Antitumor effects of fotemustine and busulfan against a human neuroblastoma xenograft

We examined whether or not fotemustine, a new nitrosourea derivative, and b usulfan, an agent already clinically used, are effective against human neur oblastoma, using a human neuroblastoma xenograft model designated TNB9. The maximum inhibition rate (MIR) of fotemustine against the TNB9 model was 44 .6% with a total dose of fotemustine of 75 mg/kg, indicating that fotemusti ne is not effective against TNB9. The MIR of busulfan against the same mode l was 26.7% when a total dose of 135 mg/kg was administered orally to nude mice. Busulfan was also suspended in carboxymethylcellulose, and was admini stered intraperitoneally. The MIRs were 19.4% and 36.4% when busulfan was a dministered intraperitoneally at a total dose of 40 mg/kg and 60 mg/kg, res pectively The total doses of 40 mg/kg and 60 mg/kg did not show any adverse effects on mice, but were found to be ineffective against TNB9, indicating that busulfan might not be an effective chemotherapeutic agent against hum an neuroblastoma.