Antitumor effects of pirarubicin and epirubicin in combination with doxifluridine and cisplatin against mouse P388 leukemia.

In vivo antitumor activity of pirarubicin (THP) and epirubucin (EPI) in combination with doxifluridine (5'-DFUR) and cisplatin (CDDP) were examined using mouse P388 leukemia. THP (1.25-7.5 mg/kg) or EPI (1.25-15 mg/kg) was given intravenously on day 1, and then 5'-DFUR (125 or 250 mg/kg/day) and CDDP (4 mg/kg) were given orally on days 1-4 and intravenously on day 5 after tumor inoculation, respectively. Both THP and EPI enhanced the antitumor of a combination of 5'-DFUR and CDDP. The enhancement by THP was additive or synergistic, while that by EPI was additive. Cured animals were observed in the combination of THP with the two drugs, but not in that of EPI. Thus, in combination with 5'-DFUR and CDDP, THP was more effective against P388 leukemia than was EPI. The combination therapy using THP, 5'-DFUR and CDDP may be a novel chemotherapeutic approach to a variable type of tumors in clinical trials.