Encapsulated pig islets

Wellington, July 22 NZPA - Australian researchers have called for their government to lift a moratorium on xenotransplants -- implanting animal tissues in humans -- as New Zealand diabetics are injected with piglet islet cells.

Biotechnology entrepreneur Living Cell Technologies (LCT) has started its clinical trials at an Auckland hospital.

LCT said today its trial of encapsulated pig islet cells -- being implanted in insulin-dependent diabetics -- had started at Middlemore Hospital, under endocrinologist John Baker.

The director of the clinical trials unit at the Centre for Clinical Research and Effective Practice, in Auckland, Dr Baker said they had more than 200 volunteers.

"They have diabetes that is difficult to control despite best efforts with their current treatment regimen," he said.

The NZ Government restricted the trial to patients with "brittle diabetes", also called labile diabetes, a relatively rare uncontrolled type 1 diabetes, which often causes victims to experience extreme swings in blood sugar levels.

The company's chief executive, Paul Tan, said the trial was extending LCT's clinical programme and complemented the clinical and commercialisation programme it has under way in Russia.

Professor Bob Elliott, the founder of LCT and its medical director, said the doses of encapsulated pig islet cells being implanted in the New Zealand trial were two to three times more than the initial doses in Russia.

The implants, expected to be marketed as DiabecellB, are tissue taken from the pancreas of piglets bred and killed for the purpose and are designed to normalise blood glucose levels in type 1 diabetes sufferers.

A wrapping of seaweed-based gel means the insulin-producing cells can work in the abdomen without triggering an immune reaction in the patient, which means there is no need for risky immunosuppressive drugs.

Type 1 diabetes occurs when the body's own immune system destroys the insulin-producing cells of the pancreas (called beta cells), and occurs in 5 to 10 percent of the world's 200 million diabetics.

It often leads to kidney failure, blindness, nerve damage, life-threatening cardiovascular disease and limb amputations, and existing treatment options include daily injections of insulin.

In Australia -- where trials are still banned as a result of a five-year government moratorium placed on xenotransplantation in 2004 -- Professor John Dwyer, a clinical immunologist at the University of New South Wales, said the start of the New Zealand trial was an important development for Australian scientists.

"The safe transplantation of insulin producing cells would offer us by far the best technique for controlling diabetes in millions of sufferers globally," he said. "These clinical trials are essential as there is no other way of studying the potential benefits except by transplanting these cells into humans."

Such a technique had enormous potential to reduce suffering and the enormous costs involved in treating diabetes and its many complications.

"The approval of this trial in New Zealand will hopefully lead to a reconsideration of the current moratorium on xenotransplantation in Australia," he said.

"The Australian government should lift its ban on Australian clinical researchers doing similar trials".

Prof Elliott has already carried out similar clinical trials on New Zealanders, before being shut down by health officials who were concerned about the potential for pig retroviruses to move into the human population.

Six patients were injected in Auckland with pig islet cells in 1996 and one, Michael Helyer, of Auckland, was still gaining insulin from them when he was tested again a decade later.

Four of the eight New Zealand patients will receive double the initial dose used in Russia, followed by four patients to receive triple the dose.

In Russia, LCT is forming a subsidiary called LCT Biomedical Ltd, headed by Natalia Dolgova to obtain approval for a study of the new treatment in at least two Russian centres, and register the product to be available to diabetics in Russia.

The regulatory process has already been started, according to LCT's New Zealand-based regional director for Russia, Olga Garkavenko, who said that product will be registerable by October 2011.

The pig tissue for these patients would be supplied from New Zealand. Trials in other countries -- implanting pancreatic cells from brain-dead humans -- have required heavy use of immuno-suppressive drugs to avoid rejection by the patient's immune system. Human islet cell transplants cost about $US300,000 ($NZ430,000) a patient.