ANTHRACYCLINES - A REVIEW OF GENERAL AND SPECIAL TOXICITY STUDIES

Preclinical safety assessment data on doxorubicin (DOXO), epirubicin ( EPI), idarubicin (IDA) and methoxymorpholinodoxorubicin (MORPHO), from mouse, rat and dog studies are reviewed. These data are put into pers pective allowing for extrapolations across species, doses and dose reg imens with recommendations for proper human use. The compounds were ad ministered intravenously or intraperitoneally in studies ranging from single dose to multiple dose studies of different durations. The compo unds were given once, daily, weekly or cyclically. In the cyclic admin istration studies, DOXO, EPI, and IDA were given for 3 consecutive day s a week for 6 or 13 weeks; MORPHO was given for 3 consecutive days a week every three weeks for a total of 9 cycles. The duration of the cy clic studies was from 6-26 weeks. Daily dose studies lasted from 4-26 weeks. In the single dose studies the recovery ranged from 4 weeks to one year; in the multiple dose studies from 4 to 8 weeks. A few specia l studies were also considered. In all studies reviewed, 2 different t ypes of toxicity were observed. These toxicities occur also in man. Th e first is the acute toxicity, which is the consequence of cytotoxicit y and expresses the exaggerated pharmacological activity of the compou nds. The target sites in all 3 species and in man include the hemolymp hopoietic system (HLPS), the gastrointestinal (GI) tract, skin and tes tes; all renewing cell types. The second type of toxicity is the chron ic progressive toxicity. This toxicity is the expression and result of sustained disruption of cytoplasmic homeostasis and occurs in non-ren ewing cell types. The target sites include the heart (both animals and man), kidneys (rodents) and peripheral nervous system (PNS) (rodents) . From single administration animal data, chronicity, site and magnitu de of toxicities can be predicted in man. Despite strong mitogenic sti muli in the rat, there is no evidence that there is a potential for he molympho- or hepatocarcinogenicity with these compounds.