A New Zealand biotech company's world-first trial injecting pig cells into human brains has been stopped after researchers were unable to confirm findings in their initial studies on rats.
The heavily-promoted clinical trial was run at Auckland Hospital on behalf of Living Cell Technologies.
A scientific paper showing the treatment worked on rats, a requirement to have the project approved by New Zealand authorities - has been retracted.
The journal which initially published the research, Regenerative Medicine, says the authors were unable to reconfirm their reported results.
A New Zealand woman with Parkinson's disease has already had specially treated pig cells injected into her brain.
But plans to inject a further three patients have been put on hold.
The company however says the retraction of the research paper that helped it get Government approval for the trial does not mean the method is unsafe.
Living Cell Technologies' managing director Andrea Grant says the paper has been retracted because laboratory books on the preliminary studies on rats were incomplete.
Dr Grant says a fourth woman, who already has pig cells implanted in her brain, is healthy.
"It's only a small portion of the data that we've actually retracted, so I am comfortable that the trial should have begun at the time based on the data."
Living Cells Technology is listed on the Australian stock exchange although company is headquartered in Auckland.
