The US Food and Drug Administration (FDA) is planning to allow clinical trials testing of the transplantation of pig organs into humans.
If the agency follows through, the trials could be a key step in an effort to ease the critical shortage of human donor organs. It is however unclear when the trials would begin.
The research proposals are likely to be handled on a case-by-case basis.
The proposal comes in the wake of a handful of experimental surgeries involving pig organ transplants (xenotranplantation). This included the first pig-to-human heart transplant at the University of Maryland Medical Centre Baltimore – the critically ill patient, David Bennett, lived for two months after the groundbreaking surgery.