2-Cyanoethyl urea and its derivatives as potential immunostimulants in experimental cancer therapy

Since a few years the class of 2-cyanoaziridines has been investigated thoroughly in terms of their immunomodulating ability. In this paper it will be exemplified by 2-cyanoethyl urea (CEU), the open-chain cleavage product of 1-carbamoyl-2-cyanoaziridine, that derivatives failing the three-membered aziridine ring can also act as immunostimulants. CEU elevates the number of leukocytes and lymphocytes in the circulating blood of rats over a long period of time and stimulates humoral and cellular immune reactions in mice as was shown by estimation of plaque-forming spleen cells and measurements of footpad swelling. Since CEU is very low toxic, even in heavy doses, its use in clinical trials seems to be justified for improving immune parameters in human cancer patients.