One‐Year Heterotopic Cardiac Xenograft Survival in a Pig to Baboon Model

We have now demonstrated that the heterotopic pig cardiac xenograft survival in a baboon can exceed 1 year by utilizing porcine hearts with customized genetics (alpha galactosyl transferase gene knock out [GTKO] to eliminate alpha Gal antibody-mediated rejection, transgenic expression of human complement regulatory protein [hCD46] to inhibit complement activation and human thrombomodulin molecules [hTBM] to prevent coagulation) (Revivicor, Inc., Blacksburg, VA) and an immunomodulatory treatment regimen consisting of co-stimulation blockade by a primatized anti-CD40 antibody (clone 2C10R4; 50mg/kg/weekly), anti-CD20 antibody (19mg/kg on days 14, 7, 0 and 7), antithymocyte globulin (5mg/kg on days 2 and 1), mycophenolate mofetil (20mg/kg twice a day) and steroids (2mg/kg tapered off in 4–6 weeks). Graft survival of all five animals in this group is shown in Table 1.