Neck-and-neck in xenotransplant race

Alexion concluded a license agreement with Biotechnology Research and Development Corp. (BRDC) for porcine embryonic stem cells and related technologies to produce transgenic swine whose organs can be used for human transplants. The technology will permit Alexion to engineer porcine embryonic stem cells to bear human complement inhibitory factors, while at the same time removing genes that encode for antigens that would trigger rejection. These embryonic stem cells, formed early in the division of the fertilized egg, can now be maintained in the laboratory, thanks to a growth factor licensed last month from AMRAD Corp. Ltd. of Australia.

Engineering genes into stem cells will generate genetically identical transgenic offspring, which is crucial for xenograft quality control, said Bell...