RUBOXYL, A NEW NITROXYL DERIVATIVE OF DAUNORUBICIN - ACUTE TOXICITY AND ANTITUMOR EFFECT IN ANIMALS

Ruboxyl (RBX), a new nitroxyl derivative anthracycline, showed an inte resting cytotoxic effect on in vitro established human cell lines and an antitumor activity in tumor-bearing animals. In this study, we furt her investigated the antitumor effect of this drug compared to Doxorub icin (DX) in four in vivo systems of experimental murine tumors. Our d ata demonstrate that RBX had little effect on the growth of primary tu mor, and on the survival, in mice bearing Lewis lung carcinoma (3LL), while the drug showed a higher effect on the growth of B 16 melanoma. In both the experimental murine systems the activity of RBX was simila r to that exerted by DX. As regards the leukemia models, RBX induced a significant increase on survival in mice bearing both L1210 or L5178Y leukemias. However, the effect on survival and the number of long-ter m survivors (LTS) were lower than that observed following DX treatment .