Last century primate to human xenotransplantation was attempted and it became quickly clear that genetic modifications would be required to surmount the species barrier.
Dolly the Cloned Sheep
The cloning of Dolly the sheep in 1996 served as a trigger for the potential development of cloned, genetically modified pigs aimed at xenotransplantation. Hype grew through the first transgenic pig and the first αGal knock out pig in 2002.
CRISPR
The advent of CRISPR gene editing in 2013 was critical for xenotransplantation. CRISPRs could knock out potential xenoantigens with orders of magnitude higher efficiency.
Improved Immunosuppression
Survival of multi-xenoantigen knockout pig kidneys in non-human primates exceeded the 12 month milestone in 2016. By 2018, survival was further improved with improvements in the immunosuppressive regimen.
Hype Curve
The advancement of xenotransplantation followed the Dunning-Kruger effect typified by the Gartner Hype-Cycle Curve in biotech. The events in Xenotransplantation are plotted on the Gartner hype curve below.
The Stage is Set
The environment is now set for rapid advances in xenotransplantation where resources are needed to overcome well defined obstacles. The basic scientific discoveries have already been made; the path forward is now development, not research.