Methods of inhibiting transplant rejecton in mammals using rapamycin and derivatives and prodrugs thereof

This invention provides a method of inhibiting organ or tissue transplant rejection in a mammal in need thereof, comprising administering to said mammal a transplant rejection inhibiting amount of rapamycin. Also disclosed is a method of inhibiting organ or tissue transplant rejection in a mammal in need thereof, comprising administering to said mammal (a) an amount of rapamycin in combination with (b) an amount of one or more other chemotherapeutic agents for inhibiting transplant rejection, e.g., azathioprine, corticosteroids, cyclosporin and FK506, said amounts of (a) and (b) together being effective to inhibit transplant rejection and to maintain inhibition of transplant rejection.