HD Blog

What did the trial involve?

The trial was conducted using a fairly standard rat model of Huntington's (The rats have quinolinic acid injected into the striatum (a part of the brain), which results in the rats displaying pathology and clinical presentation that mimics HD).

The rats were injected with either rat or piglet choroid plexus cell clusters (see attached abstract for details re: Choroid Plexus) encapsulated in alginate into the area immediately prior to inducing the lesions.

What were the results?

A remarkable prevention of the behavioural, pathological and clinical changes - around 80%. The animals recovered extremely well.

Where to from here?

The trials are being repeated in non-human primates first, using piglet choroid plexus - these should be completed by mid February 2005.

This is a necessary step to applying for regulatory approvals in order to begin Phase 1 human trials. How long these approvals take is uncertain. There are strong non-scientific prejudices against the use of animal cells, which may be difficult to overcome. In Australia we hope to hear from the regulatory body in December, as to whether or not they will be able to process an application.
Further research is also required to determine how long the treatment effect will last. The therapeutic cells are very hardy and last a long time (6 months) in artificial conditions (cell culture). The animal experiments that were conducted went for 6 weeks and the restorative effect remained for that time. It now needs to be determined if predictions can be made as to how long the treatment may last.

If the human trials are approved, what will they involve?

At present the trial would involve the injection of a small volume of encapsulated pig choroid plexus cells into the brain striatum of patients who are already experiencing severe symptoms of the disease. A small 'burr hole' would be made in the skull and a needle positioned by stereotactic means. An alternative might be to inject into the ventricles of the brain - this is yet to be determined.

What sort of time-frame are we looking at?

There are two stages. The company will know whether the treatment works or not in the larger (primate) animal model, hopefully by February 2005.

If it works, they will apply to do the human phase 1 study. The company is hopeful that phase 1 could be underway by the middle of 2005 - but this is in the hands of the regulators.