The binding of thio-TEPA in human serum and to isolated serum protein fractions

Summary Binding of triethylenethiophosphoramide (thio-TEPA) in serum from healthy individuals and from cancer patients and its binding to isolated serum protein fractions were studied by equilibrium dialysis. A drug-protein binding in the order of 10% was demonstrated in serum, with little interindividual variation. The protein binding of thio-TEPA seemed to be restricted to albumin and lipoproteins, with the greatest affinity to albumin. The previously reported selective binding of thio-TEPA to gamma globulin was contrary to our findings. The almost insignificant degree of serum protein binding of thio-TEPA indicates that the drug is well suited for use in cancer drug combinations.The work described in this paper was supported by grants from The Norwegian Cancer Society (Oslo), the Regional Hospital (Trondheim), and Trondheim Cancer Society (Trondheim)During the work Bjørn Hagen was a research fellow in The Norwegian Cancer Society