Influence of leukemia P388 on plasma concentration-time profiles of bendamustine in B6D2F1 mice.

It was the aim of this study to investigate whether leukemia P388 being an important murine transplantation tumor may alter the plasma concentration-time profiles of the alkylating antineoplastic agent bendamustine (1) in mice. In an advanced tumor stage the rapid decline of 1 plasma levels was found to be retarded in tumor-bearing in comparison to tumor-free animals both after i.v. and p.o. drug administration. These changes cannot be explained by the neoplasia-related depression of drug metabolism whereas the 1-containing ascitic fluid may be a possible reason for the prolonged drug levels in plasma. After p.o. administration of 1, the bioavailability of the drug was found to be increased in the leukemia-bearing animals.