TRIal designs for DElivery of Novel Therapies for Neurodegeneration (TRIDENT)

End of project summary

Huntington’s Disease (HD) is a rare, inherited disease that causes problems with movement, thinking and behaviour, which get worse over time and eventually lead to death. The genetic cause of the disease leads to the death of cells in the brain known as neurons. There is no cure and there are no medicines that can slow down the progress of the disease. It may be possible to repair the damage to the brain by replacing the neurons lost to the disease with new, unaffected cells. This is known as cell replacement therapy (CRT). We think that adding new cells to the brain will help mend the lost connections and make the problems with movement, thinking and behaviour in HD better. This trial aimed to look at the safety of putting cells into the brains of people with HD. We also wanted to know if the trial design we chose worked well in practice and if the participants taking part in the trial were happy with what they were asked to do. 

• It was not possible to transplant foetal cells into the brain of any participant during this trial. This was partly due to suspension of trial activities over the pandemic and partly due to a combination of complex logistical factors made significantly worse by the COVID-19 pandemic. 
   
• Post-pandemic, there were changes to the way in which foetal tissue could be collected locally, this has implications for foetal transplantation moving forward. 
   
• Delivering CRT and other advanced therapies (such as gene therapies) is complex and would benefit from specialised facilities that offer protection from wider healthcare pressures. 
   
• The Trial Within a Cohort design for investigating CRT in people with HD works well both for the people taking part in the research and the clinicians and researchers running the study. 
   
• The importance of including the patient voice has been highlighted by the interviews we conducted with participants; they are supportive of CRT and supported research in this area. 
   
• Through this trial we have developed a suitable framework for future CRT studies in HD, including all necessary process documentation.