Diabetes sufferers are hoping for a cure with a long-awaited Government decision giving the go-ahead to a clinical trial transplanting pig tissue into humans.
Diabetes sufferers are ecstatic, but the decision has outraged opponents of genetic engineering and disturbed some clinicians, who warn the trial could unleash pig viruses into the human population.
Auckland biotech company Living Cell Technologies finally received provisional approval from Health Minister David Cunliffe yesterday, 18 months after getting the all-clear from Medsafe.
The independent trial at Middlemore Hospital could begin early next year.
Eight type-1 diabetics will receive injections of capsules containing insulin-producing cells from Auckland Island pigs, which are disease-free after living in isolation for 200 years.
An Auckland study in 1996 was aborted because of fears pig viruses could infect humans.
Patients in a Russian trial that started last June have been able to cut their insulin dependence between 25 and 100 per cent.
The bid for New Zealand approval was boosted last year after researchers discovered pig cells injected into Matamata man Michael Helyer in 1996 were still producing insulin.
LCT chief executive Paul Tan said he had been waiting 12 years for the trial to restart.
"Political and commercial interests" and "junk science" had almost scuttled the venture, he said.
"It got Medsafe approval in April 2007, it had ethics approval, so there were no ethical or safety concerns. The only conclusion you can draw is the holdup was political."
Green MP Sue Kedgley said if there was "even a tiny potential" for pig viruses to cross over into humans, the trial should be stopped.
"It would be like opening Pandora's box and, once those viruses were unleashed, it would be impossible to undo it."
Some clinicians have also expressed reservations.
Professor Patrick Manning, president of the Society for the Study of Diabetes, said Mr Cunliffe should release the evidence proving the trial met international guidelines.
The technique should be proven to work in animals before human trials could start, he said.
"There's no doubt it will be a major breakthrough if successful, but we have to be very careful about the benefits and risks, which are as yet unknowable."
Mr Cunliffe said he had carefully considered the issues and put public safety first.
"I make no apologies for the time it has taken to get the level of assurance that I believe the New Zealand public would expect."
After the matter was first discussed by the Cabinet in March, he sought a report from the National Health Committee and Medsafe provided advice regarding international regulatory developments.
"I had to balance the high probability of doing significant good for a number of people if it was successful against the low possibility of doing great harm to the general population if it resulted in the spread of porcine retrovirus."
LCT is building a $2.5 million piggery at Awarua, near Invercargill, to breed the pigs in strictly controlled conditions.
Diabetes New Zealand estimates 15,000 Kiwis have type-1 diabetes, including 3500 children and teenagers.