Parkinson's pig-cell trial approved

Viewed under a microscope, choroid plexus cells from pigs are almost identical to human cells, which is why the therapy may be successful. Photo / Supplied

Therapy of brain injections has potential against disease once 'ick factor' overcome

New Zealand scientists have been approved to test a treatment for "the saddest of diseases" which involves injecting cells from a pig's brain into a patient.

Hoping for a breakthrough in the battle against Parkinson's disease, Living Cell Technologies announced it had the go-ahead to undertake clinical trials which will pit the treatment against the present gold standard, deep brain stimulation.

Both techniques insert a catheter into the damaged part of a patient's brain. In deep brain stimulation, electrodes are put through the catheter and an electric pulse used to heighten brain activity. In pig cell therapy, capsules containing living cells that repair brain damage are injected.

"It's the equivalent of a biological tea bag," said chief executive Andrea Grant. "Only the good stuff comes out."

The company has produced a similar treatment for diabetes, and Dr Grant said that though this was controversial from a safety and animal ethics standpoint, most of those hurdles had been overcome.

"There's also an 'ick' factor, for want of a better word. As in, 'Are you going to put a pig cell in my brain?"' Dr Grant said. "But it's just a cell in a capsule for patients. There's nothing pig about it by that point."

There was a huge unmet need among Parkinson's sufferers, she said. "Once you have Parkinson's, you know exactly what will happen. Every patient goes down the same pathway, and it's very unpleasant."

She said a commercial treatment was still some years away, with two more phases of trials likely to be needed.

The pigs' brain cells - specifically choroid plexus cells - are taken from young pigs unaltered. The treatment works because the functioning of pig and human brains are so alike.

"There's not a lot that sets us apart," Dr Grant said. "The cell type that we're using is present in the human brain as well. The architecture is almost identical to a human."

The trial's principal investigator is Dr Barry Snow, an internationally recognised clinician and researcher who leads the Auckland Movement Disorders Clinic at the Auckland District Health Board.

"Parkinson's is a disorder clinicians can help manage but can't reverse," he said, "so this represents an exciting new potential option for patients."

Q&A

What is Parkinson's disease?

A gradual degeneration of brain cells causing disability, tremors, loss of balance and movement, cognitive impairment.

How many people in New Zealand are affected?

About 10,000 New Zealanders are said to have the condition. Globally, about one in 500 people are affected, and 1 per cent of people older than 60.

Can it be treated?

Existing chemical treatments, which attempt to top up levels of dopamine in the brain, a key neurotransmitter, generally become ineffective within five years.

How does the new treatment work?

Choroid plexus cells from the lining of pigs' brain cavities are put in seaweed-based capsules and injected into the damaged parts of human brains. The pig cells are thought to function identically to human choroid plexus cells to repair brain tissue.

Why pigs?

Most chemicals in pigs are remarkably similar to those in people, making inter-species transplants possible. The concept has been around for 40 years because pig proteins are so close to humans'.