N-trifluoroacetyladriamycin-14-valerate, an analog with greater experimental antitumor activity and less toxicity than adriamycin.

N-Trifluoroacetyladriamycin-14-valerate (AD 32), an analog of adriamycin, exhibits significantly greater antitumor activity than does adriamycin or daunorubicin in two experimental mouse tumor systems under similar assay conditions (C57BL X DBA/2 F1 male mice, agents administered i.p. each day for Days 1 to 4). Against the P388 leukemia at optimal dosages, AD 32 gave a +429% increase in median life-span with 3 of 5 60-day survivors compared to +132% for adriamycin (no 30-day survivors). In the L1210 leukemia system, AD 32 at several dosages consistently and reproducibly effected an increase in lifespan in excess of 445%, with a high percentage of 60+-day survivors compared to adriamycin (+42 to +54% ILS; no 30-day survivors). The reduced toxicity of AD 32 was evidenced by its optimal dose range, which is significantly greater than the lethal dose for 100% of mice of adriamycin, and by its lack of delayed toxicity. In vitro, AD 32 was somewhat less effective than was adriamycin in inhibiting the growth of CCRF-CEM cells; enzymatic conversion of AD 32 by cell-free culture medium was not observed. The unique growth-inhibitory properties of this analog indicate that the therapeutic effectiveness of the anthracycline antitumor antibiotics can be retained or enhanced by substitution on the glycosidic amino group.