Animal tests begin for Parkinson's therapy 

Source: BBCMonkeys used in experiments in Japan to study human Parkinson's disease and amyotrophic lateral sclerosis or ALS

TransTasman biotech start-up Living Cell Technology (LCT) says it plans to start testing brain cells from piglets in primates to see if they can be used as a therapy for Parkinson's disease.

"We are proceeding to primate studies for Parkinson's pretty soon," LCT medical director, Professor Bob Elliott said yesterday.

The primate studies were needed to test the safety of injecting tissue straight into the brain, but these would have to be done outside New Zealand because such testing here would require specific ministerial approval.

Elliott told a media briefing on xenotransplants that clinical trials of brain treatments were still years away.

The company yesterday started work on clinical trials at Middlemore Hospital of insulin-producing pig cells taken from the piglets and inserted in patients with unstable type-1 diabetes to create extra insulin.

The company tested transplant techniques on monkeys in Singapore, but Elliott says he believes the diabetes "model' in primates is flawed because tests on eight animals only got one of them off insulin.

That was why LCT had jumped to human diabetes clinical trials in Russia and New Zealand, without following the pattern of pre-clinical trials in primates.

The company has also been investigating whether human liver cells grown in test tubes may be able to stop uncontrolled bleeding in haemophiliacs.

"We've tried brain choroid plexus cells, we've tried liver cells... there are many other cell types we could use, even just using the tissues themselves."

Elliott said pre-clinical testing for implants of brain tissue were being done in small animals such as laboratory rats in New Zealand, and there had previously been one trial in a chimpanzee for Huntingdon's disease.

Huntington's causes chorea an uncontrollable twisting, almost dance-like movements which slowly destroys the ability to walk and talk, leading to behavioural changes and dementia.

Research on both the brain and islet cell transplants from pigs was supported by New Zealand taxpayers, through the Government's Foundation for Research Science and Technology.

The company has said animal studies showed that its planned brain product, NeurotrophinCell, improved limb function in a Parkinson's disease rat model.

Parkinson's disease is caused by degeneration of the cells in the brain that regulate dopamine and affects 107 people per 100,000 worldwide. It occurs more frequently with increasing age. As the "dopaminergic" brain cells die, the dopamine supply decreases and becomes irregular.

The efficacy of existing treatments with dopamine replacement fade over time.

Elliott made his first implants of pig islet cells into New Zealand diabetics in 1996, but was stopped by official concerns that pig viruses could be introduced into the human population.

New Zealand medical authorities blocked the trials being re-started in Rarotonga, and LCT was later listed on the Australian stock exchange to fund monkey trials in Singapore.