Cystostatic efficacy of DNA-complexes of adriamycin, daunomycin, and actinomycin D. II. Comparative in vivo studies in an Ehrlich-ascites tumor.

The cytostatic efficacy of the antibiotics adriamycin, daunomycin and actinomycin D and of DNA-complexes of these compounds was compared in an Ehrlich ascites tumor in vivo. Various doses of the individual drugs and their DNA-complexes were injected intraperitoneally into female NMRI mice following 8 days after inoculation of 10(6) Ehrlich ascites cells. Survival analyses of animals demonstrated that by addition of DNA therapeutic indices were improved for adriamycin, daunomycin and actinomycin D, DNA alone had no effect on this tumor. Since earlier biochemical data (Seeber et al., 1977) had shown decreased in vitro cytotoxicity of DNA-bound antibiotics, this increase in therapeutic efficacy is probably due to an altered pharmacological behaviour after complex formation with a prolongation of effective intraperitoneal drug levels and decreased systemic toxicity.