Comparative study in mice of the toxicity, pharmacology, and therapeutic activity of daunorubicin-DNA and doxorubicin-DNA complexes.

We have compared the toxicologic, pharmacologic, and therapeutic properties of the DNA complexes of daunorubicin and doxorubicin, after intravenous (IV) administration into mice. The overall toxicity of doxorubicin is significantly reduced after IV injection as a DNA complex while daunorubicin-DNA is as toxic as free daunorubicin. On hemopoietic stem cells, daunorubicin-DNA was found to be more cytotoxic than daunorubicin, while the opposite was observed with doxorubicin and doxorubicin-DNA. Both complexes are more effective than the corresponding free drugs on the L1210 murine leukemia, when given IV at equitoxic doses. The tissue uptake in mice, after IV administration, is generally lower when the drugs are given bound to DNA. The stability of the two DNA complexes is very different in the bloodstream: daunorubicin-DNA behaves more like a prodrug of daunorubicin, while doxorubicin-DNA, remaining stable in the bloodstream, meets much more the requirements of an ideal drug-macromoleculare carrier entity.