September, UniQure disclosed pivotal data from their AMT-130 programme, showing that their gene therapy — a technology that has fallen out of favour with the equity market in recent years — was able to alter the course of the disease. In patients receiving a high dose of the therapy, disease progression slowed by 75% compared to a matched external control group of 940 patients when assessed using an overall disease score over three years. AMT-130, a one-dose gene therapy, also demonstrated strong efficacy in other areas. It reduced total functional capacity progression by 60%, with favourable changes observed in the ability to move, cognitive capabilities, and attention.

Interestingly, levels of NfL (neurofilament light chain) decreased below the initial baseline level. NfL is a biomarker of neuronal damage and disease progression, particularly in Huntington's disease. Therefore, one would expect levels to increase as the disease progresses. However, in this trial, NfL levels returned to below baseline for patients treated with gene therapy, which is another strong signal of efficacy.

The treatment was well tolerated, with only a few serious adverse events occurring during administration and fully resolving afterwards. The absence of new safety concerns reassured investors of this drug's attractive long-term profile.

The company plans to meet with the FDA this year to discuss the findings of the clinical study and intends to submit an application for drug approval in the first quarter of 2026. This is the next step towards offering patients burdened by this debilitating disease a new and effective treatment option.