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New hope has been offered to sufferers of Parkinson's disease after patients taking part in a new gene-therapy trial showed dramatic improvement.
The therapy, developed in an Auckland-American collaboration, improved symptoms by 25 to 30 per cent on average, although this result is from a preliminary trial designed to check safety, not effectiveness.
In the five patients who experienced the greatest benefit, the improvement was 40 to 65 per cent. The first of the patients was treated nearly four years ago.
"We are extremely encouraged by these results," said one of the researchers, neuro-scientist Professor Matthew During, who divides his time between Auckland University and Ohio State University.
The gene therapy was given to 12 patients with severe Parkinson's disease, for whom current treatments had stopped working.
Parkinson's affects around 7000 New Zealanders. It is characterised by trembling, rigid posture, slow movements and a shuffling gait. It is caused by the loss of the nerve cells that make dopamine, a chemical messenger important for movement.
The trial therapy delivers a gene called GAD. The gene enables production of a substance called GABA, which is released by nerve cells to calm overactivity in the brain.
Using a hollow needle and catheter, the genes, carried by a safe virus, are put in the sub-thalamic nucleus, a walnut-sized part of the brain that is extremely overactive in people with the disease.
Professor During said last night from the US that some patients were given higher doses than others. While the study, published in the Lancet medical journal's latest edition, was not powerful enough to compare outcomes, "there was a suggestion that the higher doses worked better".
The findings suggested gene therapy might be safe for various neuro-degenerative diseases, including Alzheimer's and Huntington's.
Professor During has previously expressed hope that a trial could be extended to New Zealand, but said last night the country's regulatory environment was not conducive to trialling experimental drugs.
